超顺磁性纳米材料对镉污染稻田土壤微生物和酶的影响

以磁性纳米Fe3O4和羟基磷灰石等为原料,制备出超顺磁性纳米Fe3O4-磷酸盐功能化材料(MFH),通过在镉污染稻田土壤中投加MFH,对土壤进行磁选修复.选择对Cd具有高、低富集两种水稻,在修复后土壤中进行盆栽试验,研究MFH磁选修复对土壤微生物和酶的影响,探究该材料应用于农田镉污染修复的可能性.结果表明,施用MFH修...

Effects of Superparamagnetic Nanomaterials on Soil Microorganisms and Enzymes in Cadmium-Contaminated Paddy Fields

Using Fe₃O₄ and hydroxyapatite as raw materials, superparamagnetic nanometer-sized Fe₃O₄-phosphate functionalized materials (MFH) were prepared. Soil was subsequently magnetically repaired by adding MFH to cadmium-contaminated paddy field soil. Two kinds of rice with high (Yuzhenxiang) and low (Xiangwanxian-13) cadmium enrichment were selected for conduct pot experiments to study the effect of MFH magnetic separation on soil microorganisms and enzymes, and explore the possibility of application in the remediation of cadmium-polluted farmland. The results showed that MFH application improved the soil remediation effect, with significantly reduced total Cd (38.9%) and available Cd (27.3%) contents. In addition, the Cd content of the two kinds of rice grain was significantly reduced. After MFH magnetic separation, soil microbial community diversity and richness were decreased during the jointing, heading, and maturing stages of the two rice varieties. Treatment of cultivated Yuzhenxiang rice with high concentrations of Cd significantly increased the abundance of dominant Firmicute bacteria in the rice field during the jointing and heading stages. With the use of MFH in the magnetic separation, urease, catalase, and soil peroxidase activity were improved during the jointing, heading, and maturing stages of the two rice soils. The POD enzyme activity in the soil planted with Yuzhenxiang was slightly higher than that planted with Xiangwanxian-13, while urease activity showed the opposite trend.