Evaluating efficiency of H₂O₂ on removal of organic matter from drinking water

Abstract

H₂O₂ has been widely used because of intensified pollution of water resources like rivers, lakes, and dams to organic matters and formation of carcinogenic disinfection by-products (DBPs). This study aimed at evaluating the rate of organic matter removal from drinking water by H₂O_2. Water samples were taken from Gharasoo River and effluent of wastewater treatment plant in Farabi hospital. Samples containing humus organic matters (A, B, C, and D) as well as pesticides including Diazinon and 2,4-dichlorophenoxy-acetic acid (2,4-D) were also prepared. Measurements were performed using a spectrophotometer at a wavelength of 253.7 nm. COD decreased as the concentration of H₂O₂ increased in all the samples and maximum removal was observed at the concentration of 10 mg/l of H₂O₂. In the samples containing humus, COD removal rates were also increased by increasing hydrogen peroxide doses with the highest removal rates of 81, 70.9, 65.21, and 62.85% observed for humus A, B, C, and D, respectively. The lowest absorption rate occurred at neutral pH and high correlation coefficient (i.e. R² = 0.92) which was observed between COD removal and absorption rates of organic matter for all the samples. According to the results, it can be concluded that H₂O₂ is an appropriate oxidant for the removal of organic matter from drinking water. On the other hand, COD due to these materials can be estimated through measuring their absorption rates.

Keywords:

• Organic matter
• H₂O₂
• Water treatment
• Drinking water