Coagulation Performance of Activated Neem Leaf Powder in Treating Low Strength Dye Waste Water

Abstract

The use of chemical coagulants is not recommended because it affects health and economic considerations. Therefore, plant-based coagulants are preferred for treating waste water. It is very cheap and easily available; also it will not have any health hazards. A new coagulant is obtained through neem leaf powder, and has been found effective in the removal of dangerous pollutants from dyeing waste water. From the experimental investigations, it has been found that the removal efficiency of neem leaf powder is higher. It is attained by altering the pH of the solution and by adding the PAC solution as a coagulant aid. The pH was altered from acidic to basic condition for each dosage of neem leaf powder. Among these different dosages and pH values, the optimum dosage was obtained as 6 g/L at the range of pH = 4 along with the PAC solution. In this pH, it was found that transmittance was increased along with the removal of COD, BOD, ammonia, iron and chromium. Also, the absorbance value reached 0.27 which is sufficient. The result shows that the removal of 80% of BOD and 95% of COD is obtained. Also, iron was reduced to 85% and chromium removals of 55% were achieved.