Coagulation-flocculation studies of laboratory wastewater using different combinations

This study was conducted on the wastewater of pcsir laboratories complex lahore. both single as well as blended form was used in order to achieve maximum results and to reduce the cost. these experiments were conducted in hudson jars of one liter capacity using the coagulation technique for the removal of total suspended solids (tss) and turbidity. the ph range was 6-8 and 4-10 for treatment. four coagulants were used such as fecl3,alcl3,alum,and feso4,to remove the turbidity in single and blended form. results of single coagulant are fecl3 from 39.7 to 11.51 ntu; alcl3 from 47.48 to 11.8 ntu. alum 43 to 25.3ntu.feso4 showed increasing trend in turbidity 53 to 120 ntu.the blended set of coagulants alcl3+alum turbidity from 45 to 18.55 ntu. the alcl3 and fecl3 showed almost similar results but after overnight settling results were excellent and alum showed also good results. the turbidity was removed from 54 to 27 ntu,48 to 22 ntu,44 to 17 ntu,and after overnight settling 33 to 4 ntu. the results of blended coagulants fecl 3+alcl3 after one,two and three hours settling were also studied and found best and blend alcl3+alum showed also similar trend and the blend of alum+fecl3 after overnight settling was excellent. the same coagulants and its blended form were used for tss removal and results are 278 to 7 mg/l,in blended form alcl3+alum show similar results but alum + fecl3 showed excellent results. the tss and turbidity removal was 87 %,97.5%.