Добірка наукової літератури з теми "Sewage Waste minimization Massachusetts"

In recent decades, minimization and recycling/reuse policies were introduced to reduce the quantities of generated waste and for alternative waste recovery. Organic wastes represent 46% of total global solid waste. Possible uses of organic wastes include using it as fertilizer and amendment for soil, for energy recovery and for the production of chemical substances. Sewage sludge disposal and reuse are identified as future problems concerning waste. The total amount of sludge generated in the entire world has increased dramatically, and this tendency is expected to increase significantly in the years to come. In most developed countries, special attention is given to sewage sludge treatment in order to improve the quality and safety of using it on the ground surface. Sewage sludge pyrolysis is considered an acceptable method, from an economic and ecological perspective, for the beneficial reuse of sewage sludge. This method has many advantages because, during the pyrolysis process, the sludge volume is reduced by 80%, pathogenic agents and hazardous compounds from sewage sludge are eliminated, metals are immobilized in solid residue and organic and inorganic fractions are immobilized in a stabilized form of pyrolytic residues (biochar). The biochar generated by sewage sludge pyrolysis does not contain pathogenic agents and is rich in carbon and nutrients.

Abstract Primary or secondary sewage sludge in medium and large WWTP are most often processed by anaerobic digestion, as a method of conditioning, sludge quantity minimization and biogas production. With the aim to achieve the best results of sludge processing several modifications of technologies were suggested, investigated and introduced in the full technical scale. Various sludge pretreatment technologies before anaerobic treatment have been widely investigated and partially introduced. Obviously, there are always some limitations and some negative side effects. Selected aspects have been presented and discussed. The problem of nitrogen has been highlighted on the basis of the carried out investigations. The single and two step - mesophilic and thermophilic - anaerobic waste activated sludge digestion processes, preceded by preliminary hydrolysis were investigated. The aim of lab-scale experiments was pre-treatment of the sludge by means of low intensive alkaline and hydrodynamic disintegration. Depending on the pretreatment technologies and the digestion temperature large ammonia concentrations, up to 1800 mg NH4/dm3 have been measured. Return of the sludge liquor to the main sewage treatment line means additional nitrogen removal costs. Possible solutions are discussed.

A large chemical complex like BASF AG in Ludwigshafen has a high demand of process and cooling water. Therefore, water protection and wastewater treatment are predominant tasks. With the help of a dual sewage system for the separate discharge of cooling water and process water an efficient wastewater management is made possible. The cooling water is continuously supervised for contaminations and directly discharged into the river Rhine whereas the process water is treated in a central wastewater treatment plant. The daily amount of wastewater treated is up to 600,000 m3. The BOD5 removal is about 98% and the TOC and COD removal about 88%. As wastewater management is closely connected to waste minimization several examples for waste minimization processes are discussed. Furthermore, also important topics of environmental safety of the products produced at BASF AG are presented.

Similar to other types of waste, sewage sludge (SS) must be minimized, not only to respect the European Directive 2018/851 on waste, but also because the cost of sludge management is approximately 50% of the total running costs of a wastewater treatment plant (WWTP). Usually, minimization technologies can involve sewage sludge production with three different strategies: (i) adopting a process in the water line that reduces the production of sludge; (ii) reducing the water content (dewatering processes) or (iii) reducing the fraction of volatile solids (stabilization). This review, based on more than 130 papers, aims to provide essential information on the process, such as the advantages, the drawbacks and the results of their application. Moreover, significant information on the technologies still under development is provided. Finally, this review reports a discussion on the impact of the application of the proposed processes in the sludge line on a WWTP with a capacity exceeding 100,000 population equivalent (PE).

The management of solid waste presents a challenge for developing countries as thegeneration of waste is increasing at a rapid and alarming rate. Much awareness towards thesustainability and technological advances for solid waste management has been implemented toreduce the generation of unnecessary waste. The recycling of this waste is being applied to producevaluable organic matter, which can be used as fertilizers or amendments to improve the soil structure.This review studies the sustainable transformation of various types of biomass waste such as animalmanure, sewage sludge, municipal solid waste, and food waste, into organic fertilizers and theirimpact on waste minimization and agricultural enhancement. The side effects of these organicfertilizers towards the soil are evaluated as the characteristics of these fertilizers will differ dependingon the types of waste used, in addition to the varying chemical composition of the organic fertilizers.This work will provide an insight to the potential management of biomass waste to be produced intoorganic fertilizer and the advantages of substituting chemical fertilizer with organic fertilizer derivedfrom the biomass waste.

Sewage sludge is the consequence of successful wastewater treatment. With the increasing number of wastewater treatment facilities and increasing intensity of treatment the amount of sludge produced will grow. The task of sludge treatment and disposal will therefore assume a significant place in environmental quality control. Sewage sludge is considered both a valuable resource possibly for agriculture, and a waste material which must be disposed of safely. Thus, regional solutions must be aimed for if available sites for agricultural application or a limited number of disposal sites are to be used wisely. Technically and economically feasible alternatives of treatment (and disposal) are numerous. The selection process to be discussed in this paper is a minimization of overall cost and/or an optimization of process reliability and cost. There exist proven mathematical tools for the solution of such optimization problems; in this instance dynamic programming routines have been utilized. The applicability of these methods, as well as their limits, are shown in a practical case study.

The usage of natural sorbents in sewage water treatment technologies, in particular agro-industrial complex, has a number of environmental and economic advantages. Non-traditional sorbents, which are concentrated in many parts of Ukraine, are cheap raw materials for sewage water treatment. The sorption properties of the upland and lowland peat species of the Gamaliivka-Grybovychi deposit, which were studied early, indicate their high sorption capacity for ammonium ions, which, if they enter water bodies, cause a number of environmental problems. According to the results of the ecological assessment of sewage water of meat processing facility, the chicken processing facility and milk processing plant, it was found out the exceedance of the acceptable limits for the content of ammoniacal nitrogen, respectively: 1.3–3 MPC; 3.8 MPC and 2.5 MPC. This component is a water pollutant and a “crop” of yield in agriculture, since nitrogen is an important element of plant nutrition. The rational usage of natural resources involves the complex usage of natural resources. The nitrogen absorbed by ammonium peat, as well as the peat itself is a sufficient fertilizing land, so the use of used peat complex in agriculture allows to solve not only problems of fertilizers, but also to achieve greening in sewage water treatment technologies. Greening as a whole is a result of waste minimization, and today there are two main areas: new technological non-waste technology together with low-waste technology and waste regeneration. This paper presents a comparison of the physiological indices of plants, depending on the application of the species and form of Gamaliivka-Grybovychi peat deposit, Yavoriv district, when fertilizing the substrate (sand as a background) of the study areas. The influence on the quality of ascent and growth of vegetative culture – watercress, natural form of the top and lowland peat species, as well as their waste forms obtained as a result of the process of purification of ammonium ions, modeling the sewage water of the agro-industrial complex, was investigated. The mass of the harvest from the experimental fields was determined and compared. The differences of lowland and upland peat species are due to its origin, which significantly affects their chemical composition. The plants fuelled with peat are much higher in the mass than those crops that were grown with adding of peat substrate into the lowland. However, the used form of lowland peat provided a 1.57 times higher harvested crop yield than the used upland sample of the studied sorbent.

The issues concerning the management of sewage sludge produced in wastewater treatment plants are becoming more important in Europe due to: (i) the modification of sludge quality (biological and chemical sludge are often mixed with negative impacts on sludge management, especially for land application); (ii) the evolution of legislation (landfill disposal is banned in many European countries); and (iii) the technologies for energy and material recovery from sludge not being fully applied in all European Member States. Furthermore, Directive 2018/851/EC introduced the waste hierarchy that involved a new strategy with the prevention in waste production and the minimization of landfill disposal. In this context, biological sewage sludge can be treated in order to produce more stabilized residues: the biosolids. In some European countries, the reuse of biosolids as soil improver/fertilizer in arable crops represents the most used option. In order to control the quality of biosolids used for land application, every Member State has issued a national regulation based on the European directive. The aim of this work is to compare the different approaches provided by European Member States for the reuse of biosolids in agricultural soils. A focus on the regulation of countries that reuse significant amount of biosolids for land application was performed. Finally, a detailed study on Italian legislation both at national and regional levels is reported.

.Dewatered sludge is one of the largest contributors of waste materials in Malaysia and it indirectly elevates local environmental problems. The use of this waste material as an alternative fuel can be an effective solution as it not only contributes as an energy source but also solves environmental issues related to sludge disposal. In this study Advanced System for Process Engineering (ASPEN) was employed to simulate the combustion reactions of dewatered sludge based on the minimization of total Gibbs energy of the system. Analysis of combustion products was carried out and compared with previous works. The simulation results showed good agreement with the results obtained by other authors. The results showed that NOx and SO2emission for poultry sludge is lower than that of coal and sewage sludge. Sensitivity analysis to study the effect of changing reactor temperature and excess air on the products concentration suggested that the operational parameters would be highly influential on the combustion products.

Household hazardous waste (HHW) disposal contributes significantly to the cost of HHW collection programs. In addition, disposal of HHW can contribute to the toxicity of leachate from landfill, heavy metals in ash from waste incinerators, and heavy metals and toxic organic compounds in composted material and sewage sludge. Other options such as product substitution, waste minimization, reuse, or recycling should be considered to help reduce costs and disposal concerns. An estimate of the volumes and types of HHW accumulated by collection programs, their recycling and reuse options, and treatment and disposal requirements are presented.Recycling, reuse, or disposal of collected wastes depends upon the market for the recycled material, the availability of recycling or disposal facilities, transportation facilities, and the potential to reuse the waste material without treatment. The costs of disposing of HHW are relatively high but can be offset by co-funding from manufacturing associations and local businesses. A disposal fee could also be applied to household hazardous products, thus placing the cost burden on the purchaser.Public education can assist in reducing the volumes of HHW and public pressure is also forcing companies to eliminate hazardous compounds in household products. If effective consumer education continues, the increasing demand for non-hazardous substitutes will significantly reduce the volume of household hazardous products, consequently reducing HHW. Key words: household hazardous waste, waste disposal, waste recycling, waste reuse, waste management.

Thesis (MSc)--Stellenbosch University, 2000.
ENGLISH ABSTRACT: A severely polluted industrial effluent is generated by the local gelatinmanufacturing industry. Due to increasingly stringent restrictions on discharge qualities enforced by the National Water Act of 1998 and National Environmental Management Act of 1998, as well as increasing trade-effluent charges implemented via the Local Municipal Bylaws, the industry is compelled to consider a system to pre-treat the polluted effluent. A study was undertaken to examine the viability of anaerobic treatment of the gelatin-manufacturing effluent, since the anaerobic digestion technology is well recognised for the high success rate in the treatment of high-strength, complex wastewaters. Various laboratory and pilot-scale studies were done, using different hybrid Upflow Anaerobic Sludge Blanket (UASB) and contact designs. Two mesophilic laboratory-scale hybrid UASB digester designs, fitted with polyethylene (AD-1) and polyurethane (AD-2), performed well at a hydraulic retention time (HRT) of 1.0 d. Chemical oxygen demand (COD) removal efficiencies of up to 90% (avg. 53%) for AD-1 and 83% (avg. 60%) for AD-2 at organic loading rates (OLR) of 9.56 and 4.62 kg COD.m-3.d-1, respectively, were obtained. High sulphate (S04) removal efficiencies of up to 96% (avg. 86%) for AD-1 and 98% (avg. 82%) for AD-2 were also achieved, respectively. A maximum total solid (TS) removal of 65% (avg. 25%) for AD-1 and 62% (avg. 28%) for AD-2 was reported. An average methane content of 80% (AD-1) and 79% (AD-2) with average methane yields per COD removed of 2.19 and 1.86 m3. kg CODremoved.df-o1r AD-1 and AD-2 were found, respectively. When the same digesters (AD-1 and AD-2) were combined in a muItiphase series configuration, a total COD removal efficiency of up to 97% (avg. 80%) at an OLR of 8.32 kg COD.m-3.d-1,was achieved. Excellent total S04 removals of 96% (avg. 69%) were accomplished. Up to 82% TS (avg. 29%) was also removed during this study and the biogas consisted of 89% methane (avg. 79%). For this multi-phase combination up to 92% volatile fatty acids (VFA) (avg. 48%) were removed, indicating possible selective phase separation of the respective fatty acid producing/utilising bacterial populations. The use of a laboratory-scale UASB bioreactor with recirculation, resulted in COD removal efficiencies of up to 96% (avg. 51%) at an HRT of 3.0 d, and 95% (avg. 54%) at a HRT of 1.0 d. Low performances were generally found, with average S04 and TS removals of 59% (max. 97%) and 26% (max. 67%), respectively at an HRT of 1.0 d. The biogas production was very low throughout the study (0.05 - 0.63 I,d-1 ). A pilot-scale UASB reactor (300 I) was constructed and performed satisfactory with a 58% average COD removal and maximum of 96%. S04 and TS removals up to 96% (avg. 44%) and 93% (avg. 63%), respectively, were obtained. The methane content of the biogas was 85%. The pilot-scale studies were conducted under actual field conditions, where various shock and organic loads had to be absorbed by the system. The pilot-scale contact configuration (300 I) did not perform satisfactory as a result of continuous blockages experienced in the feed and recirculation lines. Maximum COD, S04, VFA and TS removal efficiencies of 41% (avg. 27%), 62% (avg. 41%), 64% (avg. 27%) and 39% (avg. 21%), respectively, were obtained. The results of all the studies indicated acceptable COD removals with increasing OLR's. Indications of the presence of active methanogenic and sulphate-reducing bacterial populations were apparent throughout the studies. One possibility for the successful start-up and commissioning of the anaerobic reactors was the use of a well-adjusted biomass, which consisted of highly selected and adapted microbial consortium for the specific gelatinmanufacturing effluent. It was clear from this study that gelatin-manufacturing effluent can be treated successfully, especially with the use of the UASB design. A welldefined data base was constructed which could be of great value for further upscaling to a full-scale digester.
AFRIKAANSE OPSOMMING: 'n Hoogs besoedelde industriele uitvloeisel word gegenereer deur die plaaslike gelatien-vervaardigings industrie. As gevolg van toenemende streng beperkings op die kwaliteit van uitvloeisels wat bepaal word deur die Nasionale Water Wet van 1998 en Nasionale Omgewings Bestuurs Wet van 1998, asook toenemende munisipale heffings wat geimplementeer word via Plaaslike Munisipale Wette, word die industrie verplig om die uitvloeisel vooraf te behandel. 'n Studie is onderneem om die lewensvatbaarheid van anaërobe behandeling van gelatien-vervaardigings uitvloeisel te ondersoek, aangesien anaërobe verterings tegnologie alombekend is vir die goeie sukses behaal in die behandeling van hoë-sterkte, komplekse uitvloeisels. Verskeie laboratorium- en loods-skaal studies is gedoen, met verskillende hibried Opvloei Anaërobe Slykkombers (OAS) en kontak ontwerpe. Goeie werksverrigting was verkry by 'n hidroliese retensie tyd (HRT) van 1.0 d met twee mesofiliese laboratorium-skaal hibried OAS verteerder ontwerpe wat uitgevoer was met poli-etileen (AD-1) en poli-uretaan (AD-2) materiaal. Chemiese suurstof behoefte (CSB) verwyderings van so hoog as 90% (gem. 53%) vir AD-1 en 83% (gem. 60%) vir AD-2 by organiese ladingstempo's (OLT) van 9.56 en 4.62 kg CSB.m-3.d-1,was onderskeidelik verkry. Hoë sulfaat (S04) verwyderings van tot 96% (gem. 86%) vir AD-1 en 98% (gem. 82%) vir AD-2 was ook onderskeidelik verkry. 'n Maksimum totale vaste stof (TVS) verwydering van 65% (gem. 25%) vir AD-1 en 62% (gem. 28%) vir AD-2 is gerapporteer. 'n Gemiddelde metaan inhoud van 80% (AD-1) en 79% (AD-2) met 'n gemiddelde metaan opbrengs per CSB verwyder van 2.19 en 1.86 m3.kg CSBverwyder.dv-i1r AD-1 en AD-2, was onderskeidelik gevind. Met die aanwending van dieselfde twee verteerders (AD-1 en AD-2) in 'n series gekoppelde multi-fase konfigurasie, is 'n totale CSB verwydering so hoog as 97% (gem. 80%) verkry by 'n OLT van 8.32 kg CSB.m-3.d-1. Uitstekende totale S04 verwydering van 96% (gem. 69%) is behaal. Tot 82% TVS (gem. 29%) was vewyder gedurende die studie en die biogas het uit 89% metaan (gem. 79%) bestaan. Vir die multi-fase kombinasie is 'n maksimum van 92% vlugtige vetsure (WS) (gem. 48%) verwyder, wat dui op die moontlike skeiding van selektiewe fases van die onderskeie vetsuur produserende/verbruiker bakteriële populasies. CSB verwydering van tot 96% (gem. 51%) by 'n HRT van 3.0 d en 95% (gem. 54%) met 'n HRT van 1.0 d was verkry, tydens die gebruik van In laboratorium-skaal OAS bioreaktor met hersirkulasie. Lae werksverrigting was oor die algemeen waargeneem, met gemiddelde S04 en TVS verwyderings van 59% (maks. 97%) en 26% (maks. 67%) by In HRT van 1.0 d. Die biogas produksie was baie laag gedurende die studie (0.05 - 0.63 I,d-\ In Loods-skaal OAS verteerder was opgerig en bevredigende resultate was verkry met In gemiddeld van 58% CSB verwydering en maksimum van 96%. S04 en TVS verwyderings so hoog as 96% (gem. 44%) en 93% (gem. 63%) is onderskeidelik verkry. Die metaan inhoud van die biogas was 85%. Die loods-skaal studie was uitgevoer gedurende ware veld kondisies, waartydens verskeie skok en organiese ladings deur die sisteem geabsorbeer is. Die loods-skaal kontak konfigurasie (300 I) het nie bevredigende resultate getoon nie, as gevolg van voortdurende blokkasies wat ondervind is in die toevoer en hersirkulasie pype. Maksimum CSB, S04, WS en TVS verwyderings van 41% (gem. 27%), 62% (gem. 41%), 64% (gem. 27%) en 39% (gem. 21%) was onderskeidelik verkry. Die resultate van al die studies het aanvaarbare CSB verwydering aangedui by toenemende OLT's. Indikasies van aktiewe metanogene en sulfaat-reduserende bakteriële populasies was ook teenwoordig gedurende die studies. Die suksesvolle aansit-prosedure en begin van die anaërobe verteerders kan toegeskryf word aan die gebruik van In goed aangepaste biomassa, wat uit hoogs selektiewe en aangepaste mikrobiese populasies vir die spesifieke uitvloeisel bestaan. Hierdie studie het getoon dat gelatien-vervaardigings uitvloeisel suksesvol met die OAS ontwerp behandel kan word. In Goed gedefinieerde data basis kan voorsien word, wat van groot waarde sal wees vir verdere opgradering na In volskaalse verteerder.

Thesis (MTech (Public Management))--Cape Peninsula University of Technology, 2017.
The communities of Khayelitsha face problems with regard to managing waste. Increase on the generation of solid waste in the households by the members of the community; far exceed the townships’ ability and capability for safe disposal. Littering in the township is also a persistent problem, despite various clean–up and anti-litter promotional campaigns and programs introduced by local government, private organizations and other community interest groups. The persistent problem of litter and mismanagement of solid waste in the household should be addressed. The rationale and assumption underpinning this study was that waste management problems are related to social norms and attitude of the people of Khayelitsha. To investigate this phenomenon, the study adopted a qualitative paradigm. 300 heads of household residing in Khayelitsha for more than 5 years were surveyed, and door to door interview questions were conducted in 2016 June. Data from the questionnaire were analysed using Thematic and coding analysis. NVivo software was used to generate frequency tables. The responses to most interview questions were consistent for all categories of respondents and did not vary according to respondents’ background, such as gender, location household size or education. The study showed that social norms and attitudes towards waste minimisation in Khayelitsha are related to the entire waste management operation, and householders in Khayelitsha think similarly. To improve waste management in Khayelitsha the following are recommended: • Government and business need to consider incentives to minimise waste; • Government needs to improve waste management service facilities and build recycling centre which are accessible to the community; and • Government and non-governmental organizations and community members should consider awareness, education and training programs on waste wise management.

O presente estudo objetiva avaliar a influência da substituição de areia natural por diferentes teores de Lodo de Estação de Tratamento de Água (Lodo de ETA) na produção de concretos ambientalmente amigáveis. O procedimento experimental abrangeu a coleta e caracterização das matérias-primas, o estudo de dosagem do concreto produzido com diferentes teores de substituição de Lodo Úmido (LU) e Lodo Calcinado (LC) e a avaliação das misturas produzidas no aspecto técnico, econômico e ambiental. As amostras de Lodo utilizadas foram coletadas na ETA Tamanduá, localizada em Foz do Iguaçu, PR, em três períodos distintos durante o ano de 2014. No estudo de dosagem fez-se a substituição de LU (in natura) por areia natural nos teores de 0, 5, 7 e 10% em concretos de relação água/cimento (a/c) 0,45, 0,55 e 0,65 e de LC (temperatura de 900 ºC) nos teores de 0, 5, 10 e 20% em misturas de a/c 0,55, avaliando-se as propriedades no estado fresco (trabalhabilidade) e no estado endurecido (resistência à compressão axial, resistência à tração, módulo de elasticidade, absorção de água e lixiviação). A partir dos resultados obtidos constatou-se que a adição de até 20% de LC propiciou aumento nas propriedades mecânicas do concreto, podendo ser empregado em concretos estruturais, desde que realizados estudos de durabilidade. Já a adição de lodo de ETA úmido reduziu significativamente a resistência do concreto, sendo indicado do ponto de vista técnico um teor de substituição de até 5% para aplicações em concretos, desde que não estruturais. Do ponto de vista econômico, em relação ao concreto de referência, concretos produzidos com LU resultaram em menor custo de produção enquanto que concretos com LC maior. Pela análise termogravimétrica o lodo poderá ser calcinado a menores temperaturas (de 300 a 500 oC), promovendo economia energética no processo de tratamento térmico, resultando num melhoramento no aspecto econômico e ambiental da aplicação do Lodo calcinado na produção de concretos. Por meio da viabilidade ambiental, os resultados demonstraram que os níveis de concentração das substâncias analisadas no ensaio de lixiviação atendem ao limite máximo permitido, assegurando a saúde humana e ambiental. A sustentabilidade do aproveitamento do lodo em concreto confirma-se pela redução na extração de recursos naturais, contribuindo principalmente, na diminuição do lançamento de lodo em corpos hídricos, e ao atendimento dos requisitos do sistema de gestão e legislação ambiental vigente. por teores mais elevados de lodo, analisando a viabilidade econômica e ambiental vinculada ao processo de calcinação.
The aim of this study is to evaluate the influence of replacing natural sand by different levels of Water Treatment Plant Sludge (WTP sludge) in the production of environmentally friendly concrete. The experiment included the collection and characterization of raw materials, the concrete dosing study produced with different sludge replacement levels of Wet Sludge (WS) and Calcined Sludge (CS) and the evaluation of the produced mixtures with regards the technical, economic and environmental aspect. The sludge samples used in the study were collected from the Tamandua ETA, located in Foz do Iguaçu, Paraná, in three different periods during the year 2014. In the dosage of study, WS (in natura) was substituted by natural sand in the levels of 0, 5, 7 and 10% in concrete with water/cement ratio (w/c) of 0.45, 0.55 and 0.65 and CS (temperature of 900 °C) in levels of 0, 5, 10 and 20% in mixtures with w/c of 0.55, evaluating the properties in the fresh state (workability) and in the hardened state (resistance to axial compression, tensile strength, elastic modulus, water absorption and leaching). From the results obtained it was found that the addition of CS up to 20% resulted in an increase in the mechanical properties of concrete, therefore it can be used in structural concrete, provided that durability studies are carried out. With regards WS, its addition significantly reduces the strength of concrete and is suitable, from a technical point of view, a replacement level up to 5% for applications in concrete, provided that not structural. From an economic point of view, in comparison to the reference concrete, concrete produced with WS resulted in lower production cost while concrete with CS the cost was higher. By thermogravimetric analysis, the sludge may be calcined at lower temperatures (300 to 500 °C), leading to energy saving in the heat treatment process, resulting in an improvement in the economic and environmental factor in the application of the calcinated sludge in the production of concrete. With regards the environmental viability, the results demonstrated that the levels of concentration of the substances analyzed in the leaching test meet the maximum allowed limit, ensuring environmental and human health. The sustainability of sludge use in concrete is confirmed by the reduction in the extraction of natural resources, contributing mainly to the decreas of sludge release in water bodies, and upon satisfying the requirements of the management and environmental legislation system. Further studies should be conducted to assess the effect of replacing sand for higher levels of sludge, analyzing the economic and environmental viability linked to the calcination process.

The hydrometallurgical refining of platinum group metals results in large volumes of liquid waste that requires suitable treatment before any disposal can be contemplated. The wastewater streams are characterized by extremes of pH, high inorganic ion content (such as chloride), significant residual metal loads and small amounts of entrained organic compounds. Historically these effluents were housed in evaporation reservoirs, however lack of space and growing water demands have led Anglo Platinum to consider treatment of these effluents. The aim of this study was to investigate whether biological wastewater treatment could produce water suitable for onsite reuse. Bench-scale activated sludge and anaerobic digestion for co-treatment of an acidic refinery waste stream with domestic wastewater were used to give preliminary data. Activated sludge showed better water treatment at lab scale in terms of removal efficiencies of ammonia (approximately 25%, cf. 20% in anaerobic digestion) and COD (70% cf. 43% in digestion) and greater robustness when biomass health was compared. Activated sludge was consequently selected for a pilot plant trial. The pilot plant was operated on-site and performed comparably with the bench-scale system, however challenges in the clarifier design led to losses of biomass and poor effluent quality (suspended solids washout). The pilot plant was unable to alter the pH of the feed, but a two week maturation period resulted in the pH increasing from 5.3 to 7.0. Tests on algal treatment as an alternative or follow-on unit operation to activated sludge showed it not to be a viable process. The activated sludge effluent was assessed for onsite reuse in flotation and it was found that there was no significant difference between its flotation performance and that of the process water currently used, indicating the effluent generated by the biological treatment system can be used successfully for flotation. Flotation is the method whereby minerals refining operations recover minerals of interest from ore through the addition of chemicals and aeration of the ore slurry. Target minerals adhere to the bubbles and can be removed from the process.

In 1886, James Olcott, a farmer, “having been bred in the old anti-slavery reform,” gave a speech before the Agricultural Board of Connecticut. Recalling an earlier age, he encouraged his audience and “the common people” of Connecticut to “agitate, agitate,” in order to “cleanse” the state of the “social evil” of the pollution “by sewage from families and factories, festering in every pool, and mill pond—formerly trout holes.” Olcott reminded the farmers that “our best hold on polluted streams reform lies in the fact that the mischief has brought on us its calamitous consequences in this country with such rapidity that men and women too not very greyhaired and in full bodily and mental vigor can shut their eyes and review the whole matter from its beginning.” The history Olcott conjured up was the transformation of a clean, clear environment from “one of the most salubrious to one of the worst in the world.” The change was intimately linked to the rise of industrial cities like Bellows Falls, Chicopee, Hartford, New Britain, and Holyoke. Although Olcott’s remembrance of the past was partly colored by romantic notions of a purer age, the pollution he pointed to was indeed a problem of growing obviousness and concern. Reflecting the rapid change that had occurred over the last quarter century, the Massachusetts State Board of Health complained that with the growth of densely populated industrial cities, the old habits of disposing of waste contributed to “a large part of the filth in our state,” and that “often the water which is used for domestic purposes [is disposed of] by being thrown upon the surface of the ground, or collected in loosewalled vaults and cesspools,” which might have been acceptable in a rural community but caused concern in the new industrial cities. As the New Hampshire Board of Health noted in 1887, looking back over the last few decades, “when men mass, . . . the conditions at once become aggravated. . . . Man comes in with his artificial constructions and sweeps away much of this economy of nature.”

The reforms of the late nineteenth century did help protect New England’s drinking water. The plague of water-borne diseases that made the region’s cities so infamously dangerous to live in seemed to be in retreat. For a moment, it looked as if the new century would bring a world in which there did not have to be trade-offs between economic development and environmental quality. The ideal articulated by Lyman and Mills—that professional expertise would transcend conflicts of interests between manufacturers and reformers—seemed at hand. Yet there were still problems that these optimists overlooked. And these problems broke into view again in the new century. Despite the health gains, New England’s rivers and streams continued to receive massive influxes of pollution of both industrial wastes and human sewage. The larger cities along the major river systems continued their practice of dumping raw sewage downstream, while manufacturers still saw running water as a natural disposal system for their wastes. Industrial wastes, although less central in the conversation around public health and the environment, were clearly polluting water systems, and reformers never completely gave up the struggle to clean water of industrial pollutants. In its 1896 report, the Massachusetts State Board of Health discussed possible solutions to the problems of “waste liquors or sewage from those manufacturing industries in the State which pollute or threaten to pollute our rivers and ponds.” The Lawrence station experimented with different methods of removing industrial wastes. Yet the “problem of successful and economical disposal of this sewage [remained].” As people began to look at clean water as an aesthetic as well as a health issue, the ability of water to sustain live fish, which had been dismissed twenty years earlier, now became a concern. Commissions on fisheries that had focused attention on fishways and fish cultivation in the nineteenth century began to revisit the issue of water pollution as they noticed their hatchery fish dying in polluted waters; oyster growers complained to the commissions that their oyster beds were being polluted.

When James Olcott spoke before Connecticut farmers for “anti-stream pollution,” he urged the public to mobilize to stop water pollution by “ignorant or reckless capitalists.” In identifying the “ignorant and reckless capitalists,” Olcott focused the attention of the farmers on industrial waste and the role of manufacturers in their search for profits in causing pollution. Although manufacturers and the courts argued that industrialization brought wealth and prosperity to New England and hence was a general good, Olcott challenged this idea. He saw the issue as a conflict between industrialization and its costs on the one hand and the public good on the other. Concern over industrial pollution and the potential conflict between it and public health had already arisen in Massachusetts. Although the Massachusetts State Board of Health realized that the interests of the “capitalists” and those of the public health officials might be in conflict, in 1872 it hoped that with improved knowledge, “a way will be eventually found to joining them into harmonious relations,” much as Lyman believed science and technology would resolve the conflict between fishers and mill owners. The board's interest in “harmonious relations” also reflected a realization that at least for the last several years, the courts had seen pollution as an inevitable consequence of civilization and had been favorable toward industrialists, especially if no obvious alternative to dumping pollution existed. In 1866, William Merrifield sued Nathan Lombard because Lombard had dumped “Vitriol and other noxious substances” into the stream above Merrifield's factory, “corrupting” the water so badly that it destroyed his boiler. Chief Justice Bigelow ruled that Lombard had invaded Merrifield's rights. “Each riparian owner,” the judge wrote, “has the right to use the water for any reasonable and proper purpose. . . . An injury to the purity or quality of the water to the detriment of the other riparian owners, constitutes in legal effect, a wrong.” In 1872, Merrifield again went to court, claiming the City of Worcester regularly dumped sewage into Mill Brook, by which the waters became greatly corrupted and unfit to use.”