Tratamento Avançado de Efluente de Reator UASB por Membrana de Microfiltração Associado à Desinfecção por Radiação Ultravioleta

Abstract

ResumoA baixa eficiência dos reatores UASB, no que se refere às remoções de nutrientes, patogênicos e matéria orgânica, faz com que seja necessário o pós-tratamento, a fim de melhorar a qualidade do efluente gerado. Assim sendo, investigou-se nesse estudo a utilização da microfiltração associada à desinfecção por radiação ultravioleta como alternativa ao tratamento avançado de esgotos. Para isso, foram coletadas amostras de efluente de reator UASB a fim de realizar ensaios em sistema piloto de microfiltração, utilizando-se em uma das amostras a pré-coagulação com tanino vegetal. Keywords: Membrane Filtration, Post-sewage Treatment, UV Radiation.The low efficiency of UASB bioreactors, regarding the removal of nutrient, organic matter and pathogens, makes it necessary to carry out a post treatment, in order to improve the quality of the effluent. Accordingly, this research has examined the use of microfiltration associated to the disinfection by the ultraviolet radiation, as an option to this post treatment. For so, were collected samples of UASB reactors' effluent, in order to carry out some tests on a pilot microfiltration system, using in one of the samples pre-coagulation with vegetable tannin. After, all the microfiltrated samples were inserted in a UV reactor, applying different radiation doses, ranging from 43.8 to 194.9 mWs.cm -2, to simulate the disinfection. The system used showed good results in terms of turbidity removal, apparent color, true color, phosphorus, nitrogen, total solids, total suspended solids and COD, reaching in the best operating condition, the following values: 1.90 uT, 15 uC, 10 uC, 0.94 mg/L, 17.64 mg/L, 123 mg/L, 0 mg/L and 10 mg/L, respectively, which represent the following removal percentages: 91.3%, 93.6%, 82.0%, 55.1%, 26.3%, 35% and 86.1%. The inactivation obtained for E. coli, total coliforms, colifagos and Clostridium perfrigens was satisfactory, achieving a higher inactivation than the detection limit of the method used, when submitted to the highests tested radiation doses. The average permeate flux ranged from 55.2 to 133.6 L.m

Study of Wastewater Treatment Plants in Operation with UASB Reactors in the Municipality of Juazeiro do Norte-Ceará

“…The Vila 3 Marias WWTP (UASB + Chlorination) obtained a satisfactory result in the reduction of pathogens according to the legislation, only in the months of April (100 CFU/100 mL) and June (1 CFU/100 mL), the E. coli values in the treated effluent being still quite high when compared with some authors [32,33]. Anaerobic reactors are not designed for the purpose of removal of microorganisms, this being a consequence of the retention of solids [14].…”

Effect of ultraviolet radiation on inactivation of microorganisms present in Brazilian diesel fuel

“…The literature indicates that UV radiation has been used as an important tool for microbiological control in several areas, as in sanitary sewage, rainwater, and effluent treatments. 23,24,44 In many cases it was found that UV radiation can achieve effectiveness of more than 90% against E. coli, C. perfringens and total coliforms. 24 In this study it was found that UV radiation can achieve 99% efficiency in diesel oil treatment against microorganisms.…”

“…Many studies have reported the use of UV irradiation for the disinfection of aqueous media. The technique has been applied to domestic effluents, to inactivate the eggs of Ascaris sp., 22 as well as for sewage disinfection, 23 and for the post‐treatment of an upflow anaerobic sludge blanket (UASB) reactor, and the effects on Escherichia coli , Clostridium perfringens , total coliforms, and coliphages in effluent have been evaluated 24 . However, an extensive literature search found no studies of the use of UV radiation to control microorganisms in fuels.…”