Addition of Thiourea Host Monomer to Polymer Flocculants to Improve Selectivity of Phosphate Sorption

• 作者: Alex M. Cullen Kevin J. McInnes Netochi O. Adeolokun Robert J. Lascano Sarah Pickle Scott A. Senseman Timothy J. Fuhrer Timothy S. Goebel Todd A. Davis
• 来源期刊: 农业化学和环境(英文)
• 学科: 化学
• 关键词: Molecular Recognition THIOUREA Polymers FLOCCULANTS PHOSPHATE
• 年，卷（期）: 2020,（3）
• 页码范围: 147-158
• 页数: 12页
• 分类号: O62

摘要

Inorganic phosphate is a common nutrient that is applied as a fertilizer to both agricultural fields as well as urban settings such as private yards, public parks and other urban landscaping. While phosphate typically binds tightly to soil, movement of phosphate off of application sites can occur through soil erosion. The soil and its bound phosphate can then end up in surface waters such as rivers and lakes. Phosphate found in surface water bodies exists both as bound to the suspended clay as well as that free in solution. Elevated phosphate concentration in surface waters can lead to algal blooms and eutrophication. While the phosphate bound to clay in suspension in surface water bodies can be removed by commercially available polymer flocculants, the phosphate that is free in solution is more challenging as it is usually found in low concentrations and other anionic salts are generally present in higher concentrations. To remove phosphate from contaminated water systems, where other anions exist at higher concentrations, it is favorable to have a method of removal that is selective for phosphate. As a proof of principle, thiourea derivatized polymer flocculants were examined for the selective removal of phosphate in the presence of competing anions. The polymer flocculants exhibited selectivity for phosphate through hydrogen bonding and were effective at removing up to 43% of phosphate from simulated wastewater. Computational studies and </span>^{<span style="font-family:Verdana;">1</span>}<span style="font-family:Verdana;">H NMR were used to investigate the selectivity of the thiourea monomer for phosphate over competing anions such as chloride and sulfate.