摘要
以硅藻土为原料,通过引入钢渣复合的方法制备硅藻土复合吸附剂,采用X射线衍射(XRD)、付立叶变换红外光谱(FTIR)、扫面电镜(SEM)和能谱分析(EDS)对其表征,并且对氨氮吸附过程中的动力学性能和热力学性能进行了研究。研究结果显示,硅藻土复合吸附剂中可能有新的晶相和新的基团生成;硅藻土和钢渣中的金属物质相互作用形成了无机硅酸盐聚合物,硅藻土复合吸附剂中钙、镁、铝、铁等金属元素的含量有所增加。准二级动力学模型更适合描述氨氮在硅藻土复合吸附剂上吸附行为。硅藻土复合吸附剂吸附氨氮的热力学参数(△Go、△Ho和△So)表明,硅藻土复合吸附剂对氨氮的吸附是自发进行的,而且是一个吸热过程,其表观活化能E a接近40 kJ/mol,说明物理吸附与化学吸附同时存在于该吸附过程中,且以物理吸附为主。
In the paper, the composite absorbent was prepared by using diatomite and steel slag as raw materials. The absorption ability, phase composition, microstructure and elemental analysis of this composite were characterized by FTIR, XRD, SEM and EDS. The kinetics and thermodynamics of ammonia nitrogen adsorption were investigated. The results showed that by combining with steel slag, some new crystalline phases and bonds might emerge in the composite absorbent. The metallic contents in steel slag interacted with diatomite, led to the formation of inorganic polymerized silicon complex and the increase of the element content of calcium, magnesium, aluminum and ferrum in the composite absorbent. Evaluation of the experimental data in terms of adsorption kinetics revealed that the adsorption was followed more accurately by the pseudo-second-order kinetic model. The calculated thermodynamic parameters （△G°, △H° and △S°） showed that the adsorption was spontaneous and endothermie. Moreover, the apparent activation energy was close to 40 kJ/mol, indicating that there were physical adsorption and chemical adsorption during the adsorption process, and the physisorption took the dominant role.
出处
《硅酸盐通报》
CAS
CSCD
北大核心
2014年第2期308-314,共7页
Bulletin of the Chinese Ceramic Society
关键词
硅藻土
复合吸附剂
氨氮
动力学
热力学
diatomite
composite absorbent
ammonia nitrogen
kinetics
thermodynamics
