논문 상세보기
pp.73-81
Adsorption process using granular activated carbon(GAC) has been considered as one of the most effective water treatment technologies to remove humic acid which is recognized as trihalomethane(THM) precursor in chlorination. To design the most effective GAC process, it is necessary to conduct the test of adsorption performance by means of isothem, batch rate and column studies and to select the most effective activated carbon according to raw materials of GAC-lignite and coconut shell. The objective of this study is to investigate the adsorption performance of humic acid on two activated carbons- lignite activated carbon(LAC) and coconut shell activated carbon(CAC) made in Korea. It is available to represent UV-abs and trihalomethane formation potential(THMFP) as concentration of humic acid due to good relationship. The adsorption capacity of humic acid is not concerned with surface area of activated carbon but with pore size related to about 100 A, and then LAC forming at the extent of mesopore is found to be eight times more effective in adsorption capacity than CAC forming at micropore. The adsorption capacity of LAC and CAC is better at pH 5.5 than at pH 7. Pore and surface diffusion coefficients calculated from the diffusion model are 7.61×10 exp (13)㎡/sec, 3.52×10 exp(-15) ㎡/sec for CAC, and 3.38×10 exp (-12)㎡/sec and Ds=1.48×10 exp (-15)㎡/sec for GAC respectively. From the results of column test it shows that the performance of LAC is also better than CAC and the optimal EBCT(Empty Bed Contact Time) is 4.52min. and activated carbon removes selectively the components of humic acid to be easily formed to THM.
