Enhancing filtrate quality of turbid water incorporating seeds of Strychnos potatorum, pads of Cactus opuntia and mucilage extracted from the fruits of Coccinia indica as coagulants.

Abstract

In the present study the plant based coagulants namely, the seeds of Strychnos potatorum, pads of Cactus opuntia and mucilage extracted from the fruits of Coccinia indica in powder forms were applied to a water treatment sequence comprising coagulation-flocculation-sedimentationsand filtration. The study was conducted on synthetic turbid water created by kaolin. Emphasis was given to the filtration aspect of the treatment using synthetic turbid water. The performance of filter was defined by the quality of water and the head loss development across the filter bed. The optimum dose obtained from Batch coagulation-sedimentation test conducted for S. potatorum, Cactus and Coccinia indica were 1.5 mg/l, 30 mg/l, 0.5 mg/l were applied for filtration test and turbid waters with the supernatant turbidities obtained from batch coagulationsedimentation test (14 NTU in the case of S. potatorum, 17 NTU in the case of Cactus and 13 NTU in the case of Coccinia indica) were fed as an influent to the filter. The filtrate turbidities obtained after filtration were 0 NTU, 1NTU and 0 NTU which are lesser than 5 NTU (the guideline value recommended by WHO).Thus the use of natural coagulants improved the filtrate quality.