Department of Soil Science, College of Agriculture, Bu-Ali Sina University, Azadegan Street, Hamadan 65174, Iran.
J Environ Manage. 2012 Sep 30;107:147-58. doi: 10.1016/j.jenvman.2012.04.007. Epub 2012 May 29.
This study was carried out to investigate the transport of Escherichia coli NAR and bromide (Br) through repacked (R) and weathered (W) soil columns. A suspension containing E. coli NAR and Br were leached and the effluent from the weathered soil columns had greater contaminant concentrations than that from the repacked soil columns. The time to the concentration peak of (C(max)) E. coli NAR and Br increased in the order CL-W < SL-W < SL-R < CL-R. The breakthrough sequence suggests the formation of a heterogeneous soil pore network induced by weathering and the importance of accelerated flow in the weathered columns. The dual-permeability model in HYDRUS-1D software was used to simulate the E. coli NAR and Br transport parameters by inverse modeling. Parameters of the attachment-detachment model were calculated using the dual-permeability model parameters fitted to the BTCs of E. coli NAR. A greater attachment coefficient associated with soil repacking and the finer textured clayey soil demonstrated the importance of adsorbent site and smaller pore spacing in these treatments. Smaller attachment and adsorption isotherm coefficients in weathered soil columns suggest the need for further research to validate this as a predictive model for the risks for vadose zone contaminant transport.
本研究旨在探讨大肠杆菌 NAR 和溴化物（Br）在重新包装（R）和风化（W）土壤柱中的迁移。含有大肠杆菌 NAR 和 Br 的悬浮液被淋滤，风化土壤柱的流出物的污染物浓度大于重新包装土壤柱的流出物。大肠杆菌 NAR 和 Br 的浓度峰值（C（max））的到达时间按 CL-W < SL-W < SL-R < CL-R 的顺序增加。突破顺序表明风化引起的非均相土壤孔隙网络的形成以及风化柱中加速流动的重要性。HYDRUS-1D 软件中的双重渗透率模型通过反演建模用于模拟大肠杆菌 NAR 和 Br 的传输参数。使用双重渗透率模型参数计算附着-脱附模型的参数，这些参数拟合了大肠杆菌 NAR 的 BTC。与土壤重新包装和质地更细的粘性土壤相关的更大附着系数表明，在这些处理中，吸附剂位和更小的孔径间距很重要。风化土壤柱中较小的附着和吸附等温线系数表明需要进一步研究来验证这是一个预测模型，用于预测包气带污染物迁移的风险。
