Rejane Helena Ribeiro da Costa

Tecnologias para o tratamento de dejetos de suínos

Com este trabalho apresentaram-se os problemas ambientais provenientes da suinocultura no Sul do Brasil, as formas adotadas de criacao dos animais e suas relacoes economicas, sociais e ambientais. No Estado de Santa Catarina concentra-se o maior rebanho nacional, da ordem de 4,5 milhoes de cabecas, gerando aproximadamente 150.000 empregos diretos, possuindo 25.000 propriedades produtoras de animais. Em termos ambientais, a suinocultura e um setor com baixa qualidade ambiental, pois apenas 15% das propriedades dispoem, de alguma forma, de manejo de dejetos. Com o objetivo de contribuir na busca da qualidade ambiental para este setor, apresentam-se orientacoes tecnologicas, definidas a partir de resultados de pesquisas, com metodologias para reduzir a poluicao ambiental em funcao das carateristicas da propriedade, das localidades e da tendencia mundial.

Effect of particulate organic substrate on aerobic granulation and operating conditions of sequencing batch reactors

The formation and application of aerobic granules for the treatment of real wastewaters still remains challenging. The high fraction of particulate organic matter (XS) present in real wastewaters can affect the granulation process. The present study aims at understanding to what extent the presence of XS affects the granule formation and the quality of the treated effluent. A second objective was to evaluate how the operating conditions of an aerobic granular sludge (AGS) reactor must be adapted to overcome the effects of the presence of XS. Two reactors fed with synthetic wastewaters were operated in absence (R1) or presence (R2) of starch as proxy for XS. Different operating conditions were evaluated. Our results indicated that the presence of XS in the wastewater reduces the kinetic of granule formation. After 52 d of operation, the fraction of granules reached only 21% in R2, while in R1 this fraction was of 54%. The granules grown in presence of XS had irregular and filamentous outgrowths in the surface, which affected the settleability of the biomass and therefore the quality of the effluent. An extension of the anaerobic phase in R2 led to the formation of more compact granules with a better settling ability. A high fraction of granules was obtained in both reactors after an increase of the selection pressure for fast-settling biomass, but the quality of the effluent remained low. Operating the reactors in a simultaneous fill-and-draw mode at a low selection pressure for fast-settling biomass showed to be beneficial for substrate removal efficiency and for suppressing filamentous overgrowth. Average removal efficiencies for total COD, soluble COD, ammonium, and phosphate were 87 ± 4%, 95 ± 1%, 92 ± 10%, and 87 ± 12% for R1, and 72 ± 12%, 86 ± 5%, 71 ± 12%, and 77 ± 11% for R2, respectively. Overall our study demonstrates that the operating conditions of AGS reactors must be adapted according to the wastewater composition. When treating effluents that contain XS, the selection pressure should be significantly reduced.

Plankton biomass in secondary ponds treating piggery waste

Este trabalho teve como objetivo estudar a biomassa do plâncton encontrado em um sistema de tratamento de dejetos suinos, formado por uma serie de lagoas. Foram monitoradas 1 lagoa de alta taxa (LAT), 2 lagoas de maturacao (LM1, LM2) (sistema A) e 1 lagoa de aguapes (LAG) (sistema B), durante 32 semanas, por meio de variaveis fisico-quimicas tais como pH, temperatura, oxigenio dissolvido, demanda quimica de oxigenio, compostos nitrogenados e fosforo total. Igualmente, foram feitas identificacoes da biomassa planctonica, a nivel de genero, e calculados indices ecologicos que permitem descrever o seu desenvolvimento dentro das lagoas. O sistema de tratamento para dejetos suinos apresentou boa eficiencia na remocao de materia orgânica (DQOs) e nutrientes (nitrogenio, amonia, nitrato, nitrito e fosforo). Os resultados mostraram baixa riqueza de especies, a qual esteve associada a populacao mono-especifica de Chlorella sp. A densidade dos protozoarios foi inversamente proporcional a densidade das cloroficeas na LAT (que apresentou altas concentracoes de DQO, nitratos e nitritos e SS) e na LAG (com baixas concentracoes de DQO soluvel e OD). Constatou-se que a maior diversidade de especies ocorreu nas ultimas lagoas da serie (LM2 e LAG), onde havia baixa concentracao de nutrientes (compostos nitrogenados e fosforo total). As cloroficeas apresentaram a maior densidade relativa (> 97%). O indice de Jaccard atingiu 100% somente quando Chlorella sp e, as vezes, diatomaceas foram encontradas na entrada e na saida do sistema (A ou B). A produtividade da biomassa algal foi em torno de 10 gSST/m2/dia na LAT, 8 gSST/m2/dia na LAG e inferior nas outras lagoas. O coeficiente de variacao (CV) das cloroficeas variou entre 0 e 1,5 nas lagoas LAT e LAG, porem manteve-se constante em 0,9 ate a 10a semana na LM1 e em torno de 0,5 durante todo o periodo experimental na LM2; para a clorofila a, este coeficiente apresentou-se muito variavel em todas as lagoas.

Tratamiento de efluentes del cultivo de Litopenaeus vannamei por sedimentación y filtración por la ostra Crassostrea rhizophorae

Efficiency in removing particulate matter and dissolved nutrients from Litopenaeus vannamei shrimp farming effluents was evaluated at laboratory scale employing a combined two-stage system of sedi- mentation and filtration by the oyster Crassostrea rhizophorae; three hydraulic residence times (HRT) were used: 6, 12, and 24 h. For the sedimentation process, 100-L tanks were filled with 90 L of the effluent. For the filtration process, 50-L tanks were filled with 20 L of the effluent supernatant corresponding to each HRT of the sedimentation stage. All experimental units were seeded with 15 adult oysters with a mean weight of 80 g and a biomass of 1200 g tank -1 . One tank with empty oyster shells was used as a control for each HRT. The re- sults showed that, in the sedimentation process, the best performance was obtained at 24 h, with 56.1% re- moval by turbidity, 36.3% by total volatile solids, 31.0% by BOD5, and 21.4% by ammonium. In the filtration process, removal efficiency was highest at 6 h, with 62.1% removal by turbidity, 69.4% by total suspended solids, 35.4% by total volatile solids, 100% by chlorophyll a, and 17.2% by BOD5, when compared with the control tank. In the filtration process, the ammonium concentration increased for all HRTs. The integrated re- moval efficiency for the sedimentation and filtration processes showed significantly improved performance at

Modelling and Optimisation of Stabilisation Ponds System for the Treatment of Swine Wastes: organic Matter Evaluation

The fast increase of the swine production, specially in the west region of Santa Catarina, Brazil, did not have a parallel program for the valorisation of its dejection, not even processes for the treatment of the organic residues. Most of the producers keep their animals confined in small areas, having as a consequence the production of a large volume of wastes in the same place. This waste is diluted in water used to clean the bays, resulting in contamination of the watercourse. Thus, it is necessary to develop treatment processes to minimise the environmental problems caused by the swine breeding activities. The stabilisation ponds have been used due to its excellent efficiency in the removal of the organic matters, solids, nutrients and faecal coliforms; besides the low implantation and maintenance costs. This work was assisted in a series of four stabilisation ponds, real scale, treating swine wastes in Concordia/SC at CNPSA. The ponds system was evaluated during a period of 20 months, objecting to get its principal work parameters, as well as information about the capital and operational costs, in order to adjust the equations to model and optimise the systems about the removal of the organic matters.

Treatment of shrimp effluent by sedimentation and oyster filtration using Crassostrea gigas and C. rhizophorae

Efficiency in removing particulate matter from Litopenaeus vannamei shrimp culture effluent was assessed in laboratory scale employing sedimentation and oysters Crassostrea gigas and C. rhizophorae filtration processes. Cylindroconical tanks (100 L) were used in duplicate for sedimentation and 50-L in triplicate for oyster filtration. Fifteen oysters of each species weighing 76-80 g were stocked in each of the filtration treatment experimental units (biomass of 1065 - 1174 g oyster per unit). The control treatment was a tank similar to those used in the filtration treatment but with empty oyster shells. Hydraulic retention time of the effluent was of 6 hours in each treatment. First, effluent went through sedimentation, and then the supernatant went through the filtration tanks. Temperature, pH, dissolved oxygen, salinity, turbidity, total suspended solids, total volatile solids, chlorophyll a and BOD5 were evaluated. During sedimentation and filtration, temperature, pH, salinity and dissolved oxygen concentration remained stable. Sedimentation removed 18, 5.6, 27.5, 45.40 and 23.2% of turbidity, total suspended solids, total volatile solids, chlorophyll a and BOD5, respectively. Chlorophyll a and BOD5 after sedimentation presented significant difference (P<0.05) from the farm crude effluent. For the filtration treatment, C. rhizophorae was more efficient removing 62.1, 70.6, 36.1, 100 and 17.2% of turbidity, total suspended solids, total volatile solids, chlorophyll a and BOD5, respectively, whereas C. gigas removed 56.3, 41.2, 27.8, 51.4 and 8.0% of the same parameters. Statistically comparing C. rhizophorae and C. gigas performances, there were differences (P<0.05) in removing total suspended solids, total volatile solids and chlorophyll a.

Tratamento de esgoto sanitário em reator híbrido em bateladas sequenciais: eficiência e estabilidade na remoção de matéria orgânica e nutrientes (N, P)

This paper presents the results about the behavior of a sequencing batch hybrid reactor on combined removal of carbonaceous matter, nitrogen and phosphorus from sewage. Operated in 8-hour cycles, the reactor had a nylon net fixed inside. Loads between 0.39 and 1.35 kg COD.m-3.day-1, 42 and 60 gN-NH4-m-3.day-1 and 51 and 70 gP-PO4-m-3.day-1 were tested. The reactor operated as a stable system and showed good depuration conditions. The carbonaceous matter removal was high, with 92 and 80% efficiencies average to BOD5 and COD, respectively. The nutrients removal varied between 59 and 71% for total nitrogen and between 45 and 67% for total phosphorus. In both, sludge in suspension and the biofilm, occurrence of ammonium-oxidizing bacteria and microorganisms responsible for denitrification and biological phosphorus removal was observed.

Tratamiento de efluentes del cultivo de Litopenaeus vannamei mediante procesos de sedimentación, filtración y absorción

) y nitrato (N-N03) fueron reducidos en 53,6%, 49,6% y 70,2%, respectivamente, en relacion a los valores del estanque control. Los tratamientos combinados de sedimentacion, filtracion y absorcion, bacterias totales (95,1%), turbidez (97,1%) solidos suspendidos totales (81,3%), clorofila-a (99,1%), amonio (54,1%), nitrito (58,0%), nitrato (69,2%) y fosfato (52,9%), presentaron una alta eficiencia de remocion, en relacion a los valores del efluente bruto. Se concluye que la combinacion de tratamientos mejora significativamente la calidad de los efluentes del cultivo del camaron Litopenaeus vannamei. Palabras clave: efluente, camaron, sedimentacion, biofiltracion, macroalga, ostra. Treatments of effluents from Litopenaeus vannamei shrimp cultures through sedimentation, filtration and absorption

The potential of denitrification for the stabilization of activated sludge processes affected by low alkalinity problems

In this study, the problems provoked by nitrification of wastewater with low alkalinity were analyzed in a pilot sequencing batch activated sludge reactor (SBR). Decrease in pH resulted in disappearence of protozoa. De-flocculation of the activated sludge floc started below pH 6.5, resulting in enhanced effluent turbidity and loss of bacteria. Nitrification efficiency was affected below pH 6.2. The denitrification activity was not sufficient to keep up the pH, due to a low C/N ratio of the wastewater. Based on alkalinity and ammonia concentration of the wastewater and the necessary denitrification rate to prevent operational problems, was developed a prognostic diagram. The applicability of this diagram was tested for the SBR with excellent results. The diagram could be applied to optimize the operation of wastewater treatment plants affected by problems with low alkalinity wastewater.

Avaliação de sistema de tratamento de dejetos suínos instalado no estado de Santa Catarina

Os dejetos suinos contribuem de forma significativa em prol da degradacao dos recursos naturais e para a diminuicao da qualidade de vida na regiao sul do estado de Santa Catarina, Brasil. O excesso de dejetos gerados pelo grande numero dos suinos por unidade de area dificulta a solucao do problema. Este trabalho teve como objetivo avaliar o comportamento de um sistema de tratamento de dejetos suinos, em serie e em escala real, composto de unidades anaerobias, unidades aerobias e pos-tratamento. Os parâmetros analisados foram: DBO, DQO, PT, P-PO4, N-NH3, NTK, pH, clorofila a, biomassa algal, coliformes totais e coliformes fecais (Escherichia coli). O sistema mostrou que apos um ano de funcionamento as eficiencias de remocao foram satisfatorias para materia orgânica e nutrientes, alcancando valores de 97% para DBO, 95% para DQO, 88% para N-NH3 e 74% para PT/P-PO4, mesmo com as variacoes de vazao e de carga orgânica aplicada. Entretanto, a remocao de coliformes fecais nas unidades aerobias foi baixa, reduzindo somente 0,86 unidades log na lagoa facultativa aerada e 0,80 unidades log na lagoa de maturacao.