Improvement of NOM Removal from Water Resources by Modifying the Coagulation Process

As a result of the regulations on dbps, interest in nom removal is increasing and many water treatmentplants in developed countries have started to measure the concentration of toc in their finished waters.promulgation of the rules will substantially increase these efforts in other countries too. since the cost oftoc (and dbps) determination was high, it was decided to study the traditional analysis of cod as asurrogate measure to detect the organic constituents in raw water and the extent to which optimizedcoagulation with ferric chloride can increase cod removal. the two water samples studied belonged to karajand jajrood rivers. for both samples the observed values of cod removal by coagulation at lower ph (about1-1.5 ph values less than the regular ph) were about 85-95 percent without making water turbidityunacceptable. in order to determine the effects of organic content on coagulation, synthetic samples were alsoprepared with much higher cod values. again, considerable increases in cod removal have been observedfor most of these samples only by decreasing 0.5-2 ph value. the results indicated that a modifiedcoagulation process without need to much increasing the amount of coagulant can be developed for thesewater samples.