共查询到20条相似文献,搜索用时 93 毫秒
1.
综述了近年来各种改性沸石对于硝酸盐污染物吸附处理的研究进展,从表面活性剂改性、酸溶液改性、碱溶液改性和金属盐溶液改性几个改性方法出发,介绍了这几种方法对天然沸石的改性机理,对改性沸石吸附处理水中硝酸盐污染物的前景进行了展望,包括寻找新型改性材料、将几种不同改性方法进行组合,以减少单一改性方法不足,为后续新型改性沸石方法提供参考。 相似文献
2.
改性沸石去除水中有机污染物的研究进展 总被引:2,自引:0,他引:2
概述了沸石的物理、化学性质及结构特征,介绍了采用沸石处理有机污染物时所采用的不同改性方法以及改性后对不同有机物的去除效果。综述了沸石在改性和处理有机污染物过程中所涉及到的反应机理及相关理论,总结了沸石改性和应用方面存在的问题及今后研究的方向。 相似文献
3.
4.
研究了锰改性沸石(MOCZ)对水中砷的吸附效果、影响因素及其吸附除砷的机理。结果表明,当原水中的砷浓度为100μg·L-1时,在MOCZ与砷的质量比为100:1、温度为25℃、接触时间为240min、水样pH值为6~7的条件下,MOCZ对砷的去除率达到900.4以上,吸附后水样中砷浓度为9.50μg·L-1,低于《生活饮用水卫生标准》的要求(≤10μg·L-1)。Langmuir吸附等温模型能较好地描述MOCZ对水中砷的吸附行为,拟合曲线的相关系数R2=0.9856,初步推测为单层吸附。 相似文献
5.
6.
氮是地球上所用生命体的必需营养物质。然而水体中氮含量过高将导致水体富营养化。目前去除水中低浓度氨氮常用的方法包括生物法、高级氧化法、折点氯化法、离子交换法以及吸附法,其中吸附法因其易操作、无二次污染而被认为是目前较佳的处理技术。本文采用化学浸渍方法对天然沸石进行改性,以提高对水中氨氮的选择吸附性。当改性剂NaCl浓度为1 M,改性固液比为5 g/L,改性时间为7 h,得到的改性沸石(N-Z)对氨氮去除效果最佳。在中性条件下,地表水常见共存离子对N-Z去除水中氨氮具有一定影响。 相似文献
7.
为了减少NO3-N污染对水环境和人体健康的危害,寻求经济有效的控制水体中NO3-N污染的技术至关重要。本研究利用湿地植物芦苇为原材料,在不同温度下烧制制备生物碳。同时采用FeCl3对生物碳进行不同方法的改性提高其对水中NO3-N的吸附性能。结果表明,碳化温度600℃,烧制时间2h,碱性FeCl3溶液浸泡24h的最佳条件下形成的生物碳(BC600)对NO3-N的吸附能力最强,达到1.97mg-N/L。SEM进行表面形态分析可得,BC600孔隙中加载了大量的氧化铁,可有效去除水中的NO3-N。本研究可为农业废秸秆的综合利用和水中硝酸盐的脱除提供了理论依据。 相似文献
8.
采用柠檬酸钠联合高温煅烧制备改性沸石,利用响应曲面法优化制备参数,通过批次吸附实验探究了改性沸石去除水中氨的特性及机理。结果表明:柠檬酸钠质量分数为2.24%,煅烧温度为395.72℃,煅烧时间为3.58 h条件下制备的改性沸石效果最佳;在投加量为10 g/L条件下处理20 mg/L氨,去除率达到80.21%,较天然沸石提高35.62%。SEM和BET表明改性后沸石孔径增大了1.48倍。吸附氨的最佳pH为6,阳离子共存对吸附氨的影响顺序为:K+>Ca2+>Mg2+>Na+;拟二级动力学和Langmuir模型可更好地描述氨吸附过程,改性沸石循环5次后的氨去除率依然可达70.49%。本研究制备的改性沸石可作为吸附剂用于水中氨的高效去除。 相似文献
9.
酸改性沸石去除高浓度甲醛废水的研究 总被引:1,自引:0,他引:1
用盐酸对天然沸石进行改性得到酸改性沸石,通过静态吸附实验研究了酸改性沸石对废水中甲醛的吸附性能。研究表明在293 K时,酸改性沸石对甲醛的平衡吸附量为255 mg/g,最佳吸附pH值为6.5,吸附平衡时间为2 h。 相似文献
10.
11.
磷素是水体富营养化的主要限制性因子,合适的除磷方法对控制水体富营养化具有重要意义。吸附法是一种经济、高效、操作简单的除磷方法,但如何选择合适的吸附材料是其应用的关键。La应用于常规吸附材料改性可提高其吸附磷酸盐的性能,同时可提高La利用效率。为进一步促进La改性吸附材料脱除水体磷酸盐的发展,本文归纳了国内外关于La改性吸附材料应用于水体磷酸盐脱除的相关研究,介绍了La改性吸附材料脱除磷酸盐的能力,分析了La改性吸附材料脱除磷酸盐的机理、主要影响因素以及解吸磷酸盐的特性。同时在此基础上提出未来应制备出对实际水体磷酸盐脱除高效和选择性强的La改性吸附材料,深入研究吸附材料制备机理以及脱除磷酸盐机理,探明吸附材料解吸磷酸盐的简单方法,并作出吸附材料解吸循环使用的经济效益评价。 相似文献
12.
13.
14.
ABSTRACTHydrous titanium dioxide was impregnated on the surface of zeolite to obtain a kind of hydrous TiO2/zeolite (HTiO2/ZFA) adsorbent using the hydrothermal method. HTiO2/ZFA was characterised by scanning electron microscopy combined with energy-dispersive spectrometer, X-ray diffraction, Fourier transform infrared, particle size distribution; and the pH of zero point charge measurement and its performance for Cu(II) adsorption were investigated. It was shown that Ti was not inserted into the skeleton of ZFA and hydrous TiO2 loaded on the surface was amorphous. The pHzpc of HTiO2/ZFA decreased to pH 5.5 from pH 6.5 of ZFA. Cu(II) adsorption was favoured in a pH range of 3.0–6.0, and 90% copper could be removed in first 30?min for 60?mg?L–1 Cu(II) solution. The Langmuir isotherm model could well describe the adsorption isotherm data and the maximal Cu(II) adsorption capacity reached 251.9?mg?g–1. Moreover, the HTiO2/ZFA could be desorbed by HCl solution for further use, which implied an effective application in wastewater treatment. 相似文献
15.
In this work the fly ash was modified by sulfuric acid for the removal of phosphate. It was found that modification of fly ash could significantly enhance the phosphate immobilization ability of the fly ash. The specific surface area of the fly ash increased from 8.8 to 32.5 m2/g after treated with sulfuric acid. The modification of the fly ash also resulted in the mobilization of acid-soluble metal ions due to partial or complete dissolution of the metals under the acidic conditions. Both adsorption and precipitation contributed to the removal of phosphate by the modified fly ash but precipitation was a major mechanism of phosphate removal. The experimental results showed that adsorption of phosphate by the modified fly ash was rapid, the removal percentage of phosphate could reach maximum in 5 min. In the range of 5–9, pH did not significantly affect the removal of phosphate and the removal percentage of phosphate increased with the increase of adsorbent dosage. The adsorption of phosphate by the modified fly ash could be described well by Langmuir isotherm equation, the Langmuir constant Q0 was 9.15 mg g−1. The XRD patterns and the SEM images of modified fly ash after sorption revealed that CaHPO4·2H2O was formed in the removal of phosphate. In addition, phosphate also formed precipitate with aluminum and iron. 相似文献
16.
Yi Liu Yuru Kang Dajian Huang Aiqin Wang 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2012,87(7):1010-1016
BACKGROUND: The adsorption of Cu2+ from aqueous solution using crosslinked chitosan hydrogels impregnated with Congo Red (CR) by ion‐imprint technology was systematically investigated with particular reference to the effects of contact time, pH, and initial concentration on adsorption. RESULTS: The adsorption capacity of the crosslinked chitosan without impregnation was only 68.68 mg g?1 for Cu2+. However, the adsorption capacity increased from 77.42 (without imprint ion) to 84.54 mg g?1 (imprint ion content 0.5 mmol) after the chitosan was impregnated with a ratio of 1/12 of CR to chitosan. The as‐prepared adsorbents were found to be pH‐dependent and the process of adsorption agreed well with the Freundlich isotherm. The loaded adsorbents could be regenerated and reused without the appreciable loss of capacity. CONCLUSION: Chitosan hydrogels impregnated with CR showed higher Cu2+ adsorption capacities compared with those prepared conventionally without imprint ion, and thus developed a good approach to increase Cu2+ adsorption efficiency in the treatment of waste‐water. Copyright © 2012 Society of Chemical Industry 相似文献
17.
18.
19.
20.
以橡椀栲胶为原料,通过双氧水氧化降解改性,研究水解类橡椀单宁改性后对铜离子溶液的吸附沉淀以及pH值、金属溶液初始浓度对铜离子吸附沉淀容量的影响和规律。结果表明,氧化橡椀单宁对Cu2+的吸附平衡符合Freundlich方程。改性后吸附沉淀容量受初始浓度影响较大,初始浓度为20 mg/L时基本不发生吸附沉淀,试验最大初始浓度100 mg/L时吸附量达到39.300 mg/g。 相似文献