Okawa Kiyokazu, Suzuki Kazuyoshi, Takeshita Toshihiro, Nakano Katsuyuki
Institute for Recycling and Environmental Control System, Fukuoka University, 10 Koyocho, Wakamatsu-ku, Kitakyushu 808 0002, Japan.
Water Res. 2007 Mar;41(5):1045-51. doi: 10.1016/j.watres.2006.10.032. Epub 2007 Jan 16.
The objective of this study is to clarify the regeneration of granular activated carbon (GAC) adsorbed trichloroethylene (TCE) using wet peroxide oxidation (WPO). TCE and TOC concentrations decreased during WPO, whereas Cl(-) accumulated in water indicating that TCE was not only decomposed but was also mineralized to Cl(-) and CO(2) using WPO. Regeneration efficiencies (q/q(0)) of GAC regenerated at 150, 165 and 180 degrees C (initial pH 4) were 0.36, 0.45, 0.48, respectively. In addition, regeneration efficiencies of GAC regenerated in the solution of various initial pH (2.5, 3.0, 4.0) at 180 degrees C were 0.71, 0.60, 0.48, respectively. These results suggest that regeneration of GAC is more effective at higher reaction temperature and lower initial pH of the solution. In the repeated regeneration of GAC, the adsorption capacity of GAC for TCE gradually decreased and regeneration efficiency of the regenerated GAC at sixth step was 0.40. The adsorption capacity loss of regenerated GAC is probably due to oxidation of GAC during WPO.
本研究的目的是阐明使用湿式过氧化氢氧化法(WPO)对颗粒活性炭(GAC)吸附的三氯乙烯(TCE)进行再生。在WPO过程中,TCE和总有机碳(TOC)浓度降低,而Cl(-)在水中积累,这表明TCE不仅被分解,而且还通过WPO被矿化为Cl(-)和CO(2)。在150、165和180℃(初始pH值为4)下再生的GAC的再生效率(q/q(0))分别为0.36、0.45、0.48。此外,在180℃下于各种初始pH值(2.5、3.0、4.0)的溶液中再生的GAC的再生效率分别为0.71、0.60、0.48。这些结果表明,在较高的反应温度和较低的溶液初始pH值下,GAC的再生更有效。在GAC的重复再生过程中,GAC对TCE的吸附容量逐渐降低,并且在第六步再生的GAC的再生效率为0.40。再生GAC的吸附容量损失可能是由于WPO过程中GAC被氧化。