Background : The nutrition role of phosporous to macroscopic and microscopic plants is well known. Discharge a source of phosphorous to surface water sources ultimately results in eutrophication. The present study was conducted to determine the effect of electrochemical process on phosphorous removal from activated sludge effluent. Samples were collected from wastewater treatment plant effluent of Kashan University of Medical Science Campus.

Materials and methods : The study was carried out as a bench scale experimental type using batch system and the effects of electrical current, type of electrodes, reaction time and initial characteristics of samples (temperature, pH, and electro conductivity) were investigated. Ineach run, 1500ml secondary effluent was placed in an electrolytic cell equipped with magnetic stirrer. The anode and cathode was each made of 4 pieces of still (or aluminium) 1.5cm apart, which both were submerged in the sample. The total effective area of used electrodes was 336cm² and the input power was controlled by an ammeter and voltmeter. Reduction of total phosphorous to less than 1mg/L-P (as standard) was considered as the desired removal.

Results : The results showed that by increment in direct current and reaction time the phosphorous removal efficiency will increased and the still electrodes are slightly more efficient than aluminum ones. Adjustment of temperature, pH and electroconductivity of samples, each in a special range, improve s the efficacy. To obtain best results the required electrical current density and reaction time are recommended to be in the range of 1.78-3.57 mamp/cm² and 10-30 minutes, respectively.

Conclusion: Electrochemical process by using steel electrode can successfully remove total phosphorous that is remained in activated sludge effluent, of course, there is no need to adjust temperature, pH, and electro conductivity.