Alternative Chemical Treatments of Raw Water for Production the Drinking Water in Baghdad City


We found that the specification of raw water for Tigris river in Baghdad city ( approximately from the midpoint of water stream in the city ) was a good and need no effective treatments because the main pollutants are the turbidity and Total Suspended Solids (TSS) which represent the major pollutants only. These could be treated efficiently through the use of the new chemical treatment other than the alum and producing a large quantity of drinking water with high quality. The work included the collection and analysis of raw water samples from Tigris river during the first six months of 2011 at Alwahda project laboratories and our laboratories in university of technology . analysis results for raw water during this period showed that a number of determinants were within the acceptable range of the Iraqi drinking water specification ( especially the Total Hardness TH , 260 – 500 mg / l ; Alkalinity , 150 – 170 mg / l as CaCO3 and Total Dissolved Solids TDS , less than 800 mg / l) . The Turbidity and Total Suspended Solids ( TSS ) were not within acceptable values of Iraqi specification for drinking water and ranged between 14 -180 NTU and 27 – 362 mg / l respectively . We have used in our study a group of coagulant agents and flocculents like ferric chloride , wood ash and also the new manufactured organic compounds named ( XX-1 and poly XX-1 ) which have a good affinity to the heavy metals . The results showed that treatment the alum with ferric chloride at concentrations of 8 mg / l and 4 mg / l respectively and treatment with ferric chloride in concentration 8 mg /l were the best in decreasing the turbidity and TSS .The treatment with ferric chloride and the mixture of XX-1 and Ash gave negative results .The results showed the ability of synthetic organic XX-1 to remove the heavy metals from raw water , but have less ability to reduce the turbidity and TSS . It also observed the effect of ash in decreasing the turbidity and suspended solids when used with a alum .The clearness time was reduced to less than one hour after treatment with ferric chloride compared with alum (that use in Alwahda project ) . The results showed high efficiency for ferric chloride in reducing microbial contaminants especially the Total Viable Count (TVC) and coliform viable count . The effect of ferric chloride was started from 10 mg / l compared with the alum treatment . Microbial contamination decreased about 4 log by using 20 mg / l of ferric chloride to become 102 cell / 100 ml compared with the alum treatment (106 cell / 100 ml )