Investigating the optimal amount of chlorine consumption in the disinfection of the effluent of the Arak sewage treatment plant

Since chlorine is a highly toxic substance, if it is combined with organic elements in the wastewater, it causes the creation of odorous compounds and causes the creation of byproducts in the wastewater, and some of them are known as carcinogenic compounds. There are special parameters related to the use of chlorine for the treatment of waste materials and it can be said with certainty that the use of chlorine increases with the increase in the amount of BOD in the waste materials and changes along with the changes in the amount of BOD. Therefore, this research has tried to find the optimal amount of chlorine consumption, which is effective in disinfection and production of trihalomethanes, by conducting tests on several parameters of the effluent samples in different seasons of the year, including (temperature, pH, COD, BOD, total coliform and human excreta coliform, etc.) should be checked. Therefore, Arak Arak-activated sludge wastewater treatment plant was selected as a pilot. Then the results of the research using statistical methods (Pearson's correlation) showed that the amount of chlorine consumption in different seasons of the year changed with the change of weather conditions and microbial load, and in hot seasons chlorine consumption increased and in cold seasons it decreased and the amount of chlorine consumption It has a strong correlation and a significant relationship with the amount of coliform, and in this research, the optimal point of chlorine consumption was at the highest amount of coliform in the range between 15,000-20,000 kg.