纳米TiO_2对土壤水分运动及离子迁移过程影响的试验研究  

Experimental Study on Effects of Nano TiO_2 on Water Movement,Solute Transport in Soil Columns

作　　者：吕金榜[1] 周蓓蓓[1] 王全九[1] 胡梓超 潘二恒 

机构地区：[1]西安理工大学水利水电学院西北旱区生态水利工程国家重点实验室培育基地,西安710048

出　　处：《水土保持研究》2015年第5期58-61,66,共5页Research of Soil and Water Conservation

基　　金：国家自然科学基金重点项目(51239009);国家自然科学基金面上项目(41371239);陕西省科技支撑项目(2013KJXX-38);陕西省水利专项支撑计划(2012slkj-04;2013Slkj-04);陕西省自然科学基金(2015JQ5161)

摘　　要：为了研究纳米TiO2对土壤水分养分运动及重金属吸附过程的影响,基于室内一维垂直定水头土柱试验,采用扰动黄绵土均匀添加不同含量纳米TiO2作为研究对象(质量含量分别为0,0.001,0.005,0.01,0.05g/g),分别测定土壤累积入渗量曲线、水分特征曲线、溶质穿透曲线及重金属等温吸附曲线。结果表明:(1)纳米TiO2对土壤水分入渗过程产生阻碍作用,入渗率随着纳米TiO2含量增加而减小;(2)纳米TiO2可以提高土壤的持水能力,随着纳米TiO2含量增加,相同土壤水吸力下的土壤含水量增大,进气吸力(α)随纳米TiO2含量增加而增大,形状参数(n)随之减小;(3)纳米TiO2可以有效提高土壤吸持惰性离子能力,随纳米TiO2含量增加,初始穿透时间提前,完全穿透时间延长,弥散度增大。(4)相同平衡浓度,随着纳米TiO2含量的增加,Cu2+吸附量加大。采用Langmuir方程拟合Cu2+等温吸附曲线,最大吸附量(Sm)随着纳米TiO2含量增加而增大。研究可为改善黄绵土保水保肥性及重金属污染的治理提供理论依据。Based on disturbed one-dimensional loessial soil columns,we studied the effects of different nano TiO2contents（0g/g,0.001g/g,0.005g/g,0.01g/g and 0.05g/g）on water movement,solute transport as well as metal adsorption.Cumulative infiltration,the moisture characteristic curves,solute breakthrough curves and isothermal adsorption curve of heavy metals were measured separately during the experimental process.The main results were showed as follows.（1）The nano TiO2 inhibited the process of soil water infiltration and the infiltration rate decreased with the increase of nano TiO2 contents.（2）Nano TiO2 can improve the water-holding capacity of soil,while under the same soil water suction,soil water contents and the inlet suction（α）increased with the increase of nano TiO2 contents,but the shape parameter（n）decreased.（3）Nano TiO2 improved soil solute holding ability effectively;with the increase of nano TiO2 contents,initial penetration time advanced and the dispersivity increased,but the breakthrough time prolonged.（4）With respect to the same equilibrium concentration,the Cu^2＋adsorption quantity increased with the increase of nano TiO2 contents.Cu^2＋isothermal adsorption curves could be described by the Langmuir equation,and it was found that the maximum adsorption（Sm）increased with the increase of TiO2 contents.These results could provide the theoretical basis for the improvement of soil water and nutrient capacity as well as heavy metal pollution control.

关 键 词：纳米TIO2 土壤入渗 水分特征曲线 溶质穿透曲线 等温吸附曲线 

分 类 号：S152[农业科学—土壤学]