The Key Laboratory of Water and Sediment Sciences, Ministry of Education, School of Environment, Beijing Normal University, Beijing, PR China.
J Hazard Mater. 2012 Feb 15;203-204:145-50. doi: 10.1016/j.jhazmat.2011.11.084. Epub 2011 Dec 7.
Effects of low molecular weight organic acids (LMWOAs; citric acid, oxalic acid and tartaric acid) on phosphorus (P) adsorption by ferric-alum water treatment residuals (FARs) were studied. Both batch and column experiments indicated that the effects of LMWOAs on P adsorption were closely related to adsorption time. Initially, all acids presented inhibitory function on P adsorption. The inhibition became weaker with time, eventually promoting P adsorption for citric acid and tartaric acid. In the column experiment with a 61-day duration, high P adsorption rates (>55%) were observed for the test groups containing citric acid and tartaric acid. Interestingly, higher pH likely enhanced P adsorption with the effects of LMWOAs and a distinct relationship between LMWOAs' effects on P adsorption and their concentrations was not observed. Moreover, fractionation of the adsorbed P from the FARs demonstrated that oxalic acid reduced P adsorption capacity, while citric acid and tartaric acid increased. Based on the forms of Fe and Al existing in the FARs and Fourier transform infrared spectroscopy analyses, LMWOAs can promote P adsorption through activating crystalline Fe/Al and preventing crystallization of amorphous Fe/Al to increase P adsorption sites, and can also inhibit P adsorption by competition with adsorption sites.
研究了低分子量有机酸（柠檬酸、草酸和酒石酸）对铁铝水处理残渣（FAR）吸附磷（P）的影响。批实验和柱实验均表明，有机酸对 P 吸附的影响与吸附时间密切相关。最初，所有酸都对 P 的吸附表现出抑制作用。随着时间的推移，抑制作用减弱，最终促进了柠檬酸和酒石酸对 P 的吸附。在持续 61 天的柱实验中，含有柠檬酸和酒石酸的实验组表现出较高的 P 吸附率（>55%）。有趣的是，较高的 pH 值可能增强了 LMWOAs 对 P 吸附的影响，且没有观察到 LMWOAs 对 P 吸附的影响与其浓度之间存在明显的关系。此外，从 FARs 中吸附的 P 的分级表明，草酸降低了 P 的吸附能力，而柠檬酸和酒石酸则增加了 P 的吸附能力。基于 FARs 中存在的铁和铝的形态以及傅里叶变换红外光谱分析，LMWOAs 可以通过激活结晶态的 Fe/Al 并防止非晶态 Fe/Al 的结晶来增加 P 吸附位点，从而促进 P 吸附，并且还可以通过与吸附位点的竞争来抑制 P 吸附。
