Liu Dan, Huang Zhanbin, Men Shuhui, Huang Zhen, Wang Chunrong
School of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China E-mail:
Water Sci Technol. 2019 Jun;79(11):2175-2184. doi: 10.2166/wst.2019.218.
The aim of this study was to reveal the mechanism of nitrogen and phosphorus adsorption by humic acids (HAs). HAs were extracted from weathered coal and used as adsorbents of urea-N and phosphate-P in water. The effect of different factors was considered, such as the initial concentration of urea-N and phosphate-P, temperature, and pH. The surface characteristics of the HAs were analyzed by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, and Fourier transform infrared spectrometry. The results of batch adsorption experiments showed high effectiveness for nitrogen adsorption, the kinetics fitted with the pseudo-second-order model, and the isotherm followed the Langmuir model. For phosphorus adsorption, the data fitted well with the Weber and Morris model and the adsorption isotherms followed both the Langmuir and Freundlich isotherm models. The experimental results indicated that the adsorption behavior of HAs was both an endothermic and spontaneous process. These findings can be used as a reference for the mitigation of non-point source pollution and the application of fertilizer in agriculture.
本研究的目的是揭示腐殖酸（HAs）对氮和磷的吸附机制。从风化煤中提取腐殖酸，并将其用作水中尿素氮和磷酸盐磷的吸附剂。考虑了不同因素的影响，如尿素氮和磷酸盐磷的初始浓度、温度和pH值。通过X射线衍射、扫描电子显微镜、能量色散X射线光谱和傅里叶变换红外光谱对腐殖酸的表面特性进行了分析。批量吸附实验结果表明，氮吸附效果良好，动力学符合准二级模型，等温线符合朗缪尔模型。对于磷吸附，数据与韦伯和莫里斯模型拟合良好，吸附等温线符合朗缪尔和弗伦德利希等温线模型。实验结果表明，腐殖酸的吸附行为是一个吸热且自发的过程。这些发现可为减轻面源污染和农业肥料施用提供参考。
