Zhang Lihui, Zhang Chen, Zhang Caoyang, Li Weili, Zhou Yanbiao, Wang Yabo, Du Gangfeng
School of Chemistry and Environment Engineering, Pingdingshan University, 467000, Pingdingshan, China.
Sci Rep. 2025 Sep 1;15(1):32105. doi: 10.1038/s41598-025-16876-8.
Biochar is an excellent adsorbent for organic pollutants, but the removal effect for inorganic phosphorus is not satisfactory. In order to improve its phosphorus removal effect, ZnAl-LDH modified plane trees' bark biochar was presented in this paper. The plane trees' bark biochar was prepared by chemical-activation method by utilizing KCO as the activation agent. And then, ZnAl-LDH modified biochar was prepared by in-situ co-precipitation method with ammonia as the precipitate agent. As the sample was as little as 10 mg, the adsorption ratio was about 93% for the 25 mL of 20 mg/L PO. The saturated adsorption capacity for PO was 103.1 mg/g, calculated by Langmuir equation, revealing the adsorption was mainly mono-molecular layer adsorption. The possible adsorption mechanism of phosphate mainly contained interlayer anion exchange, surface complexion and ligand exchange. Moreover, the absorbed sample were soaked in 5.5% NaCO solution for phosphate desorption, nearly 60% of the absorbed phosphate could be recovered and may reuse in the future.
生物炭是一种优良的有机污染物吸附剂，但对无机磷的去除效果并不理想。为了提高其除磷效果，本文提出了锌铝层状双氢氧化物（ZnAl-LDH）改性的杨树树皮生物炭。杨树树皮生物炭采用化学活化法制备，以碳酸钾（KCO）作为活化剂。然后，以氨水作为沉淀剂，通过原位共沉淀法制备了ZnAl-LDH改性生物炭。当样品量低至10 mg时，对于25 mL 20 mg/L的磷酸根（PO），吸附率约为93%。通过朗缪尔方程计算得出，对磷酸根的饱和吸附容量为103.1 mg/g，表明该吸附主要为单分子层吸附。磷酸盐可能的吸附机制主要包括层间阴离子交换、表面络合和配体交换。此外，将吸附后的样品浸泡在5.5%的碳酸钠（NaCO）溶液中进行磷酸盐解吸，可以回收近60%吸附的磷酸盐，并且未来可能可重复使用。
