悬铃木树皮生物炭/锌铝层状双氢氧化物的制备及其对磷酸盐的吸附性能与回收

Preparation of plane trees' bark biochar/ZnAl-LDH and its adsorption performance for phosphate and recovery.

作者信息

Zhang Lihui, Zhang Chen, Zhang Caoyang, Li Weili, Zhou Yanbiao, Wang Yabo, Du Gangfeng

机构信息

School of Chemistry and Environment Engineering, Pingdingshan University, 467000, Pingdingshan, China.

出版信息

Sci Rep. 2025 Sep 1;15(1):32105. doi: 10.1038/s41598-025-16876-8.

DOI:10.1038/s41598-025-16876-8

PMID:40890174

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC12402136/

Abstract

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.

摘要

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。