黄河、长江、钱塘江水样中胶体对铅吸附络合容量的影响

The Effect of Colloid on Adsorbtive Complexing Capacify of Lead in Huanghe, Changjiang and Qiantangjiang Freshwater

用过滤和切向超滤将黄河、长江和钱塘江的水样分成＜ １ ．０μｍ 、＜ ０ ．４μｍ 和＜ ５０００Ｄａｌｔｏｎ （ 相当于１ ．５ｎｍ 孔径） 三种级分，对铅在不同级分上的吸附络合容量进行了初步探讨。铅在不同级分上的吸附络合容量差别很大，滤膜孔径越小，吸附络合容量越小。的黄河水样真溶液中的配体对铅的键合能力相对较强，而粒级较大的络合能力相对较弱；长江水样较大粒级的配体对铅的键合能力相对较强；钱塘江水样的各粒级配体的键合能力相似。胶体对三种江河水体的吸附络合容量具有很大贡献，黄河水样＜ １ ．０μｍ 的吸附络合容量中，１ ．５ｎｍ ～１ ．０μｍ 的胶体部分的吸附络合容量占总量的８２ ．５ ％ ，其中以０ ．４ ～１ ．０μｍ 大粒径胶体为主；长江和钱塘江水样中１ ．５ｎｍ ～１ ．０μｍ 的胶体部分的吸附络合容量分别达到了总量的５７ ．７ ％ 和５６ ．８ ％ 。

Three fractions of<1.0μm,<0.4μm and <5000Dalton (corresponding to 1.5nm) in Huanghe, Changjiang and Qiantangjiang freshwater were separated by filtration and cross flow ultrafiltration. The adsorptive complexing capacities (A.C.C.) of lead in different fractions were primarily discussed. The A.C.C. of lead in successive filtrates were remarkably different. The smaller the membrane pore was, the smaller the A.C.C. was. The adsorptive capacity of colloids contributed most to the total A.C.C.. The complexing capability of lead with ligands in truly dissolved fraction was relatively stronger than that in larger size fraction for the Huanghe freshwater sample. The complexing capability of lead with ligands in larger size fraction was relatively stronger for the Changjiang freshwater sample. The complexing capabilities of lead with ligands in different size fractions were similar. In the A.C.C. of <1.0μm fraction in Huanghe sample, the A.C.C. of 1.5nm～1.0μm colloid accounted for 82.5% of total A.C.C., that of 0.4～1.0μm colloid was the main contributor, The A.C.C. of 1.5nm～1.0μm colloid in Changjiang and Qiantangjiang samples accounted for 57.7 % and 56.8% of total A.C.C., respectively.