School of Metallurgy and Environment, Central South University, Changsha, 410083, Hunan, China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Institute of Environmental Engineering, Central South University, Changsha, 410083, Hunan, China.
School of Metallurgy and Environment, Central South University, Changsha, 410083, Hunan, China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Institute of Environmental Engineering, Central South University, Changsha, 410083, Hunan, China; Hunan Chemical Geological Engineering Exploration Institute Co., Ltd., Changsha, 410004, Hunan, China.
Environ Pollut. 2022 Nov 1;312:119953. doi: 10.1016/j.envpol.2022.119953. Epub 2022 Aug 23.
Since lead, cadmium and arsenic have completely opposite chemical behaviors, it is very difficult to stabilize all these three heavy metals simultaneously. Herein, a novel iron-doped hydroxyapatite composite (Fe-HAP) was developed via an ultrasonic-assisted microwave hydrothermal method for the simultaneous remediation of lead-, cadmium-, and arsenic-co-contaminated soil in Hunan Province, South China. Using DTPA/sodium bicarbonate extractant to extract bioavailable Pb, Cd and As in soil after Fe-HAP remediation for 60 days, the immobilization efficiencies were 79.77%, 51.3% and 37.5% for Pb, Cd and As, respectively. The soil extractable and exchangeable fractions of Pb, Cd and As decreased significantly. In batch experiments, the adsorption kinetics of Pb, Cd and As on Fe-HAP were well described by pseudo-second-order models, indicating that the adsorption is controlled by chemisorption. In the Langmuir adsorption isotherm, the maximum adsorption capacities of Cd and As(V) were 476.2 mg g and 195.69 mg g, respectively, while Pb fit the Freundlich model better. The XRD, SEM and XPS analyses indicated that Fe-HAP formed stable minerals of Pb(PO)OH, Cd(PO)·4HO, Cd(OH) and Fe(AsO)·6HO with Pb, Cd and As. Overall, its facile and efficient immobilization performance indicate that Fe-HAP has potential for practical applications in integrative remediation of Pb-, Cd-, and As- co-contaminated soil.
由于铅、镉和砷具有完全相反的化学行为，因此同时稳定这三种重金属是非常困难的。在此，通过超声辅助微波水热法开发了一种新型铁掺杂羟基磷灰石复合材料（Fe-HAP），用于同时修复华南湖南省受铅、镉和砷复合污染的土壤。使用 DTPA/碳酸氢钠提取剂提取 Fe-HAP 修复 60 天后土壤中生物有效态 Pb、Cd 和 As，Pb、Cd 和 As 的固定效率分别为 79.77%、51.3%和 37.5%。土壤中 Pb、Cd 和 As 的可提取和可交换部分显著减少。在批实验中，Pb、Cd 和 As 在 Fe-HAP 上的吸附动力学很好地符合准二级模型，表明吸附受化学吸附控制。在 Langmuir 吸附等温线中，Cd 和 As(V)的最大吸附容量分别为 476.2 mg g 和 195.69 mg g，而 Pb 更符合 Freundlich 模型。XRD、SEM 和 XPS 分析表明，Fe-HAP 形成了稳定的 Pb(PO)OH、Cd(PO)·4HO、Cd(OH)和 Fe(AsO)·6HO 矿物，其中含有 Pb、Cd 和 As。总的来说，其简便高效的固定化性能表明，Fe-HAP 具有在 Pb、Cd 和 As 复合污染土壤的综合修复中实际应用的潜力。
