Tratamento de efluentes da indústria química pela combinação de processos biológicos e físico-químicos visando ao reúso

Abstract

In this work a case study an industrial unit responsible for the production of pesticides was carried out, in which it was evaluated the efficiency of organic matter and ammonium nitrogen removal from a mixture of industrial wastewater pre-treated by activated carbon (4 %) and sanitary wastewater (96 %) in a moving bed biofilm reactor (MBBR). The average COD and ammonium removal was 86 % and 88 %, respectively. In order to evaluate the possibility of reuse and the impact caused by the addition of the treated wastewater from the MBBR and of a lubricant industry wastewater (LUB), inserted in the industrial complex, coagulation/flocculation, sand filtration and cartridge filtration processes were evaluated as pre-treatment of reverse osmosis (RO), in the RIO (receiving body water), RM (85 % RIO + 15 % effluent from MBBR) and RML (80 % RIO + 15 % effluent from MBBR + 5 % LUB). As the obtained results after the cartridge filter did not meet the required parameters for RO module feeding, the ultrafiltration process was inserted into the pretreatment sequence, as the permeate obtained exhibited acceptable quality for RO. Besides, the addition of wastewaters did not affect the performance of the pretreatment processes for RO. Therefore, the combination of used treatment processes allows the zero disposal of the wastewater treated by the MBBR and that of lubricants industry and their reuse in the industrial processes.