天然丝光沸石表面重构改性及其在水中去除重金属的应用  

Surface Modification of Natural Mordenite and Its Application in Removal of Heavy Metals from Aqueous Solution

作　　者：王喆[1,2,3] 谭科艳 梁明会[3] 蔡敬怡[2,3] 侯士田 王悦 江鹏[3] WANG Zhe;TAN Ke-yan;LIANG Ming-hui;CAI Jing-yi;HOU Shi-tian;WANG Yue;JIANG Peng(College of Civil Engineering,Tongji University,Shanghai 200092,China;Key Laboratory of Eco-Geochemistry,Ministry of Natural Resources;National Research Center for Geoanalysis,Beijing 100037,China;National Center for Nanoscience and Technology,Beijing 100190,China)

机构地区：[1]同济大学土木工程学院,上海200092 [2]自然资源部生态地球化学重点实验室国家地质实验测试中心,北京100037 [3]国家纳米科学中心,北京100190

出　　处：《岩矿测试》2018年第6期678-686,共9页Rock and Mineral Analysis

基　　金：中国地质科学院基本科研业务费项目(YYWF201722; YYWF201617)

摘　　要：天然丝光沸石作为一种绿色廉价多孔材料广泛应用于环境治理中去除重金属,目前报道的天然沸石对重金属的去除率多在60%～90%,提升其去除效率已成为研究热点。本文采用正硅酸乙酯对天然丝光沸石进行表面重构改性,通过TEM、XRD、BET等手段表征其形貌和结构。结果表明:正硅酸乙酯水解生成的SiO_2可与天然丝光沸石复合形成新颖的"SiO_2/丝光沸石",原沸石表面包覆了新生纳米SiO_2孔结构,同时没有损坏原始沸石的多孔结构,使改性沸石材料兼具了天然丝光沸石和纳米SiO_2孔结构优点,增强了对重金属离子的吸附能力。该改性材料对水中Pb^(2+)、Cd^(2+)、Zn^(2+)和Mn^(2+)的最高吸附率为99. 3%、97. 1%、98. 3%和97. 0%,且极少解吸,性能稳定。考虑经济成本并保证合适吸附率的情况下选择吸附效率最佳的投加量,得到改性材料对初始浓度10 mg/L的Pb^(2+)、Cd^(2+)、Zn^(2+)、Mn^(2+)溶液的最佳投加量分别为0. 5 g/L、2 g/L、2 g/L、5 g/L,可为中试和规模应用提供参考。较之焙烧、酸、碱、盐和有机改性,本改性方式对多种重金属均有高的吸附率,并显现出操作简便、成本低和环境友好等优势,具有较好应用前景。BACKGROUND:Natural mordenite is widely used as a green and cheap porous material to remove heavy metals in environmental treatment.Currently,the removal rate of heavy metals by natural zeolites is from 60%to 90%,and improving its removal efficiency has been a hot topic. OBJECTIVES:To reconstruct and modify natural mordenite by tetraethyl orthosilicate,and determine its effect on the removal of heavy metals in water. METHODS:The morphology and structure of the modified mordenites were characterized by TEM,XRD and BET. RESULTS:The SiO 2 hydrolyzed by tetraethyl orthosilicate can be combined with natural mordenite to form a new‘SiO 2/mordenite’.The surface of the original mordenite is coated with the pore structure of the new nano-SiO 2 without damaging the porous structure of the original mordenite.The modified mordenite combines the advantages of natural mordenite and nano-SiO 2 pore structure,enhancing the adsorption of heavy metal ions.The highest adsorption rate of modified mordenite for Pb^2+,Cd^2+,Zn^2+,and Mn^2+was 99.3%,97.1%,98.3%,and 97.0%,respectively.The modified mordenites were minimally desorbed during the entire process and have stable performance.Considering the cost and the appropriate adsorption rate,the best dosage of adsorption efficiency is selected.The optimal dosage of Pb^2+,Cd^2+,Zn^2+and Mn^2+solutions for the initial concentration of 10 mg/L is 0.5,2,2 and 5 g/L,respectively.It can provide a reference for a pilot experiment and scale applications. CONCLUSIONS:Compared with roasting,acid,alkali,salt and organic modification,this modification method has a high adsorption rate for a variety of heavy metals,and shows the advantages of simple operation,low cost and environmental friendliness,making it a good application prospect.

关 键 词：天然丝光沸石 二氧化硅 改性 重金属 吸附 

分 类 号：P578.974[天文地球—矿物学] O613.72[天文地球—地质学]