磷酸盐对纳米TiO_2在土壤中迁移的影响  

Influence of phosphate on the transport of nTiO_2 in soil column

作　　者：刘诚 孙强 张刚 张玥 徐楠 

机构地区：[1]苏州科技大学化学生物与材料工程学院,江苏苏州215009 [2]江苏省环境功能材料重点实验室,江苏苏州215009

出　　处：《苏州科技大学学报（自然科学版）》2018年第3期44-50,共7页Journal of Suzhou University of Science and Technology（Natural Science Edition）

基　　金：国家自然科学基金面上研究项目(21377090)

摘　　要：通过探索不同浓度NaNO_3背景溶液中纳米二氧化钛(nTiO_2)表面Zeta电位的变化,研究有无磷酸盐(P)时,nTiO_2在土壤柱中迁移的规律。结果表明:背景浓度的增加,降低了nTiO_2表面的负电位,而P存在时,nTiO_2表面负电位绝对值增加。因此,nTiO_2在低NaNO_3浓度且P存在时具有较好的稳定性。迁移实验证明P的存在促进了nTiO_2的迁移,且随着NaNO_3浓度增加,nTiO_2在土壤柱中的滞留增强。两点动力学吸附模型很好的模拟了穿透曲线,模型结果表明:P存在时,nTiO_2在位点1处的吸附作用或阻塞效应明显减弱,NaNO_3浓度增加,应变作用增加,从而抑制了nTiO_2在土壤柱中的迁移。The transport behavior of nanoparticles titanium dioxides（nTiO2） in soil column with or without phosphate（P） were investigated in different concentration of NaNO3 electrolyte solutions. The possible mechanism was also studied by analyzing the corresponding zeta potentials of nTiO2 under various conditions. Experimental results show that the zeta potential of nTiO2 becomes more negative with the increase of the ionic concentration（IC）. The negative charge increases with the augment of P. In the presence of P and low NaNO3,nTiO2 takes higher stabilization. The transport experiments suggest that the presence of P favors the transportability of nTiO2 in soil column. In addition,the increase of NaNO3 concentration inhibits the retention of nTiO2. The breakthrough curves（BTCs） of nTiO2 in sand columns can be fitted well with two-site kinetic attachment model. The modeling results suggest that the attachment or blocking of nTiO2 on site 1 is obviously weakened in the presence of P. The straining interaction increases with the increase of the concentration of NaNO3,resulting in the transport compression of nTiO2 particles in soil column.

关 键 词：纳米二氧化钛 ZETA电位 迁移 磷酸盐 

分 类 号：X522[环境科学与工程—环境工程]