Nessa pesquisa foi realizado um estudo experimental da potencialidade do emprego da ozonização após tratamento anaeróbio de efluentes, no que se refere a dosagem, tempo de contato, alcalinidade, aplicação conjunta com peróxido de hidrogênio, quantidade de ozônio consumida e oxidação de matéria orgânica. O estudo proposto foi executado por meio de: (a) estudos preliminares; (b) testes preliminares; (c) experimento I, empregando ozônio sem variação da alcalinidade afluente; (d) experimento II, empregando ozônio com variação da alcalinidade afluente; (e) experimento III, empregando ozônio combinado com peróxido de hidrogênio sem variação da alcalinidade afluente; (f) verificação da desinfecção; (g) análise crítica dos resultados. Fez-se comparação entre os parâmetros de análise, a dosagem de ozônio consumida e o tempo de contato e entre a qualidade do efluente ozonizado e os critérios de qualidade para reuso de efluentes, permitindo chegar as seguintes conclusões: (i) a maior parte do teor de ozônio consumido durante a ozonização é consumido nos primeiros 5 minutos; (ii) o consumo de ozônio pode ser melhor entendido analisando-se a variável dose instantânea aplicada de ozônio; (iii) o comportamento da transferência de ozônio é influenciado por três fatores: hidrodinâmica do reator, quantidade de ozônio, disponível para reagir e características do efluente; (iv) a variação no pH indica o grau de oxidação atingido no processo; (v) a presença de nitrato favorece a oxidação;(vi) a ozonização é um processo muito eficiente para desinfetar efluentes. A inativação de coliformes totais e fecais atingiu 7,51 e 6,98 Log, respectivamente; (vii) a massa de ozônio por tempo regula a taxa de remoção de DQO enquanto a dose média, a eficiência de remoção de DQO; (viii) Com o consumo de 32,46 +/- 8,19 mg/L de ozônio em 25 minutos de ozonização chegou-se a remoção média de DQO e Turbidez de 48,33 mais ou menos 2,90% e 89,22 +/- 0,35%, respectivamente; (ix) a adição de peróxido de hidrogênio melhorou significativamente a eficiência de remoção de DQO e de carbono. Sem adicionar o peróxido de hidrogênio, precisou-se de 25 minutos de ozonização para se atingir cerca de 25% de remoção de DQO; enquanto que, adicionando peróxido de hidrogênio na razão O3/H2O2 de aproximadamente 0,30, este tempo foi de apenas 10 minutos e a remoção de carbono total dobrou de valor; (x) o efluente ozonizado deve passar por tratamento adicional antes de ser lançado no corpo receptor ou ser reusado. / In this research an experimental study of the potentiality of employment of the ozonization was accomplished after anaerobic treatment, in what refers the dose, time of contact, alkalinity, application combined with hydrogen peroxide, amount of consumed ozone and oxidation of organic matter. The proposed study was executed by means of: (a) preliminary studies; (b) preliminary tests; (c) experiment I, using ozone without variation of the affluent alkalinity; (d) experiment II, using ozone with variation of the affluent alkalinity; (and) experiment III, using ozone combined with hydrogen peroxide without variation of the affluent alkalinity; (f) verification of the disinfection; (g) critical analysis of the results. The results were analyzed by means of graphs, it was make itself comparison among analysis parameters, transferred ozone dose and time of contact and among quality of ozonized effluent and quality criterion for effluent reuse. Permitting arrive the following conclusions: (i) the most of the content of consumed ozone during the ozonization is consumed in the first 5 minutes; (ii) the consumed ozone can be better understood analyzing itself the variable applied instant ozone dose; (iii) the behavior from the ozone transference is influenced by three factors: hydrodynamic of the reactor, quantity of ozone available to react and characteristics of the effluent; (iv) the change in pH shows the reached rank of oxidation in the process; (v) the presenceof nitrate favors to oxidation; (vi) the ozonization is a very efficient process to disinfect effluent. The inativation of total and fecal coliforms reached 7,51 and 6,98 Log, respectively; (vii) the mass of ozone controls the rate of COD removal while the medium dose controls the efficiency of COD removal; (viii) with the consumption of ozone of 32,46 +/- 8,19 mg/L in 25 minutes of ozonization, it arrived COD and turbidity medium removals of 48,33 +/- 2,90% and 89,22 +/- 0,35%, respectively; (ix) the addition of hydrogen peroxide improved significantly the efficiency of COD and carbon removal. Without adding hydrogen peroxide, it was needed 25 minutes of ozonization to reach about 25% of COD removal; while that, adding hydrogen peroxide in reason O3/H2O2of approximately 0,30, this time was only 10 minutes and total carbon removal double; (ix) the ozonized e to be submitted an additional treatment before of its discharge in the surface water or its reused.

Avaliou-se o desempenho do reator anaeróbio em batelada seqüencial com biomassa imobilizada (ASBBR) no tratamento de soro de queijo quanto submetido a diferentes estratégias de alimentação e cargas orgânicas volumétricas (COV). O reator operou com agitação mecânica através de impelidor do tipo hélice na rotação de 500 rpm. Um volume de 2 litros foi alimentado por ciclo com 1 litro de volume residual, totalizando 3 litros. O substrato utilizado foi soro de queijo desidratado reconstituído. Suplementou-se o sistema com NaHCO3 na razão de 50% NaHCO3/DQO. Foram testadas as seguintes COVs: 2, 4, 8 e 12 gDQO/l.d. Para ciclos de 8 horas e em cada COV, três estratégias de alimentação foram testadas: (a) operação em batelada com ciclo de 8 horas, (b) batelada alimentada de 2 horas (c) batelada alimentada de 4 horas. Na COV de 2 gDQO/l.d, a conversão de matéria orgânica como DQO em amostras filtradas foi de 92, 96 e 91% para as estratégias de alimentação (a), (b) e (c), respectivamente. Para a COV de 4 gDQO/l.d, o desempenho foi de 94, 97 e 93%, respectivamente. Para a COV de 8 gDQO/l.d houve redução nas eficiências de conversão a 83, 85 e 86%, respectivamente. O aumento da COV para 12 gDQO/l.d, resultou na redução em eficiências de 72, 73 e 81%, respectivamente. Os perfis durante os ciclos da concentração de ácidos voláteis totais mostraram que, apesar do aumento gradual com o tempo de enchimento aumentando, nenhuma diferença significativa foi detectada em termos dos seus valores máximos. Foi observada a redução de ácido propiônico como conseqüência do aumento do tempo de enchimento. Assim, para COV de 2 e 4 gDQO/l.d, a estratégia de alimentação (b) proporcionou maiores eficiências de conversão e estabilidade operacional, enquanto que este comportamento foi observado na estratégia de alimentação (c) para os valores de COV de 8 e 12 gDQO/l.d. / The performance of an anaerobic sequencing batch biofilm reactor (ASBBR) treating cheese whey was evaluated when subjected to different feeding strategies and volumetric organic loads (VOL). The reactor operated under mechanical stirring provided by helix impellers at rotor speed of 500 rpm. A volume of 2 l was fed per cycle with 1 l of residual volume, totalizing 3 l. Reconstituted dehydrated cheese whey was used as substrate. NaHCO3 was supplemented at a ratio of 50% NaHCO3/COD. The following VOLs were tested: 2, 4, 8 and 12 gCOD/l.d. For 8-h cycles and each value of VOL three feed strategies were tested: (a) batch operation with 8-h cycle; (b) 2-h fed-batch operation; and (c) 4-h fed-batch. In the VOL of 2 gCOD/l.d, organic matter conversions as COD were 92, 96 and 91%, for feeding strategies (a), (b) and (c), respectively. For the VOL of 4 gCOD/l.d, performance values were 94, 97 and 93%, respectively. For the VOL of 8 gCOD/l.d there was a reduction in conversion efficiency to 84, 85 and 86%, respectively. The increase of VOL to 12 gCOD/l.d resulted in the reduction in efficiency of 78, 73 and 81%, respectively. The profiles of total volatile acids concentration obtained during the cycles showed that despite its gradual increase with the increasingly filling time, no significant differences were detected in terms of maximum values. Reduction in proprionic acid concentration along the cycle were observed as consequence of the increase of the filling time. Thus, for VOL of 2 and 4 gCOD/l.d feeding strategy (b) provided higher conversion efficiency and operation stability. This behavior was similar to that observed for the feeding strategy (c) at the VOL of 8 and 12 gCOD/l.d.

O presente projeto avaliou um reator anaeróbio operado em batelada e batelada alimentada seqüenciais (ASBR), em ciclos de 8 horas, utilizando biomassa granulada e agitação mecânica em um draft-tube, alimentado com água residuária sintética (500 mgDQO/L), contendo sulfato em diferentes relações DQO/[\'SO IND.4\' POT.2-\']. Em todos os ensaios o reator apresentou uma operação estável, produzindo alcalinidade e com concentração de ácidos voláteis totais em níveis adequados. Para os tempos de alimentação de 10 min, 3 h e 6 h, respectivamente, as eficiências de remoção de sulfato foram de 30, 72 e 72% nas operações nas quais o reator foi alimentado com uma relação DQO/[\'SO IND.4\'POT.2-\'] de 1,34. Nos ensaios nos quais o reator foi alimentado na relação DQO/[\'SO IND.4\'POT. 2-\'] de 0,67, as eficiências para a redução de sulfato foram de 25, 58 e 55%, respectivamente. Na operação com relação DQO/[\'SO IND.4\'POT.2-\'] de 0,34, as eficiências para redução de sulfato foram de 23, 37 e 27%, respectivamente. Desta maneira, pode-se concluir que as operações em batelada alimentada favoreceram a remoção de sulfato, enquanto foi observado que nas operações em batelada a remoção de matéria orgânica atingiu melhores eficiências. / This present work evaluate an anaerobic sequencing batch reactor (ASBR), fed in batch and fed-batch, and cycles of 8 hours, using granulated biomass and mechanical stirring in a draft-tube, fed with synthetic wastewater (500 mgCOD/L), enriched with sulfate in some COD/[\'SO IND.4\'POT.2-\'] relations. In all operations the reactor showed a stable operation, producing alkalinity and maintaining the volatile acids in adequate levels. Considering the fed periods of 10 min, 3 h and 6 h, respectively, the removal efficiencies of the sulfate was 30, 72 e 72%, in the operations when the reactor was fed with a COD/[\'SO IND.4\'POT.2-\'] relation of 1,34. In the essays when the reactor was fed in COD/[\'SO IND.4\'POT.2-\'] relation of 0,67, the efficiencies of the sulfate reduction was 25, 58 e 55%, respectively. When the reactor was operated with COD/[\'SO IND.4\'POT.2-\'] relation of 0,34, the efficiencies of sulfate reduction 23, 37 e 27%, respectively. Thus, is possible to conclude that the operations in fed-batch increased the efficiency of sulfate removal, at what time was observed that in batch operations the organic matter removal attained improved efficiencies.

Submeteu-se um reator anaeróbio operado em batelada seqüencial a diferentes tempos de enchimento, com o objetivo de verificar-se o desempenho do sistema. O reator, construído em acrílico e com capacidade de 6,3 L, tratou por ciclo um volume de 2,5 L de esgoto sintético com concentração de aproximadamente 500 mgDQO/L. O sistema foi operado à temperatura de 30 graus mais ou menos 1, com duração de 8 h para cada ciclo (tC) e agitação de 500 rpm implementada mecanicamente. Cubos de espuma de poliuretano foram usados como suporte para imobilização da biomassa. No início de cada ciclo, o reator foi carregado com 60 % do volume do esgoto; o restante foi preenchido durante tempos de enchimento (tF) que caracterizaram as diferentes estratégias de alimentação. Os resultados obtidos demonstram que para razões tF/tC <= 0,5 o sistema alcança médias de remoção de matéria orgânica acima de 75 % e 70% para amostras filtradas e não filtradas, respectivamente. Nos ensaios em que tF/tC > 0,5, registrou-se perda na eficiência e formação de polímeros extracelulares, apesar da estabilidade observada. O estudo contribuiu para o melhor entendimento do sistema e definição de técnicas de operação em futuras aplicações. / An anaerobic sequencing batch reactor was operated at different fill times with the objective to asses system performance. The reactor, made of plexiglas and with a capacity of 6.3 L, treated per cycle 2.5 L of synthetic wastewater with a concentration of nearly 500 mgCOD/L. The system was operated at a temperature of 30oC, with 8-h cycles (tC) and mechanical agitation rate of 500 rpm. Cubic particles of polyurethane foam were used as support material for anaerobic biomass immobilization. At the start of each cycle, the reactor was fed with 60 % of the wastewater volume, the remainder was filled at different feeding times (tF) that characterized the different feeding strategies. The results obtained showed that for a ratio of tF/tC <= 0.5 the system attained average filtered and non-filtered substrate removal efficiency of 75 % and 70 %, respectively. Ratios of tF/tC > 0.5, resulted in loss in efficiency and formation of extra cellular polymers, in spite of system stability. The study contributed to a better understanding of the system and definition of operational techniques for future applications.

Os exopolissacarídeos (EPS) insolúveis produzidos em processos de tratamento anaeróbios de certos tipos de água residuárias são indesejáveis devido a problemas operacionais que podem vir causar, inviabilizando, muitas vezes, o processo. O reator anaeróbio operado em bateladas seqüenciais contendo biomassa imobilizada (ASBBR) é uma nova configuração de reator que vem sendo estudada no tratamento de águas residuárias cujos resultados são positivos, no entanto em algumas condições observou-se a produção de EPS que inviabilizou o processo. Para evitar estes problemas operacionais em escala real é importante saber os fatores que favorecem a produção de EPS nestes sistemas. Portanto, os objetivos deste trabalho foram verificar a influência de diferentes fontes de carbono e a relação carbono/nitrogênio (C/N), na produção e composição de polímeros extracelulares (EPS) e no desempenho do ASBBR contendo biomassa imobilizada em espuma de poliuretano. As fontes de carbono utilizadas foram glicose, extrato de carne, óleo de soja, as três fontes de carbono juntas, e os ácidos acético, butírico e propiônico juntos. Nos experimentos variando-se a relação C/N utilizou-se glicose como fonte de carbono e uréia como fonte de nitrogênio. As relações C/N foram 13,6 (C/N1), 6,8 (C/N2) e 3,4 (C/N3) gC/gN. Para verificar a influência das condições de microaerofilia na produção do EPS, foi feito também um experimento borbulhando gás nitrogênio, mantendo sob anaerobiose estrita e utilizando glicose como fonte de carbono. Em todos os experimentos o reator foi alimentado com 1000 mgDQO/L. O reator atingiu eficiências médias de remoção da matéria orgânica de 82% em todas as condições, exceto quando o reator foi alimentado com óleo de soja, pois constatou-se o fenômeno de adsorção no material suporte. A produção de EPS por grama de fonte de carbono fornecida foi de 23,6 mg, 13,3 mg, 9,0 mg, 5,9 mg, 5,7 mg, 2,6 mg e 1,4 mg quando o reator foi alimentado com glicose na relação C/N1, óleo de soja, ácidos voláteis, glicose na relação C/N2, glicose/extrato de carne/óleo de soja, glicose na relação C/N3 e extrato de carne, respectivamente. Em condições de anaerobiose estrita não foi observada a produção de EPS. Os resultados sugerem que, a fonte de carbono, condição de microaerofilia e alta relação C/N favorecem a produção de EPS. Por meio de ensaios enzimáticos, com celulase combinada, verificou-se que o principal exopolissacarídeo presente no material polimérico foi celulose. Comparando os espectros de infravermelho das amostras de EPS constatou-se que as diferentes condições nutricionais não influenciaram na composição do polímero. A celulose bacteriana produzida, nesses casos, apresenta organizações alomórficas diferentes quando há glicose no substrato, constatada pelas análises de raios-X. / The insoluble exopolysaccharides (EPS) produced in anaerobic treatment processes from some kinds of wastewater are unwelcome due to operational problems that it may cause, making the process unfeasible most of times. The anaerobic sequential batch biofilm reactor (ASBBR), containing immobilized biomass, is a new configuration of reactor that has been studied for wastewater treatment with positive results. Nevertheless, it was verified the production of EPS in some conditions, which made the process impracticable. To avoid these operational problems in full scale it is important to know the factors that enhance EPS production on those systems. Thus, the objectives of this work were investigating the influence of different carbon sources and the relation carbon/nitrogen (C/N), on the production and composition of extracellular polymers (EPS) and on the performance of the ASBBR with immobilized biomass in polyurethane foam. The carbon sources used were glucose, meat extract, soybean oil, the three carbon sources combined and acetic, butyric and propionic acids combined. On the experiments with variation of C/N relation, glucose was used as carbon source and urea as nitrogen source. The C/N relations were: 13.6 (C/N1), 6.8 (C/N2) and 3.4 (C/N3) gC/gN. Another experiment was accomplished to verify the influence of microerophilic conditions on EPS production, bubbling nitrogen gas, keeping under strict anaerobic conditions and using glucose as carbon source. The reactor was fed with 1000 mgDQO/L in all experiments, achieving 82% of organic substance removal average efficiency, except when fed with soybean oil. At this condition it was verified the adsorption phenomenon in the material support. The yield of EPS was 23.60 mg/g carbon, 13.3 mg/g carbon , 9.0 mg/g carbon, 5.9 mg/g carbon, 5.70 mg/g carbon, 2.6 mg/g carbon and 1.4 mg/g carbon when the reactor was fed with glucose in the relation C/N2, glucose/meat extract/soybean oil, glucose in the relation C/N3 and meat extract, respectively. The production of EPS was not observed at strict anaerobic conditions. Results suggest that the carbon source, microerophilic condition and high C/N relation favor EPS production. Through enzymatic tests with combined cellulase, it was verified that cellulose was the main exopolysaccharide present at the polymeric material. Furthermore, polymers composition is not influenced by different nutritional conditions, comparing infrared spectra of EPS samples. In these cases, the produced bacterial cellulose presents different allomorphic organizations as showed by X-rays analysis.

Made available in DSpace on 2015-09-25T12:23:30Z (GMT). No. of bitstreams: 1 VANESSA F SILVA.pdf: 1400231 bytes, checksum: fb9f24d41beb924c130d174f918f19f8 (MD5) Previous issue date: 2005-12-22 / The objective of this thesis is to evaluate the performance of anaerobic filter with baffles (FAC) for the post treatment of anaerobic effluent and using rings cut from PET bottles as filling medium. The experiment was carried out in three phases characterized by the hydraulic retention times of 7, 9 and 10 days, respectively. The analysis of the UASB and FAC effluents was carried out weekly to evaluate the removal efficiency of organic material expressed as BOD5 e COD, solids and its different fractions, nutrients (nitrogen and phosphorus) and indicators of faecal contamination (thermotolerant Coliforms). The results showed that there were no significant differences between the FAC effluent during the three phases with respect to organic material and suspended solids (at 5% significance level), but there were differences in the electric conductivity, nitrogen and thermotolerant Coliforms. The FAC presented good performance of organic material removal (65% for COD and 64% for BOD5 during the first phase) and suspended solids (81% for TSS and 83% for VSS during the first phase). Thus it can be noted that the FAC presented good post treatment efficiency of anaerobic effluents, resulting in clarified effluent with low concentrations of organic material (12mg BOD5.L-1), suspended solids (<10 mg TSS. L-1) and turbidity (<10 UNT). With respect to sanitary quality the produced effluent had concentrations of thermotolerant in the range of 103 to 104 UFC.100 mL-1, hence above the standards established by the WHO (1989) for utilization in irrigation without restrictions. / O presente trabalho teve como objetivo avaliar o desempenho de filtro anaeróbio de chicanas (FAC) no pós-tratamento de efluente anaeróbio, usando garrafas PET como material de enchimento. O experimento foi realizado em três fases, delimitado pelos três tempos de detenção hidráulicas, 7, 9 e 10 dias, respectivamente. As análises dos efluentes do reator UASB e do FAC foram realizadas semanalmente, averiguando a remoção de matéria orgânica na forma de DBO5 e DQO, sólidos e suas frações, nutrientes (nitrogênio e fósforo) e indicadores de contaminação fecal (coliformes termotolerantes). Os resultados mostraram que não ocorreram diferenças significativas no efluente do FAC entre as três fases, em relação a matéria orgânica e sólidos (ao nível de 5%), mas houve diferença quanto a condutividade elétrica, nitrogênio e coliformes termotolerantes. O FAC apresentou bom desempenho quanto à remoção de matéria orgânica (65% para DQO e 64% para DBO5 durante a 1ª fase) e sólidos suspensos (81% para SST e 83% para SSV durante a 1ª fase). Diante desses resultados, observa-se que o FAC apresentou boa eficiência no pós-tratamento de efluente anaeróbio resultando em um efluente clarificado com baixas concentrações de matéria orgânica (12mg DBO5.L-1), sólidos suspensos (<10 mg SST. L-1) e turbidez (<10 UNT). Com relação à qualidade sanitária, o efluente produzido apresentava concentrações de coliformes termotolerantes variando de 103 a 104 UFC.100 mL-1, portanto valores acima dos padrões estabelecidos pelo OMS (1989) para ser utilizado em irrigação irrestrita.

Este trabalho apresenta e discute os resultados obtidos na operação de quatro reatores anaeróbios operados em bateladas seqüenciais, projetados em escala piloto, para tratamento de 7,8 m3.dia-1 de esgotos sanitários, coletados da rede coletora que atravessa o Campus da USP de São Carlos. Cada sistema (1,2 m3) foi concebido para tratamento de 1,95 m3.dia-1 de esgoto sanitário, com concepções geométricas (relação L-altura/D-diâmetro), mecânicas (agitação mecânica ou recirculação de líquido) e tipo de retenção de biomassa diferentes. Três unidades eram do tipo ASBR (anaerobic sequencing batch reactor) e outro tipo ASBBR (anaerobic sequencing batch biofilm reactor) com leito fixo composto de matrizes cúbicas de espuma de poliuretano. Os ciclos operacionais tinham duração de oito horas perfazendo no total três ciclos por dia em cada sistema. O monitoramento dos reatores incluiu a determinação de DQO, pH, sólidos em suspensão totais (SST) e voláteis, ácidos voláteis totais, alcalinidade no afluente e efluente, bem como a concentração de metano no biogás. O ensaio experimental foi dividido em duas etapas distintas, sendo que na primeira (227 dias), os reatores não receberam inóculo e na segunda (66 dias) houve a inoculação prévia de lodo anaeróbio granular. Em ambas etapas, os dois reatores ASBR com mesmo tipo de agitação por recirculação de líquido, mas com diferente relação L/D não apresentaram desempenho satisfatório. Os valores médios de eficiência de remoção de DQO e de SST foram próximos de 40% e 60%, respectivamente. No efluente a concentração média foi de 300 mgDQO/L e de 100 mgSST/L. Nos reatores, ASBR com agitação mecânica e, ASBBR com biomassa imobilizada, os resultados médios obtidos foram melhores. O reator ASBBR atingiu eficiência média de 65% e 75% em remoção de DQO e SST, enquanto no ASBR com agitação mecânica chegou-se a 60% e 85%, respectivamente. A concentração média no efluente dos reator foi de 150 mgDQO/L e 60 mgSST/L no ASBBR e 220 mgDQO/L e 50 mgSST/L no ASBR com agitação mecânica. / This study reports and discuss several data obtained using four pilot scale anaerobic sequencing batch reactor, treating 7.8 m3.d-1 of domestic sewage from the Sao Paulo University sewer treatment system (Campus- São Carlos). Each reactor system (1.2 m3) was designed for the treatment of 1.95 m3.d-1 of domestic sewage with different geometric reactor characteristics (ratio L-length/D-diameter), mechanical (mechanical mixing or liquor re-circulation) and biomass retention type. Three reactors were a conventional ASBR (anaerobic sequencing batch reactor) with granular biomass and another one, an anaerobic sequencing batch biofilm reactor (ASBBR), which was composed with cubic matrices of polyurethane foam. The reactors were operated within 8-h of a sequential batch cycle, which were attained in three cycles by day for each system. Chemical oxygen demand (COD), pH, total suspended solids (TSS), volatile fatty acids, bicarbonate alkalinity in both the influent and effluent were monitored in the different cycles. Methane concentration was also assessed in the same period using Gas Chromatography (GC). The experiments were divided in two different phases. In the first phase, which corresponded to 227 d, the reactors were not inoculated. In the second phase (66 d) the reactors were then inoculated with anaerobic granular sludge. It was observed that in both operational phases, the two ASBR reactors, with the same re-circulating process of the mixed liquor, but with different L/D ratio, showed non-satisfactory results. The average values of COD and TSS removal were close to 40 and 60%, respectively. In the effluent, the average values were of 300 mgDQO/L and 100 mgTSS/L. ASBR reactors with mechanical mixing and ASBBR reactor with immobilized biomass showed better results. The average removal efficiency observed was of 65 and 75% for COD and TSS, respectively. ASBR reactors with mechanical mixing reached the efficiency of 60 and 85% for COD and TSS removal. The average concentration in the effluent was of 150 mgDQO/L and 60 mgSST/l in the ASBBR reactor; and 220 mgCOD/L and 50 mgTSS/L in the ASBR reactor with mechanical mixing.

Increases in herd size and enforcement of water quality regulations have created an effluent disposal problem for the New Zealand dairy industry. Spray disposal to land and lagooning are commonly used but mechanical failures, management requirements and pressure on land have limited their suitability in many situations. This project was established to consider an alternative system. Initial studies revealed that anaerobic treatment in unmixed, non-insulated tanks, followed by trickling filter aeration, might be suitable. Two laboratory scale and one field treatment plant (1/15 - 1/20 full scale) were constructed to investigate the system. A factorial experimental design allowed investigation into three anaerobic treatment levels with a 3 x 3 aerobic treatment interaction nested within each anaerobic treatment. Anaerobic residence times of 5, 7.5 and 10 days provided loading rates of 1.35 - 0.63 kg COD/m3-day and 1.36 - 0.67 kg T S/m3-day. Removals between inlet and outlet averaged 71% and were insensitive to loading rate. Total solids accumulation rates of 40-50% TS input rate suggests that anaerobic tank design should be based on solids accumulation rate and cleaning frequency. The stone media trickling filter was loaded at approximately 0.61 kg COD/m3-day. Aeration periods of 1, 2 and 3 days and hydraulic loads of 2.8, 10.1 and 18.2 m3/m2-day were studied to determine their influence on treatment efficiency. Multiple regression analysis indicated that the longer residence times and higher recycle rates improved treatment efficiency. Removals varied with the measured parameters but ranged from 42-66% for COD. Design alterations to allow the final discharge to be taken from the bottom of the filter, after settling, would increase aerobic treatment efficiency above 75% COD removal. Prediction of treatment efficiencies beyond the monitored operating conditions suggested that only marginal improvements could be made. The TS accumulation rate in the aerobic phase was approximately 13% of the TS input rate or 56% of the BOD removal rate. Overall plant treatment efficiencies of 80-89% were obtained. Removals in excess of 92% could be achieved with minor design alterations. Maintenance and operational requirements were minimal. The only problem with the system was an average 15 fold increase in NO3-N and 4 fold increase in DIP under conditions for optimum removal of the other parameters. Intermittent land disposal could reduce this problem. Treatment comparison between similar laboratory plants, and between laboratory and field plants which varied by a scale factor of 56, suggests that identically designed plants would give a similar performance and that there is little scale effect. Increasing the scale only improved treatment efficiencies under unstable aerobic conditions, i.e., high recycle rates and low residence times. Increasing scale gave some decrease in maintenance and operational problems. Design of a full scale plant, based on daily pollution loads from a 250 cow dairy shed, suggests that the system is a viable proposition.

Thesis (Msc Food Sc (Food Science))--University of Stellenbosch, 2007. / The distillery industry generates large volumes of heavily polluted wastewater and thus effective wastewater treatment is essential. It has been reported that a chemical oxygen demand (COD) reduction of more than 90% can be achieved when wine distillery wastewater (WDWW) is treated in an upflow anaerobic sludge blanket (UASB) reactor. The first objective of this study was to investigate UASB treatment of WDWW and to try to enhance the efficiency by using ozonation treatments. Secondly, the impact of grain distillery wastewater (GDWW) on UASB granules was determined. The third objective was to determine whether ozonation and enzymatic treatment combinations might improve the biodegradability of GDWW and thus make GDWW more amenable to UASB treatment. It was found that UASB treatment combined with ozonation improved the WDWW treatment efficiency. When diluted WDWW (chemical oxygen demand COD = 4 000 mg.L-1) was ozonated (dose = 47 mg.L-1) in a 50 L venturi circulating contactor system, the COD reduction was 7%. When WDWW was treated in a laboratory-scale UASB reactor (substrate pH = 7.0, COD = 4 000 mg.L-1 and organic loading rate (OLR) = 4.0 kg COD.m-3.d-1), the COD reduction was 92%. When the UASB treatment was combined with either pre- or postozonation, the COD reduction was 94 and 96%, respectively. When UASB treatment was combined with pre- and post-ozonation, a COD reduction of 98% was achieved. The activity of the UASB granules was also found to improve over time, despite the addition of the ozonation treatment. It has been reported that operational problems occur when GDWW is treated in an UASB reactor as a result of the encapsulation of the granules. This was confirmed when granules from a full-scale UASB treating WDWW became encapsulated in a layer after being exposed to GDWW (COD = 4 000 mg.L-1) for 24 d. The results showed that the lipid content of the granules increased from 1.25 to 60.35 mg lipid.g-1 granule over the 24 d exposure period. Therefore, granules exposed to GDWW were encapsulated in a lipid-rich layer and as a result the contact between the GDWW and microbial consortium in the granules was reduced. The operational problems found during the industrial UASB treatment of GDWW were ascribed to the encapsulation of the granules. Combinations of ozonation (dose = 1 476 mg.L-1) generated in a 2 L bubble column and enzymatic treatments (1% FogFreeTM (FF) dosage and 2 d incubation at 35°C) were found to improve the biodegradability of GDWW. This improvement was in terms of lipid reduction in GDWW, granule activity and visual appearance of the encapsulating layer of the granules. The highest lipid reduction (90%), highest granule activity, lowest lipid content of the granules (3.74 ± 0.10 mg.g-1 granule) and best visual appearance were achieved in ozonated GDWW treated with 1% FF, followed by just ozonation. The higher lipid reduction and subsequent higher granule activity were ascribed to the reduction in lipids which resulted in the fact that fewer lipids were available to encapsulate the granules. As a result of the lipid reduction, the granule activity improved and the GDWW was made more amenable to UASB treatment. This study proved that UASB treatment combined with ozonation led to an enhancement of the treatment efficiency of WDWW. It was also found that the cause of the operational problems during UASB treatment of GDWW was as a result of the granules being encapsulated in a lipid-rich layer. It was established that treating GDWW prior to UASB treatment improved the biodegradability of GDWW. The data from the study showed that high lipid reduction in the GDWW directly led to better granule activity, lower granule lipid content and a thinner encapsulating layer. Based on the data from this study, it is recommended that GDWW be ozonated prior to other treatments because it can be done inline and the costs would be lower than that of enzymatic treatments.

Made available in DSpace on 2016-06-02T19:55:41Z (GMT). No. of bitstreams: 1 6345.pdf: 6459574 bytes, checksum: 0efe347b5498f9533e1f1366f1759ad1 (MD5) Previous issue date: 2014-10-03 / Financiadora de Estudos e Projetos / Anaerobic systems have been widely studied and used in treatment of wastewater from agriculture and others. Among the existing technologies, there are the EGSB (Expanded Granular Sludge Bed) reactors, which have emerged as improvement of UASB (Upflow Anaerobic Sludge Blanket) reactors. It was sought to evaluate the performance of an EGSB reactor using synthetic swine wastewater as substrate, increasing the volumetric organic load (2, 4, 8, 10 and 15 kgCOD.m-3.d-1) and the upflow velocity (6 and 10 m.h-1). Efficiencies higher than 83% were obtained in removal of COD, however there was a buildup of volatile acids and a possible microbial imbalance after the application of the load 10 kgDQO.m-3.d-1. The reactor showed homogeneity in microorganisms along the reactor, with the presence of bacilli of different sizes, coccus, and similar to the genera Methanosaeta and Methanosarcina. It was developed a mathematical model aiming to study in more detail the hydrodynamics of EGSB, generally regarded as continuous complete mix reactors (CSTR). For that, it was used a phenomenological model based on the mass balance of the reactor, and after the adjustment to the experimental data, it was observed that the EGSB reactor can be worked as a series of five continuous complete mix reactors (CSTR), three in the tube region and two in the separator region with kinetic intrinsic rate at approximately 7,5.10-5 L.mgSSV-1.h-1 and kinetic rate constant decreasing with increase in organic load. / Sistemas anaeróbios vêm sendo muito estudados e utilizados no tratamento de efluentes agroindústrias, entre outros. Dentre as tecnologias existentes, têm-se os reatores EGSB (Expanded Granular Sludge Bed), que surgiram como aperfeiçoamento dos reatores UASB (Upflow Anaerobic Sludge Blanket). Buscou-se avaliar o desempenho de um reator EGSB utilizando água residuária sintética de suinocultura como substrato, aumentando a carga orgânica volumétrica (2, 4, 8, 10 e 15 kgDQO.m-3.d-1) e a velocidade ascensional (6 e 10 m.h-1). Foram obtidas eficiências superiores a 83% na remoção de DQO, porém ocorreu acúmulo de ácidos voláteis, e provável desequilíbrio microbiano após aplicação da carga de 10 kgDQO.m-3.d-1. O reator apresentou certa homogeneidade nos microrganismos presentes ao longo do reator, com presença de bacilos de diferentes dimensões, cocos, e microrganismos semelhantes aos gêneros Methanosaeta e Methanosarcina. Desenvolveu-se um modelo matemático buscando estudar de maneira mais detalhada a hidrodinâmica do EGSB, geralmente considerados como reatores contínuos de mistura completa (CSTR). Para isto, utilizou-se um modelo fenomenológico, baseado no balanço de massa do reator, e após ajuste aos dados experimentais, observou-se que o reator EGSB pode ser trabalhado como uma série de cinco reatores contínuos de mistura completa (CSTR), sendo três na região do tubo do EGSB e dois na região do separador, com constante cinética intrínseca de aproximadamente 7,5.10-5 L.mgSSV-1.h-1 e com constante cinética aparente diminuindo com o aumento da carga orgânica.