淋溶土柱中铁和锰的运移淀积特征  

Characteristics of iron and manganese migration and deposition in soil columns under leaching condition

作　　者：张斌[1] 阳运秀[1] 刘凡[1] 黄丽[1] 

机构地区：[1]华中农业大学农业部长江中下游耕地保育重点实验室,武汉430070

出　　处：《华中农业大学学报》2015年第2期56-64,共9页Journal of Huazhong Agricultural University

基　　金：国家自然科学基金项目(40971143);教育部博士点基金项目(20110146110027)

摘　　要：以亚热带的棕红壤为装柱材料,用pH3.5不同浓度（0-0.08mol/L）的铁、锰单一或混合溶液淋溶土柱40次,研究在干湿交替和不同淋溶方式（铁、锰同时淋溶或交替淋溶）条件下土壤中铁、锰元素的淋溶迁移特征.结果表明随着淋溶的进行,土柱淋出液的pH 逐渐降低,淋溶40次后淋出液的pH 低于淋溶液的pH,淋出液中铁、锰的含量与淋溶液的相近;淋溶后土壤中铁、锰含量最高的为游离态,其次为非晶质态,最低的为络合态;淋溶后,土柱中铁的淀积量大于锰的淀积量,除络合态铁、锰的含量比较接近外,游离态和非晶质态铁的淀积量都远高于相应形态锰的淀积量.铁、锰同时淋溶处理的土柱中铁的淀积量高于相应交替淋溶的淀积量,而锰的淀积量则为交替淋溶处理的高于同时淋溶的淀积量,且在交替淋溶条件下,淋溶液中锰的浓度越高,土壤中铁的淀积量越大.交换性K^＋ 、Na^＋ 、Ca^2＋ 、Mg^2＋ 随着铁、锰淋溶的进行而淋失,其中Ca^2＋ 、Mg^2＋ 的流失量较大.The mixed or single solution with different Fe-Mn molar concentration(0-0.08 mol/L)with a pH value of 3.5to leach the soil columns of brown red soil for 40 times was used to study the characteristics of iron-manganese migration and deposition in alternating of wet and dry conditions with different leaching ways(simultaneously or alternately).Results showed that the pH of soil column leachate decreased gradually with progress of the leaching.After leaching 40 times,the pH of leachate was lower than that of the leaching solution,while the contents of iron and manganese oxide were similar in leachate and leaching solution.After leaching,iron and manganese oxide in the soil was in the order of the free state>amorphous state>the complex state.The deposition of iron in the soil columns was greater than that of manganese,of which the amount of free state and amorphous state iron were much higher than the corresponding amount of manganese.The content of complex state Fe and Mn were relatively close.Iron deposition amount in soil columns treated with simultaneously iron and manganese leaching were higher than that of the corresponding alternate leaching,while the amounts of manganese deposition were higher than that of iron.In alternate leaching treatments,the higher the concentrations of leaching solution of manganese,the greater the amounts of iron deposition in soils.Exchangeable sodium,potassium,calcium and magnesium ions were lost with the leaching of manganese,among which the lost amounts of calcium and magnesium ions were larger.

关 键 词：棕红壤 淋溶 铁 锰 运移 淀积 

分 类 号：P595[天文地球—地球化学]