生物炭对农业面源污染物中农药分子的吸附性能研究

生物炭广泛应用于生态修复、农业和环保领域,研究出能吸附农业面源污染物中农药(主要为乙草胺和阿特拉津除草剂)的材料,对环境保护和农业生产中的土壤修复具有重要意义。从生物炭的植物原材料、结构性质等方面进行研究,选择出具有更大吸附能的生物炭种类。采用密度泛函理论,分析生物炭分子结构和乙草胺与阿特拉津分子结构的特点及吸附能,从理论模拟角度研究微孔结构对农药分子的吸附作用和影响。结果表明:植物生物炭的主要成分和孔径大小均对乙草胺和阿特拉津分子吸附能力有一定影响,其中紫丁香基结构木质素对乙草胺和阿特拉津分子的吸附能力最强。总体上,吸附能力表现为木质素﹥纤维素﹥半纤维素,1倍孔径﹥2倍孔径﹥4倍孔径。

Research on adsorption properties of biochar for pesticide molecules of agricultural non-point source pollutants

Biochar is widely used in ecological restoration, agriculture and environmental protection. It is of great significance for soil remediation in environmental protection and agricultural production to develop materials that can adsorb pesticides (mainly acetochlor and atrazine herbicides) of agricultural non-point source pollutants. The biochars which had greater adsorption capacity were selected based on the analysis of raw materials and structural properties of biochars. The molecular structure of biochar, microporous structure and adsorption energy of acetochlor and atrazine were discussed by the density functional theory, and the adsorption and influence of microporous structure on pesticide molecules were studied by theoretical simulation. The results showed that the main components and pore size of plant biochar could affect the adsorption capacity of acetochlor and atrazine molecules, in which lilac-based structural lignin had the strongest adsorption ability on acetochlor and atrazine molecules. In general, the adsorption capacity was in the order of lignin﹥cellulose﹥hemicellulose, and 1 times pore size﹥2 times pore size﹥4 times pore size.