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RESUMO Neste trabalho, são apresentados os resultados do desempenho de dois sistemas de tratamento combinado de lixiviado de aterros sanitários e lodos de fossas. Na escala de laboratório, empregou-se um geobag de pequenas dimensões e um filtro biológico de percolação a jusante dele. Na escala real, investigou-se o desempenho de uma unidade de tratamento constituída de geobag seguido de lagoas de estabilização e wetland. Em ambos os estudos, empregou-se relação volumétrica de 4:1 (lodo de fossa:lixiviado) e adicionou-se floculante à mistura antes de sua alimentação no geobag. As remoções obtidas na unidade de campo foram superiores às alcançadas em laboratório para os parâmetros carbono orgânico dissolvido (COD) e sólidos em suspensão totais, cujas remoções foram superiores a 50 e a 95%, respectivamente. A remoção de nitrogênio amoniacal, entretanto, foi maior na instalação de bancada (68%). O desempenho desses sistemas de tratamento com relação à toxicidade para os organismos-teste Aliivibriofischeri, Daphniasimillis e Daniorerio também foi investigado.
ABSTRACT This paper presents the performance results of two combined landfill leachate and sewage sludge treatment systems. In the laboratory scale, a small geobag was followed by a trickling filter. In the real scale, the performance of a geobag treatment unit followed by stabilization and wetland lagoons was investigated. In both studies, a 4:1 volumetric ratio (pit sludge: leachate) was employed and flocculant was added to the mixture prior to feeding in the geobag. The field unit removals were higher than those obtained in the laboratory for the following parameters: dissolved organic carbon and suspended solids, whose removals were greater than 50 and 95%, respectively. Ammonium nitrogen was removed at higher percentages in the lab-scale unit (68%). The performance of both treatment units regarding toxicity to Aliivibriofischeri, Daphnia simillis and Danio rerio organisms was also investigated.
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O lodo acumulado no interior de tanques sépticos deve passar por um tratamento antes de sua adequada disposição final, pois apresenta uma fração da matéria orgânica não estabilizada, elevado teor de umidade e organismos patogênicos. Como alternativa para o tratamento do lodo, os filtros plantados com macrófitas são uma tecnologia promissora. Para se avaliar o potencial dos filtros no desaguamento e mineralização do lodo de tanque séptico, foram construídos dois filtros pilotos (F1 e F2) aplicando-se duas taxas de sólidos totais (ST) - F1: 250 kgST.m-2.ano-1; F2: 125 kgST.m-2.ano-1. Os resultados revelaram que o F2 apresentou melhor desempenho em relação ao F1 em termos de remoção de sólidos totais (96 por cento), demanda química de oxigênio (99 por cento) e nitrogênio amoniacal (72 por cento). O F2 proporcionou melhor desaguamento, com 67 por cento de umidade no lodo acumulado no leito e 33 por cento de sólidos totais.
The accumulated sludge in septic tanks has to be treated before the adequate final disposal, because of its high concentration of non-established organic matter, elevated content of moisture and pathogenic organisms. As an alternative to the treatment of sludge, the vertical flow constructed wetlands are a promising technology. To evaluate the potential of the filters in dewatering and mineralization of septic tank sludge, two pilot-scale constructed wetlands (CW1 and CW2) were implanted according with two total solids loads (TS) - CW1: 250 kgTS.m-2.year-1; CW2: 125kgTS.m-2.year-1. The results demonstrated that the CW2 had better efficiencies compared with CW1, in terms of total solids (96 percent), chemical oxygen demand (99 percent) and ammonia (72 percent) removal. CW2 also provided a better dewatering, with moisture of 67 percent in accumulated sludge and 33 percent of total solids.
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Objective To evaluate non-hazardous treatment efficiency of night soil in the three-grille mode septic tanks so as to give the evidence to government for policy-making. Methods One hundred and thirty normally runningthree-grille mode septic tanks were surveyed in five cities of Jiangsu Province in 2009. The fecal samples from first chamber and wastewater samples from third chamber were collected and examined for fecal coliform (FC) , parasite eggs including Schistosoma japonicum eggs, As-caris eggs and hookworm eggs, chemical oxygen demand ( COD), five-day chemical oxygen demand (BOD_5) and ammonia nitrogen (NH,-N) in lab. The data were analyzed by statistical software SPSS 13.0. Results The mean qualified rates of FC in the first chamber and third chamber of septic tanks were 3.1% and 100% respectively, showing significant difference (P <0.001). Hookworm eggs and Ascaris eggs were found in the first chamber of one and four septic tanks respectively and the density was one or two eggs in one hundred milliliter. The mean removal rates of FC, COD, BOD_5 and NH_3 -N were (99.96 ± 0.03) % , (60.69 ± 21.77) % , (60.13 ± 23. 20 ) % and (44. 14 ± 24.61) % , respectively. For the value of FC, COD, BOD, and NH_3 -N, there were significant difference between the first chamber and the third chamber (P_(FC) =0.000 1, P_(COD) =0.000 1, P_(BOD5) =0.000 1, P_(NH3-N) = 0.000 1, P < 0.001). Conclusion The treatment efficiency of septic tank could meet the sanitary standard for non-hazardous treatment of night soil, and it could use as a useful primary facility for human feces and urine treatment in rural areas.
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O lodo sanitário, principal subproduto do tratamento de esgotos, constitui um dos maiores problemas ambientais urbanos da atualidade. Em meio a este contexto, objetivou-se nesse estudo avaliar o processo da compostagem conjugada de lodo de tanque séptico (LS) e resíduos sólidos vegetais (RV) e determinar a importância da temperatura para o processo de sanitização do substrato tratado. O experimento, inteiramente casualizado com três tratamentos e três repetições, consistiu de nove reatores aeróbios com 100 litros de capacidade. Os resíduos foram utilizados nas seguintes proporções - T1: 100% RV; T2: 5% LS + 95% RV; T3: 10% LS + 90% RV. A compostagem aeróbia conjugada mostrou ser uma alternativa viável para destruição de ovos de helminto e estabilização dos resíduos, sendo fundamentais para tal, a temperatura, o pH e as relações ecológicas presentes nos reatores.
The sanitary sludge, principal byproduct of sewage treatment, constitutes one of the major municipal environmental problems of the present time. The present study was aimed to evaluate the composting of septic tank sludge (SS) and vegetable solid waste (VW) and to determine the importance of the temperature for the process of sanitization of the treated substrate. The experiment, entirely randomized with three treatments and three repetitions, constituted of nine aerobic reactors with 100 L capacity. The proportions of the wastes utilized were T1: 100%VW; T2: 5%SS + 95%VW; T3: 10%SS + 90%VW. The conjugated composting showed to be a feasible alternative for destruction of helminth eggs and stabilization of the wastes. The temperature, pH and ecological relations present in the reactors were fundamental for this purpose.
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Se determina el efecto mundial de los diferentes tipos de cobertura de disposición de excretas, DE, definidas en el marco del concepto "Instalaciones de Saneamiento Mejoradas", ISM, de OMS y UNICEF, sobre las tasas de mortalidad en niños menores de 5 años, TM menor 5 años. Para lograrlo se recolectaron datos de cobertura de DE en 161 países del "Programa Conjunto de Monitoreo" del 2004. Las TM menor 5 años se obtuvieron del informe "Progreso para la Infancia: un balance sobre agua y saneamiento". Los datos de ISM se clasificaron en totales, ISM-total, alcantarillado, DEA, tanques sépticos y letrinas, DET y L, y sin servicio, DESS. Se aplicaron 3 métodos estadísticos: distribución de frecuencias entre los intervalos de ambas variables, la correlación simple de Pearson entre los tipos de evacuación de excretas y las TM menor 5 años y la correlación Parcial al 95 por ciento de confianza pero controlando variables. Los resultados indican que a mayor cobertura mediante ISM-total menor es la TM menor 5 años, con una correlación de menos 0.782, mientras que las coberturas con DEA tienen mayor impacto sobre la disminución de la mortalidad que cuando se realiza por DET y L. Estos resultados se ratifican con las otras pruebas estadísticas y comprueban la hipótesis.
The worldwide effect on mortality in children under five years of age (MR < 5 years ) is determined for the different types of excreta disposal (ED) coverage, as defined in the framework of "Improved Sanitation Facilities (ISF)", established by the WHO and UNICEF. To accomplish this, ED coverage data was collected from 161 countries participating in the "Joint Monitoring Programme" in 2004. The mortality rates were obtained from "Progress for Children: A Balance on Water and Sanitation". ISF data were classified as: total (total-ISF), sewage (DEA), septic tanks and latrines (DET and L), and without services (DESS). Three statistical methods were applied: frequency distribution between the intervals of both variables, Pearson´s simple correlation between the types of excreta evacuation and the MR<5 years, and partial correlation at 95% confidence but controlling the variables. Results indicate that as total coverage (total-ISF) increases, there is a lower incidence of mortality (MR < 5 years), with a correlation of 0,782; while DEA coverage has a greater impact over mortality decrease as compared to DET and L. The results are ratified with the other statistical tests and prove the hypothesis.
Asunto(s)
Humanos , Lactante , Preescolar , Eliminación de Excretas , Mortalidad Infantil , Salud Pública , Saneamiento , Saneamiento UrbanoRESUMEN
Este trabalho teve por objetivo estudar o desempenho da macrófita taboa (Typha sp.) e a remoção de nutriente pela mesma, cultivada em quatro sistemas alagados construídos (SAC), utilizados no tratamento de efluente doméstico, pro-veniente de tanque séptico. Para tanto, foram avaliados órgãos vegetais e quantificadas as seguintes variáveis na água residuária e no tecido vegetal: nitrogênio total (N-Total), fósforo total (P-Total), sódio (Na) e potássio (K). Obtendo-se, como resultado, profundidade média de 27,15 cm, alcançada pelas raízes, bom desenvolvimento da taboa, o que possibilitou a partida do sistema aos quatro meses após o estabelecimento da vegetação e, por meio da remoção da biomassa aérea, contribuição para remoção de 1,69 por cento, 1,64 por cento, 4,94 por cento e 0,74 por cento do aporte de N-Total, P-Total, potássio e sódio, respectivamente.
This study was carried out in under to evaluate the macrophytes (Typha sp) performance and nutrient removal by the same, cropped in four constructed wetlands (SACs), used in treating the domestic wastewater proceeding from septic tank. So, were evaluated vegetable organ and the following variables quantified in either wastewater and vegetable tissue: total nitrogen (N-total), total phosphorus (P-total), sodium (Na) and potassium (K). An average depth of 27.15cm were reached by roots, as well as a satisfactory development of Thypha sp., therefore making possible to beginning the operation of the system at four months after vegetation establishment. The system made possible the following removals of the aerial biomass: 1.69 percent, 1.64 percent, 4.94 percent and 0.74 percent from the contribution of N-total, P-total, potassium and sodium, respectively.