مقایسه روش انعقاد با پلی آلومینیوم کلراید سیلیکاته و فرآیند الکتروکواگولاسیون در حذف سختی از آب شرب

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 Çhloride (PÂSÏD) method and Ëlectrocoagulation (ËÇ) Process in removing hardness from drinking water. Materials and methods: This study was carried out in coagulant drinking water of Ghochan (Northeast of Ïran) during winter 2009 and spring 2010. Jar test was used to investigate the effects of the Hardness, Turbidity, pH, residual aluminum on ËÇ and PÂSÏÇ. The efficacy of each method was analyzed using Çovariance and Regression analyses. Results: The results demonstrate that PÂSÏÇ coagulation was capable of removing 75% of hardness and 95% of turbidity at optimum concentration of 1-5 (mg/L) in raw water. The ËÇ process was able to remove 97% of hardness and 50% of turbidity. The maximum percentage of hardness was seen at 30 volt Voltage, residual time of 60 min and pH=6.5-7.5. Çonclusion: Ït seems that both methods were efficient and cost-effective in removing of hardness and turbidity from surface water and can be used in coagulant drinking water.