مقايسه روش انعقاد با پلي آلومينيوم كلرايد سيليكاته و فرآيند الكتروكواگولاسيون در حذف سختي از آب شيرين

A Comparison of Polyaluminum Silicate Chloride and Electrocoagulation Process to Removing Hardness from Drinking Water

Background and purpose: Hard water causes many problems in domestic and industrial usage. There are various techniques for removal of water hardness each with its own special advantages and disadvantages. The purpose of this study was to compare Polyaluminum Silicate Chloride (PASIC) method and Electrocoagulation (EC) Process in removing hardness from drinking water. Materials and methods: This study was carried out in coagulant drinking water of Ghouchan (Northeast of Iran) during winter 2009 to spring 2010. Jar test was used to investigate the effects of the hardness, turbidity, pH, residual aluminum on EC and PASIC. The efficacy of each method was analyzed using Covariance and Regression analyses. Results: The results demonstrate that PASIC coagulation was capable of removing 75% of hardness and 95% of turbidity at optimum concentration of 1-5 (mg/L) in raw water. The EC process was able to remove 97% of hardness and 50% of turbidity. The maximum percentage of hardness was seen at 30 volt, residual time of 60 min and pH=6.5-7.5. Conclusion: It seems that both methods were efficient and cost-effective in removing hardness and turbidity from surface water and can be used in coagulant drinking water.