Studying the effectiveness of electric current in removing bacterial contamination Coliformic from Shahrchai river water of Urmia1

Purpose: 

Water disinfection is one of the most important stages of water purification in terms of ensuring the health of consumers. Although common methods in drinking water purification can effectively control microbial factors, the formation of disinfection byproducts has made the process of using these methods a challenge. On the other hand, physical and chemical disinfectants are often limited due to their low efficiency, high price and production of toxic products. In the meantime, one of the methods that has been in the spotlight and developed a lot in recent years is the use of electricity to remove biological pollutants from water. Therefore, the aim of the current research is to study and evaluate the efficiency and effectiveness of the method of establishing the current of electricity in removing the coliform bacteria population in the Shahrchai River of Urmia.

Materials and methods:

 The present research, which is descriptive-cross-sectional, started in a period of six months from February 2018 and continued until July 2019. The water sampling process of Shahrchai River in Urmia was carried out from two stations at the entrance of the No. 1 treatment plant and at the entrance of the Golshahr treatment plant, and the samples were transferred to the laboratory within 2 to 4 hours, and the presence of coliform bacteria was studied and measured by the MPN method. Then, in order to perform the electrolysis test, an electrochemical reactor with a voltage of 220 volts consisting of two electrodes made of iron and aluminum was prepared and the electric current was established for 10, 20, 30 and 70 minutes. Next, the data results were analyzed by SPSS version 21 software.

Findings:

 The results show that the efficiency of coliform bacteria population removal depends on the pollutant source, duration, current intensity and type of electrodes. According to the results, the slope of the curve of changes in the amount of microbial contamination of the samples that were subjected to a constant current of 220 volts for 20 minutes showed a significant decrease. So that the microbial load of most samples was reduced by 50%. Therefore, it can be said that the removal efficiency has a direct relationship with the increase in time, and with the increase in the duration of the electric current in the samples, the removal rate of coliform bacteria also increases significantly.

Conclusion:

 According to the results of this research, the use of the process of establishing the current of electricity is suggested as a suitable method with high efficiency and also compatible with the environment in water disinfection.