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Nitrogen compounds, such as aqueous ammonia, are a widespread problem in the wastewater industry as they are toxic to numerous aquatic life, cause eutrophication, and contribute to various environmental concerns. Environment Canada has mandated new wastewater regulations, limiting un-ionized ammonia discharge to 1.25 mg/L, expressed as nitrogen. This study provides insight into methods for removing nitrogen compounds, specifically aqueous ammonia, from wastewater. Two wastewater treatment technologies were compared: Ultra Violet light and an electrochemical process. These treatments were evaluated individually, as well as in combination, to determine potential synergistic effects.

The absence of water catchment protection often results in contamination of drinking water supplies. Waters in South East Asia have been exploited to support extensive agriculture, industry, power generation, public water supply, fisheries and recreation use. Ammonia has been identified as a significant contaminant of drinking water because of its ability to affect the disinfection efficiency of chlorine. The interference of ammonia with chlorination is a prevalent and expensive problem faced by many water treatment plants (WTPs) located throughout South East Asia. The conventional approach for ammonia removal was to pre-chlorinate using high concentrations of chlorine, which has a number of disadvantages including the formation of disinfection by-products and high chlorine consumption. This thesis investigated the application of high rate nitrifying trickling filters (NTFs) as a means of ammonia removal from a polluted lowland water source as an alternative to pre-chlorination. NTFs are widely used for the biological remediation of ammonia rich wastewater, however their performance when required to operate under low ammonia concentrations for potable water applications was unknown. A NTF pilot facility consisting of one large-scale, and three small-scale NTFs were constructed at Hope Valley WTP in South Australia. The NTFs were operated to simulate the raw water quality of a polluted catchment identified in Indonesia (Buaran WTP), including variations in ammonia, biological oxygen demand (BOD5), and turbidity. Results confirmed that plastic-packed NTFs were able to operate equally successfully under low ammonia-N concentrations, some 10- to 50-fold lower that that of conventional wastewater applications, where complete conversion of ammonia to nitrate was consistently observed under these markedly reduced loadings. Results also showed that when operated under mass loads equivalent to typical ammonia loading criteria for wastewater NTFs, by increasing hydraulic flow¬, comparable apparent nitrification rates were achieved. These results confirmed that mass transport limitations posed by low ammonia-N concentrations on overall filter performance were insignificant. This thesis also investigated the impact of organic carbon quantity and biodegradability on the nitrification behaviour of the pilot NTF. Results demonstrated that organic carbon loading, rather than the C:N ratio, was an important regulator of filter nitrification capacity, where a linear decline in nitrification performance correlated well with sucrose and methanol augmented carbon loads. Extensive monitoring of inorganic nitrogen species down the NTF, to profile nitrification behaviour, showed sucrose-induced carbon loads greater than 870 mg sBOD5 m–2 d–1 severely suppressed nitrification throughout the entire filter bed. This study also confirmed that critical carbon loads for nitrification varied among carbon sources. In contrast to sucrose, when a more native-like carbon source was dosed (organic fertiliser), no significant decline in nitrification capacity was observed. This could be attributed to differences in carbon biodegradability. This research has provided new insights into the microbial ecology of a potable water NTF. The combination of fluorescent in situ hybridisation (FISH) and scanning electron microscopy (SEM) for in situ analysis of biofilms was successful in identifying the spatial distribution of ammonia oxidising bacteria (AOB), nitrite oxidising bacteria (NOB) and heterotrophs. When the NTF was operated under low organic loads, clusters of AOB and NOB were abundant, and were located in close proximity to each other. Uniquely, the study identified not only Nitrospira spp but also the less common Nitrobacter spp within the NTF biofilm. Biofilm analysis showed that the type of carbon source also strongly influenced the biofilms characteristics in terms of biomass ecology, morphology, and polysaccharide composition, which was correlated with NTF performance. Results showed that an increase in sBOD5 via the addition of sucrose promoted the rapid growth of filamentous heterotrophic bacteria and production of large amounts of polysaccharide. Stratification of nitrifiers and heterotrophs, and high biofilm polysaccharide concentrations were observed at all filter bed depths, which coincided with the impediment of nitrification throughout the entire filter column. High biofilm polysaccharide concentrations also coincided with a significant increase (40 %) in filter hydraulic retention time, as determined by hydraulic tracer experiments. In contrast to sucrose-fed biofilms, organic fertiliser-fed biofilms had a more uniform and dense ultra-structure dominated by many rod shaped bacteria, and was significantly lower in polysaccharide composition. This observation was coupled with superior nitrification performance. This study confirmed that a well functioning NTF is a viable, low cost alternative for ammonia removal from source water abstracted from poorly protected catchments found in many developing countries. Pre-treatment using NTFs has the potential to reduce the chlorine dose required for pre-chlorination. Thereby improving water quality by minimising the formation of disinfection by-products, and improving the control of chlorination. NTFs could also find ready application in other situations where ammonia interferes with chlorine disinfection.

New federal regulations with regards to ammonia in wastewater effluent discharge will require over 1000 existing wastewater treatment facilities to be upgraded. Although biological treatment is the most common and economical means of wastewater ammonia removal, nitrification rates can be completely impeded at cold temperatures. Moving bed biofilm reactors (MBBR) have shown promise as an upgrade nitrifying unit at pilot-scale and full-scale applications with respect to low temperature nitrification. MBBR technologies offfer the advantages of less space requirement, utilizing the whole tank volume, no sludge recycling, and no backwashing, over other attached growth systems. Two laboratory MBBRs were used in this study to investigate MBBR nitrification rates at 20deg.C, after long-term exposure to 1deg.C, and at the kinetic threshold temperature of 5deg.C. Furthermore, the biologically produced solids from the MBBR system 20deg.C and after long-term exposure to 1deg.C, and the Arrhenius temperature correction models used to predict nitrification rates after long-term exposure to 1deg.C. The nitrification rates at 1deg.C over a four month exposure period as compared to the rate at 20deg.C were 18.7 + 5.5% and 15.7 + 4.7% for the two reactors. The nitrification rate at 5deg.C was 66.2 + 3.9% and 64.4 + 3.7% compared to the rate measured at 20deg.C for reactors 1 and 2, respectively, and as such was identified as the kinetic temperature threshold. The quantity of solids detached from the nitrifying MBBR biocarriers was low and did not vary significantly at 20deg.C and after long-term exposure to 1deg.C. Lastly, a temperature correction model based on exposure time to cold temperatures, developed by Delatolla et al. (2009) showed a strong correlation to the calculated ammonia removal rates relative to 20deg.C following a gradual acclimatization period to cold temperatures. Biofilm morphology along with biomass viability at various depths in the biofilm were investigated using variable pressure electron scanning microscope imaging (VPSEM) and confocal laser scanning microscope (CLSM) imaging in combination with viability live/dead staining. The biofilm thickness along with the number of viable cells showed significant increases after long-term exposure to 1deg.C while the dead cell coverage did not show significant increases after long-term exposure to 1deg.C while the dead cell coverage did not show significant changes. Hence, this study observed higher cell activities at warm temperatures and a slightly greater quantity of biomass with lower activities at cold temperatures in nitrifying MBBR biofilms. Using DNA sequencing analysis, 'Nitrosomonas' and 'Nitrosospira' (ammonia oxidizers)as well as 'Ntrospira' (nitrite oxidizer) were identified in which no population shift was observed during 20deg.C and after long-term exposure to 1deg.C. Furthermore, a number of non-nitrifiers were identified int he biofilm during warm and cold temperatures presenting the possibility that their presence may have provided some form of protection to the nitrifiers during long-term temperature exposure.

New federal regulations with regards to ammonia in wastewater effluent discharge will require over 1000 existing wastewater treatment facilities to be upgraded. Although biological treatment is the most common and economical means of wastewater ammonia removal, nitrification rates can be completely impeded at cold temperatures. Moving bed biofilm reactors (MBBR) have shown promise as an upgrade nitrifying unit at pilot-scale and full-scale applications with respect to low temperature nitrification. MBBR technologies offfer the advantages of less space requirement, utilizing the whole tank volume, no sludge recycling, and no backwashing, over other attached growth systems. Two laboratory MBBRs were used in this study to investigate MBBR nitrification rates at 20deg.C, after long-term exposure to 1deg.C, and at the kinetic threshold temperature of 5deg.C. Furthermore, the biologically produced solids from the MBBR system 20deg.C and after long-term exposure to 1deg.C, and the Arrhenius temperature correction models used to predict nitrification rates after long-term exposure to 1deg.C. The nitrification rates at 1deg.C over a four month exposure period as compared to the rate at 20deg.C were 18.7 + 5.5% and 15.7 + 4.7% for the two reactors. The nitrification rate at 5deg.C was 66.2 + 3.9% and 64.4 + 3.7% compared to the rate measured at 20deg.C for reactors 1 and 2, respectively, and as such was identified as the kinetic temperature threshold. The quantity of solids detached from the nitrifying MBBR biocarriers was low and did not vary significantly at 20deg.C and after long-term exposure to 1deg.C. Lastly, a temperature correction model based on exposure time to cold temperatures, developed by Delatolla et al. (2009) showed a strong correlation to the calculated ammonia removal rates relative to 20deg.C following a gradual acclimatization period to cold temperatures. Biofilm morphology along with biomass viability at various depths in the biofilm were investigated using variable pressure electron scanning microscope imaging (VPSEM) and confocal laser scanning microscope (CLSM) imaging in combination with viability live/dead staining. The biofilm thickness along with the number of viable cells showed significant increases after long-term exposure to 1deg.C while the dead cell coverage did not show significant increases after long-term exposure to 1deg.C while the dead cell coverage did not show significant changes. Hence, this study observed higher cell activities at warm temperatures and a slightly greater quantity of biomass with lower activities at cold temperatures in nitrifying MBBR biofilms. Using DNA sequencing analysis, 'Nitrosomonas' and 'Nitrosospira' (ammonia oxidizers)as well as 'Ntrospira' (nitrite oxidizer) were identified in which no population shift was observed during 20deg.C and after long-term exposure to 1deg.C. Furthermore, a number of non-nitrifiers were identified int he biofilm during warm and cold temperatures presenting the possibility that their presence may have provided some form of protection to the nitrifiers during long-term temperature exposure.

Gas phase biofilters are used for controlling odors from animal facilities. Some characteristics can affect their performance and moisture content is one very important. A methodology for controlling and measuring moisture content is required to optimize these systems. An experiment was conducted to determine the appropriate placement of a set of soaker hoses 1.2 m in length for water application. It was found that the soaker hose installed in the lower region of the biofilter coupled with appropriate and timely application of water was able to minimize drying of the compost. Thermal conductance proved to be a reliable indicator for measuring the moisture content. Biofilters using the soaker hoses together with the thermal conductance as a media moisture sensor were able to maintain moisture content above 30% w.b. which provided sufficient water for microbial activity and ammonia abatement. A characterization of the ammonia and nitrous oxide concentrations was performed in order to compare the behavior of the gases when water was applied versus no water addition. These analyses revealed that the overall performance was not significantly different between treatments. But a more detailed assessment inside the biofilter media is performed; it is possible to identify different processes taking place.

Sludge digestion has gained importance in recent year because of increasing interest in energy recovery and public concern over the safety of land applied biosolids. Many new alternatives are being researched for reducing excess sludge production and for more energy production. With an increase in solids destruction, the nutrients that are contained in sludge especially nitrogen, are released to solution and can be recycled as part of filtrate or centrate stream. Nitrogen has gained importance because it has adverse effects on ecosystem's as well as human health. NH₄⁺, NO₂⁻, NO₃⁻-, and organic nitrogen are the different forms of nitrogen found in wastewater. While ammonia is toxic to aquatic life, any form of nitrogen can be utilized by cyanobacteria and result in eutrophication. NO₂/NO₃, if consumed by infants through water, can affect the oxygen uptake capability. Hence, removal of nitrogen from wastewater stream before discharging is important. The main purpose of this study was to evaluate the performance of the Cambi process, a thermophylic hydrolysis process used as a pre-treatment step prior to anaerobic digestion. Thermal hydrolysis, as a pre-treatment to anaerobic digestion increases the biological degradation of organic volatile solids and biogas production. The thermal hydrolysis process destroys pathogens and hydrolysis makes the sludge readily available for digestion, while at the same time facilitating a higher degree of separation of solid and liquid phases after digestion. Experiments were conducted in three phases for anaerobic digestion using the Cambi process as pre-treatment. The phases of study includes comparison of two temperatures for thermal hydrolysis (Cambi 150°C and Cambi 170°C), comparison of two solid retention times in anaerobic digestion (15 Day and 20 Day) and comparison of two mesophilic temperatures in anaerobic digestion (37°C and 42°C). Different experimental analyses were conducted for each phase, such as pH, bio-gas production, COD removal, VS destruction, nitrogen removal, odor and dewatering characteristics and the results are compared among all the phases. The second part of the study deals with aerobic digestion of anaerobically digested sludge for effective nitrogen removal and additional VS destruction, COD removal. An aerobic digester is operated downstream to anaerobic digester and is operated with aerobic/anoxic phase for nitrification and de-nitrification. The aerobic/anoxic phases are operated in time cycles which included 40minutes/20minutes, 20minutes/20minutes, full aeration, 10minutes/30minutes, and 12minutes/12minutes. Different time cycles are experimented and aerobic digester is optimized for effective nitrogen removal. 12minutes aerobic and 12minutes anoxic phase gave better nitrogen removal compared to all the cycles. Over all the aerobic digester gave about 92% ammonia removal, 70% VS destruction and 70% COD removal. The oxygen uptake rates (OUR's) in the aerobic digester are measured corresponding to maximum nitrogen removal. The OUR's are found to be close to 60 mg/L during maximum nitrogen removal. The effluent from both anaerobic digester and aerobic digester was collected and analyzed for dewatering capability, cake solids concentration and odor potential. / Master of Science

O lixiviado de aterros sanitários é um efluente líquido poluente devido, principalmente, à sua elevada concentração de amônia. Seu tratamento faz-se necessário para que sejam atendidas as exigências das legislações ambiental e trabalhista, além de minimizados os impactos ambientais de seu lançamento nos corpos d\'água. Esta pesquisa propõe a remoção da amônia presente no lixiviado por meio do processo físico-químico \"air stripping\", que promove a transferência da amônia da fase líquida para gasosa. Para que não se contribua com a poluição atmosférica, o efluente gasoso do \"air stripping\" deve ser tratado em solução de ácido sulfúrico ou água. A neutralização da amônia com solução de ácido sulfúrico gera o sulfato de amônio, e com água, a aquamônia. Tais subprodutos podem ser usados como fertilizantes. Nesta pesquisa, para remoção da amônia do lixiviado foi utilizada uma torre de PVC, com 2,24 m de altura e 15 cm de diâmetro, recheada com anéis do tipo Rashing de polietileno corrugados, com diâmetro de 1,5 cm e 5 cm de comprimento. As vazões de ar utilizadas foram 1200, 1600 e 3600 L/h e as vazões de lixiviado foram 18 e 30 L/h. Para ajuste no pH do lixiviado, utilizou-se hidróxido de cálcio (padrão analítico) e cal comercial. Os fluxos de líquido e ar eram em contracorrente. Para o recolhimento da amônia foram usados dois frascos de 6 L, preenchidos com 4 L de solução de ácido sulfúrico 0,4 mol/L ou água. Os resultados obtidos indicaram remoção praticamente completa de toda a amônia contida no lixiviado. Nas diferentes condições operacionais avaliadas, a concentração de amônia remanescente no lixiviado foi igual ou inferior aos 20 mg/L determinados pela Resolução 397/08 do CONAMA. Quanto ao recolhimento da amônia, a eficiência média obtida nos frascos lavadores próxima a 80%, tanto ) quando utilizada a solução de ácido sulfúrico 0,4 mol/L quanto quando utilizada água. / Sanitary landfill leachate is a pollutant liquid effluent mainly due to its high ammonia concentration. Its treatment is necessary due to environmental and labour legislation requirements, besides prevention of environmental impacts of leachate release in water bodies. This research proposes ammonia removal from leachate by air stripping process, which transfers ammonia from liquid to gaseous phase. In order to prevent atmospheric pollution, air stripping gaseous effluent must be treated with sulphuric acid solution or water. Ammonia neutralization by sulfuric generates ammonium sulfate and by water, aquammonia is generated. Such by-products may be used as fertilizer. In this research, in order to remove leachate ammonia it was used a PVC tower of 2.24 m high and 15 cm diameter, packed with Rashing rings of corrugated polyethylene of 1.5 cm diameter and 5 cm length. Air flows were 1200, 1600 and 3600 L/h and leachete flows were 18 e 30 L/h. Calcium carbonate (standard grade) and commercial hydrated lime were used for pH adjustments. Air and liquid flows were countercurrent. In order to recover ammonia, two flasks of 6 L were used and filled with 4 L of 0.4 mol/L sulfuric acid solution or water. Results showed that ammonia was almost completely removed from leachate. In all operational conditions evaluated, remaining ammonia concentration in leachate was equal or less than 20 mg/L, value established by Resolution 397/08 of Brazilian Council of the Environment. Ammonia recovery with water or a 0.4 mol/L sulfuric acid solution was about 80%.

O lixiviado de aterros sanitários é um efluente líquido poluente devido, principalmente, à sua elevada concentração de amônia. Seu tratamento faz-se necessário para que sejam atendidas as exigências das legislações ambiental e trabalhista, além de minimizados os impactos ambientais de seu lançamento nos corpos d\'água. Esta pesquisa propõe a remoção da amônia presente no lixiviado por meio do processo físico-químico \"air stripping\", que promove a transferência da amônia da fase líquida para gasosa. Para que não se contribua com a poluição atmosférica, o efluente gasoso do \"air stripping\" deve ser tratado em solução de ácido sulfúrico ou água. A neutralização da amônia com solução de ácido sulfúrico gera o sulfato de amônio, e com água, a aquamônia. Tais subprodutos podem ser usados como fertilizantes. Nesta pesquisa, para remoção da amônia do lixiviado foi utilizada uma torre de PVC, com 2,24 m de altura e 15 cm de diâmetro, recheada com anéis do tipo Rashing de polietileno corrugados, com diâmetro de 1,5 cm e 5 cm de comprimento. As vazões de ar utilizadas foram 1200, 1600 e 3600 L/h e as vazões de lixiviado foram 18 e 30 L/h. Para ajuste no pH do lixiviado, utilizou-se hidróxido de cálcio (padrão analítico) e cal comercial. Os fluxos de líquido e ar eram em contracorrente. Para o recolhimento da amônia foram usados dois frascos de 6 L, preenchidos com 4 L de solução de ácido sulfúrico 0,4 mol/L ou água. Os resultados obtidos indicaram remoção praticamente completa de toda a amônia contida no lixiviado. Nas diferentes condições operacionais avaliadas, a concentração de amônia remanescente no lixiviado foi igual ou inferior aos 20 mg/L determinados pela Resolução 397/08 do CONAMA. Quanto ao recolhimento da amônia, a eficiência média obtida nos frascos lavadores próxima a 80%, tanto ) quando utilizada a solução de ácido sulfúrico 0,4 mol/L quanto quando utilizada água. / Sanitary landfill leachate is a pollutant liquid effluent mainly due to its high ammonia concentration. Its treatment is necessary due to environmental and labour legislation requirements, besides prevention of environmental impacts of leachate release in water bodies. This research proposes ammonia removal from leachate by air stripping process, which transfers ammonia from liquid to gaseous phase. In order to prevent atmospheric pollution, air stripping gaseous effluent must be treated with sulphuric acid solution or water. Ammonia neutralization by sulfuric generates ammonium sulfate and by water, aquammonia is generated. Such by-products may be used as fertilizer. In this research, in order to remove leachate ammonia it was used a PVC tower of 2.24 m high and 15 cm diameter, packed with Rashing rings of corrugated polyethylene of 1.5 cm diameter and 5 cm length. Air flows were 1200, 1600 and 3600 L/h and leachete flows were 18 e 30 L/h. Calcium carbonate (standard grade) and commercial hydrated lime were used for pH adjustments. Air and liquid flows were countercurrent. In order to recover ammonia, two flasks of 6 L were used and filled with 4 L of 0.4 mol/L sulfuric acid solution or water. Results showed that ammonia was almost completely removed from leachate. In all operational conditions evaluated, remaining ammonia concentration in leachate was equal or less than 20 mg/L, value established by Resolution 397/08 of Brazilian Council of the Environment. Ammonia recovery with water or a 0.4 mol/L sulfuric acid solution was about 80%.