Yukhajon Pratchayaporn, Somboon Titikan, Sansuk Sira
Materials Chemistry Research Center, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand.
Department of Chemistry, Faculty of Engineering, Rajamangala University of Technology Isan, Khon Kaen Campus, Khon Kaen 40000, Thailand.
ACS Omega. 2022 Apr 26;7(18):15625-15636. doi: 10.1021/acsomega.2c00425. eCollection 2022 May 10.
A simple method to prepare phosphate/carbonate composites for use as porous sponge-like phosphate fertilizers (ps-POFs) is presented. The composites ps-POFs were prepared by ion-exchange implantation of phosphate onto the surface of vaterite-phase calcium carbonate (CaCO) microparticles. The ps-POFs obtained under the optimized conditions were found to contain a nanoscale porous network of calcium phosphate covering the CaCO support. In addition, ps-POFs exhibited two distinct phosphate release modes having different kinetics: a fast-release step over the initial 24 h period following a parabolic diffusion model, indicating controlled diffusion from external surfaces/edges, and a second slow-release step over the course of a month following the Ritger-Peppas model, indicating the release and diffusion of phosphate adsorbed at specific sites. The ps-POFs also adsorbed glyphosate well because of their porous structure and large surface area. However, glyphosate adsorption prevented phosphate release at concentrations greater than 10 mg L. The ps-POFs were tested for their effects on plant growth and showed effects similar to commercial fertilizers. In summary, these smart, eco-friendly, and multifunctional fertilizers having two-stage phosphate release could enable the application of lower amounts of fertilizer and remove excess glyphosate from the environment.
本文提出了一种制备用作多孔海绵状磷肥（ps-POFs）的磷酸盐/碳酸盐复合材料的简单方法。通过将磷酸盐离子交换植入球霰石相碳酸钙（CaCO）微粒表面来制备复合材料ps-POFs。发现在优化条件下获得的ps-POFs含有覆盖CaCO载体的磷酸钙纳米级多孔网络。此外，ps-POFs表现出两种具有不同动力学的明显磷酸盐释放模式：在最初24小时内遵循抛物线扩散模型的快速释放步骤，表明从外表面/边缘的受控扩散，以及在一个月内遵循Ritger-Peppas模型的第二个缓慢释放步骤，表明在特定位置吸附的磷酸盐的释放和扩散。由于其多孔结构和大表面积，ps-POFs对草甘膦的吸附也很好。然而，草甘膦吸附在浓度大于10 mg/L时会阻止磷酸盐释放。对ps-POFs对植物生长的影响进行了测试，结果表明其效果与商业肥料相似。总之，这些具有两阶段磷酸盐释放的智能、环保和多功能肥料可以减少肥料施用量，并从环境中去除过量的草甘膦。
