Dissertations / Theses on the topic 'Full scale plant'

Pharmaceuticals and their metabolites are known to enter the environment from the effluent of wastewater treatment plants. From statistical analysis on the usage of pharmaceuticals, and their effects on the environment, five pharmaceuticals were selected for this study (Metronidazole, Trimethoprim, Sulphamethoxazole, Paracetamol and Ranitidine). Trace concentrations of pharmaceuticals were determined using a sensitive analytical method, comprising solid phase extraction (SPE) and liquid chromatography with a mass spectrometry detector (LC- MS),operating in selected ion monitoring (SIM) mode. It was found that Metronidazole, Trimethoprim, Sulphamethoxazole, Paracetamol and Ranitidine were detected at the highest levels in the wastewater entering the Sulaibiya WWTP Kuwait, with concentrations of up to 58 ng.L , 1814 ng.L , 1669 ng.L , 2086 ng.L and 2009 -1 ng.L , respectively. High removal efficiencies of these pharmaceuticals were found in the Sulaibiya WWTP. One year study was conducted to investigate the occurrence, persistence and fate of a range of these pharmaceuticals at different sampling points at the Sulaibiya WWTP. The treatment processes consisted of screening, grit removal and diffused air activated sludge treatment (primary and secondary treatment), followed by microfiltration (MF), reverse osmosis (RO), and chlorine oxidation (tertiary treatment). During primary and secondary treatment, Metronidazole, Trimethoprim, Sulphamethoxazole, Paracetamol and Ranitidine were removed efficiently with average removals efficiencies of 83.4%, 86.1%, 77.5%, 97.5% and 77.5%, respectively. The RO system lowered these pharmaceuticals further, giving overall removal efficiencies of 97%, 99%, 99%, 100% and 100% for Metronidazole, Trimethoprim, Sulphamethoxazole, Paracetamol and Ranitidine, respectively. All selected pharmaceuticals were tested in laboratory scale reactors to assess their -1 removal by chlorination and ozonation, and results showed that 10 mg.L of chlorine -1 removed these pharmaceuticals better than 15 mg.L of ozone. Lab-scale aerobic reactors (2 L), seeded with activated sludge inoculum from the Sulaibiya WWTP and fed with different concentrations of pharmaceuticals (0.1, 1 and -1 10 mg.L ), spiked individually into a synthetic wastewater showed that the TOC could be removed efficiently without inhibition by these pharmaceuticals. The fate of Metronidazole, Trimethoprim, Sulphamethoxazole, Paracetamol and Ranitidine was investigated in a membrane bioreactors (MBR), and a sequencing batch reactors (SBR), operating under strictly aerobic, and anoxic/aerobic conditions at different concentrations of a pharmaceutical mixture (PM) of the same -1 -1 -1 pharmaceuticals (1 µg.L , 1 mg.L and 10 mg.L ). The COD and TOC removal -1 efficiency decreased when the PM concentration was increased to 10 mg.L . The removal of Metronidazole and Trimethoprim was moderately effective, and similar in all the reactors. Sulphamethoxazole and Paracetamol were removed efficiently, but -1 this decreased when the PM was increased to 10 mg.L for most of the reactors, whilst Ranitidine experienced high removal rates at all concentrations in all the reactors. Analysis of the microbial diversity in laboratory reactors treating pharmaceuticals wastewater showed decreases in microbial community diversity when the PM concentration was increased. Pure cultures of bacteria isolated on selected pharmaceutical growth media were also detected in the microbial communities of reactor sludge by performing polymerase chain reaction–denaturing gradient gel electrophoresis (PCR-DGGE).

This thesis describes the development of enhanced biological phosphorus removal (EBPR) in a lab-scale sequencing batch reactor (SBR) and the release of phosphorus during the storage and thickening of sludge produced in this reactor. In the first phase of the experimental work a fast start-up method for EBPR development was established by the addition of a pure culture of Acinetobacter lwoffi to a conventional activated sludge. Investigations revealed that the performance EBPR depended on the combination of influent COD and phosphorus values and that in the investigated range, EBPR functioned independently of the sludge retention time. Low dissolved oxygen levels had no effect on the phosphorus removal properties of the sludge. The second phase of the experimental work involved the investigation of the phosphorus released during sludge handling. It was found that phosphorus resolubilisation during sludge treatment took place in three distinct phases which included an initial period of extremely low phosphorus release. Alterations of the reactor influent and operational parameters and the sludge characteristics, affected the amount of phosphorus released during anaerobic storage and gravity thickening. It was found that for short retention times in the sludge processing units (1-48 hours), decreasing the influent phosphorus concentration, increasing the oxidised nitrogen content of the excess sludge and wasting the excess sludge from the aeration tank decreased the amount of phosphorus resolubilised. For longer retention times (2-7 days), it was found that increasing the influent COD, having a lower total phosphorus sludge content, higher sludge "stabilisation" rates and quiescent conditions of storage, decreased the amount of phosphorus released.

This thesis has investigated the effects of running the two full scale biogas digesters at Slottshagen wastewater treatment plant at 34 °C compared to 37 °C, in terms of process stability, biogas production and energy savings with the aim of saving energy and money by not heating the digesters as much. The main objective was to investigate whether it is at all possible to operate the biogas process at 34 °C or if the process becomes inhibited or otherwise unstable. If the process could be operated at 34 °C it might mean savings of both energy and money, provided that there is still a sufficient production of biogas.The experiment lasted for three months and investigated the short-term effects of the reduction of temperature. The process was monitored closely, and samples from the reactors were collected and analysed twice a week to ensure the stability of the biogas process. Several parameters were monitored online, the biogas production and methane content amongst others. Other parameters were calculated, such as the degree of degradation and specific methane production. This was done to ensure process stability and a sufficient production of biogas. The energy balance was calculated to evaluate if energy was saved by lowering the temperature in the digesters.The results show that the biogas process does remain stable at 34 °C while still producing a satisfactory amount of biogas during the short time of the experiment. Calculations show that both energy and money has been saved during the experiment. However, the system is largely dependent on seasonal variations, therefore further studies over a longer time period would be desirable. During the course of the thesis it has also become evident that the biogas process at Slottshagen is irregular in several aspects, and that it would be beneficial to even the process out, especially with regards to the hydraulic retention time. Making the process more even would enable further improvements to be made and simplify interpretations and comparisons of processstability data.

The Fourier-Mellin transform was implemented on a digital computer and applied towards the recognition and differentiation of images of plant leaves regardless of translation, rotation or scale. Translated, rotated and scaled leaf images from seven species of plants were compared: avocado ( Persea americana), trembling aspen (Populus tremuloides), lamb's-quarter (Chenopodium album), linden (Tilla americana), silver maple (Acer saccharinum), plantain (Plantago major) and sumac leaflets (Rhus typhina ). The rate of recognition was high among translated and rotated leaf images for all plant species. The rates of recognition and differentiation were poor, however, among scaled leaf images and between leaves of different species. Improvements to increase the effectiveness of the algorithm are suggested.

Cold Central Plant Recycling (CCPR) has been used by many state highway agencies to save material, money, time, and energy in pavement construction and rehabilitation. The objectives of this thesis were to: (1) perform an instrumented verification analysis, (2) evaluate the response and performance of two pavement configurations with a CCPR base layer through accelerated pavement testing (APT), and (3) construct models using mechanistic-empirical pavement design software for comparison with the APT results. The pavement configurations featured a 5-inch CCPR mixture with either a 3-inch or 1.5-inch SM-9.5D surface mixture. Each section was instrumented with strain gauges, pressure cells, and thermocouples. A heavy vehicle simulator (HVS) was used to load three replicate test sections in each lane, with the temperature controlled at 39°C at a depth of 1.5 inches. Results from the instrument verification analysis showed that the strain gauges and pressure cells used in the experiment recorded pavement responses with a high degree of repeatability. In addition, the loading condition variables (speed, wheel load, and tire inflation pressure) affected the response following the expected trends and did not affect the repeatability of the instruments. The average CV of all strain gauge and pressure cell signals was approximately 0.009 or 0.9%, and 0.004 or 0.4%, respectively. In terms of the rutting comparison, the sections with the 3-inch surface layer outperformed the sections with the thinner 1.5-inch surface layer. However, the age of the pavement at the start of testing significantly affected the rutting performance. After adjusting for the pavement age at the time of testing, the section with the thicker surface showed approximately half of the rutting of the section with the thinner surface. The results from preliminary ME Design analysis indicate that the software cannot model the studied APT sections using the default material properties and calibration factors available at the time of analysis. In particular, the software does not seem to be prepared to model the CCPR materials.
Master of Science

Includes abstract.
Includes bibliographical references.
In 2012, Anglo American Platinum assembled a technical task team of metallurgists for their concentrator operations. Although there has been extensive research in literature regarding the flotation response and behaviour of reagents, there still exists a gap between fundamental laboratory scale research and plant scale application. This thesis will focus on the development of techniques for optimising and characterising frother on a full scale plant using the Anglo American Platinum Bubble Sizer (AAPBS) which is a commonly used tool by the plant metallurgist. The techniques developed have been based on the application of fundamental research of frothers in literature. This thesis consists of three main focus areas: 1) Developing a technique for measuring the relationship between sauter mean bubble diameter and frother concentration on a full scale plant. 2) Developing a technique for estimating frother concentrations in process streams in full scale plant 3) Establishing whether the relationship between sauter mean bubble diameter and superficial gas velocity in a flotation bank of identical cells in series in a plant operating at frother concentration above the CCC is identical, and whether this can be used to detect the decrease of frother concentration to below the CCC at any point in the bank. Furthermore, the metallurgical performance of a bank with a decrease in frother concentration below the CCC midway through the bank was determined before and after the addition of frother, which was added as such that all the cells in the bank operate with a frother concentration above the CCC. There were two techniques investigated for measuring the relationship between sauter mean bubble diameter and frother concentration. Both techniques involved using the AAPBS and the use of forced air mechanically agitated tank cells. Technique 1 involved using the first rougher cell on a flotation plant, dosing frother at different rates into the cell to target different frother concentrations and then measuring the resultant bubble size whilst operating at a fixed air rate. The coalescence mechanism here was occurring in a three phase solids/aqueous/air system occurring in a continuous stirred tank. Similarly Technique 2 involved using the first rougher cell; however, the first cell was depleted of frother by bypassing the frother dosage line into the next cell. This was done to isolate the first rougher cell and to minimise disturbance to the rest of the rougher bank. Known concentrations offrother were made up in potable water and these were added into the AAPBS. Bubbles from the pulp phase enter the bubble riser tube which is long and narrow (3m x 25mm diameter) which is representative of two phase aqueous/air “plug flow” system. These bubbles coalesce to different degrees based on the known frother concentration. The resulting bubble size distribution was then be measured by taking photographs at the viewing pane of the AAPBS. The air rate in the cell was kept constant to within 0.7-0.9 cm/s and the photographs were analysed using software provided by stone three to determine the sauter mean bubble diameter and the bubble size distribution. Technique 1 was applied to Plant A UG2 concentrator which was using a polyglycol type frother called Betafroth 206C which has an undisclosed composition and a molecular weight of approximately 200 g/mol. The first rougher cell used was an Outokumpu 70 m3 forced air mechanically agitated tank cell. The results showed no clear relationship between sauter mean bubble diameter and frother concentration. Furthermore, the sauter mean bubble diameter was already very small and it appeared that the changes in between runs were more strongly linked to the superficial gas velocity than frother concentration. The fact that the sauter mean bubble diameter obtained was already small implied that the frother concentration in the cell was already high. This could have been due to an additional source of frother due to spillage or in the process water that potentially elevated the actual frother concentrations in the cell. Technique 1 also resulted in significant disturbances to the entire rougher bank because it involved changing the frother dosages to the bank. This would affect the flotation performance of the bank for a prolonged period and affect plant performance. Hence it was decided that technique 1 would not be suitable.

[EN] Anaerobic MBRs (AnMBRs) can provide the desired step towards sustainable wastewater treatment, broadening the range of application of anaerobic biotechnology to low-strength wastewaters (e.g. urban ones) or extreme environmental conditions (e.g. low operating temperatures). This alternative technology gathers the advantages of anaerobic treatment processes (e.g. low energy demand stemming from no aeration and energy recovery through methane production) jointly with the benefits of membrane technology (e.g. high quality effluent, and reduced space requirements). It is important to highlight that AnMBR may offer the possibility of operation in energy neutral or even being a net energy producer due to biogas generation. Other aspects that must be taken into account in AnMBR are the quality and nutrient recovery potential of the effluent and the low amount of sludge generated, which are of vital importance when assessing the environmental impact of a wastewater treatment plant (WWTP). The main aim of this Ph.D. thesis is to assess the economic and environmental sustainability of AnMBR technology for urban wastewater treatment at ambient temperature. Specifically, this thesis focusses on the following aspects: (1) development of a detailed and comprehensive plant-wide energy model for assessing the energy demand of different wastewater treatment systems at both steady- and unsteady-state conditions; (2) proposal of a design methodology for AnMBR technology and identification of optimal AnMBR-based configurations by applying an overall life cycle cost (LCC) analysis; (3) life cycle assessment (LCA) of AnMBR-based technology at different temperatures; and (4) evaluation of the overall sustainability (economic and environmental) of AnMBR for urban wastewater treatment. In this research work, a plant-wide energy model coupled to the extended version of the plant-wide mathematical model BNRM2 is proposed. The proposed energy model was used for assessing the energy performance of different wastewater treatment processes. In order to propose a guidelines for designing AnMBR at full-scale and to identify optimal AnMBR-based configurations, the proposed energy model and LCC were used. LCA was used to assess the environmental performance of AnMBR-based technology at different temperatures. An overall sustainability (economic and environmental) assessment was conducted for: (a) assessing the implications of design and operating decisions by including sensitivity and uncertainty analysis and navigating trade-offs across environmental and economic criteria.; and (b) comparing AnMBR to aerobic-based technologies for urban wastewater treatment. This Ph.D. thesis is enclosed in a national research project funded by the Spanish Ministry of Science and Innovation entitled "Using membrane technology for the energetic recovery of wastewater organic matter and the minimisation of the sludge produced" (MICINN project CTM2008-06809-C02-01/02). To obtain representative results that could be extrapolated to full-scale plants, this research work was carried out in an AnMBR system featuring industrial-scale hollow-fibre membrane units that was operated using effluent from the pre-treatment of the Carraixet WWTP (Valencia, Spain).
[ES] El reactor anaerobio de membranas sumergidas (AnMBR) puede proporcionar el paso deseado hacia un tratamiento sostenible del agua residual, ampliando la aplicabilidad de la biotecnología anaerobia al tratamiento de aguas residuales de baja carga (ej. agua residual urbana) o a condiciones medioambientales extremas (ej. bajas temperaturas de operación). Esta tecnología combina las ventajas de los procesos de tratamiento anaerobio (baja demanda energética gracias a la ausencia de aireación y a la recuperación energética a través de la producción de metano) con los beneficios de la tecnología de membranas (ej. efluente de alta calidad y reducidas necesidades de espacio). Cabe destacar que la tecnología AnMBR permite la posibilidad del autoabastecimiento energético del sistema debido a la generación de biogás. Otros aspectos que se deben considerar en el sistema AnMBR son el potencial de recuperación de nutrientes, la calidad del efluente generado y la baja cantidad de fangos producidos, siendo todos ellos de vital importancia cuando se evalúa el impacto medioambiental de una planta de tratamiento de aguas residuales urbanas. El objetivo principal de esta tesis doctoral es evaluar la sostenibilidad económica y medioambiental de la tecnología AnMBR para el tratamiento de aguas residuales urbanas a temperatura ambiente. Concretamente, esta tesis se centra en las siguientes tareas: (1) desarrollo de un modelo de energía detallado y completo que permita evaluar la demanda energética global de diferentes sistemas de tratamiento de aguas residuales tanto en régimen estacionario como en transitorio; (2) propuesta de una metodología de diseño e identificación de configuraciones óptimas para la implementación de la tecnología AnMBR, aplicando para ello un análisis del coste de ciclo de vida (CCV); (3) análisis del ciclo de vida (ACV) de la tecnología AnMBR a diferentes temperaturas; y (4) evaluación global de la sostenibilidad (económica y medioambiental) de la tecnología AnMBR para el tratamiento de aguas residuales urbanas. En este trabajo de investigación se propone un modelo de energía acoplado a la versión extendida del modelo matemático BNRM2. El modelo de energía propuesto se usó para evaluar la eficiencia energía de diferentes procesos de tratamiento de aguas residuales urbanas. Con el fin de proponer unas directrices para el diseño de AnMBR a escala industrial e identificar las configuraciones óptimas para la implementación de dicha tecnología, se aplicaron tanto el modelo de energía propuesto como un análisis CCV. El ACV se usó para evaluar la viabilidad medioambiental de la tecnología AnMBR a diferentes temperaturas. En este trabajo se llevó a cabo una evaluación global de la sostenibilidad (económica y medioambiental) de la tecnología AnMBR para: (a) evaluar las implicaciones que conllevan ciertas decisiones durante el diseño y operación de dicha tecnología mediante un análisis de sensibilidad e incertidumbre, y examinar las contrapartidas en función de criterios económicos y medioambientales; y (b) comparar la tecnología AnMBR con tecnologías basadas en procesos aerobios para el tratamiento de aguas residuales urbanas. Esta tesis doctoral está integrada en un proyecto nacional de investigación, subvencionado por el Ministerio de Ciencia e Innovación (MICINN), con título "Modelación de la aplicación de la tecnología de membranas para la valorización energética de la materia orgánica del agua residual y la minimización de los fangos producidos" (MICINN, proyecto CTM2008-06809-C02-01/02). Para obtener resultados representativos que puedan ser extrapolados a plantas reales, esta tesis doctoral se ha llevado a cabo utilizando un sistema AnMBR que incorpora módulos comerciales de membrana de fibra hueca. Además, esta planta es alimentada con el efluente del pre-tratamiento de la EDAR del Barranco del Carraixet (Valencia, España).
[CAT] El reactor anaerobi de membranes submergides (AnMBR) pot proporcionar el pas desitjat cap a un tractament d'aigües residuals sostenible, i suposa una extensió en l'aplicabilitat de la biotecnologia anaeròbia al tractament d'aigües residuals amb baixa càrrega (p.e. aigua residual urbana) o a condicions mediambientals extremes (p.e. baixes temperatures d'operació). Aquesta tecnologia alternativa reuneix els avantatges dels processos de tractament anaerobi (baixa demanda d'energia per l'estalvi de l'aireig i possibilitat de recuperació energètica per la producció de metà), conjuntament amb els beneficis de l'ús de de la tecnologia de membranes (p.e efluent d'alta qualitat, i reduïdes necessitats d'espai). Cal destacar que la tecnologia AnMBR permet la possibilitat de l'autoabastiment energètic del sistema degut a la generació de biogàs. Altres aspectes que s'han de considerar en el sistema AnMBR són el potencial de recuperació de nutrients, la qualitat de l'efluent i la baixa quantitat de fang generat, tots ells de vital importància quan s'avalua l'impacte mediambiental d'una planta de tractament d'aigües residuals urbanes. L'objectiu principal d'aquesta tesi doctoral és avaluar la sostenibilitat econòmica i mediambiental de la tecnologia AnMBR per al tractament d'aigües residuals urbanes a temperatura ambient. Concretament, aquesta tesi se centra en les tasques següents: (1) desenrotllament d'un detallat i complet model d'energia per al conjunt de la planta a fi d'avaluar la demanda d'energia de diferents sistemes de tractament d'aigües residuals tant en règim estacionari com en transitori; (2) proposta d'una metodologia de disseny i identificació de les configuracions òptimes de la tecnologia AnMBR mitjançant l'aplicació una anàlisi del cost de tot el cicle de vida (CCV) ; (3) anàlisi del cicle de vida (ACV) de la tecnologia AnMBR a diferents temperatures; i (4) avaluació global de la sostenibilitat (econòmica i mediambiental) de la tecnologia AnMBR per al tractament d'aigües residuals urbanes. En aquest treball d'investigació es proposa un model d'energia a nivell de tota la planta acoblat a la versió estesa del model matemàtic BNRM2. El model d'energia proposat s'ha utilitzat per a avaluar l'eficiència energètica de diferents processos de tractament d'aigües residuals urbanes. A fi de proposar unes directrius per al disseny d'AnMBR a escala industrial i identificar les configuracions òptimes de la tecnologia AnMBR, s'ha aplicat tant el model d'energia proposat, com el cost del cicle de vida (CCV). L'anàlisi del cicle de vida (ACV) s'ha utilitzat per a avaluar el rendiment mediambiental de la tecnologia AnMBR a diferents temperatures. En aquest treball s'ha dut a terme una avaluació global de la sostenibilitat (econòmica i mediambiental) de la tecnologia AnMBR per a: (a) avaluar les implicacions de les decisions de disseny i operació per mitjà d'una anàlisi de sensibilitat i incertesa i examinar les contrapartides en funció de criteris econòmics i mediambientals; i (b) comparar la tecnologia AnMBR amb tecnologies basades en processos aerobis per al tractament d'aigües residuals urbanes. Aquesta tesi doctoral està integrada en un projecte nacional d'investigació, subvencionat pel Ministerio de Ciencia e Innovación (MICINN), amb títol "Modelación de la aplicación de la tecnología de membranas para la valorización energética de la materia orgánica del agua residual y la minimización de los fangos producidos" (MICINN, projecte CTM2008-06809-C02-01/02). Per a obtenir resultats representatius que puguen ser extrapolats a plantes reals, aquesta tesi doctoral s'ha dut a terme utilitzant un sistema AnMBR que incorpora mòduls comercials de membrana de fibra buida. A més, aquesta planta és alimentada amb l'efluent del pretractament de l'EDAR del Barranc del Carraixet (València, Espanya).
Pretel Jolis, R. (2015). Environmental and economic sustainability of submerged anaerobic membrane bioreactors treating urban wastewater [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/58864
TESIS
Premiado

Els residus biodegradables reben una atenció especial en el marc legislatiu europeu actual (Revised Framework Directive 2008/98/CE) i en la seva transposició a Espanya a traves del Plan Nacional Integrado de Residuos 20082015 (PNIR), degut al significatiu impacte ambiental derivat quan aquestos residus no són tractats correctament i al seu potencial ús com recursos renovables mitjançant l’obtenció de compost i biogàs. Pel correcte tractament d’aquestos residus és imprescindible el desenvolupament d’instal·lacions i plantes de tractament eficaces i eficients. La correcta avaluació de l’efectivitat i eficiència d’aquestes instal·lacions requereix una mesura fidedigna del contingut de matèria orgànica biodegradable dels residus i per tant de la seva estabilitat. Aquesta mesura permetria: i) establir una classificació dels residus i productes en base a la seva biodegradabilitat i estabilitat; ii) la correcta avaluació de les plantes de tractament en funcionament; iii)el disseny de noves i optimitzades instal·lacions, i iv) la determinació del potencial impacte ambiental dels productes finals. La informació obtinguda mitjançant l’anàlisi de paràmetres purament físics o químics dels residus no es capaç de reflectir la naturalesa biològica dels residus. És molt extensa la bibliografia que descriu, proposa i avalua l’ús d’índexs biològics, aerobis i anaerobis, per caracteritzar els residus orgànics. De la mateixa manera, aquestos índexs, han estat proposats en diferents normatives de paises europeus com paràmetres d’estabilitat. En aquesta Tesis s’han desenvolupat noves metodologies per a la determinació d’índexs biològics aerobis i anaerobis, optimitzant les metodologies ja referenciades, eliminant les seves limitacions i ampliant la seva utilitat: índexs respiromètrics aerobis, expressats com velocitat de consum d’oxigen i consum acumulat durant un temps determinat i índexs anaerobis, expressats com producció acumulada de biogàs i metà durant un temps determinat o total. Aquestes metodologies s’han avaluat i verificat mitjançant les següents aplicacions: 1) Optimització del procés de compostatge de fangs procedents d’EDARs urbanes, determinant la relació d’estructurant‐fang mínima necessària per obtenir un producte final higienitzat i estabilitzat a escala industrial. 2) Completa avaluació d’una planta de tractament mecànic‐biològic (MBT) amb capacitat per tractar 240.000 tones/any de residus municipals, monitoratge del procés i determinació de les eficàcies d’eliminació de matèria orgànica en cada etapa. 3) Estudi específic del pretractament mecànic d’una MBT i la seva influencia en l’eliminació de matèria orgànica biodegradable. 4) Determinació de potencials totals de producció de biogàs mitjançant l’anàlisi d’índexs biològics anaerobis de curta durada. 5) Determinació de les correlacions entre indexs aerobis i anaerobis. Determinació de les correlacions entre els diferents indexs aerobis i discusió sobre la diferent informació que poden proporcionar. 6) Caracterització completa de residus basant‐se en la diferent informació proporcionada pels indexs respiromètrics aerobis. 7) Redacció d’un protocol estandarditzat per a la determinació de la biodegradabilitat de residus orgànics de diferent origen i tipologia per l’Agencia de Residus de Catalunya, basant‐se en la determinació d’índexs biològics aerobis. Els resultats obtinguts en tots aquestos treballs i estudis confirmen la idoneïtat de l’ús dels índexs biològics com mesura real del contingut de matèria orgànica biodegradable dels residus i per tant de la seva estabilitat. A més es poden considerar com un paràmetre clau pel disseny i control de plantes de tractament de residus.
Los residuos biodegradables reciben una atención especial en el marco legislativo europeo actual (Revised Framework Directive 2008/98/CE) y en su transposición en España a través del Plan Nacional Integrado de Residuos 20082015 (PNIR), debido al significativo impacto ambiental derivado cuando no son tratados correctamente y a su potencial uso como recursos renovables mediante la obtención de compost y biogás. Para ello, es imprescindible el desarrollo de instalaciones y plantas de tratamiento eficaces y eficientes. La correcta evaluación de la efectividad y eficiencia de estas instalaciones requiere una medida fidedigna del contenido de materia orgánica biodegradable de los residuos y por consiguiente de su estabilidad. Esta medida permitiría: i) establecer una clasificación de residuos y productos en base a su biodegradabilidad y a su estabilidad; ii) la correcta evaluación de las plantas en funcionamiento; iii) el diseño de nuevas y optimizadas instalaciones; y iv) la determinación del potencial de impacto ambiental de los productos finales. La información obtenida mediante el análisis de parámetros puramente físicos o químicos de los residuos no es capaz de reflejar la naturaleza biológica de los residuos. Es muy amplia la bibliografía que describe, propone y evalúa el uso de índices biológicos, aerobios y anaerobios, para caracterizar los residuos orgánicos. Asimismo, éstos índices han sido propuestos en diferentes normativas de países europeos. En esta Tesis se han desarrollado nuevas metodologías para la determinación de índices biológicos aerobios y anaerobios, optimizando las metodologías ya referenciadas, eliminando sus limitaciones y ampliando su utilidad: índices respirómetricos aerobios, expresados como velocidad de consumo de oxígeno y su consumo acumulado durante un tiempo determinado e índices anaerobios expresados como producción acumulada de biogás y metano durante un tiempo determinado o total. Estas metodologías se han evaluado y verificado mediante las siguientes aplicaciones: 1) Optimización del proceso de compostaje de lodos procedentes de EDARs urbanas, determinando la relación de estructurante‐lodo mínima necesaria para obtener un producto final higienizado y estabilizado a escala industrial. 2) Completa evaluación de una planta de tratamiento mecánico‐biológico (MBT) con capacidad para tratar 240.000 toneladas/año de residuos municipales, monitorización del proceso y determinación de las eficacias de eliminación de materia orgánica en cada etapa. 3) Estudio específico del pretratamiento mecánico de una MBT y su influencia en la eliminación de materia orgánica biodegradable. 4) Determinación de potenciales totales de producción de biogás mediante el análisis de índices biológicos anaerobios de corta duración. 5) Determinación de correlaciones entre índices aerobios y anaerobios. Determinación de correlaciones entre diferentes índices aerobios y discusión sobre la diferente información que proporcionan. 6) Caracterización completa de residuos basándose en la diferente información proporcionada por los índices respirométricos aerobios. 7) Redacción de un protocolo estandarizado para la determinación de la biodegradabilidad de residuos orgánicos de diferente origen y tipología para la Agència de Residus de Catalunya basándose en la determinación de índices biológicos aerobios. Los resultados obtenidos en todos estos trabajos confirman la idoneidad del uso de índices biológicos como medida real del contenido de materia orgánica biodegradable de los residuos y por lo tanto de su estabilidad. Además pueden considerarse como un parámetro clave para el diseño y control en plantas de tratamiento de residuos.
Biodegradable waste receives especial attention in the European Legislation (Revised Framework Directive 2008/98/CE) and this has been also reflected in Spanish Legislation in the Plan Nacional Integrado de Residuos 20082015 (PNIR), due to the high importance that this municipal solid waste fraction has on the waste treatment environmental impact when it is not treated correctly and the possibility of recycling the biodegradable waste, to finally obtain compost or/and biogas that means green energy. For this purpose is necessary to develop suitable facilities for all waste treatments and assure the correct and efficient operation of such treatment and management facilities or plants. The correct determination of process efficiency in these facilities requires a reliable measure of the biodegradable organic matter content of the wastes and their stability. This measure would allow: i) to establish a waste classification based on the biodegradability and stability; ii) the correct evaluation of plant and facilities performance; iii) the design of new and optimum facilities and waste treatments; and iv) to determinate the environmental impact of the final products of these facilities. The information given by the analysis carried out just considering physical and chemical parameters is not able to reflect the correct biological nature of the wastes. It is really considerable the bibliographic references regarding the description, use and evaluation of biological indices, both aerobic and anaerobic, to characterize organic wastes. Additionally, these indices have already been proposed in some European countries’ Legislations. In this Thesis, new methodologies have been developed to determine aerobic and anaerobic biological indices, trying to optimize the already published methodologies by detecting their weaknesses, proposing improvements and increasing their utility. The indices obtained using these methodologies are: aerobic respirometric indices, expressed as the oxygen consumption rate and cumulative oxygen consumption during a given time and anaerobic indices, expressed as cumulative biogas and methane production during a given time or total biogas or methane production. These methodologies have been assessed, evaluated and verified in different facilities, different treatments and in several works with different aims: 1) Optimization of the composting process of dewatered wastewater sludge, determining the minimum ratio of pruning waste used as bulking agent to obtain a hygienized and stabilized product in full scale facilities. 2) Complete assessment of a mechanical‐biological treatment (MBT) plant treating 240.000 tones each year of municipal solid wastes. Process monitoring an determination of process efficiency regarding organic matter biodegradation. 3) Specific study of the mechanical pretreatment in a MBT plant and how it affects to the biodegradable organic matter removal. 4) Determination of the biogas production potential using anaerobic biological indices, measured in a short experimental time. 5) To obtain correlations between aerobic and anaerobic indices. Additionally, to correlate aerobic indices among them and analyzing the different information that they provide. 6) Using the information provided by aerobic respiration indices to completely characterized organic wastes. 7) Establishment of a standardized protocol to determine the biodegradability of organic wastes, from different origin and nature using aerobic biological indices to Agència de Residus de Catalunya. The results obtained in all works and studies confirm the suitability of biological indices to be measure the biodegradable organic matter content and stability of solid wastes. Additionally, these indices can be considered as key parameters to design and control waste treatment facilities and processes.

A thesis submitted in fulfilment of the requirements for the Degree of Doctor of Philosophy in Sanitary Engineering in the Faculty of Sciences and Technology of the New University of Lisbon
This work focused on the study of the kinetics of municipal solid waste composting in four full-scale mechanical-biological treatment (MBT) plants. We investigated how well the existent plants in Portugal were being operated, and estimated their performance at optimum operation. To achieve this, volatile solids (VS) content and several environmental conditions, namely temperature (T), moisture content (MC), oxygen concentration ([O2]), and free air space (FAS), were monitored throughout the composting process. Experimental data was fitted with a first-order kinetic model, and a rate constant (k) that corrects for T, MC, [O2] and FAS conditions was obtained, i.e., k is characteristic of composting under optimum environmental conditions. The kinetic model satisfactorily described the experimental data from three MBT plants. k values ranged from 0.043 d-1 to 0.082 d-1. Modelling the fourth plant was less successful,probably due to sampling errors on the VS determinations. This is the first time that a kinetic composting model has been applied to full-scale MBT plants. We also concluded that two of the MBT plants were poorly operated. Optimization of process management with measures of simple practical implementation was estimated to be highly significant in these poorly managed plants, increasing performance by 103% in MBT1 and 53% in MBT2. In conclusion, this work highlights the importance of having process performance monitoring and optimization programs in full-scale composting systems. It is proposed that the procedures developed here are applied for this purpose. The composting model was further tested by applying it to data from lab- and full-scale studies collected from the literature. This is the first time that rate constants from a large set of data sources are corrected for T, MC, [O2] and FAS. k values from full-scale studies varied little, whereas those from lab-scale studies varied widely with k reaching much higher values. These observations indicate that: (i) factors other than those included in the model have a significant effect on the composting rate, as previously suggested; (ii) there is a large margin for improvement in the performance of real-scale systems; (iii) extrapolation of data from laboratory- to full-scale can be misleading and should be cautiously applied; and (iv) more studies of full-scale systems should be conducted, because these constitute an important control over laboratory-scale studies, especially when the aim is the optimization of the design, or operation, of full-scale systems.
European Project “AWAST; 5th Framework Programme (project n. EVK4-2000-00514)

Tidal Energy is one of the growing renewable energy technologies that is aimed at tackling global energy challenges. The Horizontal Axis Tidal Turbine (HATT) is an in-stream Tidal Energy Converter (TEC) which extracts kinetic energy from tidal flows. These tidal turbines face many reliability challenges due to their complexity, harsh operating environment and low accessibility. One of the component contributing significantly to the reliability of a TEC is the bearing supporting the rotating shaft within the nacelle. The reliability assessment of this component is essential during the design process and before their eventual deployments. This work is describes shaft bearing reliability assessment procedures. In recent years, the Offshore Renewable Energy (ORE) Catapult’s National Renewable Energy Centre has developed a dedicated multi axis test facility for full scale testing of tidal turbine nacelles and components (i.e. Nautilus). This work presents a methodology for testing tidal turbine shaft bearings in a representative manner in the full scale nacelle test rig, Nautilus. Two aspects are considered, namely the damage assessment and the damage replication in an accelerated manner. The damage assessment process considers the global loading on the shaft bearing and a Rigid Dynamics (RD) model has been applied to identify the local bearing loads. Local loads are converted to stress enabling the identification of stress-life relationship and bearing damage. The damage replication process is aimed to evaluate the 20 year damage and the Acceleration by Phase-shift (AbP) method has been developed to accelerate the cumulative damage. The AbP method enables the assessment of performance characteristics of shaft bearings in a laboratory environment, reducing failure rates, validate performance in a cost effective manner by reduced testing times. Within this work, novel processes for shaft bearing reliability assessments and demonstration are suggested and it concludes with the presentation of a recommended test plan for carrying out accelerated tests on a full scale bearing.

Deep foundations such as driven piles are often used to bypass liquefiable layers of soil and bear on more competent strata. When liquefaction occurs, the skin friction around the deep foundation goes to zero in the liquefiable layer. As the pore pressures dissipate, the soil settles. As the soil settles, negative skin friction develops owing to the downward movement of the soil surrounding the pile. To investigate the magnitude of the skin friction along the shaft three driven piles, an H-pile, a closed end pipe pile, and a concrete square pile, were instrumented and used to measure soil induced load at a site near Turrell, Arkansas following blast-induced liquefaction. Measurements were made of the load in the pile, the settlement of the ground and the settlement of piles in each case. Estimates of side friction and end-bearing resistance were obtained from Pile Driving Analyzer (PDA) measurements during driving and embedded O-cell type testing. The H-pile was driven to a depth of 94 feet, the pipe pile 74 feet, and the concrete square pile 72 feet below the ground surface to investigate the influence of pile depth in response to liquefaction. All three piles penetrated the liquefied layer and tipped out in denser sand. The soil surrounding the piles settled 2.5 inches for the H-pile, 2.8 inches for the pipe pile and 3.3 inches for the concrete square pile. The piles themselves settled 0.28 inches for the H-pile, 0.32 inches for the pipe pile, and 0.28 inches for the concrete square pile. During reconsolidation, the skin friction of the liquefied layer was 43% for the H-pile, 41% for the pipe pile, and 49% for the concrete square pile. Due to the magnitude of load felt in the piles from these tests the assumption of 50% skin friction developing in the liquefied zone is reasonable. Reduced side friction in the liquefied zone led to full mobilization of skin friction in the non-liquefied soil, and partial mobilization of end bearing capacity. The neutral plane, defined as the depth where the settlement of the soil equals the settlement of the pile, was outside of the liquefied zone in each scenario. The neutral plane method that uses mobilized end bearing measured during blasting to calculate settlement of the pile post liquefaction proved to be accurate for these three piles.

The aeration process is often the single largest consumer of electricity in a wastewater treatment plant. Aeration in biological reactors provides microorganisms with oxygen which is required to convert ammonium to nitrate. Ammonium is toxic for aqueous ecosystems and contributes to eutrophication. The importance of aeration for the treatment results in combination with the high costs motivates automatic control of the aeration process. This thesis is devoted to ammonium feedback control in municipal wastewater treatment plants. With ammonium feedback control, the aeration intensity is changed based on a measurement of the outlet ammonium concentration. The main focus of the thesis is design, implementation, evaluation and improvement of ammonium PI (proportional-integral) controllers. The benefits of ammonium feedback control are established through long-term experiments at three large wastewater treatment plants in Stockholm, Sweden. With ammonium feedback control, energy savings up to around 10 % were achieved compared to keeping the dissolved oxygen concentration constant. The experiments generated several lessons learned with regard to implementation and evaluation of controllers in full-scale operation. The thesis has established guidelines on how to design ammonium feedback controllers for situations when cost-effective operation is the overall aim. Simulations have demonstrated the importance to limit the dissolved oxygen concentration in the process and under what conditions the energy saving with ammonium feedback control is large. The final part of the thesis treats improvements of ammonium PI control through minor modifications to the control structure or controller. Three strategies were studied: gain scheduling control, repetitive control, and a strategy reacting to oxygen peaks in the last aerobic zone. The strategies all had their benefits but the ammonium feedback controller was the key factor to improved aeration control.

Thesis (S.M.)--Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2013.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 95-102).
This thesis presents a general model for the carbon footprint analysis of advanced wastewater treatment plants (WWTPs) with biological nitrogen removal processes, using a life cycle assessment (LCA) approach. Literature on greenhouse gas (GHG) emissions and LCA are reviewed and the methodology employed in the analysis is discussed. Two selected WWTPs in Madrid, Spain, i.e. La Gavia and Boadilla, are analyzed and the carbon footprints are calculated, using GaBi software by PE-international. In quantifying the N₂O emissions from the biological nitrogen removal processes in the WWTPs, huge uncertainty on N₂O emission factor is identified and thus a comprehensive study on N₂O generation and emission is conducted. Different measurement strategies are investigated and an on-site aqueous N₂O measurement is carried out at Boadilla WWTP. Estimation of N₂O emission from the plant is given and compared with other calculation results. Recommendations on future measurement campaign are provided at last. The final results have shown that a big portion of the carbon footprints from the WWTPs is from the indirect emissions of CO₂, which is caused by the intensive energy consumption. However, the emissions resulting from the N₂0 in biological nitrogen removal processes cannot be ignored. Depending on different estimation methodologies, and the operational conditions that affect the N₂O production, the N₂O emission can range from 17% to 38% of the total carbon footprint of the WWTP.
by Xin Xu.
S.M.

The Liquid Salt Cooled Reactor (LSCR) provides several potential benefits compared to pressurized water-cooled reactor systems. These include low operating pressure of the liquid salt coolant, the high burnup tolerance of the fuel, and the high operating temperatures which leads to increases in efficiency. However, due to inherently low heavy metal loading, the fuel cycle design presents specific challenges. In order to study options for optimizing the fuel design and fuel cycle, SCALE6.1 was used to create simplified models of the reactor and look at various parameters. The primary parameters of interest included packing factor and fuel enrichment. An economic analysis was performed on these results by developing a simple fuel cycle cost (FCC) model that could be used to compare the different options from an economic standpoint. The lithium enrichment of the FLiBe coolant was also investigated. The main focus was to understand the practical limitations associated with the Li-7 enrichment and whether it could be used for beneficial purposes. The main idea was to determine whether a lower-than-equilibrium enrichment could be used at reactor start up so that the Li-6 isotope acts as a burnable absorber. The results for the lithium enrichment study showed that the enrichment converges over time, but the amount of time required to reach steady state is much too long and the FLiBe coolant could not be utilized for reactivity control as a burnable absorber. The results found through this research provide reasonable guidelines for expected costs and narrow down the types of configurations that should be considered as fuel design options for the LSCR. Additionally, knowledge was gained on methods for modeling the system not only accurately but also efficiently to reduce the required computing power and time.

The goal of this thesis was to examine submerged macrophoe biomass, distribution, and ecosystem effects at scales large enough to incorporate the littoral zone into models of whole lake structure and function. Submerged macrophyte biomass and distribution was shown to be highly variable between growing seasons and primarily dependant upon air temperature and the timing of the onset of the growing season. Within a growing season, a mass balance study showed an undisturbed macrophyte bed to markedly lower phytoplankton biomass: total phosphorus ratios, although the net effect of the bed on the growing season phosphorus budget was minimal. The weedbed preferentially retained phytoplankton biomass while being a source of bacterial production to the open water. These findings were mirrored at the among lake scale, as planktonic respiration and bacterial production were higher in macrophyte dominated lakes than would be expected based on phytoplankton biomass alone. Further, phytoplankton biomass was lower than would be expected based on epilimnetic phosphorus levels, showing that the classical view of pelagic interactions that proposes phosphorus determines phytoplankton abundance, which in turn determines bacterial abundance through the production of organic carbon, becomes less relevant as macrophyte cover increases. Long term phosphorus accumulation in the littoral zone was shown to be linked to macrophyte biomass, and on average almost an order of magnitude higher than calculated from the growing season (June--October) phosphorus budget, suggesting that the bulk of phosphorus accumulation in weedbeds occurs outside of the growing season. Finally, sediment core data showed that while submerged weedbeds accumulate up to four times as much bulk sediment compared to the profundal zone, phosphorus accumulation in weedbeds is much less than observed in the profundal zone. These results strongly indicating that submerged macrophyte beds play a central role in trapping ep

Devant les difficultes essentiellement administratives et sociales posees par l'ouverture de nouveaux sites de stockage de dechets, la tendance actuelle est a l'extension laterale ou verticale de centres existants, conduisant parfois a l'adoption de geometries de pente inhabituelles pour lesquelles la stabilite des systemes geosynthetiques d'etancheite en pente (sur talus ou en couverture) devient une question cruciale. La maitrise de la stabilite de tels systemes passe par une meilleure comprehension de leur fonctionnement. Dans ce but, l'etude de la caracterisation sur plan incline des interfaces geosynthetiques a ete menee, ainsi que celle du renforcement par inclusion de geosynthetique et l'analyse de la reponse d'un systeme geosynthetique d'etancheite en vraie grandeur. Cette etude se base principalement sur des essais de laboratoire realises sur un dispositif plan incline elabore dans le cadre de ce travail. La validite de la caracterisation sur plan incline des interfaces sable/geosynthetiques est confirmee par la repetabilite, la reproductibilite et la coherence des caracteristiques d'interface obtenues vis-a-vis des tendances generales observees en boite de cisaillement direct, relatives a l'influence du confinement. Le mecanisme d'ancrage constitue le principe de base du renforcement par inclusion de geosynthetique. Les essais de renforcement realises montrent particulierement une meilleure efficacite du renforcement par inclusion pour stabiliser le sol de couverture, par rapport au renforcement classique a la base du sol. L'analyse des donnees issues d'une experimentation en vraie grandeur sur un systeme geosynthetique d'etancheite illustre particulierement la difficulte de prediction du fonctionnement d'un systeme reel, due principalement aux incertitudes de la mise en place.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
The environmental liabilities that are faced by fossil fuel industry motivate the search for renewable energy sources. Although Brazil is the second largest world producer of bioethanol, the current production deficit is expected to go up by 2015. In this direction, it is utmost important to widen the ethanol feedstock cultivated area, as well as expanding the number of production units of this biofuel. Small ethanol plants emerge as an interesting alternative for the decentralization of production. However, the design and operation of such plants require high efficiency to enable their operation. This work presents the study of modeling, simulation and control of a batch distillation column for the separation of binary mixture ethanol-water to produce hydrous ethanol fuel with a concentration between 95.1% (v/v) and 96% (v/v), according to ANP specifications. The distillation column, located at the Polytechnic College of the Federal University of Santa Maria, was used as basis for the fundamental modeling which was performed using the software EMSO. Different models of phase equilibria were analyzed, being the Van Laar model for calculating the activity coefficient of the mixture in the liquid phase, coupled with ideal vapor mixture model, the one that have shown the best results. In this study, different control strategies were also proposed and evaluated to keep the top product concentration on the ANP specification for hydrous ethanol fuel. The chosen control algorithm was the Proportional Integral designed with discrete linear parametric models and through different tuning methods found in the literature. Robustness and performance criteria were used to select the best controller. Three process variables, candidates to be the manipulated variable of the control strategy, were compared: heating steam flow rate of reboiler, cooling water flow rate of pre-condenser and reflux ratio. The results have shown that the most efficient strategy was the one in which the flow of cooling water flow rate of pre-condenser was used as the manipulated variable. Besides ensuring that concentration is kept quite close to the azeotrope formed by ethanol-water mixture, another advantage of this variable in a control strategy is to allow the production of a high hydrous ethanol fuel.
O passivo ambiental enfrentado pela indústria de combustíveis fósseis motiva a busca por fontes renováveis de energia. Embora o Brasil seja o segundo maior produtor de etanol mundial, há um déficit produtivo cuja tendência é aumentar até 2015. Nesse sentido, é muito importante ampliar as áreas de cultivo de matérias prima do etanol, bem como aumentar o número de unidades de produção deste biocombustível. Miniusinas de etanol surgem como uma alternativa interessante para a descentralização da produção, porém sua concepção e operação necessitam de grande eficiência para viabilizar o funcionamento. Este trabalho apresenta o estudo da modelagem, simulação e controle de uma coluna de destilação descontínua para a separação da mistura binária etanol-água com o objetivo de produzir etanol hidratado combustível, com concentração entre 95,1% (v/v) e 96% (v/v), conforme especificações da ANP. A coluna de destilação, localizada no Colégio Politécnico da Universidade Federal de Santa Maria, serviu de base para a modelagem fundamental, a qual foi efetuada com o uso do software EMSO. Foram analisados diferentes modelos de equilíbrio de fases, dentre os quais o modelo de Van Laar para o cálculo do coeficiente de atividade da mistura em fase líquida, aliado ao modelo de mistura vapor ideal, foi o que apresentou os melhores resultados. Neste estudo, também foram avaliadas diferentes estratégias de controle para manter a concentração do produto de topo dentro da especificação do etanol hidratado combustível exigida pela ANP. O algoritmo de controle escolhido foi o Proporcional Integral projetado com modelos paramétricos discretos lineares e através de diferentes métodos de sintonia existentes na literatura. Critérios de robustez e desempenho foram usados para a escolha do melhor controlador. Três variáveis de processo candidatas à variável manipulada na estratégia de controle foram comparadas: vazão de vapor de aquecimento no destilador, da vazão de água de resfriamento no pré-condensador e razão de refluxo. Os resultados mostraram que a estratégia mais eficiente foi aquela em que a vazão de água de resfriamento no pré-condensador foi usada como variável manipulada. Além de garantir que concentração seja mantida muito próxima a do azeótropo formado pela mistura etanol-água, a manipulação desta variável permite que uma maior quantidade de etanol hidratado combustível seja produzida.

Most mature oil reservoirs or fields tend to perform below expectations, owing to high level of associated gas production. This creates a sub-optimal performance of the oil production surface facilities; increasing oil production specific operating cost. In many scenarios oil companies flare/vent this gas. In addition to oil production constraints, associated gas flaring and venting consists an environmental disasters and economic waste. Significant steps are now being devised to utilise associated gas using different exploitation techniques. Most of the technologies requires large associated gas throughput. However, small-scale associated gas resources and non-associated natural gas reserves (commonly referred to as stranded gas or marginal field) remains largely unexploited. Thus, the objective of this thesis is to evaluate techno- economic of gas turbine engines for onsite electric power generation called gas- to-wire (GTW) using the small-scaled associated gas resources. The range of stranded flared associated gas and non-associated gas reserves considered is around 10 billion to 1 trillion standard cubic feet undergoing production decline. The gas turbine engines considered for power plant in this study are based on simple cycle or combustion turbines. Simple cycle choice of power-plant is conceived to meet certain flexibility in power plant capacity factor and availability during production decline. In addition, it represents the basic power plant module cable of being developed into other power plant types in future to meet different local energy requirements. This study developed a novel gas-to-wire techno-economic and risk analysis framework, with capability for probabilistic uncertainty analysis using Monte Carlo simulation (MCS) method. It comprises an iterative calculation of the probabilistic recoverable reserves with decline module and power plant thermodynamic performance module enabled by Turbomatch (an in-house code) and Gas Turb® software coupled with economic risk modules with @Risk® commercial software. This algorithm is a useful tool for simulating the interaction between disrupted gas production profiles induced by production decline and its effect on power plant techno-economic performance over associated gas utilization economic life. Furthermore, a divestment and make- up fuel protocol is proposed for management of gas turbine engine units to mitigate economical underperformance of power plant regime experienced due to production decline. The results show that utilization of associated gas for onsite power generation is a promising technology for converting waste to energy. Though, associated gas composition can be significant to gas turbine performance but a typical Nigerian associated gas considered is as good as a regular natural gas. The majority of capital investment risk is associated with production decline both natural and manmade. Finally, the rate of capital investment returns decreases with smaller reserves.

碩士
國立暨南國際大學
土木工程學系
94
In the study, the sludge obtained from the pilot-scale A2O system and full-scale SBR were used to test the adsorptions of heavy metal (Pb, Ni and Cd) by the activated sludge and the impacts of heavy metal on the nitrification and denitrification abilities of the activated sludge. The aim of the study was to investigate the feasibility of the treatment combination of municipal wastewater and lower level heavy metal wastewater. Results showed that the influence degree of these three kinds of heavy mentals was Ni>Cd>Pb for SAUR and Cd>Ni>Pb for SNUR. The inhibition occurred at the situation of 2 mgl-1 Ni or Cd. However, no significant inhibition occurred even though 40 mgl-1 Pb was added. When combining three metals at different concentration, no synergistic effect was found and the inhibition effect was based on the highest toxicity heavy metal. Furthermore, comparing with two systems, the result indicated that the tolerance of SBR sludge to heavy metals was better than that of A2O sludge. Both the regression equations of inhibition rate of SAUR and SNUR were first order kinetic reaction for both systems, as below: SAUR = ( SAURmax – SAURmin )‧ + SAURmin and SNUR = ( SNURmax – SNURmin )‧ + SNURmin. The adsorption ability of activated sludge to heavy metals was Pb≒Cd>Ni for both systems. And, the adsorption capacity (q) of activated sludge for heavy metal was increased with the increase of the heavy metal concentration and with the decrease of the MLVSS concentration. Experimental results also showed that the adsorption capacity of the SBR sludge was larger than that of the A2O sludge. The unculture bacteria and Beta-proteobacteria were the predominant bacteria population for both systems. In the A2O system, the floc forming bacteria Zoogloea oryzae was the only one microbial group that had been mentioned to the ability of adsorption of heavy metals by extra-cellular polysaccharide. However, Acidovorax temperans found in SBR system possesses the extra-cellular protein and can combine silver. It is possible that this bacterial group can be tolerant to the heavy metals and accumulate them. All the results of this study demonstrate that the tolerance and adsorption abilities of the SBR sludge to heavy metals was better than those of the A2O sludge. Therefore, it was suggested that the Acidovorax temperans in the SBR system played a significant role to the adsorption and tolerance of heavy metals.

Water samples were taken at the KAUST RO plant, the WDRC pilot plant and three other full-scale desalination installations in Saudi Arabia. The water was characterized using selected microbiological parameters, being conventional (heterotopic place count (HPC), total coliforms, Escherichia coli) and more novel and sensitive methods (adenosine tri-phosphate (ATP, a measure for bacterial activity), as well as total and intact bacterial cell concentrations (TDC using flow cytometry) and supporting parameters (pH, conductivity, residual chlorine and temperature). Selective samples were used to quantify the bacterial growth potential (“food for the bacteria”), applying a flow cytometer based easily Assimilable Organic Carbon (AOC) assay. Hypothesized was that no or very low bacterial numbers would occur after RO filtration in the plants due to the high rejection properties of the RO membranes and the produced water exceptionally low mineral and nutrient content. Key findings are that the (i) RO permeate contains bacterial cell concentrations exceeding 1.0 × 103 cells/mL. The highest percentage of cells are intact and active, based on the ATP and total cell counts (ii) advanced microbial parameters ATP and TDC enabled to detect and quantify bacteria numbers and activity while the less sensitive conventional plate counts based techniques did not, (iii) flow cytometer-based growth potential measurements indicate the presence of 8 µg AOC/L in the RO permeate. A typical last step in drinking water production is chlorination, effectively inactivating all the bacterial cells. The origin of the bacterial cells and the biodegradable nutrients enabling the bacterial growth in the RO permeate is not clear. There is a clear need to assess the origin of the nutrients and bacteria found in the RO produced water. It is not expected to be passing the RO membrane.

Thesis (M.S.)--University of Wisconsin--Madison, 2006.
Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 86-88).

Pilot-testing of a fluidized bed reactor used to recover phosphate in the form of struvite from a full-scale anaerobic digester supernatant was conducted on site, at the City of Penticton Advanced Wastewater Treatment Plant (AWWTP). The main objective of this study was to demonstrate the ability of the reactor, developed by the UBC phosphate recovery team, to remove at least 70 % of the phosphate in the supernatant from a full-scale digester fed with a combination of primary and secondary sludge, from a biological nutrient removal wastewater treatment plant. Results showed that the reactor was capable of removing over 80 % of the phosphate from the digester supernatant. The operation of the reactor could easily be controlled to achieve any desired level of phosphorus removal up to 90%. Reactor operation was relatively trouble free after an initial commissioning period. By the end of the experiment, it was possible to leave the reactor unattended for periods of up to 5 days without incident. Analysis of the recovered struvite crystals showed essentially pure struvite (>99 % by weight) with small amounts of calcium (<0.5 % by weight) and traces of potassium and iron. The recovered crystals had mean diameters increasing from 0.5 to 1.8 mm over the course of the study. This increasing diameter is believed to be due to changes in the crystal structure that caused them to become stronger over the course of the study. The causes of this change in crystal structure remain unknown, and require further investigation. A model was developed which was able to predict the effluent quality of the reactor based on the concentrations of magnesium, ammonia and phosphate in the reactor influent and the operating pH of the reactor. The model is based on the assumptions that the reactor effluent is at equilibrium with respect to struvite, and that magnesium, ammonia and phosphate are removed in equimolar amounts. The system equilibrium was described by an equilibrium conditional solubility product curve, developed for a sample of digester supernatant taken during the study Phosphate release from the anaerobic digestion of waste activated sludge was found to be 13% of the total phosphorus load to the treatment plant, when digesting only 40% of the secondary sludge, significantly lower than predicted in a previous study (Niedbala, 1995). This is probably due to the recent practice of discharging aluminum-rich sludge from the city drinking water treatment plant to the wastewater treatment plant. Changing this practice could result in the production of significantly greater masses of product at similar costs, thus increasing the economic viability of the process. Further studies at larger scale and of longer duration would be required to determine the steady state struvite product qualities produced by this process. The market that the product will target will also be important in order to produce a desirable and profitable product.

碩士
國立中山大學
環境工程研究所
102
This study aimed at investigating the feasibility of biotrickling filtration for eliminating VOCs (volatile organic compounds) from a stream of waste gas vented from houses for painting plastic car parts. Toluene, xylenes and isopropanol are among the main constituents of the VOCs in the vented gas. A pilot-scale biotrickling biofilter packed with plastic chips was built for the performance test to get engineering data for designing a full-scale facility for treating the gas stream with a flow of 720 Am3/min at 25oC. The pilot biotrickling biofilter (0.4 m(L)×0.4 m(W)×0.78 m(H)) was made of transparent acrylic sheets. There are six sections each packed with plastic chips of 0.4 m(L)×0.4 m(W)×0.05 m(H) in dimension and the total packing volume was 48 L. The chips are trimmed wastes for manufacturing thermal-rigid door plates in a plant located at Chia-Yi County in middle-southern Taiwan. The packed space has a space gas-solid interfacial area (the specific area) of 600 m2/m3 and a dry packing weight of 100 kg/m3. A waste gas stream with a flow rate ranging from 0.33-0.88 Nm3/min was drawn from the scrubber out of the painting houses and introduced into the filter bottom. Circulation water with added nutrients (urea, phosphoric acid, milk powder and fractose) was sprayed to the pacing surface for moistening and supplying nutrients to the microorganisms attached to the chip surfaces. The test period was 191 days, lasting from Dec. 27, 2013 to July 10, 2014. Results indicate that with an empty bed retention time (EBRT) of 4.74 s for the test gas flowing through the beds, 87-95% of 20 ppm of the THC (total hydrocarbon, expressed as methane equivalent) in the influent test gas could be removed. With an EBRT of 11.6 s, 81% of 400 ppm THC could be removed. A full-scale biofilter was scheduled for treating a total gas flow of 720 Am3/min at 25oC. Volumetric nutrient supplementation rates of milk powder 0.040 kg/m3.d, fractose 0.060 L/m3.d, urea 0.108 kg/m3.d and 85% phosphoric acid 0.0373 kg/m3.d were set. With volumetric loadings (L) of 0.86-265 g CH4/m3.h, a THC removal of 75% was expected with an EBRT of greater than 11.6 s.

Submitted in fulfilment of the requirements of the degree of Master of Technology: Biotechnology, Durban University of Technology, Durban, South Africa, 2014.
Wastewater treatment plants (WWTPs) frequently experience bulking and foaming episodes, which present operational challenges by affecting sludge settling due to the excessive proliferation of filamentous bacteria. Various control strategies have been implemented over the years to minimize filamentous growth, however, filamentous bulking still remains an unresolved problem in many WWTPs worldwide. The current study focused on developing and optimizing remedial measures viz., specific and non-specific methods to reduce problematic filamentous bacteria in a full-scale WWTP. Specific methods demonstrated the influence of plant operational parameters viz. chemical oxygen demand, influent N-NH4+, food to microorganism ratio, dissolved oxygen, temperature and pH on the abundance of filamentous bacteria. A cumulative logit model was used to determine the significant relationships between the individual filamentous bacteria at present and the prevailing plant operational parameters. Using the above statistical approach, significant observations and predictions were made with respect to the individual filamentous growth under certain operational parameters. With further validation, this model could be successfully applied to other full-scale WWTPs identifying specific parameters that could contribute to filamentous bulking, thus providing a useful guide for regulating specific filamentous growth. Non-specific control methods such as chlorine, ultraviolet irradiation and ozone treatment were investigated on filamentous bacteria using a live/dead staining technique. To achieve at least 50% reduction of filamentous bacteria, a chlorine dose of 10 mg Cl2/L was required, all filaments were killed at a dose of 22 mg Cl2/L. In addition, an effective UV and ozone dose of 4418.91 μw seconds/cm2 and ±20 mg O3/L respectively, was required to kill 50% of the filamentous bacterial population. Among the three non-specific methods, ozone treatment seemed to be an effective method in controlling the filamentous population with a low negative impact to the surrounding environment. This study serves as a useful guide on the problems and control of filamentous bulking in activated sludge plants.
M

碩士
國立中山大學
環境工程研究所
93
This research focuses on the performance study of a full-scale biofilter for treating a stream of vent gas with airborne VOCs generated from a chemical plant wastewater treatment facility. The biofilter consists of two parallel 20-ft standard containers in each a space of 5.98 m in length, 2.35 m in width and 0.50 m in height were filled with biofiltering media prepared by blending swine-manure compost and fern chips in a certain proportion. The vent gas contains methane, methanol, ethanol, acetone, dichloromethane, methyl ethyl ketone, ethyl acetate and toluene as major components and has an average flow rate of 1,320 m3/h (22 m3/min) and a temperature of 16-40oC. The purposes of this research were to confirm the VOC removal efficiency and to evaluate the elimination capacity for each VOC by monitoring operating parameters, including gas flow rate, system temperature, influent and effluent VOC concentrations of the biofilter. Experimental results show the system has a volumetric influent gas flow rate 1,153-1,470 m3/h which resulted in an average gas empty bed retention time (EBRT) of 0.64 min through the bed, a moisture of 25-70% and a pH of 2.4-6.9 for the media. Removal efficiencies of methane, methanol, ethanol, acetone, dichloromethane, MEK, ethyl acetate, toluene, NMHC and THC were 23.1, 79.3, 95.2, 82.9, 53.5, 63.7, 83.9, 41.2, 76.2 and 50.5%, respectively. Results also indicate that the VOC removal efficiency for each compound was not directly related to such important operating parameters of the biofilter as influent gas flow rate, media temperature, media pH, and the VOC concentration of the influent gas. However, the volumetric elimination rate (K) was approximately linearly varied with the corresponding loading (L) for the biodegradable VOCs in the influent gas. An average removal efficiency (K/L) of 24.5% was obtained with loadings of L < 70 g/m3h for methane. K/L of 91 and 54% were obtained for methanol with L = 0-7 and 15-22 g/m3h, respectively. Average K/L of 95% was obtained for both ethanol and acetone with L < 40 g/m3h. Removal efficiencies of 48 and 76% were obtained for methanol with L = 0-10 and 18-35 g/m3h, respectively. For MEK, an average removal of 89% was obtained with L = 0.5-4 g/m3h. Removal efficiencies of 84, 37, 48, 76 and 51% were obtained with L < 20, 0-0.2, 0.3-0.8 <60 and <120 g/m3h for ethyl acetate, toluene, NMHC and THC, respectively. This full-scale biofilter is effective in removing ethanol, ethyl acetate, acetone, methanol, and MEK. There is no significant removal efficiency for dichloromethane, toluene and methane. The performance can hopefully be improved by controlling the media in suitable conditions of moisture 50-60% and pH 7-8.

Yes
Reverse osmosis (RO) is becoming one of the most promising technologies used in wastewater treatment because it offers high rate of contaminant rejection and lower energy consumption in comparison with other thermal treatment processes. Earlier research by the same authors in respect of a distributed one-dimensional mathematical model for a single spiral-wound RO membrane module based on the solution-diffusion model has been used in this paper to simulate the rejection of NDMA (N-nitrosodimethylamine) from wastewater in a series of seven RO elements full-scale treatment plant. Firstly, the applicability of this model has been evaluated using a simulation study and the results have been compared against experimental data gathered from the literature for a given plant. Secondly, further simulation and analysis studies are carried out to assess the performance of the plant for NDMA rejection and recovery rate under different operating conditions of feed pressure, flow rate, and concentration. For the studied RO configuration, it is concluded that a maximum of 55.1% NDMA rejection can be achieved, which confirms the remaining issue of lower NDMA rejection.

Natural organic matter (NOM) is composed of a complex matrix of organic compounds originating primarily from plant and animal degradation products, including both carbon and nitrogen, and is found in all natural waters. The removal of NOM in drinking water treatment plants is of importance as its presence is associated with qualities responsible for adverse aesthetic concerns such as colour, taste, and odour. It can also substantially impact treatment processes, as it has been shown to increase coagulant and disinfectant demand, corrosion and bacterial regrowth in distribution systems, and interfere with adsorption processes. More critically, certain NOM fractions have been identified as being precursors to potentially harmful disinfection by-products (DBPs) which over time can cause a variety of cancers in humans. The goal of this research was to determine the removal of carbon and nitrogen NOM components through a full-scale municipal drinking water treatment plant employing advanced treatment strategies aimed at reducing NOM, including sand-ballasted clarification (SBC), ozonation, and biological filtration (biofiltration). Investigation into the effect of seasonal changes in raw water quality and temperature on process performance, and determination of biofilter biomass quantity and activity were also carried out. The approach used to accomplish these goals involved sampling water and biofilter media from the Holmedale Water Treatment Plant (HWTP), located in Brantford, Ontario over a period of 14 consecutive months. NOM components were identified using a recently developed NOM characterization technique, liquid chromatography-organic carbon detection (LC-OCD), which fractionates NOM based on size and provides information about the concentration of five operationally defined NOM fractions. The fractions include biopolymers, humic substances, building blocks, low molecular weight (LMW) acids & humics, and LMW neutrals. The carbon fraction of NOM was quantified further using traditional water quality indicators, such as total organic carbon (TOC), dissolved organic carbon (DOC), assimilable organic carbon (AOC), ultraviolet absorbance at 254 nm (UVA254), and specific ultraviolet absorbance (SUVA). The nitrogen fraction of NOM was primarily investigated by quantification of inorganic nitrogen forms, such as total nitrogen, nitrate and ammonia. Throughout the sampling campaign, considerable removal of carbon compounds through sand-ballasted clarification was observed. Ozonation led to a substantial increase in AOC, which was anticipated (and for the most part removed through downstream biofiltration). The performance of both sand-ballasted clarification and ozone did not change considerably with seasonal temperature changes. The biofilters were capable of considerable removal of most carbon containing compounds, although the removal of certain fractions, suspected as being biodegradable, was reduced at cold raw water temperatures. Somewhat unexpectedly, no removal of total nitrogen, nitrate, or ammonia was observed through SBC, ozonation, and/or biofiltration. Due to the limited number of peer-reviewed articles on full-scale biofilter biomass characterization, investigation into the biomass quantity, as determined by adenosine triphosphate (ATP), and biomass activity, as determined by fluorescein diacetate (FDA) hydrolysis was undertaken. A review of the available literature demonstrated that the ATP concentration at the surface of active, acclimated biofilters (with granular activated carbon [GAC] or anthracite media) is typically in the order of 102-103 ng ATP/cm3 media. Compared to this benchmark, the biofilters at the HWTP appeared to contain a considerable quantity of active biomass. Nonetheless, results from the literature review and from this investigation demonstrate that no relationship exists between biofilter performance, in terms of organic matter removal, and ATP concentration at the surface of biofilters. Further investigation was also performed to determine if the biomass within the biofilters was receiving sufficient essential nutrients, namely carbon, nitrogen, and phosphorus, for growth. Determination of the carbon:nitrogen:phosphorus (CNP) ratio in the biofilter feed, and comparison to a widely accepted benchmark of roughly 100:10:1, suggested a potential phosphorus limitation. However, good biofilter performance, in terms of AOC removal, biomass quantity, and biomass activity was consistently observed. Still, no relationship between CNP ratio and biofilter performance, biomass quantity, and biomass activity could be identified. Somewhat unexpectedly, raw water temperature did not appear to impact the biomass quantity (ATP), activity (FDA), or the CNP ratio in the biofilter feed. The results from this research provide valuable information to municipal drinking water treatment providers whose plants employ SBC, ozone, or biofiltration. For the HWTP, although seasonal changes in raw water led to decreased biofilter performance for some monitored parameters, overall NOM removal through the plant remained considerable throughout the year. These findings provide insight to municipalities and consultants as it pertains to treatment process selection during the design or upgrade of drinking water treatment plants.

Thesis (M.S.)--University of Wisconsin--Madison, 2003.
Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 61-64).

碩士
國立中山大學
海洋環境及工程學系研究所
98
Taiwan semiconductor manufacturing industry ranks top in the world for the production and has a great contribution to Taiwan economics. However, the industry produces a significant amount of volatile organic compounds (VOC) into the air. According to EPA of Taiwan, the annual VOC emission amounts from the industry were approximately five thousand tons, a major stationary source of VOC emission. The EPA has implemented the air pollution control regulation for semiconductor industry, in which the VOC emission amount should be below &lt;0.6 kg/hr or the removal efficiency should be >90% for each factory . The conventional control technologies for the VOC emissions was concentration using zeolite followed by thermal oxidation. However, the high boiling points of VOC is difficult to desorbed from zeolite and it required the water to wash the zeolite. This would reduce the removal efficiency of zeolite. This control processes have high operation cost and may produce byproducts required for further treatment. Advanced chemical oxidation process (AOP) recently has gained tremendous attention as an emerging control technology of VOC due to low treatment cost and few oxidation byproducts. The major oxidant of the technology is believed to be hydroxyl radicals, which can react organic compounds at very reaction rates. A majority of VOC emissions from the semiconductor industry are highly soluble and can be easily dissolved into water by scrubbing process. However, the wet scrubbing process can produce a significant amount of wastewater. The objective of this study was to investigate the feasibility of using wet scrubber and O3/H2O2/catalyst process on controlling the VOC emissions from the semiconductor manufacturing industry. A full scale of process of 1000 CMM flowrate was designed and built along with a semiconductor packaging facility. Results showed that major compounds of the VOC exhaust were iso-propanol, PGMEA, PGME and methyl ethyl keton. The inlet concentrations of THC significantly varied from 50 to 600 ppmv as methane. The AOP process can removed 90-95% of VOCs and the scrubbing water can be recycled and reused at least 95%. The capital cost of the system was NT20,000,000 with the annual operation cost of NT120,000 which was only 36-40% of it for the concentration using zeolite followed by thermal oxidation.

碩士
國立中山大學
環境工程研究所
88
The subject of this thesis is divided into two parts: (1) Treatment of 2-ethyl hexanol (2-EH) in an air stream by a pilot-scale biotrickling filter, and (2) Treatment of gaseous VOC emissions from a resin manufacturing plant by a full-scale biotrickling filter. Treatment of 2-Ethyl Hexanol in An Air Stream by A Pilot-Scale Biotrickling Filter 2-Ethyl Hexanol (2-EH) may release from the thermal breakdown of di-isooctyl phthalate (DOP), a commonly-used plasticizer, in the curing stage when manufacturing PVC synthetic leather and gloves. This paper reports the results of studies using a biotrickling filter (BTF) with blast-furnace slag packings (sizes = 2-4 cm and specific surface area = 120 m2/m3) for treatment of 2-EH in an air stream. The experimental setup consisted of a set of two-stage-in-series biotrickling filters. Each stage of the biotrickling filter was constructed from a 19.5-cm x 200-cm (ID x H) acrylic column packed with slags of 125 cm in height. The operation started with the conditions of recirculation liquid pH = 8.0 and rate (VL) = 8.83 m3/m2.h, a steady nutrient (ammonia nitrogen and phosphate phosphorus) addition, and without a special microbial seeding. Results indicate that, yellowish-brown biofilms on the surface of packing slags could be observed in one week and well developed in two weeks after the start-up operation. The effects of volumetric 2-EH loading (L) and superficial gas velocity (U0) on the 2-EH elimination capacity (K) and the removal efficiency (K/L) were tested. Long-term experimental results show that, in the conditions of influent 2-EH concentration C0 = 250 mg/m3, U0 = 162 m3/m2.h, and gas empty-bed-retention time EBRT = 55 s, K/L could be correlated by the equation K/L = 71.9/(72.4+L) with a correlation coefficient (R) of 0.9988. The 2-EH elimination rate was mass-transfer controlled when L<16 g/m3.h and reaction-controlled when L>16 g/m3.h. Results also indicate that nutrient addition and liquid recirculation were important for the normal operation of the BTF in eliminating the influent 2-EH. Treatment of Gaseous VOC Emissions from A Resin-Manufacturing Plant by A Full-Scale Biotrickling Filter A resin and chemical company located in Tainan County, Taiwan engages in the manufacture of PU (poly urethane), PVAC (poly vinyl acetate), PS (poly styrene), and PMMA (poly methyl methacrylate) resins from various chemical stocks. Gaseous volatile organic compounds (VOCs) emitted from the reactors include toluene, methyl ethyl ketone (MEK), acetone, vinyl chloride, styrene, butyl acetate, 2-ethyl hydroxyl acetate, and methyl methacrylate. These VOCs should be properly eliminated before discharging the reactor vents to the atmosphere. This paper reports the performance results of using a biotrickling filter (BTF) with wood packings (sizes = 2-12 cm and specific surface area = 97 m2/m3) for treating the reactor vents with a total flowrate of 80 m3/min at 20-30℃. The BTF was constructed from a 7.0 m x 6.0 m (ID x H) SUS 304 column with wood packings of 4.0 m in height. The operation started with the conditions of recirculation liquid pH = 7.0-8.0 and rate (VL) = 1.56 m3/m2.h, a steady nutrient (urea and phosphate phosphorus) addition, and without a special microbial seeding. Results indicate that, yellowish-brown biofilms on the surface of packings could be observed in one week and well developed in two weeks after the start-up operation. Long-term operation results show that, in the conditions of influent VOC concentration C0 = 200-10000 ppm (expressed in terms of methane), U0 = 125 m3/m2.h, and gas empty-bed-retention time EBRT = 115 s, K/L could be correlated by the equation K/L = 345/(467+L) with a correlation coefficient (R) of 0.9913. The VOC elimination rate was mass-transfer limited when L<45 g/m3.h, with the mass of VOCs expressed as that of methane. Results also indicate that the liquid recirculation might be interrupted for a hour without influencing the performance. Toluene was the most difficult one to eliminate among the VOCs in the gas stream.

Yes
A full-scale composite floor plate was tested to investigate the flexural behavior and in-plane effects of the floor slab in a grillage of composite beams that reduces the tendency for longitudinal splitting of the concrete slab along the line of the primary beams. This is important in cases where the steel decking is discontinuous when it is orientated parallel to the beams. In this case, it is important to demonstrate that the amount of transverse reinforcement required to transfer local forces from the shear connectors can be reduced relative to the requirements of Eurocode 4. The mechanism under study involved in-plane compression forces being developed in the slab due to the restraining action of the floor plate, which was held in position by the peripheral composite beams; while the secondary beams acted as transverse ties to resist the forces in the floor plate that would otherwise lead to splitting of the slab along the line of the primary beams. The tendency for cracking along the center line of the primary beam and at the peripheral beams was closely monitored. This is the first large floor plate test that has been carried out under laboratory conditions since the Cardington tests in the early 1990s, although those tests were not carried out to failure. This floor plate test was designed so that the longitudinal force transferred by the primary beams was relatively high (i.e., it was designed for full shear connection), but the transverse reinforcement was taken as the minimum of 0.2% of the concrete area. The test confirmed that the primary beams reached their plastic bending resistance despite the discontinuous decking and transverse reinforcement at the minimum percentage given in Eurocode 4. Based on this test, a reduction factor due to shear connectors at edge beams without U-bars is proposed.

碩士
國立交通大學
土木工程系所
107
Metallic yielding dampers (MYDs) designed to deform in an in-plane flexural mode achieves aseismatic goal, and also enhances effective utilization of material. After improving the shortcomings of other in-plane flexural dampers, the new type of MYD referred to as the in-plane oval damper (i-POD) has been proposed. Component tests prove the i-POD possessed stable and reliable energy dissipative characteristics, and also generalize empirical design formula through a comprehensive parametric study.This study continues the discussion of a way to integrate the in-plane oval damper with the structure to promote the practical application. Proposed in this thesis is to connect the full scale i-PODs to A-frame paired up and down between adjacent floors in form of a module referred to as seismic wall with i-POD inside. The story drift caused by the reciprocating motion is transformed into the amplitude of the displacement damper to form alternating tension and compression deformation, and the anti-seismic mechanism is formed by the hysteresis loop area of the elastic-plastic behavior. In this thesis, a single-layer portal steel frame structure is used as the framework to evaluate the aseismatic performance of the i-POD seismic wall, and a series of numerical simulations are designed and planned. The detailed design of the full-scale i-POD component is based on the aforementioned empirical formula combined with ANSYS analysis. The numerical simulation results of reciprocating pushover analysis show the mechanical properties of i-POD is similar to that the result of i-POD independent component analysis. As stated above, it proves that the damper and structure are connected through the i-POD seismic wall, which can fully reflect the behavior of the damper. The numerical simulation results of seismic analysis show that after adding the damper, the peak shear of column, and also the peak acceleration and displacement response top of the single-layer portal steel frame structure are significantly reduced, and the control efficiency increases with the intensity of the input excitation as larger responses increase the amplitude of the damper and dissipate more energy as a result. The i-POD component design method is verified reliably by comparison of the results of three types of i-PODs.

碩士
國立成功大學
環境工程學系碩博士班
98
Over the past decade Thin Film Transistor-Liquid Crystal Display (TFT-LCD) has become a rapidly growing optic-electronic industry. Manufacturing plants of TFT-LCD produce large amounts of high concentration industrial wastewater. In addition to organic carbon, such as dimethyl sulphoxide (DMSO, (CH3)2SO), TFT-LCD wastewater also contains significant amounts of organic nitrogen in the form of mono-ethanolamine (MEA, C2H5ONH2), and tetra-methyl ammonium hydroxide (TMAH, (CH3)4NOH). These organic nitrogen compounds make up 95% of the total nitrogen making it very difficult to meet water quality standards. This study was conducted to evaluate AOB microbial ecology and nitrification performance of three full-scale bioreactors, treating TFT-LCD wastewaters with high strength of organic nitrogen. One of the three bioreactors investigated was conventional activated sludge (CAS) system (C3) directly receiving TFT-LCD wastewaters, and the other one was an anoxic/aerobic bioreactor combined MBR (M6) directly treating TFT-LCD wastewater, while the other one was an aerobic bioreactor (F2) treating wastewater effluent from an upflow anaerobic sludge blanket (UASB) reactor. By performing molecular methods targeting on functional gene amoA of AOB, all samples from investigated bioreactors showed their presence, although their nitrification performance in different bioreactors varied from 20 to 80%. The AOB activity will be monitored by measuring the water quality changes, as well as by using Molecular Methods such as Polymerase Chain Reaction (PCR), and Terminal Restriction Fragment Length Polymorphism (T-RFLP) to identify any changes in microbial communities throughout the treatment process. T-RFLP data show that a community of Nitrosospira-like AOB seems to be the important species contributing to the nitrification of the organic nitrogen in the full-scale treatment plant. In addition to microbial ecology, batch experiments were conducted to evaluate inhibitory effects of nutrients, DMS, MEA/DMSO, OCl- on nitrification using activated sludges taken from F2 system. These results can be used as the operation to provide better recommendations for each system, and enhance the nitrification performance of full-sacle wastewater treatment plant. More studies should be done in order to have a clearer picture on the effect of different factors on nitrification in TFT-LCD wastewater treatment and enhance its nitrogen removal efficiency.

碩士
大仁科技大學
環境管理研究所
105
In this paper, three water plants including Cheng-Ching Lake (CCL), Kaotan (KT), and Mudan (MT) in southern Taiwan were compared in the efficiency of removing particles and organic matter by the treatment units which are pre-oxidized by adding different oxidant following to coagulation. In order to investigate the absorption model for removing particles and organic matter, and evaluate the feasibility of isothermal absorption model applied to some parameters like total organic carbon(TOC) and fluorescent intensity related with organic matter, the jar tests individually using CCL and MT source water were also completed at various temperature and coagulant dose. In addition, excitation emission fluorescent matrix (EEFM) combined with Parallel factor analysis (PARACFAC) was used to indicate the variation of major ingredients of organic matter in jar tests. In this research, particle’s parameters such as turbidity, average particle size and zeta potential were measured to indicate the variation of particle property. Regarding to the parameters related with the property of organic matter, EEFM obtained by fluorometer, molecular weight (MW) measured by High performance size exclusion chromatography (HPSEC) combined with DAD detector, and non-purgable dissolved organic carbon (NPDOC) measured by total organic carbon meter (TOC) were used to indicate the variation of the property of organic matter in oxidation/coagulation units. The results indicated that removing of turbidity for pre-ozonation/coagulation units of CCL is superior to that for pre-chlorination/coagulation units of MT and KT. Average particle size of colloid in units of CCL was reduced, but that in units of MT and KT was enhanced. CCL has better ability to remove NPDOC than MT and KT. The fluorescent spectrum variation related with humus including fulvc-like and humic-like in three water plants all appeared that the target peak might vanish or its intensity became weak or the shift of emission wavelength or excitation wavelength in spectrum, which might be attributed to the dose of oxidant and coagulant. Molecular weight cut-offs of organic matter detected in three water plants were distributed in 43~76 kDa, 47~110 kDa, 69~110 kDa and after oxidation/coagulation units, the peak intensity and area were greatly decreased. In addition, the jar tests for isothermal absorption model were done by individually using CCL and MT source water. The results showed that as the dose of coagulant increased , turbidity, average particle size and zeta potential absolute value decreased, and the efficiency of removing was the best at 35℃ and the optimal dose 2.5 mg-Al3+/L. The optimal dose of coagulant in removing NPDOC for CCL was 1.5 mg-Al3+/L at 15℃ and 35℃, and 1.0 mg-Al3+/L at 25℃; for MT, the optimal dose was 2 mg-Al3+/L at the above temperatures. The isothermal adsorption model of removing NPDOC by aluminum salt only fitted better at 25℃ and fitted worse at the other temperatures. The reason might be attributed to complexing of aluminum ion with organic matter, which did not follow the absorption mechanism. For jar tests of CCL source water , we found that Freundlich model (R=0.8028) applied to NPDOC removing fitted better than Langmuir model (R=0.6729) did, but for MT test, Langmuir model individually applied to NPDOC and humus-like peak intensity in EEFM had a better fit. In addition, EEFM combined with PARACFAC was used to extract the major characteristic ingredients from organic fluorescent groups in spectrum for CCL and MT source water, which appear at C1(240, 328/430 nm), C2(264,350/466 nm) and C3(224, 290/385 nm) for CCL source water , and C1(234, 308/406 nm)、C2(254, 340/454 nm) and C3(276, 370/490 nm) for MT source water. After jar tests of CCL source water, whole three components (C1, C2 and C3) in spectrum arose red shift at 15℃ and the shift was the greatest. For MT source water tests, whole three components in spectrum arose blue shift at various temperature, excitation wavelength and emission wavelength, and the shift for C1 was the greatest at 15℃ and was close at 25℃ and 35℃; the shift for C2 and C3 was the greatest at 25℃. This may be related with the different mechanisms happened in the reaction between functional group in humic matter and aluminium ion.

碩士
大仁科技大學
環境管理研究所
105
In this study, two high-level water plants, Cheng-Ching Lake (CCL) and Feng-Shan (FS), in southern Taiwan were selected to investigate the variation of the property of organic matter in treatment units including Fluidized Bed Crystallization / Rapid Filter and Post-O3 / Biological activated carbon bed；. The analytical parameters of water sampled from March to December in 2016 included particle’s parameters like Turbidity, Particle Size, and Zeta Potential, and the parameters of organic matter like Non-Purgeable Dissolved Organic Carbon (NPDOC), Excitaion Emission Fluorescent Matrix (EEFM), Molecular Weight cut-offs, Humicification Index (HIX) and Biological Index (BIX). In addition, two kinds of recycled biological filter bed which were filled with active carbon and glass balls individually were constructed in our laboratory. By treating CCL and FS source water, they were compared in variation of the property of organic matter under stable bioprocess. The results indicated that removing of turbidity was obvious in units of Fluidized Bed Crystallization / Rapid Filter for CCL and FS, and it was greater in units of Post-O3 / Bioactive Carbon Filter bed for CCL than for FS. Average particle size detected in the oulet was smaller than that in the inlet of Fluidized Bed Crystallization / Fast Filter or Post-O3 / Bioactive Carbon Filter bed for CCL, and the reduction degree of average particle size for CCL was more obvious than that for FS. Zeta potential absolute values in units of Fluidized Bed Crystallization / Rapid Filter and Post-O3 / Bioactive Carbon Filter bed for CCL and FS were mostly reduced. Organic matter belong to fulvic-like and humic-like groups in EEFM was well removed by CCL and FS. As to HIX and BIX, they enhanced more obviously in units of Post-O3 / Bioactive Carbon Filter bed than in units of Fluidized Bed Crystallization /Rapid Filter. The organic matter for molecular weight measured at UV 254 nm was obviously removed in in units of Fluidized Bed Crystallization / Rapid Filter, but the removing of organic matter for molecular weight measured at UV 210 nm was very little. The units of Post-O3 / Biological activated carbon bed have effects on removing both kinds of organic matter for molecular weight cut-offs measured at UV 254 nm and UV 210 nm. For the tests of recycled biological filter bed filled with active carbon and glass balls individually , the results indicated that before arriving at stable operation, NPDOC, UV210 and UV254 all decreased with operation time, and the reduction degree in active carbon filter bed was greater than in glass ball filter bed; total fluorescent intensity and organic matter belonging to five categories in EEFM were also more obviously removed in active carbon filter bed than in glass ball filter bed, and among five groups of organic matter, fulvic-like organic matter was removed the most.

Submitted in complete fulfillment for the degree of Doctor of Philosophy (Biotechnology), Durban University of Technology, Durban, South Africa, 2016.
Seasonal nitrification breakdown is a major problem in wastewater treatment plants which makes it difficult for the plant operators to meet discharge limits. The present study focused on understanding the seasonal impact of environmental and operational parameters on nitrifiers and nitrification, in a biological nutrient removal wastewater treatment works situated in the midlands of KwaZulu Natal. Composite sludge samples (from the aeration tank), influent and effluent water samples were collected twice a month for 237 days. A combination of fluorescent in-situ hybridization, polymerase chain reaction (PCR)-clone library, quantitative polymerase chain reaction (qPCR) were employed for characterizing and quantifying the dominant nitrifiers in the plant. In order to have more insight into the activated sludge community structure, pyrosequencing was used in profiling the amoA locus of ammonia oxidizing bacteria (AOB) community whilst Illumina sequencing was used in characterising the plant’s total bacterial community. The nonlinear effect of operating parameters and environmental conditions on nitrification was also investigated using an adaptive neuro-fuzzy inference system (ANFIS), Pearson’s correlation coefficient and quadratic models. The plant operated with higher MLSS of 6157±783 mg/L during the first phase (winter) whilst it was 4728±1282 mg/L in summer. The temperature recorded in the aeration tanks ranged from 14.2oC to 25.1oC during the period. The average ammonia removal during winter was 60.0±18% whereas it was 83±13% during summer and this was found to correlate with temperature (r = 0.7671; P = 0.0008). A significant correlation was also found between the AOB (amoA gene) copy numbers and temperature in the reactors (α= 0.05; P=0.05), with the lowest AOB abundance recorded during winter. Sanger sequencing analysis indicated that the dominant nitrifiers were Nitrosomonas spp. Nitrobacter spp. and Nitrospira spp. Pyrosequencing revealed significant differences in the AOB population which was 6 times higher during summer compared to winter. The AOB sequences related to uncultured bacterium and uncultured AOB also showed an increase of 133% and 360% respectively when the season changed from winter to summer. This study suggests that vast population of novel, ecologically significant AOB species, which remain unexploited, still inhabit the complex activated sludge communities. Based on ANFIS model, AOB increased during summer season, when temperature was 1.4-fold higher than winter (r 0.517, p 0.048), and HRT decreased by 31% as a result of rainfall (r - 0.741, p 0.002). Food: microorganism ratio (F/M) and HRT formed the optimal combination of two inputs affecting the plant’s specific nitrification (qN), and their quadratic equation showed r2-value of 0.50. This study has significantly contributed towards understanding the complex relationship between the microbial population dynamics, wastewater composition and nitrification performance in a full-scale treatment plant situated in the subtropical region. This is the first study applying ANFIS technique to describe the nitrification performance at a full-scale WWTP, subjected to dynamic operational parameters. The study also demonstrated the successful application of ANFIS for determining and ranking the impact of various operating parameters on plant’s nitrification performance, which could not be achieved by the conventional spearman correlation due to the non-linearity of the interactions during wastewater treatment. Moreover, this study also represents the first-time amoA gene targeted pyrosequencing of AOB in a full-scale activated sludge is being done.
D

碩士
國立成功大學
環境工程學系
103
The chemical oxygen demand (COD) removal and nitrogen removal performance in a full-scale anoxic/aerobic/aerobic/membrane bioreactor (A/O/O/MBR) treating the stripper (dimethyl sulphoxide (DMSO) and monoethanolamine (MEA))-containing thin film transistor liquid crystal display (TFT-LCD) wastewater were investigated and compared from simulation by BioWin software. High food to microorganism ratio (F/M ratio) and colloidal COD situations have negative impacts on nitrification. Sufficient nitrogen removal was observed when F/M ratio is less than 0.2 kg-COD/kg-VSS-day and COD and organic nitrogen of colloidal COD are lower than 200 mg/L and 20 mgN/L, repectively. Fluorescence excitation emission matrix (FEEM) and high-pressure size exclusion chromatography (HPSEC) were employed to measure colloidal COD in aerobic tank. The compound of molecular weight higher than 106 Da is the main source of colloidal COD. High molecular weight (107 Da) Aromatic protein (AP)-like molecules have negative impact on nitrification performance. The quantitative real time polymerase chain reaction (qPCR) results showed that ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) abundance more than 5×107 copy/mL provided stable ammonia oxidation. In the full-scale MBR during good nitrogen removal period, the efficiency of removal in COD and total nitrogen were found to be 97% and 85%, as compared to 95% and 49% in BioWin simulation. The batch tests showed denitrifying bacteria cannot use colloidal COD or decayed sludge as carbon sources for denitrification. Even anaerobic ammonium oxidation (ANAMMOX) reaction was not observed, nitrite disappeared considerably presumably for nitrous oxide production.

Research Doctorate - Doctor of Philosophy (PhD)
The research reported in this thesis focused on the experimental and numerical stochastic assessment of unreinforced masonry (URM) veneer wall systems (that is, timber as a flexible backup system is connected to masonry wall via metal ties), representative of those used in the contemporary constructions in Australia, under out-of-plane loading. Previous investigations have identified a need to develop an improved understanding from the detailed examination, by test and analysis, of the behaviour of wall ties and interaction between single masonry leaf and supporting frame. Although consideration of spatial and temporal variability of the material properties for a single leaf of masonry wall has been directed at developing predictive strength models for masonry, no studies have so far been carried out towards the consideration of spatial variability of all components (mortar joints, wall ties and timber studs) of the URM veneer wall system, model error and their effect on wall system strength. This PhD thesis estimates the veneer wall system's failure load from the Monte-Carlo experimental and numerical technique. In doing so, it is hoped that the stochastic finite element models developed in this study will be used to calculate the structural reliability and fragility of masonry wall systems for new and existing construction during a structure's service life. Probabilistic veneer wall tie characterisation is accomplished to generate a nonlinear tie constitutive law for the representation of the tie behaviours in the nonlinear FEA models. A total of 50 brick-tie-timber subassemblies were tested under compression and tension, and elastic stiffness, peak strength and displacement capacity were recorded for each subassembly. The best-fitted distribution, mean and COV for each point (which define the tie constitutive law) was calculated, and correlations between these points were established. Monte-Carlo experimental investigations of 18 full-scale URM veneer wall systems with theoretically identical geometries and properties under out-of-plane loading was conducted. Ten wall systems were tested under inward loading (ties are in compression), and the remaining eight were tested under outward loading (ties are in tension). For inward loading, the airbag was pushed against the veneer wall directly, while for the outward loading, polystyrene blocks were utilised to transmit the pressure from the airbag to the veneer wall. For each loading type, one specimen was tested for semi-cyclic loading to check whether the monotonic loading can capture the overall behaviour of the cyclic response. For each batch of mortar mixed, bond wrench testing was conducted at the same age as the test for the associated wall constructed using that mix. Batch to batch variabilities were statistically analysed, and probability distributions for flexural tensile strength were established. A lognormal distribution with an aggregated mean of 0.40 MPa and 0.42 MPa for inward and outward loading, respectively, was estimated for flexural tensile strengths. From the wall tests, veneer wall system behaviour was observed and measured until the collapse or 20% post-peak drop of the peak load. Tie force history along with the timber stud deflections were also recorded and analysed to understand the veneer system failure mechanism. Parallel to the wall tests, material characterisation tests for masonry were conducted to develop the material model to define the masonry in the nonlinear FEA model. After the wall tests, all timber studs used to build the veneer wall were tested to evaluate the modulus of elasticity and bending strength. Prior to stochastic finite element analysis, a deterministic model was developed using Diana FEA 10.3 which considers the mean values for masonry, tie and timber material properties obtained from the laboratory material characterisation tests. The boundary conditions and loading arrangements were established in such a way so that it can replicate the laboratory full-scale veneer wall system tests. As expected, deterministic FEA failed to estimate the wall strength (system peak load) for inward and outward loading. A deterministic FEA with characteristic strength values for all veneer wall components was also evaluated to replicate the design (weaker than average materials) behaviour. Sensitivity analysis (one and two standard deviations below and above the mean) for deterministic FEA was conducted for target input variables, the flexural tensile strength of masonry, tie capacity (stiffness and strength), and timber stiffness to understand how these parameters affect the system peak load. The system peak load is comparatively more sensitive to the masonry bond strength and tie stiffness/strength. Moreover, if the veneer cracks earlier (lower masonry strength) and redistributes the forces in those mid-range ties before the top row of ties failed, the veneer system has the potential to resist a higher magnitude peak pressure. Spatial stochastic finite element analysis considered the spatial variability (unit to unit correlation ρ=0 and 0.4) of the wall components (mortar flexural tensile strength) and compared them with non-spatial analysis. The non-spatial analysis underestimates the wall system failure compared to spatial analysis, and the spatial analysis is considered to more realistically represent the variabilities of the URM veneer wall system. Stochastic sensitivity analysis is conducted in turn to check the sensitivity of the veneer system behaviour to variability in the various input parameters, considering one parameter at a time. Moreover, all the variabilities and uncertainties observed in the laboratory wall testing are reported and quantified to make the Monte-Carlo experimental results comparable with SFEA. From the comparison, it is evident that the stochastic finite element model developed in this study can estimate the behaviour and system peak load reasonably and are considered to be from the same population as test results.

The olive oil extraction industry represents a substantial share of the economies of Mediterranean countries but leads to serious environmental problems by producing huge amounts of wastes (by-products) within a short production period. The production rate of olive oil is about 1.4-1.8 million tonnes per year in the Mediterranean, resulting in 30 million m3 of by-products and 20 million tonnes of olive pomace. A small portion of these wastes can be used as raw materials in different industries as they contain valuable natural resources. Greece has about 2300 small-scale, rural, agro-industrial units that extract olive oil. These are generally three-phase systems and their by-products include olive mill residual solids (olive pomace and leaves) and olive mill waste water. Olive mills produce significant quantities of solid wastes with outputs of 0.35 tonnes of olive pomace and 0.05 tonnes of leaves per tonne of olives. The huge quantities of olive pomace and olive leaves produced within the short oil extraction season cause serious management problems in terms of volume and space. The solid wastes (olive pomace and olive leaves) that are produced contain almost 95% organic matter and although they could be highly beneficial to agricultural soils, it has been shown that they also contain toxic compounds and lipid which increase soil hydrophobicity and decrease water retention and infiltration rate. The soils of most Mediterranean countries have low organic matter contents (<1%) which has negative impacts on agriculture. Frequent application of composted organic residues increases soil fertility, mainly by improving aggregate stability and decreasing soil bulk density. Organic amendments play a positive role in climate change abatement by soil carbon sequestration. Recurrent use of composted materials enhances soil organic nitrogen content by up to 90%. To replenish soil organic matter content and promote eco-friendly crop production, the application of olive pomace compost could be a good solution. To examine olive mill solid waste composting, four pilot-scale experiments were carried out to produce good quality compost using three phase olive mill solid waste (olive pomace, OP) and different bulking agents such as rice husk (RH), olive leaves (OL) sawdust (SD), wood shavings (WS), and chromium treated reed plants (RP). A series of parallel experiments was carried out to examine the effect final compost quality of: (a) initial moisture content, (b) water addition during the composting process, and (c) material ratios, and to also determine the toxicity level in plants and human blood lymphocytes (genotoxicity and cytotoxicity). For each experiment, six trapezoidal bins were used with dimensions 1.26 m long, 0.68 m wide and 0.73 m deep, and a total volume of 0.62 m3. The study was carried out in the facilities of the Department of Environmental and Natural Resources Management, University of Patras, Agrinio, in a closed area to maintain controlled temperature conditions. To monitor the composting process and evaluate compost quality, physicochemical parameters (temperature, moisture content, pH, electrical conductivity, organic matter, volatile solids, total organic carbon, total nitrogen, total phosphorus, potassium, sodium, and water soluble phenols) were measured at different phases. The respirometric test (O2 uptake) was performed to determine compost stability. Experimental results showed that even after short composting periods, the quality of the final product remained high. The final product had excellent physicochemical characteristics (C/N: 12.1–17.5, germination index (GI): 88.32–164.43%, Cr: 8–10 mg/kg dry mass, that fulfill1 EU requirements and can be used as a fertilizer in organic farming. To achieve higher quality of the final product, Olive pomace should be used in higher ratios than the other materials (OL, RH, WS, SD and RP). The amount (volume of humidifying agents) and time (frequency) of moisture addition also played an important role during composting. Based on the experimental results, olive mill wastes can produce a high quality soil amendment which has no phytotoxic, genotoxic or cytotoxic effects. Nevertheless, composting duration and bulking agents and their ratios are crucial factors that determine the quality of the final product. Finally, the revision of EU regulations is proposed to include genotoxic and cytotoxic evaluation of composts that enter the human food chain. A full-scale compost unit was designed based on the experimental results. For a typical small-sized olive mill, processing 30 tonnes of olives per day for a 100-day operation period, a total area of about 850 m2 is needed to compost the mill’s entire annual waste production.
Η βιομηχανία παραγωγής ελαιόλαδου αποτελεί ένα σημαντικό κομμάτι της οικονομίας στις χώρες της Μεσογείου, προκαλώντας ταυτόχρονα σημαντικά περιβαλλοντικά προβλήματα, λόγω της παραγωγής μεγάλων ποσοτήτων αποβλήτων κατά τη σύντομη περίοδο λειτουργίας των ελαιοτριβείων. Η μέση ετήσια παραγωγή ελαιολάδου στην Μεσόγειο κυμαίνεται στους 1.4-1.8 χιλιάδες τόνους, ενώ παράγονται επίσης περίπου 30 χιλιάδες m3 παραπροϊόντων και 20 χιλιάδες τόνους ελαιοπυρήνα. Μόνο ένα μικρό μέρος αυτών των παραπροϊόντων μπορεί να χρησιμοποιηθεί ως πρώτη ύλη σε διάφορες βιομηχανίες. Η Ελλάδα έχει περίπου 2300 ελαιοτριβεία μικρής κλίμακας διασπαρμένα στην ύπαιθρο. Τα ελαιοτριβεία αυτά είναι κυρίως τριφασικά και τα παραπροϊόντα τους συμπεριλαμβάνουν στερεά υπολείμματα (ελαιουρήνας και φύλλα) και υγρά απόβλητα ελαιοτριβείου. Τα ελαιοτριβεία παράγουν σημαντικές ποσότητες στερεών υπολειμμάτων παρέχοντας περίπου 0.35 τόνους ελαιοπυρήνα και 0.05 τόνους φύλλων ανά τόνο ελαιοκάρπου, παρακαλώντας σημαντικά προβλήματα στη διαχείρισης τους. Τα στερεά υπολείμματα (ελαιοπυρήνας και φύλλα) περιέχουν 95% οργανική ύλη, καθιστώντας τα δυνητικά κατάλληλα ως εδαφοβελτιωτικά, καθώς τα εδάφη των περισσότερων Μεσογειακών χωρών έχουν χαμηλή περιεκτικότητα σε οργανική ύλη (<1%) επηρεάζοντας αρνητικά την γεωργία. Τα υπολλείματα αυτά περιέχουν ωστόσο τοξικές ουσίες και έλαια, τα οποία αυξάνουν την υδροφοβικότητα του εδάφους και μειώνουν την κατακράτηση του νερού και την ρυθμό διήθησης. Έχει αποδειχθεί ότι συχνές εφαρμογές κομποστοποιημένων οργανικών υπολειμμάτων αυξάνουν την γονιμότητα του εδάφους, αυξάνοντας κυρίως τη συνολική σταθερότητα και την πυκνότητα του εδάφους. Η συχνή χρήση κομποστοποιημένων υλικών βελτιώνει την περιεκτικότητα των εδαφών σε οργανικό άζωτο του εδάφους έως και 90%. Η κομποστοποίηση ελαιοπυρήνα θα μπορούσε να αποτελέσει μια πιθανή λύση για την αναπλήρωση του περιεχομένου σε οργανική υλη των εδαφών και για την προώθηση μιας οίκοφιλικής αγροτικής παραγωγής. Για να εξεταστεί η κομποστοποιήση στερεών υπολειμμάτων ελαιοτριβείων, διεξήχθησαν 4 πειράματα πιλοτικής κλίμακας για την παραγωγή κομποστ, χρησιμοποιώντας στερεά υπολείμματα τριφασικών ελαιοτριβείων (ελαιοπυρήνας) και διαφόρους διογκωτικούς παράγοντες, όπως φλοιό ρυζιού, φύλλα ελιάς, πριονίδια, ροκανίδια, και καλάμια με υψηλή περιεκτικότητα σε χρώμιο. Σκοπός των παράλληλων πειραμάτων ήταν η εξέταση της επίδρασης στην ποιότητα του τελικού κομπόστ των: (α) αρχικού περιεχόμενου υγρασίας, (β) της προσθήκης νερού κατά την διάρκεια της κομποστοποιήσης, (γ) των ποσοστών ανάμιξης των υλικών, καθώς επίσης και ο προσδιορισμός της φυτοτοξικότητας και της γενοτοξικότητας των τελικών κομπόστ. Σε κάθε πείραμα χρησιμοποιήθηκαν 6 τραπεζοειδή πλαστικά δοχεία διαστάσεων 1.26 m σε μήκος, 0.68 m σε πλάτος και 0.73 m σε ύψος, με ολικό όγκο 0.62 m3. Οι πιλοτικές μονάδες ήταν τοποθετημένες σε κλειστό χώρο του Τμήματος Διαχείρισης Περιβάλλοντος και Φυσικών Πόρων του Πανεπιστημίου Πατρών στο Αγρίνιο, ώστε να επικρατούν σταθερές συνθήκες θερμοκρασίας. Η παρακολούθηση της κομποστοποίησης και η εκτίμηση της ποιότητας του κομπόστ, έγινε μέσω του προσδιορισμού διαφόρων φυσικοχημικών παραμέτρων (θερμοκρασία, περιεχόμενο υγρασίας, pH, ηλεκτρική αγωγιμότητα, περιεχόμενη οργανική ύλη, πτητικά στέρεα, ολικός οργανικός άνθρακας, ολικό άζωτο, ολικό φώσφορος, κάλιο, νάτριο, και ολικές φαινόλες). Για την εκτίμηση της ποιότητας του κομποστ πραγματοποιήθηκαν επίσης ρεσπιρομετρικά τεστ (κατανάλωση O2). Τα πειραματικά αποτελέσματα απέδειξαν ότι ακόμα και μετά από σύντομες περιόδους κομποστοποιήσης η ποιότητα του τελικού κομπόστ παρέμενε υψηλή. Το τελικό προϊόν είχε εξαιρετικά φυσικοχημικά χαρακτηριστικά (C/N: 12.1–17.5, δείκτης βλαστικότητας (GI): 88.32–164.43%, Cr: 8–10 mg/kg ξηρής μάζας), τα οποία είναι εντός των νομοθετικών ορίων της ΕΕ για την χρήση λιπασμάτων σε βιολογικές καλλιέργειες. Για την παραγωγή υψηλής ποιότητας κομπόστ ο ελαιοπυρήνας πρέπει να χρησιμοποιείτε σε μεγαλύτερη αναλόγια σε σχέση με τα υπόλοιπα υλικά. Η ποσότητα και η συχνότητα προσθήκης νερού παίζει επίσης σημαντικό ρόλο κατά τη κομοστοποιήση. Με βάση τα πειραματικά αποτελέσματα αποδείχθηκε ότι τα στερεά υπολείμματα ελαιοτριβείων μπορούν να παράξουν ένα υψηλής ποιότητας εδαφοβελτιωτικό, το οποίο δεν εμφανίζει φυτοτοξικότητα, γενοτοξικότητα και κυτταροτοξικότητα. Παρόλο αυτά η διάρκεια της κομποστοποίησης, οι διογκωτικοί παράγοντες και τα ποσοστά ανάμιξης των υλικών είναι κρίσιμοι παράγοντες, που επηρεάζουν την ποιότητα του τελικού προϊόντος. Επίσης αναφέρουμε ότι η νομοθεσία της ΕΕ θα πρέπει να αναθεωρηθεί συμπεριλαμβάνοντας τόσο τη γενοτοξική και την κυτταρτοξική εκτίμηση του κομπόστ πριν χρησιμοποιηθεί για βρώσιμες καλλιέργειες. Τέλος με βάση τα πειραματικά αποτελέσματα διαστασιολοήθηκε μια μονάδα πλήρους κλίμακας για την κομποστοποίηση στερεών υπολειμμάτων ελαιοτριβείου. Έτσι για ένα τυπικό μικρής κλίμακας ελαιοτριβείο, που επεξεργάζεται ημερησίως 30 τόνους ελιών και για περίοδο κομποστοποίησης 100 ημερών, χρειάζεται μια συνολική έκταση περίπου 850 m2 για τη κομπστοποίηση όλης της ετησίας ποσότητας του ελαιοπυρήνα.