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

ABSTRACT

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]. 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]. 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. The EP is more effective than Alum coagulation in the removal of turbidity and bacteriological indicators from the synthetic wastewater