You ned to study ...
Published by Jaspreet Kaur
You ned to study physicochemical parameters like pH (for both effluent and influent) temp, color, DO, BOD, COD, TDS, TSS, TS, Chloride Sulphate, Oil & grease also. to understand cause of coloration. As you using allophanic filters, which helps to reduce the coloration of iron containing waste water. I guess, Iron is not the cause.