摘要
本文分析了安徽省铜陵3处硫化物尾矿区矿砂、土壤与河流沉积物中4种核素^(238)U、^(226)Ra、^(232)Th和^(40)K的比活度,利用其γ辐射吸收剂量率(the gamma radiation absorbed dose rate,D)和年有效剂量率(annual effective dose equivalent,AEDE)开展了放射性水平评价。结果表明,3个尾矿区矿砂、土壤和沉积物的^(238)U、^(226)Ra和^(232)Th的比活度均值略高于安徽省土壤的平均水平。相关分析结果表明,A尾矿区尾矿砂剖面^(232)Th和^(40)K的比活度与pH值呈显著正相关,指示尾矿砂的氧化酸化导致了^(232)Th和^(40)K的淋失。B尾矿区沉积物和C尾矿区土壤受酸性矿山废水(acid mine drainage,AMD)影响显著,^(226)Ra与总硫呈显著正相关,指示^(226)Ra通过AMD迁移到土壤与沉积物中。3个矿区矿砂、土壤和沉积物中4种核素的D的平均值范围为66.22~136.15、81.46~96.67和85.29 nGy·h^(-1),均高于安徽省土壤的平均水平(56.7 nGy·h^(-1));而AEDE的平均值范围为406.03~834.89、499.49~592.75和522.99μSv·a^(-1),除了A尾矿区,其余2个尾矿区均高于安徽省土壤平均水平(510μSv·a^(-1)),但远低于《电离辐射防护与辐射源安全基本标准》(GB 18871—2002)规定的基本限值(1 mSv·a^(-1))。研究表明,铜陵部分硫化物尾矿氧化、酸化及AMD排放导致了放射性核素的淋失和迁移,但不会对周边生态系统造成放射性危害。
Specific activities of nuclides^(238)U,^(226)Ra,^(232)Th and^(40)K in sulfide ores,soils and river sediments around three mine tailings in City of Tongling,Anhui Province were determined,to calculate their gamma radiation absorbed dose rate(D)and annual effective dose rate(AEDE)and evaluate the corresponding level of radioactivity.The results showed that the average specific activities of^(238)U,^(226)Ra and^(232)Th in sulfide ores,soils and sediments were higher than those of soils in Anhui Province.Positive correlations between the specific activity of^(232)Th and^(40)K and pH in sulfide ore profiles suggest a leaching loss of^(232)Th and^(40)K from oxidation and acidification of sulfides in ores;the positive correlation between^(226)Ra and total sulfur in soils and river sediments suggests a source of acid mine drainage(AMD)for^(226)Ra.The average ranges of the gamma radiation absorbed dose rate for ores,soils and sediments are 66.22~136.15,81.46~96.67 and 85.29 nGy·h^(-1),respectively,higher than the average level of soils in Anhui Province(56.7 nGy·h^(-1)).Those average ranges of annual effective dose rate of soils and sediments(406.03~834.89,499.49~592.75 and 522.99μSv·a^(-1))are higher than that of soils in Anhui Province(510μSv·a^(-1))but lower than the limited value(1 mSv·a^(-1))of national standard.This study indicates that the oxidation and acidification of sulfide tailings at Tongling City resulted the leaching and transport of radionuclides between tailings and environmental media,whereas this would not cause radioactive hazards to the surrounding ecosystems.
作者
李文文
汪杰
黄涛
孙庆业
Li Wenwen;Wang Jie;Huang Tao;Sun Qingye(School of Resources and Environmental Engineering,Anhui Province Engineering Laboratory for Mine Ecological Remediation,Anhui University,Hefei 230601,China)
出处
《生态毒理学报》
CAS
CSCD
北大核心
2022年第2期290-298,共9页
Asian Journal of Ecotoxicology
基金
安徽省重点研发计划项目(201904a07020071)。
关键词
天然放射性
硫化物尾矿
土壤
河流沉积物
比活度
natural radioactivity
sulfide tailings
soils
river sediments
specific activity
作者简介
第一作者:李文文(1996-),男,硕士研究生,研究方向为生态工程与环境修复技术,E-mail:1151031542@qq.com;通讯作者:黄涛,E-mail:huangt@ahu.edu.cn。
