In this work, the effect of two different chemical surface treatments in nature, i.e., 35 wt% HCI and K2CO3, of activated carbons on surface and Cr (VI) adsorption rate characteristics were investigated in the different reaction time conditions (1, 10 and 20 h). The acid - and base values were determined by Boehm''s titration technique. And surface properties, including total pore volume, were studied in terms of BET volumetric measurement and Boer''s t-plot equation with N2-adsorption. Also, the Cr (VI) adsorption rate of activated carbons was measured using a UV spectrometer. As an experimental result, it was observed that the net heat of adsorption (E) or BET''s C (CBET) slightly decreases in botyh chemical surface treatments on activated carbons. And an increase in reaciton time led to an increase of the Cr (VI) adsorption rate determined from K1, K2and K3constants. As compared with K1, K2and K3, it was found that K1constant is more effective in the case of acid treatment on activated carbons, which can be resulted from the acid value of activated carbon surfaces. However, basically treated activated carbons were more effective, evaluated on the K2and K3than on the K1in this chemical treatment system, probably due to effect of increasing the specific surface areas of total pore volume of activated carbons.

본 연구에서는 활성탄소를 35 wt% HCI 산성 및 35 wt% K2CO3염기성 용액으로 1, 10, 20 시간 동안 각각 표면처리 하였으며 그에 따른 표면변화 및 크롬 (VI) 흡착속도를 관찰하였다. 활성탄소의 표면 산도는 Boehm의 선택 중화법을 이용하여 측정하였으며, 총 기공부피를 포함한 기공특성은 BET법고 Boer 식을 이용한 N2기체 흡착을 통하여 알아보았다. 또한 활성탄소에 크롬(VI)의 흡착속도는 UV spectrometer를 이용하였다. 그 결과 두가지 용액으로 처리된 활성탄소 모두에서 순 흡착열 (E)와 BET 상수 C (CBET)가 약간씩 감소하는 것을 관찰할 수 있었다. 흡착속도는 처리 시간이 길면 산도 증가의 영향으로 사료된다. 하지만 염기성 용액으로 처리된 활성탄소에서는 K2와 K3가 K1보다 더 우수했으며, 이는 처리에 따른 활성탄소의 비표면적 또는 총 기공 부피의 증가에 의한 영향으로 사료된다.