摘要
天然沸石具有去除阳离子氨氮的作用,但不具有去除阴离子的作用。用阳离子表面活性剂十六烷基三甲基溴化铵(HDTMA)对天然沸石进行改性。在静态条件下,利用天然沸石及改性沸石对模拟污水中氮磷的去除效果和规律进行了研究。结果表明,天然沸石对氨氮的去除率在75%以上,对磷几乎没有去除。HDTMA改性后的沸石对氨氮的去除率有所下降,但在5%之内;对磷酸盐的去除有明显提高,最佳改性剂质量浓度为30 g/L。随污染物质量浓度增加,改性沸石的吸附量增大,最后缓慢趋于平衡;吸附平衡数据与Langmuir等温吸附模型十分吻合。正交试验结果显示,混合溶液中各目标污染物之间没有相互干扰作用。氨氮的绝对浓度是改性沸石对氨氮吸附最主要的影响因素,表面活性剂质量浓度是改性沸石吸附磷酸盐最重要的影响因素。在污染物配比、污染物浓度级别、改性剂质量浓度分别为30∶5、1和30 g/L时,改性沸石对磷酸根的去除率最大,为56.6%,同时氨氮的去除率高达93.6%。
The article is engaged in a study of the simultaneous removal efficiency and the regulation of ammonia nitrogen and phosphorus by HDTMA modified zeolite nitrate. As is matter of fact,zeolite nitrate is characteristic with the anionic nitrogen compounds which can hardly be removed in sewage. In addition,it is considered to have a function for removing the cationic ammonia but not for the anion removal. In accordance with the said feature,the article has adopted a cationic surfactant and the hexadecy trimethy ammonium bromid（ HDTMA） for modifying the natural zeolite in hoping to determine the absorptive behavior of the surfactant modified zeolite（ SMZ） with ammonium and phosphate being the target absorbate. The results of our experimental study demonstrate that the phosphate removal efficiency of the modified zeolite tends to increase with the increase of the surfactant dosage. It has also been found that HDTMA-modified zeolite efficiency tends to decrease slightly due to the ammonium absorption in relation to the natural clinoptilolite,though the overall absorption power still remains strong with 60% removing rate at an ammonium initial concentration of 200 mg / L and a 30 g / L surfactant dosage. The amount of the absorbed contaminants can also be increased with the increase of the initial concentration while the removal efficiency may tend to decrease with the increase of the initial concentration. What is more,the adsorption data is fit for the Langmuir isotherm model. However,no significant mutual interference has been found in the adsorption of the mixed solution. In addition,the HDTMA-modified zeolite can also be enhanced significantly on the phosphate sorption with the maximum removal being 56. 6%. Moreover,SMZ has also been found to absorb ammonium,phosphate at the low concentration range（ 100 mg / L for ammonium and 5 mg / L for phosphate） simultaneously,which is the typical concentration in the given environment.Thus,the results of the orthogonal experiment imply that the ammonium concentration in this case acts as the main factor for ammonium sorption,rather than the surfactant concentration. For phosphate sorption,the surfactant concentration is the most important factor. Therefore,it can be concluded that SMZs enjoys a great potential for removing cations and anions simultaneously（ 93. 6% for ammonium and 56. 6% for phosphate） from the aquatic environment. Thus,the results of our research can be expected to provide a theoretical support for the modified zeolite application in the practical chemical engineering.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2015年第3期216-220,共5页
Journal of Safety and Environment
关键词
环境工程学
污水处理
氨氮
磷酸盐
表面活性剂
environmental engineering
sewage treatment
ammonia nitrogen
phosphate
surfactants
