Determination and Characterization on the Capacity of Humic Acid for the Reduction of Divalent Mercury
For understanding the capacity of humic acid (HA) for mercury (Hg2+) reduction,chemical reduction capacity (CRC),microbial reduction capacity (MRC) and native reduction capacity (NRC) by three types of HAs extracted from various sources (SH,TJ and JY) were measured respectively,following the different pre-reduction including chemical,microbial and control treatments.Three electron acceptors including mercuric chloride (HgCl2),mercuric nitrate (Hg(NO3)3) and ferric citrate (FeCit) as a reference were adapted respectively based on the Fe3+ reduction method.The principal results indicated that:(1) the capacity of HA for the reduction of Hg were significantly affected by various electron acceptors,with the RC values obtained under FeCit condition being all greatly higher than those in conditions of Hg(NO3)2 and HgCI2,which suggested that the RC obtained using Fe3+ reduction method could exaggerate the real capacity of HA for the reduction of Hg2+; (2) significant differences existed for the reduction capacity of Hg2+ by different HAs,with those of JY being the highest,which were (0.95±0.03) mmolc.mol-1 (NRC),(5.95±0.63) mmolc·mol-1 (CRC) and (6.26±0.51) mmolc.mol-1 (MRC) respectively; (3) HA in solution status had approximately 100%-691.67% higher reduction capacity than those as solid status.Meanwhile,through comparison of the differences among three RC indices,higher CRC and MRC values than NRC were observed,but no evidently difference between CRC and MRC was concluded.Thus,CRC may not be applicable to comprehensively represent the real reduction capacity of HA for Hg reduction under microbial condition.
Humic acid Electron acceptor Mercury Reduction capacity Native reduction capacity Chemical reduction capacity Microbial reduction capacity
Tao Jiang Shiqiang Wei Xuemei Li Song Lu Meijie Li
Chongqing Key Laboratory of Agricultural Resources and Environment,Chongqing 400715,China;College of Chongqing Key Laboratory of Agricultural Resources and Environment,Chongqing 400715,China Department of Applied Chemistry,Chongqing Vocational Chemical and Industry School,Chongqing 400020,C
国际会议
the 16th Meeting of the International Humic Substances Society (第十六届国际腐殖物质学会大会(IHSS 16))
杭州
英文
388-391
2012-09-09（万方平台首次上网日期，不代表论文的发表时间）