欢迎访问《环境科学学报》编辑部网站！

快速检索			高级检索

污染控制技术及原理

摘要：低分子量有机酸是微生物和植物根系分泌物中重要的组成部分.采用浸泡实验比较了4种常见低分子量有机酸(草酸、酒石酸、柠檬酸、苹果酸)对巢湖北岸东部富磷地层中岩源磷的释放量,并对浸提后的部分残渣进行磷的赋存形态分析.结果表明,当有机酸浓度小于5mmol·L^-1时,柠檬酸的释磷量最大;大于5mmol·L^-1时,草酸和酒石酸的释磷量最大,此时释磷量与有机酸的浓度具有一定的线性关系,其增加趋势远大于浓度小于5mmol·L^-1时的增加趋势,而其中草酸和酒石酸又远大于柠檬酸和苹果酸.在有机酸溶液终止pH≥4时,有机酸溶液终止pH与释磷量有较好的线性关系.在50mmol·L^-1相同浓度时,草酸对各赋存形态磷转化作用均最大,酒石酸次之.而4种酸对有机磷释放率最大,均高达97%以上,对闭蓄态磷的释放率最小.

Abstract：Organic acids of low molecular weight are important constituents of microbial and plant root exudates.This study compared the phosphorus (P) release from phosphorus-rich rocks in the eastern section of the north shore of Chaohu.The release of Pwas attributed to four common organic acids of low molecular weight (oxalic,tartaric,citric,and malic acid) which extracted and released rock P.Post-extraction residues were characterized.The results show that when organic acid concentrations were below 5 mmol·L^-1,citric acid extracted the largest amount of P.When organic acid concentrations were above 5 mmol·L^-1,a linear correlation between Prelease and concentrations of organic acids was observed.The amount of Preleased by oxalic acid and tartaric acid far exceeded that by citric and malic acids.Oxalic and tartaric acids maintained the highest efficiency in Pextraction and release.Alinear correlation was identified between Prelease and final pHvalues of the organic acid-containing solutions,when the final pH≥4.When the organic acid concentration was maintained at 50 mmol·L^-1,oxalic acid demonstrated the highest efficiency in Pextraction,followed by tartaric acid.The four organic acids as tested appeared to be the most effective in extracting organic phosphorus (Or-P,release rate up to 97%) and the least effective in extracting Oc-P (occluded phosphorus).