This study investigated the solution for two environmental issues: excess of P in water and its deficiency in soil, which is restored by transferring the adsorbed P from water into the soil using eggshell as an adsorbent. The eggshells were calcined at different temperatures to improve their adsorption capacity, and evaluated for their physical/chemical properties and P adsorption capacity. The eggshells calcined at 800 °C (CES-800) had the highest P adsorption; CaCO₃ decomposed into 23.6% of CaO and 40.8% of Ca(OH)₂, eluting more Ca that reacted with soluble P in water. X-ray diffraction analysis confirmed that CES-800 removed P as hydroxylapatite by reacting with Ca. Pseudo-first-order and Langmuir models suitably described the kinetic and equilibrium of P adsorption by CES-800, respectively. The maximum adsorption capacity of CES-800 was 108.2 mg g⁻¹. As the solution pH increased from 3 to 11, the adsorption amount decreased from 99.8 mg g⁻¹ to 62.3 mg g⁻¹. The feasibility of CES-800 as a filter medium was assessed using real lake water under dynamic flow conditions; > 90% of P removal was achieved at 158 h, and the P adsorbed was 11.5 mg g⁻¹. When CES-800 and P adsorbed CES-800 (P-CES-800) were applied to the soil at the studied rates, the earthworms were unaffected by toxicity, suggesting the use of both adsorbents in soil without adverse effects. The shoot fresh weight, tiller number, and total dry weight significantly increased in P-CES-800 applied rice plants compared to the control plants, indicating that P-CES-800 can be a good alternative to conventional P-fertilizer in rice cultivation.

本研究调查了两个环境问题的解决方案：水中 P 过量和土壤中 P 缺乏，通过使用蛋壳作为吸附剂将吸附的 P 从水中转移到土壤中来恢复。将蛋壳在不同温度下煅烧以提高其吸附能力，并评估其物理/化学性质和 P 吸附能力。800℃煅烧的蛋壳（CES-800）磷吸附量最高；CaCO ₃分解成23.6%的CaO和40.8%的Ca(OH) ₂，洗脱更多与水中可溶性 P 反应的 Ca。X 射线衍射分析证实，CES-800 通过与 Ca 反应以羟基磷灰石的形式去除 P。伪一级模型和朗缪尔模型分别恰当地描述了 CES-800 对 P 吸附的动力学和平衡。CES-800 的最大吸附容量为108.2 mg g ^-1。随着溶液pH值从3增加到11，吸附量从99.8 mg g ^-1下降到62.3 mg g ^-1。CES-800 作为过滤介质的可行性在动态流动条件下使用真实湖水进行评估；在 158 小时内实现了 > 90% 的 P 去除，吸附的 P 为 11.5 mg g ^-1. 当 CES-800 和吸附 P 的 CES-800 (P-CES-800) 以研究的比率施用于土壤时，蚯蚓不受毒性的影响，这表明在土壤中使用这两种吸附剂没有不利影响。与对照植物相比，P-CES-800 施用的水稻植株的苗重、分蘖数和总干重显着增加，表明 P-CES-800 在水稻栽培中可以很好地替代常规磷肥。