Document Type : Original Article

Authors

• Kourosh Rahmani ¹
• Ayat Rahmani ¹
• Seyed Mohammad Reza Seyed Khademi ²
• Yousuf Dadban Shahamat ³
• Kazem Godini ⁴

¹ Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran

² Domestic Water and Wastewater Corporation of Golestan Province, Gorgan, Iran

³ Environmental Health Research Center, Golestan University of Medical Sciences, Gorgan, Iran

⁴ Department of Environmental Health Engineering, Faculty of Health, Ilam University of Medical Sciences, Banganjab Complex, Ilam, Iran

Abstract

Aims: The object of the study was to identify chlorine demand factorsin water and chlorine in Kanbebein City water and eliminating of them. Materials and Methods: Concentration of free and combined residual chlorine with the methods presented in the book "Standard Methods for Water and Wastewater Examination" were measured. Other parameters such as: Temperature, TOC, TDS, pH, EC, nitrate, ammonia, total hardness, alkalinity, iron and manganese were also examined before and after of chlorination. Results: The Highest chlorine decay constant in the short time were in water well was 0.895 mgL ^-1 h ^-1 and the least amount of it was 0.0097 mgL ^-1 h ^-1 and the Highest chlorine decay constant in the long time were in water well was-0.092Lmg ^-1 h ^-1 and the least amount of it was-0.0017 Lmg ^-1 h ^-1 that correlated with nitrite, ammonia and iron concentration. Conclusion: The factors that affected short-time chlorine decay constant (k ₂ ) were nitrite, ammonia and iron and The factors that affected on long-time chlorine decay constant (k ₂ ) were Nitrite, ammonia and iron. The material removal techniques for them were the use of natural resins, zeolite, ion exchange, membrane and aeration methods, oxidation and sedimentation, and filtration.

Keywords

• Chlorination
• Disinfection
• Khanbebin City
• water