School of Chemistry and Environment, South China Normal University, Guangzhou, Guangdong, China.
Water Sci Technol. 2012;65(12):2091-7. doi: 10.2166/wst.2012.121.
Phosphorus releases into aquatic environment and its subsequent contribution to eutrophication have resulted in a widespread global pollution issue. However, phosphorus is a non-renewable source. The potential supplies of phosphorus are decreasing worldwide. Therefore, removal and recovery of phosphorus from the eutropic waters is important, emergent and necessary. In this research, experiments for recovering phosphate from eutropic waters by anion exchange combined with struvite precipitation were conducted. The results indicated that the prepared XDA-7 resin was an effective adsorbent for phosphate. The adsorption isotherm of XDA-7 resin was found to be a modified Freundlich type. The maximum phosphate adsorption (20.9 mg/g) occurred in the pH range of 6.0-8.0. Phosphate adsorbed on the XDA-7 resin was effectively desorbed with 8% NaCl solution, and the resin was able to be regenerated with 3% NaClO and 4% NaOH solutions. Phosphate desorbed from the resin was recovered as magnesium ammonium phosphate (struvite). The obtained struvite was analyzed by acid dissolution method, scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR). The struvite precipitate was found to be 75.8% in purity, a high-value fertilizer.
磷释放到水生环境中，随后对富营养化的贡献导致了广泛的全球性污染问题。然而，磷是不可再生的资源。全球范围内磷的潜在供应正在减少。因此，从富营养化水中去除和回收磷是重要的、紧急的和必要的。在这项研究中，通过阴离子交换结合鸟粪石沉淀从富营养化水中回收磷酸盐的实验进行了。结果表明，制备的 XDA-7 树脂是一种有效的磷酸盐吸附剂。XDA-7 树脂的吸附等温线被发现是一种改良的 Freundlich 型。最大磷酸盐吸附（20.9mg/g）发生在 pH 值为 6.0-8.0 的范围内。用 8%的氯化钠溶液可以有效地将吸附在 XDA-7 树脂上的磷酸盐解吸，并且可以用 3%的次氯酸钠和 4%的氢氧化钠溶液再生树脂。从树脂上解吸的磷酸盐被回收为磷酸铵镁（鸟粪石）。用酸溶解法、扫描电子显微镜（SEM）和傅里叶变换红外光谱（FTIR）对所得鸟粪石进行了分析。鸟粪石沉淀的纯度为 75.8%，是一种高价值的肥料。
