The State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China.
The State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China.
Sci Total Environ. 2018 Feb 15;615:422-430. doi: 10.1016/j.scitotenv.2017.09.084. Epub 2017 Oct 4.
Nearly 1.3 billion tons of food are discarded annually in the production process. In this study, a novel slow-release nitrogen fertilizer with water absorbency was developed using leftover rice and crosslinking methods. Urea was incorporated as the nitrogen source in a leftover rice-g-poly(acrylic acid)/montmorillonite (LR-g-PAA/MMT) network, and then the leftover rice-g-poly(acrylic acid)/montmorillonite/Urea (LR-g-PAA/MMT/Urea) retained in the soil, and used as the loss control agent for water and nutrients. Variables including concentrations of acrylic acid, montmorillonite, N,N´-methylenebis acrylamide (MBA), and potassium persulfate (KPS) were investigated. Samples were with a water absorbency of 102.6g/g in distilled water and 25.1g/g in 1.0wt% NaCl solution under optimized conditions. Swelling measurements and water-retention indicated that higher-covalent cations would aggregate the hydrogels and decrease swelling. Investigating leaching behavior showed that these samples have the potential to carry the necessary nitrogen (N). The results demonstrated that the LR-g-PAA/MMT/Urea had a low leaching losses of N (19.7%) compared with pure urea (52.3%). Therefore, the developed fertilizer may be widely applicable in agriculture and horticulture, and could provide a new platform for reusing leftover rice.
每年在生产过程中会有近 13 亿吨的食物被丢弃。在这项研究中，使用剩余的大米和交联方法开发了一种具有吸水性的新型缓释氮肥。将尿素作为氮源掺入到剩余的大米接枝-聚丙烯酸/蒙脱土（LR-g-PAA/MMT）网络中，然后将剩余的大米接枝-聚丙烯酸/蒙脱土/尿素（LR-g-PAA/MMT/Urea）保留在土壤中，用作水和养分的损耗控制剂。考察了丙烯酸、蒙脱土、N,N´-亚甲基双丙烯酰胺（MBA）和过硫酸钾（KPS）的浓度等变量。在优化条件下，样品在蒸馏水中的吸水率为 102.6g/g，在 1.0wt%NaCl 溶液中的吸水率为 25.1g/g。溶胀测量和保水表明，较高的价态阳离子会聚集水凝胶并降低溶胀度。对浸出行为的研究表明，这些样品具有携带必要氮（N）的潜力。结果表明，与纯尿素（52.3%）相比，开发的肥料中氮（N）的浸出损失率较低（19.7%）。因此，这种开发的肥料可能在农业和园艺中有广泛的应用，为剩余大米的再利用提供了一个新的平台。
