有机无机阻控剂对Pb、Cd的吸附特性及差异

摘要：随着工业的发展，我国土壤重金属污染日益严重。重金属污染不仅会导致土壤肥力退化、农产品产量降低和作物品质下降，还会严重影响环境质量和经济的可持续发展。因此，有效阻控土壤-植物系统中重金属的迁移行为，寻找有效合理的方法治理和修复重金属污染具有重要意义。本研究采用蚓粪和纳米氧化钙（nCaO）为原料，研究蚓粪- nCaO复合型阻控剂对Pb、Cd的吸附解吸特性及差异。实验结果表明：在一定的浓度范围下，V、VN1、VN2 对Pb、Cd的吸附量随着Pb、Cd浓度的增加而增大，Pb、Cd的吸附等温线与Langmuir方程拟合效果最优。对Langmuir方程进一步分析可知，在V、VN1、VN2 对Pb的吸附拟合效果中，VN2（R2=0.9880）效果最优；对Cd的吸附中，V（R2=0.9234）效果最优。在V、VN1、VN2 对Pb、Cd的解吸特性中，VN1与VN2对Pb、Cd的吸附率均高于V，因此说明VN1和VN2 对溶液中Pb、Cd的去除效率均优于V。从时间动力学来看，吸附材料对Pb、Cd的吸附量最初随着时间的增加不断上升，到了后期，吸附量则不再随着时间的增加而上升，而是趋于平缓状态。描述V、VN1、VN2对Pb的吸附动力过程的最优模型是准二级方程，吸附动力学差异较明显，而Cd的相关系数较差，吸附动力学差异不明显。在不同pH对Pb、Cd的吸附影响试验中发现，pH在V、VN1、VN2 吸附Pb、Cd的过程中均有较大影响。

Abstract：With the development of industry, the heavy metal pollution in China is becoming more and more serious. Heavy metal pollution can lead to degradation of soil fertility, decrease of agricultural production and decline of crop quality, seriously affecting environmental quality and sustainable economic development. Therefore, it is of great significance to effectively prevent the migration of heavy metals in soil-plant system and find effective and reasonable methods to control and repair heavy metal pollution.

In this study, the adsorption and desorption characteristics of vermicompost and nano calcium oxide and their compound resistance agents were studied. The experimental results showed, at the certain concentration range, the adsorption capacity of Pb and Cd by V(100% vermicompost)、VN1(95% vermicompost+5% nano calcium oxide)、VN2(90% vermicompost+10% nano calcium oxide) were increased in Pb or Cd concentrations dependent manner. Thus, the adsorption isotherm of Pb, Cd was optimized by fitting the Langmuir equation. According to the further analysis of Langmuir equation, VN2 (R2=0.9880) could most effectively adsorb Pb and V (R2=0.9234) could most effectively adsorb Cd among V、VN1、VN2. In the desorption characteristics of Pb and Cd by V, VN1 and VN2, the adsorption rates of VN1 and VN2 on Pb and Cd were higher than V. Therefore, the removal efficiencies of VN1 and VN2 on Pb and Cd in the solution were better than that of V. In terms of time dynamics, with the increase of time during the initial period, adsorption capacity of Pb, Cd were increased by adsorption material, and subsequently the adsorption quantity was no longer increased, tending to level off during the later period. The quasi-second-order equation is the optimal model for describing the adsorption process of Pb by V、VN1、VN2 and the differences of adsorption kinetics were significant. Whereas, the correlation coefficients of Cd were poor, and the adsorption kinetics differences were not significant. In the adsorption experiments of the effects of different pH on the adsorption of Pb and Cd, it was found that pH have large effects on the adsorbing process of Pb and Cd by V, VN1 and VN2.

关键词：有机、无机阻控剂；吸附；解吸； Pb、Cd污染

Keyword: Organic、inorganic inhibitor； Adsorption； Desorption； Pb、 Cd pollution

1. 引言有机无机阻控剂对Pb、Cd的吸附特性及差异:http://www.chuibin.com/huaxue/lunwen_205500.html