Treatment of Al-Dewaniya hospital wastewater by Electrocoagulation method using SS/Fe electrodes.

Abstract

The present study focused on the treatment of hospital wastewater generated from Al-Diwaniya hospital located at Al-Diwaniya city/ southern Iraq via an Electrocoagulation (EC) process with SS/Fe electrodes. Response Surface Methodology (RSM)  was used to evaluate the main effects of parameters, their simultaneous interactions and quadratic effect to achieve the optimum condition for EC process. Chemical Oxygen Demand (COD) was observed and measured for each experiment as it can be used as a good indicator of the quality of wastewater. The impacts of three factors such as current density (5-25mA/cm2), pH (4-10), and addition of NaCl(0-3g/l) were evaluated. The obtained experimental data were fitted to a second-order polynomial equation with analyzing by variance analysis (ANOVA).  The results shown that current density has the major impact on the efficiency of COD removal followed by addition of NaCl while pH has the lower effect on the COD removal under the studied range of pH. ANOVA results showed that the determination coefficient of the models was R2 98.18% confirming that the quadratic model was significance with a good fitting between the experimental and predicted results.  The optimized operating parameters were a current density of 25 mA/cm2, pH of 7.8,and NaCl addition of 3 g/l in which COD removal efficiency of 97.14% was achieved with a specific energy consumption of (30.914) kWh/kgCOD.