REMOVAL EVALUATION OF CYANOBACTERIA AND SAXITOXINS OF THE ROW WATER AFFLUENT TO WTP OF PONTA GROSSA CITY, BRAZIL, USING THE COAGULATION DIAGRAMS TO FERRIC CHLORIDE AND FENTON REAGENT

Abstract

With the increasing water quality degradation on springs used to human supply, the responsible for the operation of Water Treatment Plants (WTP) is founding innumerous problems in the plant operational routine. Therefore, they need to adequate their treatment processes in function of the present reality, which no more suits to the WTP original project. In this context, this work had as objective evaluate cyanobacteria intact cells and cyanotoxins removal by means of coagulation diagram construction for ferric chloride and Fenton Reagent. The study water was proceeding from a eutrophized spring, collected at Parshall unit of the WTP that supplies Ponta Grossa City, Brazil. After the pair of values ‘coagulant dosage versus coagulation pH’ selection in the diagrams for each coagulant, it was tried to simulate the traditional treatment, realizing sand filtration experiments after decantation (bench scale), for the selection of an adequate cationic synthetic polymer and powder activated carbon (PAC) dosages, reaching total cyanobacteria removal, saxitoxins concentration below Brazilian standards, as well as turbidity values below 0.5 NTU.