生物炭-壳聚糖磁性复合吸附剂的制备及去除地下水中铅和铜  

Preparation and Application of Biochar-Chitosan Magnetic Composite Adsorbent for Removal of Lead and Copper from Groundwater

作　　者：杨梦楠 孙晗 曹海龙 贾增华 冯政远 郑丽君 陈男 YANG Mengnan;SUN Han;CAO Hailong;JIA Zenghua;FENG Zhengyuan;ZHENG Lijun;CHEN Nan(Land and Environment Rehabilitation Center,China GEO-Engineering Corporation,Beijing 100093,China;School of Water Resources and Environment,China University of Geosciences(Beijing),Beijing 100083,China)

机构地区：[1]国土环境整治中心,中国地质工程集团有限公司,北京100093 [2]中国地质大学(北京)水资源与环境学院,地下水循环与环境演化教育部重点实验室,北京100083

出　　处：《岩矿测试》2023年第3期563-575,共13页Rock and Mineral Analysis

基　　金：企事业单位委托项目“长江流域典型金属矿山酸性土壤及地下水污染协同修复技术研发”(342021399)。

摘　　要：壳聚糖作为天然多糖有机物,具有对环境友好的特性,其含有的大量含氮官能团可吸附水中的金属离子。但壳聚糖类吸附剂在酸性条件下适应性差,实际使用过程中需要调节pH值,因此增加了运行成本。本文选用农林废弃物花生壳(CC)和玉米芯(PS)制备生物炭,与壳聚糖进行结合,并引入磁性因子Fe3O4,制备了花生壳生物炭-壳聚糖磁性复合吸附剂(PSC)和玉米芯生物炭-壳聚糖磁性复合吸附剂(CCC),并研究这两种吸附剂对水中Pb^(2+)和Cu^(2+)的吸附性能,同时利用实际含多种金属离子的地下水对所制备的材料进行实验,以评估其实际应用潜能。比表面积仪(BET)分析表征显示,CCC相比PSC的比表面积和平均孔径更大,两种吸附剂在pH 4~7范围内均表现出稳定的吸附性能。循环5个周期后,两种吸附剂仍对Pb^(2+)和Cu^(2+)的去除率保持在85%以上,表现出良好的循环利用性能。CCC对Pb^(2+)和Cu^(2+)的最大吸附容量分别为169.10mg/g和18.69mg/g,均大于PSC的最大吸附容量。同时,CCC可有效去除含重金属地下水中的多种金属离子。在处理实际含Pb^(2+)和Cu^(2+)的废水时可优先选择CCC材料作为吸附剂。吸附动力学实验结果表明,两种材料对Pb^(2+)的吸附以物理吸附为主,对Cu^(2+)的吸附以化学吸附为主。pH值影响实验和X射线光电子能谱(XPS)表征结果说明两种材料主要通过静电吸引和含氮官能团与金属离子的螯合作用去除Pb^(2+)和Cu^(2+)。本文使用农林废弃物制备生物炭降低了成本,引入的磁性因子方便了脱附过程,生物炭-壳聚糖磁性复合材料的制备方法有效地改善了壳聚糖类材料在酸性条件下的适应性,所制备的材料是一种去除地下水中Pb^(2+)和Cu^(2+)污染的有效潜在吸附剂。BACKGROUND:Wastewater containing heavy metals produced by mining,beneficiation,smelting,forging,processing,transportation,and other industries that has been improperly disposed of,leads to heavy metals entering and polluting the groundwater environment.Heavy metals can be enriched in the human body and participate in the biological cycle.Long-term accumulation of heavy metals in the human body will bring carcinogenic,teratogenic,and mutagenic risks.Adsorption has been of wide concern in the treatment of heavy metals pollution in water,due to the advantages of low operation cost,simple engineering operation and low secondary pollution.Chitosan as a natural organic polysaccharide organic matter,has the characteristics of being environmentally friendly.It contains many nitrogen-containing functional groups that can adsorb metal ions in water.However,the adaptability of chitosan adsorbents to acidic conditions is poor,so the pH value needs to be adjusted in the actual process,which increases the operating cost.Combining biochar with chitosan can not only improve the adsorption capacity of chitosan,but also improve the separation performance of biochar.However,most of the research on chitosan modified biochar concentrate on the single biochar.There are few studies on the modification of biochar from different sources by chitosan,and the interaction between chitosan and biochar is not clear.

关 键 词：生物炭 壳聚糖 吸附 铅 铜 含氮官能团 X射线光电子能谱 

分 类 号：X523[环境科学与工程—环境工程] G264.3[历史地理—考古学及博物馆学]