Tesis sobre el tema "Petrochemical wastewater treatment"

A study was undertaken to investigate developing biofilms in a petrochemical wastewater treatment plant encompassing the architecture, microflora and the chemical nature of the matrix. Biofilms were developed on glass slides immersed in the activated sludge unit and analysed at known time intervals using a range of techniques. Initially, biofilms were investigated using conventional and emerging microscopic approaches to select a suitable technique. Scanning Confocal Laser Microscopy (SCLM) allowed visualisation of biofilms in situ with minimal background interference and non-destructive and optical sectioning which were amenable to quantitative computer-enhanced microscopy. SCLM was superior over Light microscopy and Scanning Electron Microscopy. This study demonstrated biofilm growth, presence of extracellular polymer substances (EPS) in early biofilms associated with cells and the development of porous nature of mature biofilms including channel-like structures. Overall new information has been obtained on developing biofilms in an Australian petrochemical wastewater treatment plant<br>Doctor of Philosophy (PhD) (Biological Sciences)

A study was undertaken to investigate developing biofilms in a petrochemical wastewater treatment plant encompassing the architecture, microflora and the chemical nature of the matrix. Biofilms were developed on glass slides immersed in the activated sludge unit and analysed at known time intervals using a range of techniques. Initially, biofilms were investigated using conventional and emerging microscopic approaches to select a suitable technique. Scanning Confocal Laser Microscopy (SCLM) allowed visualisation of biofilms in situ with minimal background interference and non-destructive and optical sectioning which were amenable to quantitative computer-enhanced microscopy. SCLM was superior over Light microscopy and Scanning Electron Microscopy. This study demonstrated biofilm growth, presence of extracellular polymer substances (EPS) in early biofilms associated with cells and the development of porous nature of mature biofilms including channel-like structures. Overall new information has been obtained on developing biofilms in an Australian petrochemical wastewater treatment plant

Thesis (Ph.D.) (Biological Sciences) -- University of Western Sydney, 2003.<br>"Thesis submitted for the Degree of Doctor of Philosophy, University of Western Sydney, July 2003". Includes bibliography : leaves 253 - 276.

CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO<br>A indústria petroquímica constitui um dos mais importantes setores industriais no Brasil. A grande diversidade dos processos de fabricação praticados faz aumentar a necessidade de caracterização dos efluentes gerados em cada planta industrial. Em geral, os efluentes apresentam elevado teor de matéria orgânica, cuja remoção é necessária para atender às normas técnicas de descarte de efluentes industriais. Um dos processos de tratamento utilizados é a coagulação química seguida de tratamento biológico. Na coagulação química, sais de alumínio ou ferro são usados como coagulantes. Devido às grandes flutuações de carga orgânica, as quais dificultam a dosagem do coagulante, buscam-se alternativas para aprimorar o tratamento. Neste contexto, a eletrocoagulação pode servir como alternativa à coagulação química ou como pré-tratamento. O presente trabalho consistiu de ensaios de coagulação química (Jar Test) e de eletrocoagulação em escala de laboratório, utilizando efluentes gerados em uma indústria petroquímica fabricante de borracha sintética. Os ensaios permitiram comparar as eficiências de remoção de matéria orgânica por eletrocoagulação e por coagulação química, bem como comparar as eficiências desses tratamentos em escala de laboratório com aquelas obtidas na etapa de tratamento físico-químico (coagulação química e floculação) da ETEI - Estação de Tratamento de Efluentes Industriais da indústria citada. Em todos os casos, as eficiências de remoção de carga orgânica foram avaliadas pela DQO (Demanda Química de Oxigênio). Nos ensaios de coagulação química em laboratório, utilizou-se como coagulante o sulfato de alumínio. Os parâmetros investigados foram o pH ótimo de coagulação e a dosagem ótima de coagulante. Os ensaios do processo eletrolítico foram realizados em batelada com eletrodos de alumínio. Os parâmetros investigados foram a temperatura, o potencial aplicado, o pH inicial, a distância entre eletrodos, o número de eletrodos e o desgaste dos mesmos. As eficiências de remoção de DQO pelo processo de eletrocoagulação apresentaram valores até três vezes maiores que a média mensal obtida na ETEI da indústria em questão, pelo processo de coagulação química e floculação, no período da coleta das amostras, indicando a possibilidade de aplicação do tratamento eletrolítico ao efluente estudado.<br>The petrochemical industry constitutes one of the most important industrial sectors in Brazil. The great diversity of processes of manufacture makes to increase the necessity of characterization of the effluents generated in each industrial plant. In general, the effluents presents high grade of organic matter, whose removal is necessary to expect to the technical standards of discarding of industrials wastewaters. One of the used processes of treatment is the chemical coagulation followed by biological treatment. In chemical coagulation, aluminum or iron salts are used as coagulants. Because of the large fluctuations of organic load, which makes difficult the dosage of the coagulant, alternatives are being looked for the improvement of the treatment. In this context, the electrocoagulation may be an alternative to the chemical coagulation or can serve as a preliminar treatment. The present work consisted of assays of chemical coagulation (Jar Test) and of electrocoagulation in scale of laboratory, using effluent generated in a petrochemical industry manufacturer of synthetic rubber. The assays had allowed to compare the efficiencies of removal of organic matter by electrocoagulation and chemical coagulation, as well as comparing the efficiencies of these treatments in scale of laboratory with those gotten in the stage of treatment physical- chemical (chemical coagulation and flocculation) of Industrial Effluent Treatment Station of the cited industry. In all the cases, the efficiencies of organic load removal had been evaluated by the COD (Chemical Oxygen Demand). In the chemical coagulation experiments in laboratory, the aluminum sulphate was used as coagulant. The investigated parameters have been pH excellent of coagulation and the excellent dosage of coagulant. The assays of the electrolytic process had been carried through in batch with aluminum electrodes. The investigated parameters have been the temperature, the applied potential, pH initial, the distance between electrodes, the number of electrodes and the consuming of them. The efficiencies of COD removal for the electrocoagulation process reached values up to three times higher that the monthly average observed in the treatment station of the studied industry in the chemical coagulation and flocculation stage. The results indicate the possibility of application of the process in the treatment of the studied effluent.

Reaction water, a high-strength COD (chemical oxygen demand) petrochemical effluent, is generated during the Fischer-Tropsch reaction in the SASOL Synthol process at SASOL SynFuels, Secunda, South Africa. Distillation of the reaction water to remove non- and oxygenated hydrocarbons yields approximately 25 - 30 ML/d of an organic (carboxylic) acid-enriched stream (average COD of 16 000 mg/L) containing primarily C2 – C5 organic acids, light oils, aldehydes, ketones, cresols and phenols. Together with the Oily sewer water (API) and Stripped Gas Liquor (SGL) process streams, this process effluent is currently treated in ten dedicated activated sludge basins. However, the successful operation of these activated sludge systems has proven to be difficult with low organic loading rates (3.5 kg COD/m3.d) low COD removal efficiencies (<80 %) and high specific air requirements (60 - 75 m3 air/kg CODrem). It is hypothesised that these operational difficulties can be attributed to organic shock loadings, variation in volumetric and hydraulic loadings, as well as variations in the composition of the various process streams being treated. Due to the fact that the Fischer-Tropsch (Synthol) reaction water constitutes 70 % of the COD load on the activated sludge systems, alternative processes to improve the treatment cost and efficiency of the Fischer-Tropsch acid stream are being investigated. Various studies evaluating the aerobic and anaerobic treatment of Fischer-Tropsch reaction water alone in suspended growth wastewater treatment systems have proven unsuccessful. High rate fixed-film processes or biofilm reactors, of which the fluidised-bed reactors are considered to he one of the most effective and promising processes for the treatment of high-strength industrial wastewaters, could he a suitable alternative. The primary aim of this study was to evaluate the suitability of biological fluidised-bed reactors (BFBRs) for the treatment of Fischer-Tropsch reaction water. During this study, the use of aerobic and anaerobic biological fluidised-bed reactors (BFBR), using sand and granular activated carbon (GAC) as support matrices, were evaluated for the treatment of a synthetic effluent analogous to the Fischer-Tropsch reaction water stream. After inoculation, the reactors were operated in batch mode for 10 days at a bed height expansion of 30% and a temperature of 30 ºC to facilitate biofilm formation on the various support matrices. This was followed by continuous operation of the reactors at hydraulic retention times (HRTs) of 2 days. While the COD of the influent and subsequent organic loading rate (OLR) was incrementally increased from 1 600 mg/L to a maximum of 20 000 mg/L and 18 000 mg/L for the aerobic and anaerobic reactors, respectively. Once the maximum influent COD concentration had been achieved the OLR was further increased by decreasing the HRTs of the aerobic and anaerobic reactors to 24h and 8h, and 36h, 24h and 19h, respectively. The dissolved O2 concentration in the main reactor columns of the aerobic reactors was constantly maintained at 0.50 mg/L. Chemical Oxygen Demand (COD) removal efficiencies in excess of 80 % at OLR of up to 30 kg COD/m3.d were achieved in the aerobic BFBRs using both sand and GAC as support matrices. Specific air requirements were calculated to be approximately 35 and 41 m3 air/kg CODrem for the BFBRs using sand and GAC as support matrices, respectively. The oxygen transfer efficiency was calculated to be approximately 5.4 %. At high OLR (> 15 kg COD/m3.d) significant problems were experienced with plugging and subsequent channelling in the BFBR using GAC as support matrix and the reactor had to be backwashed frequently in order to remove excess biomass. Despite these backwash procedures, COD removal efficiencies recovered to previous levels within 24 hours. In contrast, no significant problems were encountered with plug formation and channelling in the BFBR using sand as support matrix. In general the overall reactor performance and COD removal efficiency of the aerobic BFBR using sand as support matrix was more stable and consistent than the BFBR using GAC as support matrix. This BFBR was also more resilient to variations in operational conditions, such as the lowering of the hydraulic retention times and changes in the influent pH. Both aerobic reactors displayed high resilience and COD removal efficiencies in excess of 80 % were achieved during shock loadings. However, both reactors were highly sensitive to changes in pH and any decrease in pH below the pKa values of the volatile fatty acids in the influent (pKa of acetic acid = 4.76) resulted in significant reductions in COD removal efficiencies. Maintenance of reactor pH above 5.0 was thus an essential facet of reactor operation. It has been reported that the VFA/alkalinity ratio can be used to assess the stability of biological reactors. The VFA/alkalinity ratios of the aerobic BFBRs containing sand and GAC as support matrices were stable (VFNalkalinity ratios of < 0.3 - 0.4) until the OLR increased above 10 kg/m3.d. At OLRs higher than 10 kg/m3.d the VFA/alkalinity ratios in the BFBR using sand support matrix increased to 4, above the failure limit value of 0.3 - 0.4. In contrast the VFA/alkalinity ratios of the BFBR using GAC support matrix remained stable until an OLR of 15 kg/m3.d was obtained, where the VFA/alkalinity ratios then increased to > 3. Towards the end of the study when an OLR of approximately 25 kg/m3.d was obtained the VFA/alkalinity ratios of both the BFBRs using sand and GAC as support matrices increased to 9 and 6 respectively, indicating the decrease in reactor stability and acidification of the process. Total solid (TS) and volatile solid (VS) concentrations in the aerobic BFBRs were initially high and decreased over time. While the total suspended solids (TSS) and volatile suspended solids (VSS) concentrations were initially low and increased over time as the OLR was increased, this is thought to be as a result of decreased HRT leading to biomass washout. The anaerobic BFBR using sand as support matrix never stabilised and COD removal efficiency remained very low (< 30 %), possibly due to the high levels of shear forces. Further studies concerning the use of sand as support matrix were subsequently terminated. An average COD removal efficiency of approximately 60 % was achieved in the anaerobic BFBR using GAC as a support matrix at organic loading rates lower than 10 kg COD/m3.d. The removal efficiency gradually decreased to 50 % as organic loading rates were increased to 20 kg COD/m3.d. At OLRs of 20 kg COD/m3.d, the biogas and methane yields of the anaerobic BFBR using GAC as support matrix were determined to be approximately 0.38 m3 biogas/kg CODrem (0.3 m3 biogas/m3reactor vol.d), and 0.20 m3 CH4/kg CODrem (0.23 m3 CH4/m3reactor vol.d), respectively. This value is 57 % of the theoretical maximum methane yield attainable (3.5 m3 CH4/kg CODrem). The methane yield increased as the OLR increased, however, when the OLR reached 8 kg/m3.d the methane yield levelled off and remained constant at approximately 2 m3 CH4/m3reactor vol.d. Although the methane content of the biogas was initially very low (< 30 %), the methane content gradually increased to 60 % at OLRs of 20 kg COD/m3.d. The anaerobic BFBR using GAC as support matrix determined that as the OLR increased (>12 kg/m3.d), the VFA/alkalinity ratio increased to approximately 5, this is indicative of the decrease in stability and acidification of the process. The anaerobic BFBR using GAC as support matrix experienced no problems with plug formation and channelling. This is due to the lower biomass production by anaerobic microorganisms than in the aerobic reactors. The TS and VS concentrations were lower than the aerobic concentrations but followed the same trend of decreasing over time, while the TSS and VSS concentrations increased due to decreased HRTs. The anaerobic BFBR was sensitive to dramatic variations in organic loading rates, pH and COD removal efficiencies decreased significantly after any shock loadings. Compared to the activated sludge systems currently being used for the biological treatment of Fischer-Tropsch reaction water at SASOL SynFuels, Secunda, South Africa, a seven-fold increase in OLR and a 55 % reduction in the specific air requirement was achieved using the aerobic BFBRs. The methane produced could also be used as an alternative source of energy. It is, however, evident that the support matrix has a significant influence on reactor performance. Excellent results were achieved using sand and GAC as support matrices in the aerobic and anaerobic BFBRs, respectively. It is thus recommended that future research be conducted on the optimisation of the use of aerobic and anaerobic BFBRs using these support matrices. Based on the results obtained from this study, it can be concluded that both aerobic and anaerobic treatment of a synthetic effluent analogous to the Fischer-Tropsch reaction water as generated by SASOL in the Fischer-Tropsch Synthol process were successful and that the application of fluidised-bed reactors (attached growth systems) could serve as a feasible alternative technology when compared to the current activated sludge treatment systems (suspended growth) currently used. Keywords: aerobic treatment, anaerobic treatment, biological fluidised-bed reactors, petrochemical effluent, Fischer-Tropsch reaction water, industrial wastewater.<br>Thesis (M. Omgewingswetenskappe)--North-West University, Potchefstroom Campus, 2004.

碩士<br>國立雲林科技大學<br>環境與安全工程系碩士班<br>95<br>This study was focus at the efficiency of petrochemical wastewater treatment by deep aeration system The treating process was carried out from August, 2004 to September, 2006. There are 7 parameters including pH, COD, BOD loading, MLSS, SV30, SS was monitored. From the result of experiment, control at pH = 7∼8, MLSS = 1000∼2000 mg/l, SV30 = 100ml/l, DO = 4∼6 mg/l, retention time = 30∼35 hrs, SVI = 80~200, BOD loading = 0.25∼0.35 kg COD/kg MLSS-day. The removal efficiency of COD is 94％ and the effluent of COD is 59.5 mg/l. This effluent can meet the effluent standard.

Acrylic acid and formaldehyde are present in several industrial wastewaters including petrochemical wastes. The objectives of this study were to determine the anaerobic degradability of acrylic acid and formaldehyde in acidogenic and methanogenic systems and anaerobic treatability of petrochemical wastewaters containing acrylic acid and formaldehyde Acetate, propionate, and glucose enrichment cultures were used in serum bottle and chemostat studies. The results showed that the acrylic acid was degraded to propionate and acetate and without acclimation it completely inhibited propionate degradation and partially inhibited acetate degradation. In both the methanogenic and acidogenic chemostats, 98% of the acrylic acid was removed. However, the acidogenic chemostat had a significantly higher acrylic acid loading rate (416 mg/L-d) than the methanogenic chemostat (16.7-66.7 mg/L-d). Even at low acrylic acid loading rates, the propionate utilizers required a long time to acclimate to acrylic acid Formaldehyde showed severe toxicity to the acetate enrichment culture. As low as 10 mg/L of formaldehyde completely inhibited acetate utilization. Formaldehyde was, however, degraded while acetate utilization was inhibited. Degradation of formaldehyde (Initial concentration $\le$30 mg/L) followed Monod model with a rate constant, k, of 0.35-0.46 d$\sp{-1}$. At higher initial concentrations ($\ge$60 mg/L), formaldehyde degradation was inhibited and partial degradation was possible. The initial formaldehyde to biomass ratio, S$\sb0$/X$\sb0$, was useful to predict the degradation potential of high concentrations of formaldehyde in batch systems. The inhibition of formaldehyde degradation in batch systems could be avoided by repeated additions of low concentrations of formaldehyde (up to 30 mg/L). Methanogenic chemostats (14-day retention time) showed degradation of 1110 mg/L of influent formaldehyde with a removal capacity of 164 mg/g VSS-day. The results also showed that the acetate enrichment culture was not acclimated to formaldehyde even after 226 days The acetate enrichment culture, acclimated to acrylic acid and formaldehyde, successfully treated 25% of the 'Wastewater B' from a petrochemical plant containing high concentrations of acrylic acid (1650 mg/L) and formaldehyde (3330 mg/L) and other constituents. The removal efficiency for acetic acid, acrylic acid, formaldehyde, and COD were 99, 99, 99, and 91%, respectively. The unacclimated acetate enrichment culture can also be used to treat 'Wastewater A' containing low concentrations of acrylic acid (240 mg/L) and formaldehyde (30 mg/L). The system had 92, 99, 99, and 62% of removal efficiency for acetate, acrylate, formaldehyde, and COD, respectively<br>acase@tulane.edu

碩士<br>國立屏東科技大學<br>環境工程與科學系<br>92<br>In this study, pilot-scale Fixed Film Reactor (FFR) and Moving Bed Biofilm Reactor (MBBR) were installed in the field to test if these pretreatments could effectively help promote the biodegradation of a petrochemical industry wastewater in a Powdered Activated Carbon Treatment (PACT) process. Biological agents were first screened in the laboratory using respirometer to determine the type and dosage to be added in the FFR. Through biological activity and pollutant removal efficiency, performance of the biological agents in the FFR was evaluated, and this evaluation will be used in the future to promote the treatment performance, increase the treatment capacity, or reduce the operation cost. Analysis of the raw wastewater from the Ta-She Industrial Wastewater Treatment Plant showed a sliding BOD effect, i.e., the BOD value increased with the dilution ratio. This indicated that there might have refractory compounds in wastewater or that biological degradation was somehow inhibited. Respirometry analysis showed that in the first 20 hours of experiment with dilution ratio less than 5, Specific Oxygen Uptake Rate (SOUR) increased with time with a slight inhibition of the biological degradation was observed. When the dilution ratio was increased to more than 8, this inhibitory effect was not visible. In the continuous operation of the FFR in the field, data indicated that the influent and effluent BOD5 were between 20-45 mg/L and 11-38 mg/L, respectively. The FFR had a better performance when operated under a Hydraulic Retention Time (HRT) of 12 hours than under 22 hours. Removal efficiencies of SS, VSS, SCOD, and BOD5 were 40.8±18.5% (n =14), 40.5±18.5% (n =14), 28.14±8.46 (n =14), and 43.5±12.7% (n =14), respectively. When the MBBR was operated under a total HRT of 35.2 hours, results showed the averaged removal efficiencies of SS, VSS, SCOD, and BOD5 were 45.1± 21.8% (n =12), 44.5± 26.6% (n =12), 44.7±20.9 (n =12), and 53.9±32.1% (n =12), respectively. When the FFR was operated under a HRT of 12 hours with an addition of 5 ppm bioagent B, results showed a significant improvement in the performance, with the averaged removal efficiencies of SS, VSS, SCOD, and BOD5 were increased to 59.7±8.6% (n =5), 63.8±7.8% (n =5), 57.6±14.3 (n =5), and 66.9±17.4% (n =5), respectively. After daily addition of 5 ppm bioagent B in the FFR, the VSS/SS (0.58 ±0.09, n =5) was found to be less than effluent VSS/SS (0.65 ±0.08, n=5). This indicated that the addition of the bioagent could improve degradation of the VSS in the FFR. The ratio of SCOD/TCOD remained almost identical between the influent and the effluent indicated SCOD/TCOD remained almost identical between the influent and the effluent indicated that degradation of soluble COD was improved by the addition of bioagent. Similar trends were observed in the BOD5/SCOD. When bioagent B was added, this ratio from the influent to the effluent was decreased from 0.16 to 0.12, and when bioagent A was added, this ratio was significantly decreased from 0.23 to 0.13. It was found from this study that, FFR had the traditional biological treatment capability and rational removal efficiency, and could be applied after the primary sedimentation tank to reduce the organic loading to the PACT process. When bioagent was added, further degradation of refractory compounds could be expected. Due to its low initial cost, easy operation, and small land requirement, FFR can be applied in combination with other processes to reduce the organic loading to subsequent treatment processes. When operated under a HRT of 12 hours, the averaged TCOD removal efficiency was 31.5 ± 11.1% (n =14). When the bioagent was added, the TCOD removal efficiency could be increased to 57.1 ± 16.7% (n =5).

碩士<br>國立高雄海洋科技大學<br>海洋環境工程研究所<br>101<br>The wastewater of wastewater treatment plants in petrochemical industry contains large quantity of VOCs (Volatile Organic Compounds), and the domestic regulatory standards of VOCs for the industry in early years was less developed; therefore, wastewater without proper treatment was wantonly discharged, causing pollution problems came out one after the other, coupled with volatile characteristics of such pollution substances, so a superior emission condition was formed under the high perturbation of treatment process. Therefore, wastewater treatment plants in petrochemical industry have both of: (1) liquid phase secondary pollution caused by improperly treated wastewater; and (2) gas phase secondary pollution through emission pathway resulted from factors such as water body perturbation caused by wastewater treatment process. Therefore, this study took a wastewater treatment plant in northern Kaohsiung petrochemical factory as an example and conducted a ten day-times collection and analysis of water and gas samples to monitor the pollution species and concentration trends in liquid phase and gas phase in the factory site, and explore the current situation of secondary pollution caused by water flow and gas emission pathways. This study then coordinated with relevant regulatory standards to develop secondary pollution preventive and control measures for reducing pollutants entering into environment, and actually achieved the objective of pollution reduction. The study results reveal that: (1) this factory site receives three kinds of manufacturing process wastewater with PVC manufacturing process as main contributing source, and the concentration of the wastewater is between 685-123,000 μg/L, overall speaking, the concentration is very unstable and thus increases the workload of subsequent treatment units; (2) the main compounds in wastewater in sequence are dichloromethane (1,786 μg/L), 1,2-dichloroethane, vinyl chloride, chloroform, and methylene chloride, showing that the most major pollutant in the studied factory site is Cl-VOCs and it accounts for 96% of overall pollutants; (3) the gas sample analysis shows a consistent result with the water body analysis, with methylene chloride (787 μg/m3) as the most major pollutant, and the monitoring results in various treatment units show that an emission problem really exists and the most major emission source comes from the pre-treatment unit with bio-reacting tank having an additional aeration system (4,377 μg/m3); (4) through the result of comparison between dynamic sampling equipment and CANISTER sampling, revealed that using a dynamic sampling equipment is indeed better than directly using CANISTER sampling and can better approach the theoretical value, the ratio is between 1~4.12, this not only corroborates that the emission problem is actually serious than expected, but also can even provide as sampling correction for future studies; and (5) coordinated with relevant regulatory standards to conduct comparison and exploration, in terms of liquid phase it can not fully comply with emission control standards, which exceeds the standard by up to 44%, and in terms of gas phase it is also unable to comply with the regulatory standards, so the treatment units are required to carry out secondary preventive and control measures including tank body closing and emission gas recycling processing against top emission gases. Through this study, it is understood that the major pollution problem of wastewater treatment plants in petrochemical industry lies in the secondary pollution caused by emission side. Although it can be improved by establishing relevant secondary pollution preventive and control measures against gas emission, however, these measures can only be partially applied, and yet more accurate simulations and researches are required for various compounds. So if want to fundamentally get rid of all pollution problems through tracing to their origins, it is also required to proceed from water body, such that not only can sustainably resolve pollution problems, and also can help to reduce the requirement of building additional secondary pollution preventive control measures.

碩士<br>輔英科技大學<br>環境工程與科學系碩士班<br>100<br>The petrochemical industry produces substantial amounts of wastewater containing various types and concentrations of volatile organic compounds (VOCs). The emission of VOCs causes bad air quality as well as health damages to people in and around the wastewater treatment plant. This research focuses on wastewater treatment plants of petrochemical industries. Stainless steel canisters were used to collect air samples on the surface of the wastewater. The sample is then analyzed using gas chromatography mass spectrometry (GC/MS) to determine the VOCs. Results from the analysis were used to estimate the total VOCs emission from the petrochemical wastewater treatment plant. The results of this research indicate that the equalization basin has the highest VOCs concentration of 173.83 ppb, whereas aeration basin has the lowest VOCs concentration of 9.59 ppb. Ethylbenzene is the most prominent VOC with a concentration of 60.67 ppb, followed by toluene, which has a concentration of 51.51 ppb. Several compounds out of the 30 compounds controlled by the environmental department were present. This includes benzene, styrene, ethylbenzene, toluene, and xylene. 1,3-butadiene belongs to Group 1 of the IARC classification, and acrylonitrile, ethylbenzene, and styrene belongs to group 2B. According to the results, most VOCs emission comes from the equalization basin and amounts to 24.721 kg/year, primary sedimentation basin emits 1.31 kg/year, aeration basin emits 2.32 kg/year, final sedimentation tank emits 5.06 kg/year, and sand filter emits 0.69 kg/year. The total emission of VOCs from the petrochemical wastewater plant is 86.48 kg/year.

碩士<br>南臺科技大學<br>工業管理研究所<br>107<br>Water recycling is the current trend. Furthermore, procedure for chemical waste water processing is more numerous and diverse than other common sewage treatment method. It has mainly has three levels of processing. Chemical waste water is a mixture with many elemental composition. This research reduces suspended solids (SS) and chemical oxygen demand (COD) in the waste water using the first level processing method. This research used a mixture experiment design, the simplex centroid design, and studied the machine mixing speed under a preset temperature and proportion of the total flow and the proportion of the 3 waste water components to find out the best parameter value for SS and the COD optimization. After analysis, the best proportion of elements was observed to be A factory with total flow of 35%, B factory with total flow of 50%, and factory C with total flow of 15%. The best system regulation variable machine mixing speed is 30 rpm, and best total flow is 15000 CMD. The findings showed SS improved 35% and COD improved 36.4% . These findings can be used as future reference for flow processing.

碩士<br>國立中山大學<br>環境工程研究所<br>103<br>ABSTRACT In conventional wastewater treatment processes, carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) are formed and/or emitted through energy consumption, anaerobic reactions and sludge digestion, and biotransformation of dissolved nitrogen-containing compounds in water, respectively. Due to substantial impact of global warming on the environment, it is important to reduce the emissions of GHG such as CO2, CH4, and N2O from wastewater treatment processes and to understand influential factors to develop effective and efficient control strategies in the future. In this study, a petrochemical wastewater treatment plant in the Ren-Da Industrial Complex located in the north of Kaohsiung City, Taiwan was selected. Two different approaches, the continuous in-situ monitoring by an on-site measuring equipment and sampling with a floating chamber equipped with an infrared gas analyzer was employed to investigate the greenhouse gas emissions from wastewater surface in different treatment units. The monitored concentrations were further applied to estimate the total GHG emission, emission factors, and emission fluxes. In addition, lab-scale bioreactor experiments were conducted in batch to understand the effects of various operational parameters on the greenhouse gas emissions in the aerobic biological granular activated carbon (GAC) treatment process of the WWTP. The concentration variation data acquired in the experiments were further used to estimate the mass transfer rates coefficients, and fluxes between the air and water phases, fugacity and possible variations of air-phase concentrations with time. The results showed different characteristics with respect to the emissions of three greenhouse gases in different treatment units in the wastewater of interest. In winter, the total emissions of CO2, CH4, and N2O were 223.3 ± 15.53 kgCO2e d-1, 28.22 ± 9.62 kgCO2e d-1, and 491.7 ± 96.85 kgCO2e d-1, respectively. In summer, the emissions of CO2, CH4, and N2O were 258.41 ± 8.92 kgCO2e d-1, 37.74 ± 6.12 kgCO2e d-1, and 427.03 ± 33.37 kgCO2e d-1, respectively. The equalization tank, the aeration tank, and the final settling tank constituted the highest GHG emitted from the treatment units of the WWTP. The lab-scale experiments simulating the aerobic biological process showed that, reducing the aeration rate in the experiments conducted increased the emission concentration of N2O and CO2, respectively, which also led to high mass transfer rates. Although the concentrations of specific greenhouse gases were elevated by reducing the aeration rate, but this could reduce the energy consumption of the WWTP, causing the reduction of aeration rate at the aeration tank as one of the possible strategies to reduce the associated greenhouse gas emissions. The effects of changing the sludge concentration ratio within a limited range from the original concentration to avoid adversely affecting the treatment performance of the process might also possibly reduce the GHG concentration in aeration tank to avoid adversely affecting the performance of the treatment process. Reducing the SRT affects the GHG concentrations as high GHG concentrations are emitted when the SRT was reduced. These findings suggested that the results acquired from the continuous monitoring and lab-scale simulation experiments could be further used to develop life cycle assessment models and hence can establish novel technical strategies with expected profits of lower greenhouse gas emissions and lower treatment costs.

碩士<br>國立高雄第一科技大學<br>環境與安全衛生工程所<br>91<br>The wastewater treatment plant of Da-she petrochemical industrial park is used as an example for stability investigation in this study from 2000-2002. The central framework is to study the rationality, correctness and representation of experiment data from plant laboratory. The aim of this study is not only made operators under- stand the current problem-solving condition of whole plant, evaluate the performance of each processing element and if the process is properly controlled at present, but also help setting up the management of contingencies. The study method is, after we get data each time, we key in rapidly. If we find obvious relationship between one item and the variation of COD or SS, we treat it as a reason of abnormality. Through data verification, we use operating diary as evidence and discuss with operating staff. When everything is confirmed, we can search into the most probably reason of aggravation of water quality. From the result of this study, we find four main reasons result in abnormality: a rapid rise in influent concentration (25.7%), added a lot of activated carbon (17.7%), unknown (12.1%), and damage of sludge return device/pipeline (10.8%). And the four main reasons for SS abnormality is: a rapid rise in influent concentration (17.2%), unknown (14%), damage of sludge return device/pipeline (14%), and bad settling of sludge (9.4%). About the PACT /W AR system, it can remove SS in wastewater efficiently through the proportion between COD, SS and BOD, and tertiary treat- ment system collocate with sand filter. But the removal of dissolved biorefractory COD in petrochemical wastewater is not as significant as SS. For the operating parameters of PACT system, COD concentration of effluents decreased, and the COD removal increased relatively. If there is no apparent biological reaction, extending sludge age can’t increase the removal. When F/M is raised, the COD removal of aeration tanks increased, but the effect is not significant as hydraulic retention time is between 11.5~36.5 hours. The COD removal is influenced by microorganisms, concentration of activated carbon and ash. Finally, we build up COD removal model with each influence parameter(R2=0.84): COD%=0.9473×MLVC(g/l)-15.4×MLSA(g/l)+71.449×MLBio(g/l) + 3.2092×MLVC(g/l) ×MLbio(g/l)-24.06×SA(day)+3.2725×HRT(hr)+1.9694×SA(day) ×HRT(hr)-0.1PAC(kg)+1161.6×F/M(day-1)+0.0062×Q(CMD)-0.48×CODi(mg/l).

碩士<br>國立中山大學<br>環境工程研究所<br>107<br>In this study, the immersed microfiltration system (SMF) was combined with the reverse osmosis system (RO) module to recover and reuse the secondary treatment discharge water in the petrochemical plant, and the effects of various operational variables of the module on the wastewater treatment effect were discussed. In order to find out the best operating parameters of the model plant for the secondary discharge water recovery of the petrochemical plant, and to initially evaluate the treatment cost, to evaluate the feasibility of this module for the secondary treatment of wastewater discharge technology in the petrochemical industry, as a future Reference for research development and practical application. The results show that after the secondary discharge water of the petrochemical plant is treated by the SMF unit, the removal efficiency of various pollutants is about 60% of SS and about 40~60% of removal rate of COD, but there is no removal efficiency for conductivity; After the subsequent treatment, the removal efficiency of various pollutants is improved, the conductivity is up to 98% removal rate, SS is about 80% removal rate, COD is about 60~98% removal rate, ammonia nitrogen is about 90% removal rate, nitrate nitrogen About 81.8% removal rate, phosphate removal rate of about 99.1%; after water quality recovery by SMF/RO treatment, it meets the standards of secondary recovery water and industrial water. The SMF system is designed with an immersed hollow fiber membrane. The flux design is not higher than 20LMH. If the conductivity of wastewater inflow is maintained at 4,000~5,000 μs/cm, the CIP cleaning frequency of the SMF system is estimated to be 1.5~2 months. If the conductivity of wastewater inflow is > 6,000μs/cm, the CIP cleaning frequency of SMF system is estimated to be 1 month; while the recovery rate of RO module design is 55 % ~ 65%, and the membrane flux is not more than 18 LMH. If the wastewater inflow conductivity is 4,000 ~ 8,000 μs/cm, the operating pressure is 8 ~ 12 kg/cm2 and the scale inhibitor is added, the CIP cleaning frequency of the RO system is estimated to be 1 ~ 2 months. If the conductivity of the influent water is controlled from 4,000 μs/cm to 5,000 μs/cm, the system can operate smoothly and maintain the most economical operating conditions. In terms of recycling to approximate industrial water 500 CMD, operating costs mainly include electricity, drugs and consumables. The unit operates at a cost of approximately 13.14 yuan/m3. If a second-stage RO equipment is added, it can meet the requirements of the approximate pure water quality, and the unit operation cost is about 16.01 yuan/m3. Wastewater recycling can save (1) the cost of industrial pipe discharge (2) industrial water fee, if it is added to pure water, because of the excellent water quality, it can also save (3) pure water treatment, resin regeneration and other costs, it is worth further evaluation It is economical.

Tese de mestrado em Microbiologia Aplicada, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2015<br>O petróleo é um dos elementos mais relevantes para a economia mundial, pelo que o aumento do consumo de petróleo a nível mundial tem crescido ao longo dos anos. A produção mundial de petróleo é superior a três biliões de toneladas por ano, e os stocks de petróleo são significativos em muitas regiões do globo. O petróleo não só é uma fonte de energia, mas também é usado na produção de muitos químicos, como plásticos e cosméticos. A exploração das reservas de petróleo, a transformação do petróleo nas refinarias, os derrames e as águas resultantes da limpeza de reservatórios cria volumes elevadíssimos de efluentes que, devido à grande produção mundial de petróleo, estão sempre a aumentar. Estas águas residuais, com elevadas concentrações de poluentes, necessitam de um tratamento, usualmente complexo e caro. Estes factos originaram um interesse crescente pelo estudo de efluentes contaminados da indústria petroquímica assim como dos possíveis processos de tratamento (biológicos e químicos). Um dos grupos de poluentes mais tóxicos que tem sido detectado nos efluentes de refinaria são os hidrocarbonetos de petróleo, nomeadamente alifáticos e aromáticos. Os hidrocarbonetos aromáticos policíclicos (PAHs) são dos componentes que merecem mais destaque e preocupação, devido à sua toxicidade (nomeadamente carcinogenicidade), persistência ambiental e resistência à degradação microbiana. Os PAHs de elevada massa molecular tendem a adsorver aos sedimentos, o que diminui o seu impacto ambiental, enquanto que os PAHs de baixa massa molecular se dissolvem mais facilmente em água, sendo transportados para as águas subterrâneas ou de superfície, tendo assim um maior impacto ambiental. De entre os 16 PAHs que fazem parte da lista de poluentes considerados prioritários pela Agência de Protecção Ambiental dos Estados Unidos (USEPA), foi seleccionado para este estudo o acenafteno, cujas fontes principais são as refinarias de petróleo e a queima do carvão. A biodegradação apresenta vantagens do ponto de vista económico e ambiental em relação aos processos convencionais frequentemente usados para remoção de PAHs. Devido à presença destes compostos no meio ambiente, os microrganismos desenvolveram vias metabólicas para poder removê-los. Os microrganismos que biodegradam estes compostos na presença de oxigénio (aerobiose) são conhecidos desde o início do século XX, tendo sido feitos muitos estudos de biodegradação de PAHs em condições de aerobiose. No final dos anos 80, foram caracterizados microrganismos capazes de degradar hidrocarbonetos em condições de anaerobiose, e estudos posteriores demonstraram que estes microrganismos realizam degradação por vias metabólicas totalmente diferentes das usadas no metabolismo aeróbio. No entanto, a biodegradação em condições de anaerobiose está ainda menos explorada e o seu estudo poderá ser importante, uma vez que não há oxigénio disponível em todos os ambientes onde os PAHs estão presentes (por exemplo em sedimentos a grandes profundidades e em reservatórios de petróleo). O objectivo deste estudo é a identificação de um consórcio de bactérias nativas do efluente da refinaria da GALP, localizada em Sines, com resistência toxicológica e capacidade de biodegradação de acenafteno em condições de anaerobiose. Para tal, foram formulados e testados diferentes meios de cultura ricos em nutrientes, sais minerais, aceitadores de electrões e fontes de carbono diferentes (glucose e lactato), de modo a promover o máximo crescimento anaeróbio das bactérias presentes neste efluente. Foram seguidas duas estratégias de enriquecimento da comunidade microbiana. Numa das abordagens, o inóculo centrifugado foi adicionado ao meio de cultura num reactor, enquanto que na outra abordagem igual quantidade do efluente de refinaria e meio de cultura foram combinados no mesmo reactor. Em cada estratégia, a fonte de carbono usada foi diferente: glucose ou lactato. Em todos os reactores foi adicionado acenafteno a uma concentração de 100 μg/L. Ao longo do enriquecimento o crescimento microbiano foi seguido por medição da densidade óptica a 600 nm, enquanto que a monitorização da concentração de acenafteno foi efectuada por cromatografia em fase líquida. Foi também realizada a sequenciação do RNA ribossomal 16S para compreender a dinâmica das comunidades microbianas durante o enriquecimento nos diferentes reactores. A comparação dos diferentes reactores permitiu compreender que o crescimento da comunidade microbiana não depende da estratégia de inoculação seguida. O lactato foi seleccionado como a fonte de carbono a usar nos ensaios de resistência e biodegradação subsequentes por promover maior crescimento e biodiversidade da população microbiana. A comunidade obtida tinha como phyla maioritários Proteobacteria (68%) e Firmicutes (31%), enquanto a minoria era constituída por Actinobacteria (0.3%), Synergistetes (0.003%), Thermotogae (0.002%) e Deinococcus-Thermus (0.002%). Em termos de classes, o phylum Proteobacteria apresentou com predominância as seguintes classes: Betaproteobacteria (56%), Alphaproteobacteria (10%), Proteobacteria não classificadas (1%) e Gamaproteobacteria (0.5%). Por sua vez, o phylum Firmicutes teve como classe maioritária Clostridia (28%) e como membros menos representados Firmicutes não classificados (3%) e Bacilli (0.009%). Os phyla minoritários foram representados pelas classes Actinobacteria (0.3%), Synergistia (0.003%), Thermotogae (0.002%) e Deinococci (0.002%). Para testar a toxicidade do acenafteno para a comunidade bacteriana seleccionada após o enriquecimento, assim como a sua estabilidade, foram realizados testes de resistência, onde se testaram diferentes concentrações de acenafteno (100-1500 μg/L). Os reactores não inoculados foram usados como controlos de adsorção, para testar a estabilidade do acenafteno. Tal como no ensaio anterior, o crescimento da comunidade foi acompanhado por medição da densidade óptica a 600 nm e a concentração de acenafteno foi monitorizada por cromatografia em fase líquida. Estes testes sugeriram que a concentração mais adequada para realizar os ensaios de biodegradação é 100 μg/L. Os ensaios de biodegradação tiveram como objectivo avaliar o potencial de remoção do acenafteno pela comunidade microbiana na ausência e na presença de lactato, de forma a compreender se o acenafteno poderia ser usado como fonte de carbono única pelas bactérias ou se a presença de lactato seria necessária. Tal como no ensaio anterior, o crescimento da comunidade e a concentração de acenafteno foram monitorizadas. Para caracterizar e comparar as comunidades microbianas na presença e ausência de lactato, no início e no final do ensaio de biodegradação nos dois reactores, foi também efectuada sequenciação do RNA ribossomal 16S. Verificou-se que o lactato é necessário para o crescimento da população microbiana e que a remoção do composto é maior na sua presença, sugerindo que a existência de uma fonte de carbono extra é necessária para a remoção do composto pela comunidade microbiana seleccionada após o enriquecimento. Na ausência de lactato obteve-se maioritariamente Proteobacteria (79%) e Firmicutes (15%), sendo que o phylum Proteobacteria teve como classes predominantes Gamaproteobacteria (46%) e Betaprotebacteria (27%), enquanto o phylum Firmicutes foi principalmente representado por Clostridia (14%) e Bacilli (0.08%). Na presença de lactato os phyla maioritários foram os mesmos, sendo que Proteobacteria foi ligeiramente mais abundante (84%) e Firmicutes ligeiramente menos abundante (6.4%). A principal diferença foi que a classe Betaproteobacteria passou a ser maioritária (66%), seguido da classe Alphaproteobacteria (14%) e por último Gamaproteobacteria (0.04%), enquanto o phylum Firmicutes foi principalmente representado por Clostridia (3.2%) e Bacilli (0.5%). A instabilidade do acenafteno verificada através da sua remoção na ausência da biomassa em todos os ensaios realizados sugere que a sua remoção na presença da biomassa resultou não só de uma acção biológica, mas provavelmente também da adsorção ao vidro, o que poderá estar relacionado com a instabilidade que caracteriza os hidrocarbonetos policíclicos aromáticos de baixa massa molecular e a sua hidrofobicidade. Os resultados obtidos e descritos nesta tese indicam que o acenafteno é um composto instável e que a sua remoção por biodegradação só será uma vantagem se os tempos de residência nas estações de tratamento para os processos biológicos forem curtos.<br>The demand for petroleum is always increasing. Therefore, refineries also face an increasing problem: to treat large volumes of oily wastewater containing hazardous compounds such as polycyclic aromatic hydrocarbons (PAHs). Acenaphthene, a polycyclic aromatic hydrocarbon, is among the 16 PAHs considered priority by the United States Environmental Protection Agency due to its environmental persistence and toxicity. Biodegradation treatment offers advantages in terms of environmental protection and costs over conventional treatments to remove PAHs from these oily wastewaters. Biodegradation of PAHs is not only possible under aerobic conditions, but also under anaerobic conditions. Oxygen is not present in all the environments containing PAHs and there are not a lot of studies addressing the biodegradation of acenaphthene under anaerobic conditions by microbial communities from refinery wastewaters. Therefore, further assessment in terms of the removal of this compound was carried out in the scope of the present thesis. The aim of this thesis was to identify a consortium of bacteria, from a refinery wastewater, that could be able to remove acenaphthene under anaerobic conditions. The refinery wastewater used to enrich the microbial community was obtained from the GALP refinery, located in Sines. Two different approaches were followed during the enrichment in terms of inoculation and carbon source (lactate and glucose). Since the microbial community growing in the presence of lactate presented higher growth and diversity, it was further addressed in resistance and biodegradation assays. The most abundant phyla of the community obtained were Proteobacteria (68%) and Firmicutes (31%). Betaproteobacteria (56%) and Alphaproteobacteria (10%) were the classes most represented of phylum Proteobacteria, whereas Clostridia (28%) was the most abundant class of phylum Firmicutes. Resistance assays were carried out to assess the toxicity of acenaphthene to the microbial community as well as its stability by spiking acenaphthene in the reactors at different concentrations (100-1500 μg/L). This assay showed that the compound has less toxicity for the community at the lowest concentrations and presents some instability. Based on these results, it was decided to carry out subsequent biodegradation assays using acenaphthene at 100 μg/L. The biodegradation assay was performed to assess the ability of the microbial community to degrade acenaphthene with and without lactate as an additional carbon source. It was observed that acenaphthene is mainly removed in the presence of lactate and that the taxonomic profile of the microbial community is different depending on the presence of lactate. In its absence, Proteobacteria (79%) and Firmicutes (15%) were the most abundant phyla. The major classes of phylum Proteobacteria were Gammaproteobacteria (46%) and Betaprotebacteria (27%), whereas phylum Firmicutes was mainly represented by Clostridia (14%) and Bacilli (0.08%). In the presence of lactate, the most abundant phyla were similar, although Proteobacteria were slightly more abundant (84%) and Firmicutes were slightly less abundant (6.4%). The main difference was that Betaproteobacteria became the most abundant class (66%), followed by Alphaproteobacteria (14%) and Gammaproteobacteria (0.04%), whereas phylum Firmicutes was mainly represented by Clostridia (3.2%) and Bacilli (0.5%).The instability of acenaphthene observed through its removal in the absence of bacteria in all the assays suggests that acenaphthene removal is not only due to bacterial metabolism, but probably also due to its adsorption to the glass of reactors, which can be related with the instability and hydrophobicity of polycyclic aromatic hydrocarbons (PAHs) of low molecular weight like acenaphthene. The results obtained and described in this thesis allow concluding that acenaphthene is an unstable compound and that its removal by biodegradation will be advantageous only if short residence times are used in biological treatments in wastewater treatment plants.

碩士<br>國立中山大學<br>環境工程研究所<br>101<br>Degree of biodegradation of organic pollutants in some petrochemical wastewaters can possibly be affected by several factors such as high organic concentrations, refractory chemical and salinity in raw wastewaters. Reaction temperature and pH are two possible affecting factors during treatment. This study focused on the improvement of effluent qualities of a wastewater treatment plant for treating raw wastewaters originated from a naphtha-cracking plant, a VCM (vinyl chloride monomer) plant, and an acrylonitrile (AN) plant. The combined wastewater has a design flow rate of 20,000 m3/day (CMD) and a COD (chemical oxygen demand) of 1,200 mg/L. The wastewater was treated first by two biotrickling filters (BF) in parallel followed by two activated sludge (AS) ponds in parallel. COD values in the effluent from the BF and the AS were around 900 and 200 mg/L, respectively. The BFs emitted odorous foul gas containing ammonia, mercaptans, hydrogen sulfide, and various volatile organic compounds (VOC) which polluted the nearby and downstream ambient air. This study focused on the feasibility test by bypassing the BFs and treating the wastewater by connecting the two AS ponds in series for the purposes of eliminating four gas emission from the BFs and upgrading the effluent COD removal. A pilot test shows that by the approach, effluent COD could decrease from 164 to 138 mg/L. By supplementing 1 mL/L milk to the high-salinity wastewater and keeping pH of the treating wastewater at 7.5, COD removal could be over 60%. By lowering the treating wastewater to 25±1oC, COD removal could achieve to over 80%. Results from AN wastewater treatment indicate that by diluting the wastewater to an influent COD of around 600 mg/L, 60% COD of the wastewater could be removed. However, no COD could be removed with an influent COD of over 1,000 mg/L because of the toxicity of the ingredient compounds to the microorganisms in the AS system.