Urbanisation leads to increases in stormwater runoff, resulting in elevated contaminant (e.g. metal, sediment, and nutrient pollutant) loads, decreased local infiltration and greater peak flow intensities. Heavy metal contaminants of concern, primarily copper (Cu), lead (Pb), and zinc (Zn), originate from a variety of sources including wear-and-tear of vehicle parts, corrosion of alloy roofs, legacy petroleum contamination, and multifarious construction practices. Different technologies have been used to mitigate stormwater runoff, ranging from traditional drainage networks fitted with concrete proprietary devices (e.g. vortex sediment separators and filters) to more environmentally integrated sustainable solutions. Rain gardens, a type of Sustainable Urban Drainage System (SUDS) or Water Sensitive Urban Design (WSUD), are employed to control stormwater peak flows and runoff volumes and simultaneously reduce contaminant loads to neighbouring waterways through biologically-active landscaped design. Despite increases in use of rain gardens as a best management practice (BMP) to treat urban stormwater runoff, there is a dearth of knowledge about their treatment and infiltration performance worldwide. It is believed that incorporating topsoil into rain garden design is likely to improve contaminant removal efficiencies (Davis et al. 2001; ARC 2003; Fletcher et al. 2004; Carpenter and Hallam 2010), but design recommendations are not informed by performance data which is limiting. Performance data is necessary for understanding the long-term responses of bioinfiltrative treatment systems and for modelling efforts aiming to predict their mitigation behaviour (Fletcher et al. 2004). In order to evaluate the influence of substrate composition on stormwater treatment and hydraulic effectiveness in rain gardens, mesocosm-scale (180 L, 0.17 m2) laboratory systems were established. Saturated (constant-head) hydraulic conductivity was determined before and after contaminant (Cu, Zn, Pb and nutrients) removal experiments on three rain garden systems comprising various proportions of organic topsoil. Raw stormwater runoff from a neighbouring Christchurch city catchment was collected, characterised, and applied in the removal efficiency experiments. The system with only topsoil had the lowest saturated hydraulic conductivity (160 mm/hr initial to 164 mm/hr final) and poorest metal (Cu, Zn) removal efficiency (Cu 0.3%, Zn 60.5% and Pb 89.5%) at a ‘standard’ contaminant loading rate (Cu = 5.99 ± 0.73 µg/min, Zn = 57.89 ± 6.06 µg/min, Pb = 13.65 ± 2.80 µg/min). The sand-only system demonstrated good metal removal (Cu 56.4%, Zn 73.5%, and Pb 81.6%) with hydraulic conductivity (up to 805 mm/hr) adequate for practical implementation (i.e. greater than the 13 mm/hr minimum requirement (ARC 2003; MDE 2009; SFPUC 2009)). Overall, total metal amounts in the effluent were <50% of influent loads for all experiments, with the exception of Cu in the topsoil-only system, whose removal was negligible (0.3%). Greater metal removal was observed when effluent pH was elevated (up to pH 7.38). The pH increase (from an initial pH of 6.23 in raw stormwater) was provided by the calcareous sand, whereas the topsoil-only system lacked an alkaline source. Consequently, organic topsoil had poorer contaminant removal due to higher dissolved metal fractions, which are more difficult to immobilise at the lower pH. The relationship between pH and dissolved fraction was highly significant (Pearson’s Correlation, p < 0.0001, df = 74) for Cu, Zn, and Pb. Mesocosm-scale systems were then re-established with a calcareous substrate supplement to quantify the effects of pH augmentation on contaminant removal and hydraulic efficiencies. Mussel shells, a waste product from the shell-fish industry, were employed in two different volumetric proportions. Metal removal efficiency was increased in systems with mussel shells (Cu up to 46.6%, Zn up to 80.2%, Pb up to 88.7%) compared to the topsoil-only system (Cu 27.5%, Zn 55.5%, Pb 81.0%). Larger increases in removal efficiency were seen for Cu and Zn because increases in pH from mussel shell enhanced particulate fractions, which are easier to remove in filtration systems, while Pb is mainly in the particulate form at influent pH (Morrison et al. 1990). Effluent from systems with mussel shells also had higher hardness (hardness up to 101.7 mg/L as CaCO3) compared with 22.4 mg/L as CaCO3 in topsoil-only effluent. Hardness reduces metal ecotoxicity (Hyne et al. 2005). Results of these experiments show that mussel shells are a promising rain garden substrate capable of increasing metal removal efficiency and also decreasing metal ecotoxicity in effluent of bioinfiltration systems. Concurrently, an operational field-scale “rain garden” (42 m3; 60 m2) in Christchurch was monitored for hydraulic throughput and contaminant removal. The field system performed extremely well at mitigating peak flows, detaining water throughout storm events and removing total suspended solids (TSS) (90.6% average removal). However, the system failed to reduce effluent median total metal concentrations (Cu = 15.9 µg/L, Zn = 139.6 µg/L, Pb = 11.7 µg/L) below relevant ANZECC guidelines (Cu = 1.8 µg/L, Zn = 15.0 µg/L, Pb = 5.6 µg/L) highlighting the opportunity to optimise these field designs to improve metal removal.

No description available.

Many different stormwater control measures (SCMs) can be implemented in order to mitigate issues with polluted stormwater flows into receiving water bodies.  The treatment function of  SCMs is commonly based on the removal of particles by sedimentation, thereby also removing pollutants associated with particles. In recent years, more attention has been given to characterizing and understanding of different particle size fractions and their association with pollutants commonly found in stormwater. It has become increasingly clear that the smaller sized particles are very important pollutant transporters and should be considered when designing and implementing SCMs. However, the settling velocities for smaller sized particles are very low and may not be effectively removed in existing SCMs. One treatment process with a proven ability to enhance sedimentation is coagulation/flocculation, widespread in water and wastewater treatment, but with very few accounts of it being used in a stormwater context. This thesis aims to investigate the treatability of stormwater with a coagulation/flocculation process. This includes the determination of operating conditions, the dominating coagulation mechanism and the reduction efficiency of stormwater related pollutants. The objectives of the thesis were achieved in laboratory tests treating stormwater in a jar-testing procedure. An initial screening of primary coagulants and flocculant aids was conducted using an urban snowmelt mixture. Five of the chemicals were then selected for an extended testing regime which was setup up to determine the operating conditions where maximal turbidity reduction was attained by measuring the pH, conductivity, alkalinity and zeta-potential over the tested doses for each coagulant. Criteria used for chemical selection included high turbidity reduction, low dose requirement and low pH/alkalinity impacts. Charge reversal was observed at positive zeta-potential indicating that the dominating coagulation mechanism was charge neutralization. The content of turbidity/total suspended solids, total organic carbon, total metals and hydrocarbons by &gt;90%. Dissolved copper was reduced by 40% on average, and the reduction rates for dissolved zinc were varying with up to a 300% increase, presumably due to changes in pH, leading to a higher mobility. Changes in the particle size distribution after coagulation/flocculation as compared to sedimentation indicated an effect on the size fraction corresponding to smaller particles. The performance of the coagulation/flocculation process was also tested on road runoff collected from a central road in Luleå with a high traffic intensity. Two coagulants were tested, iron chloride and pre-hydrolyzed aluminum chloride. Reduction rates for the total metal fraction were &gt;90% on average for both coagulants, but for the dissolved metal fractions differences could be observed between the coagulants with the iron chloride resulting in higher reductions for dissolved chrome (57% compared to 34%) and copper (47% compared to 30%). Both products increased the dissolved fractions of nickel and zinc due to lower final pH.

No processo de lodos ativados por batelada, a definição de um ciclo operacional é de fundamental importância para o bom funcionamento de uma estação de tratamento de esgotos que utiliza esse tipo de tratamento. A adoção de um ciclo adequado pode trazer vários benefícios como o aumento da eficiência de tratamento, a introdução da remoção da matéria nitrogenada, por meio dos processos de nitrificação e desnitrificação do efluente e até diminuir o consumo de energia que é relativamente alto nesse tipo de tratamento. Foi aplicada então, a definição do ciclo operacional à ETE Bueno de Andrada que utiliza o processo de lodos ativados por batelada aeróbio para o tratamento da fase líquida. Foram experimentados alguns ciclos de operação com tempos e estratégias diferentes, variando-se os tempos de aeração, mistura, enchimento ou sedimentação. A aplicabilidade de cada estratégia de ciclo foi avaliada em termos da eficiência de remoção da matéria orgânica carbonácea, retratada com as análises de DBO e DQO do esgoto afluente e do efluente final. Foi desenvolvido também, o processo de automação da ETE Bueno de Andrada com o estudo e ajuste de um programa computacional que gera um arquivo de controle utilizado para controle do ciclo de operação dos SBRs. Os resultados mostraram que os ciclos operacionais entre 10 e 12h, consegue-se uma eficiência de remoção da matéria orgânica carbonácea entre 95 e 97%. / The definition of an adequate operational cycle for the batch activated sludge process is of fundamental importance for the proper operation of a sewage treatment plant. The use of a suitable cycle can bring many benefits namely the increase of the treatment efficiency, the introduction of the nitrogen organic material removal through the nitrification and denitrification process of the eflluent and the decrease of energy consumption that is relatively high in this process. The operational cycle definition is then applied to the Sewage Treatment Plant of Bueno de Andrada that use the aerobic batch activated sludge process for the liquid phase treatment. Some operational cycles are experimented with different times and strategies, changing the aeration, rnixture, filling or sedimentation times. The applicability of each cycle strategy was checked by the carbon organic material removal efficiency, measured through the BOD and COD analyses of the influent sewage and the treated eflluent. It was developed, too, the automation process of the Sewage Treatment Plant of Bueno de Andrada, cornplementing and adjusting the control computer program for the PLC that controls the SBRs operational cycle. The results showed that with operational cycles between 10 and 12 hours, the removal efficiency of the carbon organic material was between 95 and 97%.

Submitted by Jaqueline Silva (jtas29@gmail.com) on 2014-09-04T20:30:32Z No. of bitstreams: 2 Victor Vinicius Batista Machado.pdf: 3743876 bytes, checksum: 6aa979a3852bec9e7757e6ab93e868ac (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-09-04T20:30:32Z (GMT). No. of bitstreams: 2 Victor Vinicius Batista Machado.pdf: 3743876 bytes, checksum: 6aa979a3852bec9e7757e6ab93e868ac (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2011-08-26 / The dairy industries represent one of the most important sectors for the economy of Goiás. The intense industrialization, together with the lack of specialized labor, means that these industries generally produce without any concern for the waste generated. Besides solid waste, these industries generate effluents with high levels of pollution that can affect the water and soil quality, in water bodies into which they flow. Faced with this scenario, the need arose to carry out a study of the risks inherent to this type of effluent, both from a physical-chemical and ecotoxicological point of view. For this purpose, acute toxicity studies were carried out with the Zebrafish (Danio rerio), to evaluate the toxicity of the effluents in pre-defined points of the Wastewater Treatment Plant (WTP) analyzed (points A, D and F). To evaluate the efficiency of the WTP, some physical-chemical parameters were measured (pH, conductivity, cloudiness, BOD, COD, TS, OG among others), and a chemical analysis was carried out of the metals Zn, Cd, Cu and Pb. To determine the solid residues in the effluent, thermogravimetric analyses were performed. Through mathematical models, the efficiency of the WTP was evaluated in terms of the parameters measured, which throughout the treatment process, proved inefficient, presenting mainly negative values. The tests of acute toxicity carried out with the test organisms in contact with the effluent from the dairy effluent, collected in various points of the plant, enabled the LC50 to be calculated, which indicated a moderate to high toxicity of the effluents analyzed. / As indústrias de laticínios representam um dos setores mais importantes para a economia de Goiás. Devido à intensa industrialização aliada à falta de mão de obra especializada, faz com que essas indústrias produzam, na maioria das vezes, sem se preocuparem com os resíduos gerados. Além dos resíduos sólidos essas indústrias geram efluentes com alta carga poluidora podendo afetar a qualidade da água dos corpos de água receptores e dos solos. Diante desse cenário, surgiu a necessidade de se realizar um estudo dos riscos inerentes a esse tipo de efluente, tanto no ponto de vista físicoquímico como do ecotoxicológico. Para isso foram realizados estudos de toxicidade aguda, com o peixe Danio rerio, para a avaliação da toxicidade dos efluentes em pontos pré-definidos da Estação de Tratamento de Efluentes (ETE) analisada (pontos A, D e F). Para avaliar a eficiência da ETE foram medidos alguns parâmetros físico-químicos (pH, condutividade, turbidez, DBO, DQO, ST, OG entre outros) bem como foi realizada uma análise química dos metais Zn, Cd, Cu e Pb. Para os resíduos sólidos desse efluente foram realizadas análises termogravimétricas. Avaliou-se através de modelos matemáticos a eficiência da ETE quanto aos parâmetros medidos, que ao longo de todo o processo de tratamento se mostrou ineficiente, apresentando na sua maioria, valores negativos. Os testes de toxicidade aguda realizados com os organismos teste em contato com o efluente do laticínio, coletado em diversos pontos da estação, permitiram o cálculo da CL50 que indicou uma toxidade moderada a muito tóxica dos efluentes analisados.

No processo de lodos ativados por batelada, a definição de um ciclo operacional é de fundamental importância para o bom funcionamento de uma estação de tratamento de esgotos que utiliza esse tipo de tratamento. A adoção de um ciclo adequado pode trazer vários benefícios como o aumento da eficiência de tratamento, a introdução da remoção da matéria nitrogenada, por meio dos processos de nitrificação e desnitrificação do efluente e até diminuir o consumo de energia que é relativamente alto nesse tipo de tratamento. Foi aplicada então, a definição do ciclo operacional à ETE Bueno de Andrada que utiliza o processo de lodos ativados por batelada aeróbio para o tratamento da fase líquida. Foram experimentados alguns ciclos de operação com tempos e estratégias diferentes, variando-se os tempos de aeração, mistura, enchimento ou sedimentação. A aplicabilidade de cada estratégia de ciclo foi avaliada em termos da eficiência de remoção da matéria orgânica carbonácea, retratada com as análises de DBO e DQO do esgoto afluente e do efluente final. Foi desenvolvido também, o processo de automação da ETE Bueno de Andrada com o estudo e ajuste de um programa computacional que gera um arquivo de controle utilizado para controle do ciclo de operação dos SBRs. Os resultados mostraram que os ciclos operacionais entre 10 e 12h, consegue-se uma eficiência de remoção da matéria orgânica carbonácea entre 95 e 97%. / The definition of an adequate operational cycle for the batch activated sludge process is of fundamental importance for the proper operation of a sewage treatment plant. The use of a suitable cycle can bring many benefits namely the increase of the treatment efficiency, the introduction of the nitrogen organic material removal through the nitrification and denitrification process of the eflluent and the decrease of energy consumption that is relatively high in this process. The operational cycle definition is then applied to the Sewage Treatment Plant of Bueno de Andrada that use the aerobic batch activated sludge process for the liquid phase treatment. Some operational cycles are experimented with different times and strategies, changing the aeration, rnixture, filling or sedimentation times. The applicability of each cycle strategy was checked by the carbon organic material removal efficiency, measured through the BOD and COD analyses of the influent sewage and the treated eflluent. It was developed, too, the automation process of the Sewage Treatment Plant of Bueno de Andrada, cornplementing and adjusting the control computer program for the PLC that controls the SBRs operational cycle. The results showed that with operational cycles between 10 and 12 hours, the removal efficiency of the carbon organic material was between 95 and 97%.

The main theme of this thesis is the usage of the test investigating the formation potential of trihalogenmethanes (THM FP) and its comparison with conventional indicators of water quality (CODMn, A254 and colours). As for the experimental part of the thesis, rating of the effectiveness of selected technological procedures has been applied (e.g.: coagulation, adsorption and ozonation in the act of treatment of artificially prepared water model with a higher content of humic substances in laboratory conditions). Based on the obtained results, it was found that the common indicators of water quality have very similar attributes and also complete each other. On the contrary, those attributes of indicators may not be sufficient in case of the evaluation of water quality with high content of humic substances. The findings made illustrate that the THM FP test enables the accurate evaluation of water quality, especially in connection with the content of an organic material susceptible to chemical changes. THM formation potential has proved its high value and also has confirmed that it can appropriately complete the other standarts that are being used for assessing the quality of treated water up to nowadays.