Drinking water softening with electrocoagulation process: Influence of direct and alternating currents as inductive with different arrangement rod electrodes and polarity inverter

Document Type : Research Note


1 - Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran - Center for Solid Waste Research, Institute for Environmental Research, Tehran University of Medical Sciences, Tehran, Iran

2 - Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran - Center for Water Quality Research (CWQR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran

3 Department of Toxicology and Pharmacology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran

4 Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran

5 Environmental Health Engineering Research Center, Kerman University of Medical Sciences, Kerman, Iran


Electrocoagulation process with direct and alternative current as inductive by using Fe and Al rods with different arrangements and polarity inverter and the factors related to the efficacy of the process. EC process efficacy was investigated in a batch mode under different conditions. Also the amount of energy and electrode consumption and the amount of sludge produced were determined. The highest efficiency of decreasing total hardness (98.26%) and calcium hardness (87.69%) was obtained by using alternative current with Fe-Al electrode arrangement under optimal conditions (pH of 9, current density of 9 mA/cm2 and reaction time of 12 min). Optimum charge loading was 0.54 F/m3. The maximum energy and electrode were consumed in optimum current density by using direct current, which was 2.47 kwh/m3 and 2.12 kg/m3, respectively. The maximum sludge production was in optimum current density by using alternative current of 0.098 kg/m3 and with the settleability of 0.075 L/g and by using direct current with disposing capacity of 0.063 L/g. This study showed that EC technology by using alternative current and using Fe electrodes can be used as an alternative and new method for decreasing water hardness with high efficiency and low energy consumption.


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