Avaliação do sistema de lodo ativado de uma lavanderia industrial através da caracterização físico-química e microbiológica

Abstract

Industrial laundries constitute a branch of chemical industry that makes use of biological degradation for effluents depuration, through either an aerobic or anaerobic process. In this paper, the activated sludge system was approached, which consists of a mechanical or diffuse aeration tank that provides oxygen to the micro fauna present at the effluent for the biochemical oxidation of both organic and inorganic compounds. Therefore, the secondary decanters used after the aeration tank, end up receiving an effluent with a milder organic load and is able to release a clarified effluent. The objective of this paper was to evaluate the activated sludge system of a industrial laundry through analyses physicochemical and microbiological having an improvement in treatment. The physicochemical analyses were done together with the microbiological ones in order to characterize the activated sludge composition. The system is in an industrial laundry located in the city of Almirante Tamandaré, Paraná. The results show an addition to a high organic load and high solids in suspension and diversity of microorganisms. The high outflow of effluent to the tank and an inefficient aeration made difficult the work of the micro fauna in debugging the carbonaceous matter and promoting its development. Changing the effluent treatment flowchart on month of May resulted in a decrease of efficiency on the reduction of BOD, one of the indicators that evaluates the effectiveness of the system. The results after the modification in the sequence of tanks – aeration prior to equalization phase – indicate the importance in following the model of biological treatment according to the references in this area. This paper showed that the characterization of the effluent generated at an industrial laundry is extremely important a correct characterization and its monitoring to reduce the risks and impacts of this industry.