Shandong Academy of Agricultural Sciences, Institute of Agricultural Resources and Environment, Key Laboratory of Wastes Matrix Utilization, Ministry of Agriculture, Shandong Provincial Engineering Research Center of Environmental Protection Fertilizers, Jinan, 250100, PR China; State Key Laboratory of Nutrition Resources Integrated Utilization, Linshu, 276700, PR China.
College of Resources and Environment, Shandong Agricultural University, Taian, 271018, PR China.
Chemosphere. 2020 Sep;255:126976. doi: 10.1016/j.chemosphere.2020.126976. Epub 2020 May 4.
Bentonite was modified by introducing humic acid (HA) into interlayer space of bentonite. The structural and physicochemical properties of modified bentonite were determined by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), X-ray powder diffraction (XRD) and thermogravimetric analysis (TGA). The results showed that HA could enter the bentonite interlayer and increase the interlayer distance. Moreover, we were also investigated the high adsorption capacity and thermodynamics of modified bentonite to NH cations in solutions. Under the same conditions, the NH adsorption efficiency of modified bentonite (96.4%) was 69.2% higher compared with the natural bentonite (57.0%). The pseudo-second order kinetic model well fit the adsorption kinetics of NH on modified bentonite, indicating that the adsorption type was chemical adsorption or chemisorptions. The isotherms fit well with Langmuir model, and the separation factor revealed that NH on modified bentonite belonged to favorable adsorption. Compared with the natural bentonite, the modified bentonite exhibited a much lower leaching loss of NH-N and NO-N in soil. Meanwhile, the loss of nitrogen caused by NH volatilization and NO emission from soil could also be significantly attenuated by the combined application of modified bentonite and urea. The slower nitrogen release in the treatment combining modified bentonite and urea resulted in a greater yield and nitrogen uptake of wheat. Collectively, the modified bentonite could be used as nitrogen fertilizer synergist to enhance the nitrogen use efficiency.
膨润土通过引入腐殖酸（HA）进入层间空间来改性。通过傅里叶变换红外光谱（FT-IR）、扫描电子显微镜（SEM）、X 射线粉末衍射（XRD）和热重分析（TGA）确定了改性膨润土的结构和物理化学性质。结果表明，HA 可以进入膨润土的层间并增加层间距。此外，我们还研究了改性膨润土对溶液中 NH 阳离子的高吸附容量和热力学。在相同条件下，改性膨润土（96.4%）对 NH 的吸附效率比天然膨润土（57.0%）高 69.2%。NH 在改性膨润土上的吸附动力学较好地符合伪二级动力学模型，表明吸附类型为化学吸附或化学吸附。等温线很好地符合朗缪尔模型，分离因子表明 NH 在改性膨润土上属于有利吸附。与天然膨润土相比，改性膨润土在土壤中 NH-N 和 NO-N 的浸出损失要低得多。同时，改性膨润土和尿素的联合施用也能显著减弱 NH 挥发和 NO 从土壤中排放引起的氮损失。在结合使用改性膨润土和尿素的处理中，氮的释放速度较慢，导致小麦的产量和氮吸收量增加。总的来说，改性膨润土可用作氮肥增效剂，以提高氮素利用率。
