Reduction by enhanced coagulation of dissolved organic nitrogen as a precursor of N-nitrosodimethylamine
Phanawan Tongchang, Jindalak Kumsuvan, Warangkana Na Phatthalung, Chaisri Suksaroj, Aunnop Wongrueng, Charongpun Musikavong
Journal of Environmental Science and Health Part A · 2018
Raw water from the Banglen (BL) water treatment plant (WTP) and Bangkhen (BK) WTP in central Thailand and Hatyai (HY) WTP in southern Thailand was investigated for dissolved organic nitrogen (DON) reduction. The DON(mg N/L) and the dissolved organic carbon (DOC)/DON ratio were 0.34 and 21, 0.24 and 18, and 1.12 and 3 for the raw waters from BL, BK, and HY WTPs, respectively. Polyaluminum chloride (PACl) dosages of 150, 80, and 40 mg/L at pH 7 were the optimal coagulation conditions for the raw waters from BL, BK, and HY WTPs, respectively, and could reduce DON by 50%, 42%, and 42%, respectively. PACl and powder activated carbon (PAC, both in mg/L) at 150 and 20, 80 and 20, and 40 and 60 could reduce DON in the raw waters from BL, BK, and HY WTPs by 71%, 67%, and 29%, respectively. DOC/DON values of water treated with PACl were similar to those of raw water. DOC/DON values of water treated with PACl and PAC were lower than those of raw water. N-nitrosodimethylamine (NDMA) formation potentials of raw water, water treated with PACl, or both PACl and PAC, and organic fractions of BL, BK, and HY WTPs were below the detection limits of 542 and 237 ng/L, respectively. Reductions in fluorescence intensities of tryptophan-like substances at peaks 240/350 and 280/350 (nmEx/nmEm) were moderately (correlation coefficient, R = 0.85 and 0.86) and fairly (R = 0.59, 0.67, and 0.75) correlated with DON reduction.
Reduction by enhanced coagulation of dissolved organic nitrogen as a precursor of N-nitrosodimethylamine Part A Toxic/hazardous substances & environmental engineering
Phanawan Tongchang, Jindalak Kumsuvan, Warangkana Na Phatthalung, Chaisri Suksaroj, Aunnop Wongrueng, Charongpun Musikavong
Journal of Environmental Science and Health Part A Environmental Science and Engineering and Toxicology · 2018
Raw water from the Banglen (BL) water treatment plant (WTP) and Bangkhen (BK) WTP in central Thailand and Hatyai (HY) WTP in southern Thailand was investigated for dissolved organic nitrogen (DON) reduction. The DON(mg N/L) and the dissolved organic carbon (DOC)/DON ratio were 0.34 and 21, 0.24 and 18, and 1.12 and 3 for the raw waters from BL, BK, and HY WTPs, respectively. Polyaluminum chloride (PACl) dosages of 150, 80, and 40 mg/L at pH 7 were the optimal coagulation conditions for the raw waters from BL, BK, and HY WTPs, respectively, and could reduce DON by 50%, 42%, and 42%, respectively. PACl and powder activated carbon (PAC, both in mg/L) at 150 and 20, 80 and 20, and 40 and 60 could reduce DON in the raw waters from BL, BK, and HY WTPs by 71%, 67%, and 29%, respectively. DOC/DON values of water treated with PACl were similar to those of raw water. DOC/DON values of water treated with PACl and PAC were lower than those of raw water. N-nitrosodimethylamine (NDMA) formation potentials of raw water, water treated with PACl, or both PACl and PAC, and organic fractions of BL, BK, and HY WTPs were below the detection limits of 542 and 237 ng/L, respectively. Reductions in fluorescence intensities of tryptophan-like substances at peaks 240/350 and 280/350 (nmEₓ/nmEₘ) were moderately (correlation coefficient, R = 0.85 and 0.86) and fairly (R = 0.59, 0.67, and 0.75) correlated with DON reduction.
Relationships between Trihalomethane Formation Potential and Surrogate Parameters for Dissolved Organic Matter in Reservoir Water and Treated Wastewater in Thailand
Charongpun Musikavong
Asia-Pacific Journal of Science and Technology · 2017
Relationships between trihalomethane formation potential (THMFP) and dissolved organic matter (DOM) surrogate parameters including dissolved organic carbon (DOC), ultraviolet adsorption at wavelength 254 nm (UV-254) and specific ultraviolet adsorption (SUVA) were investigated from six water sources in Thailand. Five raw water supply sources were Mae-Hia Reservoir, Aung-Keaw Reservoir, Mae-Kuang Reservoir in Chaing Mai province, the Bhumibol Dam Reservoir in Tak Province, and the Northern-Region Industrial Estate Reservoir in Lamphun province, Thailand. One treated wastewater was effluent water from the central wastewater treatment plant of the Northern-Region Industrial Estate. The coagulation process was utilized to remove DOM from all water samples. In the case of raw water, coagulated water, hydrophobic organic fraction and hydrophilic organic fraction of reservoir water, moderate correlations were obtained from relationships between THMFP and DOC, (R2 of 0.83) and between THMFP and UV-254 (R2 of 0.77). Correlations were significant at the 0.01 level. A poor correlation was obtained from relationship between THMFP and SUVA (R2 of 0.34). The fitting equation for predicting THMFP in reservoir water and its coagulated water could be expressed as follows: THMFP ( g/L) = 73.67DOC (mg/L) + 86.8. In case of treated wastewater and its coagulated water, moderate correlation (R2 of 0.84), good correlation (R2 = 0.96) and moderate correlation (R2 of 0.81) were observed from relationships between THMFP and DOC, THMFP and UV-254, and between THMFP and SUVA, respectively. Correlations were significant at the 0.01 level. The appropriate equation for predicting THMFP in treated wastewater and its coagulated water could be expressed as follows: THMFP ( g/L) = 813.3DOC (mg/L) + 310. In conclusion, DOC and UV-254, therefore, moderately correlated with THMFP in both reservoir water and treated wastewater. SUVA moderately correlated with THMFP in treated wastewater; however, it did not relate to THMFP in reservoir water in Thailand.