Investigation of the seventh profile of the trihalometan potential in Ulutan Dam drinking water treatment plants

In this study, seasonal variation of trihalomethane formation concentrations resulted from chlorination of surface waters containing natural organic matter is investigated. Also, Ulutan Dam in Zongudak was used as a study area in this study. First of all, the analyzes of total organic carbon (TOC), UV absorbance at 254 nm wavelength (UV254) and Specific UV Absorbance (SUVA) known as surrogate parameters for organic matters have been performed at Ulutan Dam water samples in four seasons, respectively. Accordingly, the amount of TOC was 5.37 mg / L to 4.84 mg / L, the UV254 values were 0.16 to 0.118 cm-1, and accordingly the SUVA values were 3.26 L / mg.m to 2.27 L / mg.m. On the other hand, the highest THMOP value (349.89 µg / L) was measured in winter and the lowest THMOP (214.36 µg / L) was determined in summer as a result of chlorination of Ulutan dam water samples. In other words; The result of chlorination of water samples containing hydrophobic DOM with the highest SUVA value (3.26 L / mg.m). In contrast, the lowest THMOP (214.36 µg / L) was the result of chlorination of water samples containing hydrophilic DOM with the lowest SUVA value (2.27 L / mg.m). Coagulation experiments in the laboratory, the highest TOC removal was investigated by using THM and TOC removal by using Aluminum sulphate (Alum) (Al2(SO4)3) and Polyaluminium chloride (PAC) coagulants. The highest TOC removal of water samples from alum was decreased from 4.9mg / L to 2.11 mg / L in winter and UV254 value from 0.16 mg / L to 0.068 mg / L in winter. The TOC removal efficiency was 56% and UV254 removal was 57.5%. Based on these results, the remitted THMOP rates (57%) were highest in the dose of alum (100 mg / L) and in winter, while the lowest THMOP removal (41.21%) was observed in the same alum dose in autumn. In PAC coagulant samples, the highest TOC removal was decreased from 5.37 mg / L to 3.99 mg / l in winter and the UV254 value decreased from 0.122 mg / L to 0.079 mg / L. The TOC removal efficiency was calculated as 41% and UV254 removal as 51%. Based on these results, THMOP rates (46.82%) were highest in alum (100 mg / L) and in winter, while the lowest THMOP removal (32.38%) was in autumn. One of the most important results obtained in this study is that the highest THMOP value is seen as a result of chlorination of hydrophobic organics, but it is revealed that lower concentrations of THM are formed as a result of chlorination of hydrophilic organics.