浓度与pH互作下表没食子儿茶素没食子酸脂(EGCG)对黄壤Al、Fe、Mn迁移的影响

Effects of Epigallocatechin Gallate(EGCG)on Migration of Al,Fe and Mn in Yellow Earth Under the Interactions of Concentrations and pH Values

对淋溶环境下黄壤的Al、Fe、Mn浓度进行分析,探讨浓度与pH互作下表没食子儿茶素没食子酸脂(EGCG)对黄壤Al、Fe、Mn迁移的影响。采用二因素四水平完全随机试验,用48个不同浓度和pH组合的EGCG溶液对黄壤进行间歇淋溶,测定淋出液中Al、Fe、Mn浓度,分析黄壤Al、Fe、Mn迁移总量和迁移过程。结果表明,黄壤Al、Fe、Mn迁移总量在浓度与pH互作下均有显著差异;高浓度(5.00mmol/L)高pH(5.5)EGCG溶液有利于Al和Fe的迁移,迁移总量分别为180.24mg/L和41.15mg/L;而EGCG溶液在高浓度(5.00mmol/L)低pH(3.5)时有利于Mn的迁移,其迁移总量为4.50mg/L;Al、Fe、Mn迁移总量在浓度与pH互作下主要表现为Al>Fe>Mn。随着淋溶的进行,淋出液中Al和Mn浓度在中后期(大致在第8次取样后)均逐渐降低;但随着中、高浓度(1.00,5.00mmol/L)高pH(5.5)、高浓度(5.00mmol/L)中pH(4.5)的EGCG溶液淋溶的进行,淋出液Fe浓度先增加后降低;当EGCG浓度与低pH(3.5)互作时,淋出液Fe浓度随淋溶的进行整体呈现明显的升高趋势。EGCG溶液的淋溶对土壤Al/Mn毒的治理有一定效果,且淋溶前期的效果更明显,但EGCG溶液不具备同时经济高效治理土壤Al/Mn毒的优势。

The concentrations of Al,Fe and Mn in Yellow Earth under the leaching environment was analyzed,and the effects of Epigallocatechin Gallate（EGCG）on the migration of Al,Fe and Mn under the interactions of concentrations and pH values.A completely randomized experiment with two factors was carried out,in which 48 EGCG solutions combined from different concentrations and pH values was designed to leach the Yellow Earth discontinuously.The concentrations of Al,Fe and Mn in leaching solutions were measured to analyze the migration volumes and migration processes of Al,Fe and Mn.The results indicated that the migration volumes of Al,Fe and Mn in Yellow Earth varied significantly under the interactions of concentrations and pH values.The EGCG solution with high concentration and high pH value would facilitate the migration of Al and Fe,whose volumes were 180.24mg/L and 41.15mg/L,respectively.However,the EGCG solution with high concentration and low pH value would be conducive to the migration of Mn,whose volume was4.50mg/L.The migration volumes of the three elements under the different interactions of concentrations and pH values followed the order of Al〉Fe〉Mn.Generally speaking,the concentrations of Al and Mn in the leachate decreased gradually in the middle-late leaching stage.However,the Fe concentrations in the leachate first increased and then decreased in the leaching processes,as the EGCG solutions with middle concentration and high pH,high concentration and high pH,and high concentration and middle pH;whilethe Fe concentrations showed a significant rising trend,when the concentrations of EGCG interacted with a lower pH value.It is suggested that the leaching of EGCG has a positive effect on the treatment of soil Al/Mn toxicity in a certain degree,especially at the early stage of leaching.Whereas,EGCG could not be used to control Al/Mn toxicity in soil at the same time.