节点文献
镍污染场地抽出-处理数值模拟及渗透系数对修复效果影响
Numerical simulation of pump-and-treat of nickel contaminated site and influence of permeability coefficient on remediation effect
【摘要】 为研究污染场地渗透系数对抽出-处理效果的影响,以某镍(Ni)污染场地为例,构建了二维均质非稳定地下水流模型,并基于该模型进行考虑溶质对流、弥散、吸附的抽出-处理模拟,研究了不同含水介质及抽水流量对修复效果的影响.结果表明:水动力模型模拟结果与场地实测地下水水位基本吻合,均方根误差为0.006 m,模型可以较好地刻画场地地下水流场.通过对比3处抽水井位置下Ni的修复效果,认为3个方案中抽水井位于污染羽中心的方案最佳.在相同抽水流量下,渗透系数越大,地下水监测站点GW1处Ni浓度越高,GW2处Ni浓度越低,但污染羽面积也越大.当含水层为黄土或粉砂时,若抽水流量为40 m~3/d, GW1和GW2两处Ni浓度无法降低至0.1 mg/L,若抽水流量为80 m~3/d或120 m~3/d,则GW1和GW2两处在3 a内Ni浓度可以降低至0.1 mg/L.当含水层为细砂时,GW1处Ni浓度在3种抽水流量场景下均无法降低至0.1 mg/L,而GW2处Ni浓度在3 a内均能满足地下水Ⅳ类水质标准.相同水文地质条件下,抽水流量越大,达到地下水Ⅳ类水质标准的时间越短,但抽水总量越大.研究结果可为污染场地地下水抽出-处理实施的可行性提供一定的科学依据.
【Abstract】 To study the influence of permeability coefficient on the pump-and-treat effect in contaminated sites, a two-dimensional homogeneous and unsteady groundwater flow model is constructed taking a nickel(Ni) contaminated site as an example. The model considers solute advection, dispersion and adsorption in simulating the pump-and-treat process to study the impact of different aquifer media and pumping rates on remediation effect. The results indicate that hydrodynamic model simulation result closely matches the measured groundwater level at the site, with a root mean square error of 0.006 m, demonstrating the model′s ability to depict the groundwater flow field at the site effectively. Comparative analysis of the remediation effects of Ni at three pumping well locations suggests that the scheme positioning the pumping well at the center of the contaminant plume is the most optimal among the three schemes. With the same pumping rate, higher permeability coefficients correspond to higher Ni concentrations at groundwater monitoring site GW1, lower Ni concentrations at GW2, yet with a larger contaminant plume area. For aquifers of loess or silty sand, if the pumping rate is 40 m~3/d, Ni concentrations at GW1 and GW2 cannot be reduced to 0.1 mg/L. However, at pumping rates of 80 m~3/d or 120 m~3/d, Ni concentrations at both GW1 and GW2 can decrease to 0.1 mg/L within three years. In the case of a fine sand aquifer, Ni concentrations at GW1 cannot decrease to 0.1 mg/L under any of the three pumping rates scenarios, while at GW2 Ni concentrations can meet Class Ⅳ groundwater quality standards within three years. Under similar hydrogeological conditions, higher pumping rates lead to a shorter duration to achieve Class Ⅳ groundwater quality standards, but result in a larger total volume of pumped water. The research findings provide scientific insights into the feasibility of implementing pump-and-treat for remediating groundwater in contaminated sites.
【Key words】 pump-and-treat; permeability coefficient; numerical simulation; remediation effect;
- 【文献出处】 大连理工大学学报 ,Journal of Dalian University of Technology , 编辑部邮箱 ,2025年01期
- 【分类号】X523
- 【下载频次】26