Comparing the effect of electrochemical process and Alum coagulation in removing turbidity and coliform bacteria from the synthetic wastewater

Background: Nowadays, 1.1 billion people in the world do not have access to a safe and adequate water supply. So, seeking more efficient water treatment methods are a critical need. This study designed to compare the effects of the electrochemical process (EP) and Alum coagulation on turbidity and coliform bacteria removal from the synthetic wastewater (SW). Materials and Methods: This experimental study was conducted on five SW samples in a batch system. First, the optimum Alum dosage and pH were determined by Jar-test. Thereafter, samples were subjected to coagulation and 10 samples were taken before and after the process. The EP was accomplished on each five SW samples. In each run, a 600 mA DC was applied on 1700 ml of SW using aluminum electrodes for 1 hour and one sample was taken every 10 minutes (35 samples). The turbidity and most probably numbers of total coliforms were confirmed and the fecal coliforms as well as the heterotrophic plate count (HPC) were determined for all samples according to the standard methods book instructions (21st edition).Results: The optimum Alum dosage and pH range for coagulation were 16mg/L and 7 pH units, respectively. Using coagulation, the removal efficiencies for the total, confirmed and fecal coliforms were 80.57, 48.89, and 65.59, respectively. Moreover, the removal efficiencies for HPC and turbidity were 89.92 and 91.11, respectively. The EP not only removed 100 of the coliforms, but also reduced both HPC and turbidity to 91.05 and 96.31, respectively. Conclusion: The EP is more effective than Alum coagulation in the removal of turbidity and bacteriological indicators from the synthetic wastewater.