USO DE REATOR DE LEITO ESTÁTICO GRANULAR NO TRATAMENTO DE ÁGUAS RESIDUÁRIAS DE LATICÍNIOS

Objetivou-se, com a realização deste trabalho, avaliar o desempenho de um reator de leito estático granular no tratamento de solução sintética simulando águas residuárias de indústrias de laticínios. Amostras do afluente e do efluente do reator foram submetidas às análises de DQO, turbidez, condutividade elétrica e pH. De acordo com os resultados obtidos, pode-se concluir que o sistema mostrou ser alternativa promissora para tratamento de águas residuárias oriundas de laticínios, apresentando, com um tempo de detenção hidráulica de 48 horas, eficiências médias de 96% na remoção de DQO e 93% na de turbidez. Ademais, observou-se que proporcionou a manutenção da alcalinidade no meio, possibilitando que o processo fosse conduzido em condições de estabilidade. O tratamento da água residuária sintética estudada com o uso do reator de leito estático granular proporcionou atendimento à legislação para lançamento de efluentes em corpos hídricos no que tange à concentração de matéria orgânica.Palavras-chave: tratamento anaeróbio; efluente de laticínios; remoção de DQO; reator biológico. USE OF THE STATIC GRANULAR BED REACTOR IN TREATMENT OF DAIRY WASTEWATER ABSTRACT: The aim of this work was to evaluate the performance of a static granular bed reactor to treat synthetic solution simulating wastewater from dairy industries. Influent and effluent samples were analyzed for COD, turbidity, electrical conductivity and pH. According to the results obtained, it can be concluded that the system proved to be a promising alternative for treatment of effluents from dairy industry, presenting, with a hydraulic residence time of 48 hours, average efficiencies of 96% for COD removal and 93% for turbidity removal. Furthermore, it was observed the maintaining of alkalinity in the medium, indicating an operation under stable conditions. The treatment of dairy wastewater using static granular bed reactor provided appropriate effluent according to law for discharging on water bodies regarding organic matter concentration.Keywords: anaerobic treatment; wastewater of dairy products; COD removal; biological reactor.

Performance evaluation and kinetic parameter analysis for static granular bed reactor (SGBR) for treating poultry slaughterhouse wastewater at mesophilic condition

Poultry slaughterhouses consume a substantial quantity of potable water during processing of live birds. Subsequently, high strength poultry slaughterhouse wastewater (PSW) is generated at different stages during poultry product processing. In this study, a Static Granular Bed Reactor (SGBR) was used to treat the PSW from a poultry processing facility in the Western Cape, South Africa. The performance of the SGBR was primarily evaluated for chemical oxygen demand (tCOD) removal with the kinetics of the treatment process for PSW being evaluated using both the Grau second-order and the modified Stover-Kincannon models to predict the effluent COD. The overall treatment efficiency averaged >80% when the SGBR was operated at steady state for 110 days' experimental trial. On the basis of the experimental results, the predicted values of the tCOD concentration using the Grau second-order and modified Stover Kincannon model were inconsistent with the experimental data indicating an insignificant correlation with predicted tCOD concentration being higher than the experimental data. The high variation between the modelled and experimental data based on both the Grau second order and modified Stover-Kincannon model was observed at higher organic loading rates when the reactor was fed with undiluted influent, phenomena attributed to tCOD entrapped inside the SGBR, especially during periods of clogging caused by the accumulation of suspended solids in the underdrain.

Optimization of the COD Removal Efficiency for a Static Granular Bed Reactor Treating Poultry Slaughterhouse Wastewater

In this study, the efficiency of an anaerobic treatment system for wastewater from a South African poultry slaughterhouse was evaluated using a lab-scale static granular bed reactor (SGBR). The down-flow SGBR (2 L) was operated continuously for 138 days under mesophilic conditions (35-37 ˚C), at hydraulic retention times (HRTs) ranging from 24 to 96 h and average organic loading rates (OLRs) of 0.78 to 5.74 g COD/L.day. The SGBR achieved an average chemical oxygen demand (COD) removal efficiency of 80% and the maximum COD removal achieved was 95%, at an HRT of 24 h and average OLR of 5.74 g COD/L.day. The optimization of the SGBR, with regard to a suitable HRT and OLR, was determined using response surface methodology (RSM). The optimal SGBR performance with regard to the maximum COD removal efficiency was predicted for an OLR of 12.49 g COD/L.day and a HRT of 24 h, resulting in a 95.5% COD removal efficiency. The model R2 of 0.9638 indicated that the model is a good fit and is suitable to predict the COD removal efficiency for the SGBR.

Treatment of poultry slaughterhouse wastewater using a static granular bed reactor (SGBR) coupled with ultrafiltration (UF) membrane system

The South African poultry industry has grown exponentially in recent years due to an increased demand for their products. As a result, poultry plants consume large volumes of high quality water to ensure that hygienically safe poultry products are produced. Furthermore, poultry industries generate high strength wastewater, which can be treated successfully at low cost using anaerobic digesters. In this study, the performance of a bench-scale mesophilic static granular bed reactor (SGBR) containing fully anaerobic granules coupled with an ultrafiltration (UF) membrane system, as a post-treatment system, was investigated. The poultry slaughterhouse wastewater was characterized by a chemical oxygen demand (COD) range between 1,223 and 9,695mg/L, average biological oxygen demand of 2,375mg/L and average fats, oil and grease (FOG) of 554mg/L. The SGBR anaerobic reactor was operated for 9 weeks at different hydraulic retention times (HRTs), i.e. 55 and 40 h, with an average organic loading rate (OLR) of 1.01 and 3.14g COD/L.day. The SGBR results showed an average COD, total suspended solids (TSS) and FOG removal of 93%, 95% and 90% respectively, for both OLR. The UF post-treatment results showed an average of COD, TSS and FOG removal of 64%, 88% and 48%, respectively. The overall COD, TSS and FOG removal of the system (SGBR and UF membrane) was 98%, 99.8%, and 92.4%, respectively. The results of the combined SGBR reactor coupled with the UF membrane showed a potential to ensure environmentally friendly treatment of poultry slaughterhouse wastewater.