State Key Laboratory of Environment Health (Incubation), Key Laboratory of Environment and Health, Ministry of Education, Key Laboratory of Environment and Health (Wuhan), Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, China.
Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China.
Sci Rep. 2016 Sep 16;6:33573. doi: 10.1038/srep33573.
Wastewater irrigation is a very important resource for heavy metal pollution in soil and then accumulation in vegetable crops. In this study, a polyethylenimine (PEI)-grafted gelatin sponge was prepared to effectively adsorb heavy metals during wastewater irrigation. Based on the strong water adsorption ability, wastewater remained in the PEI-grafted gelatin sponge for a sufficient time for the heavy metals to interact with the sorbents. The binding capacities of Pb(II) ions and Cd(II) ions on the PEI-grafted gelatin sponge were 66 mg g(-1) and 65 mg g(-1), which were much more than those on the gelatin sponge (9.75 mg g(-1) and 9.35 mg g(-1)). Subsequently, the PEI-grafted gelatin sponge was spread on the surface of soil planted with garlic and then sprayed with synthetic wastewater. The concentrations of cadmium and lead in the garlic leaves were 1.59 mg kg(-1) and 5.69 mg kg(-1), respectively, which were much lower than those (15.78 mg kg(-1) and 27.98 mg kg(-1)) without the gelatin sponge, and the removal efficiencies were 89.9% and 79.7%. The PEI-grafting gelatin sponge could effectively remove heavy metals during wastewater irrigation, which improved the soil environment and reduced human exposure to heavy metals.
污水灌溉是土壤中重金属污染和随后积累在蔬菜作物中的一个非常重要的资源。在本研究中，制备了一种接枝聚乙烯亚胺（PEI）的明胶海绵，以在污水灌溉过程中有效吸附重金属。基于强的水吸附能力，污水在接枝 PEI 的明胶海绵中停留足够的时间，以使重金属与吸附剂相互作用。PEI 接枝明胶海绵对 Pb(II)离子和 Cd(II)离子的结合容量分别为 66mg g(-1)和 65mg g(-1)，远高于明胶海绵（9.75mg g(-1)和 9.35mg g(-1)）。随后，将接枝 PEI 的明胶海绵铺在种植大蒜的土壤表面，然后喷洒合成污水。大蒜叶片中的镉和铅浓度分别为 1.59mg kg(-1)和 5.69mg kg(-1)，远低于没有明胶海绵时的浓度（15.78mg kg(-1)和 27.98mg kg(-1)），去除效率分别为 89.9%和 79.7%。PEI 接枝明胶海绵可有效去除污水灌溉过程中的重金属，改善土壤环境，减少人体对重金属的暴露。
