基于Hydrus-1D的渭北旱塬塬梁沟壑区土壤中氟化物运移规律的研究

Fluoride Migration Characteristic in Weibei Dry Plateau Soil Based on Hydrus-1D

以陕西渭北旱塬塬梁沟壑区为研究对象,运用Hydrus-1D数值模拟,分析研究区不同初始含水量(θ_(0))情境下土壤中氟化物的运移特征。结果表明:空间上不同θ_(0)下土壤氟化物浓度(CF-)随着深度的增加先增大后减小,365 d之前低θ_(0)下土壤对氟化物的吸附性更大;365 d与1095 d之间低θ_(0)下土壤对氟化物的吸附性更小;时间上不同θ_(0)的土壤CF-变化,前期快速吸附阶段(0~100 d),土壤以淋滤为主,低θ_(0)土壤的吸附能力小;中期吸附衰减阶段(100~365 d),期间土壤对氟化物吸附占主要地位,埋深较浅的土壤(0~2 m)低θ_(0)土壤的吸附能力大;后期吸附稳定阶段(365~10950 d),期间土壤中氟化物浓度降速较小,随着时间的延长,低θ_(0)土壤的吸附能力变大。可见渭北旱塬塬梁沟壑区土壤中CF-受θ_(0)影响,研究区工厂建设应该做好防护层的布置,以防止污染物泄露对土壤产生污染。

In this study,the fluoride migration characteristics in soil under different initial water content(θ_(0))are analyzed by indoor and outdoor experiments and HYDRUS-1D numerical simulation in the beam and gully region of the Weibei dryland,Shanxi Province.The results show that the fluoride concentration(Cf-)in soil increased first and then decreased with the increase of depth in different soils in space,and the adsorption of fluoride in low θ_(0) soil was greater before 365 days.Between 365 d and 1095 d,the adsorption of fluoride to the soil at low θ_(0) was smaller.In the early stage of rapid adsorption(0~100 d),the soil was mainly leached,and the adsorption capacity of low θ_(0) was small.In the middle phase of adsorption decay(100~365 d),the fluoride adsorption of soil was dominant,and the adsorption capacity of low θ_(0) with shallow burial depth(0~2 m)was high.In the later stable adsorption stage(365~10950 d),the decrease rate of fluoride concentration in the soil was small,and the adsorption capacity of the low θ_(0) increased with the extension of time.The θ_(0) has effect on CF-in the soil in the Weibei dry plateau.It is necessary to arrange the protective layer in the early stage and monitor it in the later stage in the study of plant construction in the district,so as to prevent soil pollution caused by pollutant leakage.