Application of LC-OCD for the characterization and removal of NOM in Han River

摘要

LC-OCD which consisted of SEC(Size Exclusion Chromatography) of direct injection mode and high-sensitive organic carbon detector was used to find out the origins and the characteristics of NOM of Paldang raw water and evaluate the NOM removal in conventional water treatment plant. The Paldang raw water from Jul. 2005 to Feb. 2006 showed pedogenic Fulvic Acid characteristic of which origin is soil and those from Mar. 2006 to Jun. 2006 to aquagenic Fulvic Acid characteristic of which origin algae population. The TOC values varied in the range from 1.1 to 2.0 ㎎/L for 1 year. The average percentage of each constituting material groups were 55% for humic substances, 18% for neutral substances, 10% polysaccharides and 0.4% small acids. We could conclude that July seemed to have the highest THMs among disinfection by-products by the analysis of the SUVA and humic substances. The average NOM removal efficiency of coagulation and sedimentation using PAC was 43% and it was the highest value among the water treatment processes. We could confirm that large portion of humic substances including biopolymer which were known as precursor of disinfection by-products and some portions of building blocks and acids could be removed in the coagulation and sedimentation processes. The removal efficiency through the coagulation, sedimentation and following rapid sand filtration was about 10%. BDOC removal efficiencies were in the range from 9 to 20%, which were somewhat low because of short contact time of rapid sand filtration.