有机酸对几种土壤吸附铜的影响

[WT4HZ]EFFECT OF ORGANIC ACIDS ON ABSORPTIVE Cu IN SOIL

在一定离子强度和 p H值下 ,向几种不同的土壤中加入外源有机酸 ,研究有机酸对土壤吸附 Cu2 + 的影响 ,结果表明 :几种土壤对铜的吸附量随着铜浓度的增加而增加 ,但当铜浓度达到一定值时 ,吸附量不再发生变化。几种土壤对铜的最大吸附量的大小顺序为黄棕壤 >砖红壤 >红壤 >赤红壤 ;有机酸对土壤吸附铜既有促进作用 ,又有抑制作用 ,即吸附曲线呈峰型 ;不同有机酸对土壤吸附铜的影响不同 ,其中柠檬酸对吸附的抑制和促进作用都很强烈 ,草酸对吸附的促进作用较弱 ,抑制作用较强 ,而乙酸对吸附所起的作用则与草酸正好相反 ;同种有机酸对不同土壤吸附铜的影响不同。其中三种有机酸对黄棕壤吸附铜的促进作用都很弱 ,而对砖红壤吸附的促进作用则强。

WT5BZ]Effects of organic acid on absorptive Cu in soils is studied on condition that several organic acids being added into the soils under definite ion intensity and pH control. The result shows the amount of Cu absorption in several kinds of soils increases with the increasing of Cu concentration. But it will not change when Cu concentration get to a definite amount. The absorbing amount of Cu among four types of soils is that, Yellow-brown soil>Latosol>Red soil> Latosolic red soil. Organic acid not only stimulates, but also restrains the absorption of Cu in soil. The effect of different organic acids on absorption of Cu is different. The function on both of stimulating and restraining the absorption of Cu by citric acid are stronger than that by oxalic acid. The function on restraint by oxalic acid is strong, but the function on stimulation is weak. The function of acetic acid is contrary to oxalic acid. Same organic acid has different effect on absorption of Cu in different soils. Three kinds of organic acids used in this test has less affection on stimulating the absorption of Cu in Yellow-brown soil than that in Latosol.