摘要
利用酸、碱、盐、水及煅烧等对钢渣颗粒进行改性，研究改性方法、煅烧温度和煅烧时间对钢渣吸附除磷的影响，并通过表面特征分析、吸附动力学试验和吸附等温试验研究优选改性钢渣和未改性钢渣吸附除磷的特征。结果表明，粒径为0．9～2mm的钢渣经过3mol／L NaOH浸泡24h和800℃煅烧1h改性后对磷的吸附效果最佳，最大吸附量可达13．39mg／g，比未改性钢渣提高了60．75％。扫描电镜和比表面积分析可知，钢渣经碱改性后表面变粗糙，吸附孔径变小，比表面积和孔容变大。准一级动力学模型能较好地描述未改性钢渣对磷的吸附过程，碱改性钢渣的吸附动力学过程则符合Elovich模型。未改性和碱改性钢渣对磷的吸附过程均可用Langmuir吸附等温方程较好地拟合。
The given article has its main goal to study a new method of how to remove the phosphate in the sewage through adsorption by using modified granular steel slag. The modified granular steel slag can be prepared in a few ways, e.g. through modifying acid, alkali, sah, water, and/or heat. For our research goal, we have investigat- ed the adsorption efficiency of different modified methods, the effect of calcination temperature and calcination time on the modified slags. In addition, we have also explored the phosphate adsorption features on the modified and unmodified steel slag by means of analyzing the surface characteristics, adsorption kinetics, and adsorption isotherms. The results of our investigation show that alkali, salt, water and heat modification can all help to increase the adsorptive amount of phos- phate once they were modified whereas the modified salt, water and heat refuse to bring about any significant difference. What the experiment can mean is that heat seems to play the primary role in the mod- ification, though acid modification tends to reduce significantly the adsorption of the phosphate. In addition, when the slags （0.9 - 2 mm） were allowed to get immersed in 3 moL/L NaOH for 24 h, and then heated at a temperature of 800 ~C for 1 h, the maximum adsorp- tive power can be expected to reach 13.39 mg/g, an increase rate of 60.75% as compared to the unmodified steel one. The results of Electronic Microscope Scanning and BET indicate that the steel slag may tend to have a rougher surface, smaller adsorption pore size, larger specific surface area, and bigger pore volume after alkali modi- fication. The nitrogen adsorption isotherms on both unmodified and alkali-modified granular steel slag turn ,to come in conformity with Type 11 Isotherm Model of International Union of Pure and Applied Chemistry. Thus, it can be seen from the pore size that the holes in both unmodified and alkali modified granular steel slag were mainly of mesopore. On the one hand, the dynamic adsorption data of unmodi- fied steel slag can well be described by pseudo first-order kinetics, on the other hand, the dynamic adsorption of alkali modified steel slag prove to be in accord with Elovich model. The adsorption of phosphate both on the alkali-modified and unmodified steel slag were well fitted by Langmuir adsorption isotherm model. Furthermore, the adsorption buffer capacities on the alkali-modified granular steel slag prove to be stronger than on the unmodified granular steel slag.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2012年第6期66-71,共6页
Journal of Safety and Environment
基金
国家水体污染控制与治理科技重大专项(2008ZX07314-006)
关键词
环境科学技术基础学科
改性
钢渣颗粒
磷酸盐
吸附
basic disciplines of environmental science and technology
modification
granular steel slag
phosphate
adsorption
