碱改性沸石吸附铅和氨氮性能及对稀土矿山土壤的修复作用  

Alkali-Modified Zeolite:Adsorption Performance for Pb and Ammonia-Nitrogen and Its Remediation Effect on Soil from Rare Earth Mines

作　　者：林小淳 刘晓瑜[1,2] 袁欣 张隆隆[1,2] 刘斯文 冯亚鑫 赵晓倩[3] 黄园英 LIN Xiaochun;LIU Xiaoyu;YUAN Xin;ZHANG Longlong;LIU Siwen;FENG Yaxin;ZHAO Xiaoqian;HUANG Yuanying(National Research Center for Geoanalysis,Beijing 100037,China;Key Laboratory of Ministry of Natural Resources for Eco-Geochemistry,Beijing 100037,China;School of Water Resources and Environment,China University of Geosciences(Beijing),Beijing 100083,China)

机构地区：[1]国家地质实验测试中心,北京100037 [2]自然资源部生态地球化学重点实验室,北京100037 [3]中国地质大学(北京)水资源与环境学院,北京100083

出　　处：《岩矿测试》2023年第6期1177-1188,共12页Rock and Mineral Analysis

基　　金：国家重点研发计划项目“离子型稀土矿浸矿场地土壤污染控制及生态功能恢复技术”(2019YFC1805103);中国地质调查局地质调查项目“典型硫化物矿集区生态地质调查与修复技术支撑”(DD20230754)。

摘　　要：针对废弃离子型稀土矿山中的重金属铅和氨氮复合污染问题,本文采用木醋液、氢氧化钠、木醋液-氢氧化钠对天然沸石进行改性,利用扫描电镜(SEM)、比表面积测定(BET)、X射线衍射(XRD)分析改性前后沸石的微观结构和物相组成变化。开展室内模拟溶液中吸附动力实验;以现场采集的土壤为基质,进行柱淋滤实验及土壤中稳定化实验,分析了天然沸石和氯化钠、氢氧化钠、木醋液-氢氧化钠三种不同改性沸石对铅和氨氮的形态影响。结果表明:碱改性沸石和碱+木醋液改性沸石对200mg/L铅的去除率超过94%,对30mg/L氨氮的去除率大于65%;2%(质量百分比)为碱改性沸石的最佳添加比例,使土壤中铅有效态固化率达52%,氨氮由不稳定态向稳定态转化。现场中试实验证明,添加修复材料6个月后,碱改性沸石吸附稳定土壤中氨氮达94.61%。碱改性沸石不仅制备工艺简单,价格便宜,无二次污染,而且对土壤中铅和氨氮复合污染有很好的稳定化效果,可作为用于废弃稀土矿山土壤修复稳定化材料之一。BACKGROUND:Co-contaminated soils in rare earth mining areas,particularly with Pb and ammonia-nitrogen,present a significant environmental challenge.These contaminants have the potential for lasting,irreversible effects on both ecosystems and human health.Therefore,developing efficient,sustainable,and cost-effective soil remediation techniques is critical.Remediation in these areas is not only vital for reducing environmental pollution and protecting ecosystems but also supports sustainable mining practices and resource utilization.Current research in this field,especially regarding Pb and ammonia-nitrogen co-contamination,is limited.Zeolite adsorption,a popular method globally,is effective in treating heavy metal contamination in soils,showing superior results over lime and phosphate treatments.However,enhancing the adsorption capacity of natural zeolite is necessary,for which various modification methods are being explored.Among these,wood vinegar,a product of biomass pyrolysis,shows promise in improving pollutant removal due to its antimicrobial properties.This study explores the potential of wood vinegar as an additive to alkali-modified zeolite to stabilize heavy metals and ammonia-nitrogen in soils.OBJECTIVES:In order to tackle the remediation of co-contaminated soil in rare earth mines.METHODS:Wood vinegar,sodium hydroxide,and wood vinegar-sodium hydroxide were employed for zeolite modification,and Pb and ammonia-nitrogen speciation were determined by a continuous extraction method.Dynamic adsorption experiments were conducted to preliminarily analyze distinct modified zeolites’adsorption performance.Optimal mixing ratio of modified zeolites with soil samples was determined by column leaching experiments.Through indoor stabilization experiments,the stabilization effects of different modified zeolites on Pb and ammonia-nitrogen were compared,and chemical speciation changes and their environmental implications were discussed.Investigating the stabilizing impact of various modified zeolites on soil Pb and am

关 键 词：改性沸石 离子型稀土矿山 铅有效态 氨氮形态 土壤修复 

分 类 号：TD167[矿业工程—矿山地质测量] X53[环境科学与工程—环境工程]