Verificação da tratabilidade de água residuária oriunda de beneficiamento do açaí por processo físico-químico

Abstract

This work aims to study the wastewater treatability coming from açaí processing plant, trougth jar test assay to get the best conditions for the physical-chemical wastewater treatment. For this, two experimental steps was done:1) Quantitative and qualitative characterization of raw wastewater to elaborate flow hydrograph and hydric balance. 2) Assay coagulation/flocculation/oxidation on jar test using hydrated lime, tannin, sodium hypochlorite, polyaluminium cloride and polymer. In treatability test dosage was varied for each product and analyzed in the clarified effluent variables: pH, apparent color, turbidity and COD. It was also determined the treated effluent quality index and the qualitative characterization of effluent of the proposed treatment, beyond the physical characterization of the sludge. Furthermore, it was estimated monthly cost of chemicals products for proposed treatment. By the results for wastewater quantitative characterization were obtained flow of Qméd = 305 L/h; Qmax = 521 L/h and Qmin = 183 L/h and qesp. of 0.51 L/kg.d. To the water balance was found that weight of water used is 112.4 ton/d, generating 7.30 ton/d of wastewater, water in the pulp mass equal to 49.36 ton/d and water loss of 55.81 ton/d. For treatability tests the best result was obtained for the combination polyaluminium (18mg/L) and polymer (30 mg/l) at pH 8.0, resulting in apparent color removal 98.5%; 99.8% of turbidity and COD equal to 90% . In the physical characterization of sludge was found values: density of 1.002 and specific mass equal to 1001.8 kg/m³, moisture content of 98.9%, and the SV/ST equal to 73%. In the cost estimate with chemical products was obtained R$4,77/month, representing R$0,022/m³ of treated effluent. We conclude that this effluent treatment is viable for physical-chemical treatment process.