PILOT PLANT STUDY ON NATURAL WATER COAGULANTS AS COAGULAN AIDS FOR WATER SUPPLY

B BINA, M.R SHAH MANSOURI, A.R CHINAII

Abstract


Introduction: Natural plant coagulants have an important role to play in provision of portable water to rural communities in the developing world. The plant material that their coagulation properties have been confirmed in previous lab scale studies and can be found widely in Iran was selected as coagulant aids. Pilot plant study was done to evaluate the efficiency of natural material such as Starch/Gum Tragacanth, Fenugreek and Yeast as coagulant aids in conjunction with comercial alum.
Methods: The pilot was placed in Isfahan Water Treatment Plant (IWTP) and efficiency of these materials in removal of turbidity from raw water enters the IWTP was evaluated. The results indicated while these materials were used as coagulant aids in concentration of 1-5 mg/l conjunction with alum are able to reduced the turbidity and final residuals turbidity meets the standards limits.
Results: The coagulation efficiency of these material were found to be effected by certain physico-chemical factors, namely, concentration of suspended solids, divalent cation metal and time of agitation. The relative importance of these variable was evaluated. The results of COD test proved that the natural coagulant aids in the optimum doses produce no any significant organic residual.
Discussion: Economical considerations showed that using of these material as coagulant aids can cause reduction in alum consumption and in some cases are more econmical than synthetic polyelectrolyte.

Keywords


Alum, Water coagulants, Environmental Health, Isfahan, Water supply