Tratamento de efluente de fecularia utilizando coagulação/floculação e separação por membranas

Abstract

This research aimed to study the treatment of manipueira by combined process of coagulation/flocculation and membrane separation, targeting the non-potable reuse this water. For pretreatment of the effluent triage was performed using five natural coagulants (Acquapol WW, and S5T Tanfloc POP, ST, SG), a chemical (Al2SO4) and a cationic flocculant (Zetag ® 8185).Experimental designs Plackett & Burman (PB12) followed by a full factorial 2k was used in order to obtain the best experimental conditions in the process. The supernatant obtained in step of coagulation/flocculation under went a process of separation of micro-and ultrafiltration membranes varying pressures (0,6, 1 and 1,4 bar), permeate flows being analyzed, fouling and removal efficiency.The raw sewage and water resulting from treatment in the best conditions of coagulation/flocculation and filtration, under went a toxicity test using brine shrimp body. From the selected sorting the sedimentation time 15 minutes and Tanfloc POP among the natural coagulants.The best condition of operation of the coagulation/flocculation obtained through experimental planning was 1 min to 10 min, TMR TML, 180 rpm for VMR and 10 rpm of VML, pH of 8.5 and coagulant concentration of 440 mg L-1, with removals of 88,5% to turbidity and 78,9% color. The model adjusted to the data in the color parameter removal complete factorial planning using coagulant Tanfloc POP. The tests of filtration (MF and UF) presented on pressure of 1,4 bar, above 95% removal of colour and turbidity, and above 60% for nitrogen and COT, but with lower COD removal (less than 70%). The toxicityof that treated wastewater (66% and 100%) reported toxic to the test organism due to the presence of free cyanide. The permeated obtained (MF) could be used for less noble purposes among the classes (2, 3 and 4) suggested by the ABNT NBR 13,696/1997. The results obtained in this study demonstrate the potential of C/F, MF and UF, for treatment of manipueira.