Relationship between groundwater cadmium and vicinity resident urine cadmium levels in the non-ferrous metal smelting area,China

● This study systematically examined the relationship between groundwater Cd and UCL. ● The study covered 211 UCL and sociological characteristic from nine groundwater samples. ● We found a significant positive correlation between groundwater Cd and UCL. ● Smoking status and education level also significantly affected UCL. Cadmium (Cd) has received widespread attention owing to its persistent toxicity and non-degradability. Cd in the human body is mainly absorbed from the external environment and is usually assessed using urinary Cd. Hunan Province is the heartland of the Chinese non-ferrous mining area, where several serious Cd pollution events have occurred, including high levels of Cd in the urine of residents. However, the environmental factors influencing high urinary Cd levels (UCLs) in nearby residents remain unclear. Therefore, 211 nearby residents’ UCLs and the corresponding sociological characteristics from nine groundwater samples in this area were analyzed using statistical analysis models. Groundwater Cd concentration ranged from 0.02 to 1.15 μg/L, aligning with class III of the national standard; the range of UCL of nearby residents was 0.37–36.60 μg/L, exceeding the national guideline of 0–2.5 μg/L. Groundwater Cd levels were positively correlated with the UCL (P < 0.001, correlation coefficient 95 % CI = 9.68, R² = 0.06). In addition, sociological characteristics, such as smoking status and education level, also affect UCL. All results indicate that local governments should strengthen the prevention and abatement of groundwater Cd pollution. This study is the first to systematically evaluate the relationship between groundwater Cd and UCL using internal and external environmental exposure data. These findings provide essential bases for relevant departments to reduce Cd exposure in regions where the heavy metal industry is globally prevalent.     

重金属污染土壤植物修复及进展

土壤污染是当今面临的一个重要环境问题。常规的土壤污染物理化学治理技术 ,如客土换土法、冲洗法、热处理、固化、玻璃化、动电修复法等 ,由于其技术要求高或经济成本高昂 ,对土壤结构的扰动破坏较严重 ,因而 ,大规模推广应用存在较大问题。重金属超累积植物的不断发现 ,使人们认识到有可能利用植物于土壤污染的治理修复。自 2 0世纪 90年代起 ,植物修复成为环境污染治理研究领域的一个前沿性课题。研究表明 ,通过植物的吸收、挥发、根滤、稳定等作用 ,可以净化土壤或水体中金属污染物 ,达到净化环境的目的。近 10年来 ,在超累积植物的找寻培育、植物根际微生物共存体系研究、植物对重金属的耐忍性、超量吸收及其解毒机制以及植物修复的工艺技术方面已有不少研究 ,并取得长足的进展 ,现代分子生物学的发展以及基因工程技术的应用有可能使植物修复技术取得根本性的突破。     

矸石基X型分子筛对水中Co2+、Cu2+、Cd2+和Cr3+的去除

以煤矸石为原料,采用碱熔后水热合成法制备X型分子筛并进行XRD、SEM、BET和Zeta电位分析。研究其对水中Co2+、Cu2+、Cd2+和Cr3+4种离子的吸附性能,包括吸附等温线、吸附动力学以及初始金属离子浓度、pH值对吸附性能的影响。所合成的矸石基X型分子筛的BET比表面积为676.02 m2/g,微孔孔容为0.263 cm3/g。吸附实验表明,矸石基X型分子筛能有效去除上述4种离子,同时实现煤矸石的资源化和金属离子的去除。4种离子的平衡吸附量均随初始浓度的增大而增大,相同条件下平衡吸附量的大小顺序为Cd2+>Cr3+>Cu2+>Co2+。准二级动力学模型能很好地描述4种离子的吸附动力行为。Langmuir模型对Co2+、Cu2+和Cd2+吸附的拟合较Freundlich模型高,说明其主要表现为物理吸附过程。4种离子的吸附速率均由液膜扩散和颗粒内扩散共同控制。     

粘土矿物与重金属界面反应的研究进展

介绍了3种粘土吸附剂：蒙脱石、高岭石和伊利石对重金属的吸附、脱附等界面反应机理，以及粘土矿物对重金属的选择性及对吸附的影响因素。另外，还探讨了为提高其吸附性能而进行的改性方法。     

SGA对垃圾焚烧飞灰中重金属的固化性能研究

根据EPA1311、HJ／T299—2007、HJ／T300—2007和HJ557—2009等国内外不同标准,研究了深圳某垃圾焚烧发电厂垃圾焚烧飞灰的浸出毒性,探讨了六硫代胍基甲酸（sixthioguanidineacid,SGA）、二甲基二硫代氨基甲酸盐（sodiumdimethyldithiocarbamate,SDD）和Ca（OH）2浓度对垃圾焚烧飞灰中重金属的固定性能的影响。研究结果表明,随着浸提液pH的降低,该厂焚烧飞灰中大部分金属元素的浸出量增大,焚烧飞灰浸出液中的cd、Ni、Ph和zn浓度分别超过国家危险废物鉴别标准（GB5085．3—2007）规定值的4．75倍、1．47倍、6．72倍和2．20倍,属于危险废弃物,必须进行稳定化处理。当固化剂SGA加入量为0．1mol／kg时,稳定化后的重金属浸出浓度已经低于危险废物鉴别标准,且对Cd、Cr、Cu和Pb的固化性能优于SDD和Ca（OH）2;当固化剂SGA、SDD和Ca（OH）2加入量为0．5mol／kg时,稳定化后的焚烧飞灰重金属浸出浓度均低于国家危险废物鉴别标准（GB5085．3-2007）中的规定值。与SDD和Ca（OH）：相比,SGA对垃圾焚烧飞灰中重金属的固化处理更具有优势。     

应用TOXI模型进行重金属在河流中迁移转化规律的研究

ＴＯＸＩ模型是美国环保局的ＷＡＳＰ（水质分析模拟程序）中的一部分。由于该模型考虑了污染物质在河流中溶解态，颗粒态和底泥态的分布关系，对于模拟重金属在河流中的浓度变化效果较好。为保证计算结果的可靠性，首先应对重金属浓度的衰减变化特性进行研究，本文重点讨论的是重金属在河流中迁移转化的过程，并如何将这一过程用数学公式来进行模拟。     

Potentially toxic metal contamination of urban soils and roadside dust in Shanghai, China

A detailed investigation was conducted to understand the contamination characteristics of a selected set of potentially toxic metals in Shanghai. The amount of Pb, Zn, Cu, Cr, Cd and Ni were determined from 273 soil/dust samples collected within urban area. The results indicated that concentration of all metals except Ni in soils was significant, and metal pollution was even severer in roadside dust. A series of metal spatial distribution maps were created through geostatistical analysis, and the pollution hotspots tended to associate with city core area, major road junctions, and the regions close to industrial zones. In attempt of identifying the source of metals through geostatistical and multivariate statistical analyses, it was concluded as follows: Pb, Zn and Cu mainly originated from traffic contaminants; soil Ni was associated with natural concentration; Cd largely came from point-sourced industrial pollution; and Cr, Ni in dust were mainly related to atmospheric deposition.     

应用地质累积指数评价攀枝花地区土壤重金属污染

应用地质累积指数对攀枝花地区昔格达组粘土中重金属污染进行了评价研究。结果表明，各重金属元素污染较严重的地区分布在宝顶煤矿、太平煤矿、攀钢冶钢厂、攀钢矿山、尾矿坝等工矿区，污染较轻微的地区分布在红格、新九等农业区。各元素的污染程度上看，该区As和Cu污染较重，Cd,Pb,Zn次之，而Cr污染最轻微。     

垃圾污染质在天然黏土屏障中运移情况的调查

通过对杨府山垃圾卫生填埋场的实地调查,重点调查了距垃圾场外边缘以南500m土壤中重金属含量,与国家环保局给出的土壤背景值比较,发现对人类健康有较大影响的Pb,Mn,Cu,Cd的浓度值均大大超过国家规定标准,污染指数分别达到了5.9959,2.0974,4.2021,2.4864,9.2204,其中镉的污染最为严重,并讨论了天然黏土屏障在污染质运移过程中的控制作用,及今后屏障材料的发展方向。该研究结果对该地区进行环境治理的必要性提供了科学依据。     

Heavy metals pollution in poultry and livestock feeds and manures under intensive farming in Jiangsu Province, China

The heavy metals pollution in poultry and livestock feeds and manures under intensive farming in Jiangsu Province was investigated. 97 feed and manure samples were sampled from 31 farming plants in 10 major cities of Jiangsu. 14 metals, including Zn, Cu, Pb, Cd, Cr, Ni, Mo, Mn, Ba, Co, Sr, Ti, As and Hg, were analyzed after samples acid digestion. The results showed that the most feed samples contained high concentration of metals exceeding National Hygienical Standard for Feeds. Meanwhile, it was found that Cu, Zn, Pb, Cd and Cr concentrations in animal manures were also high, for example, Cu concentration in a manure sample reached to as much as 1726.3 mg/kg. Heavy metals loading quantities in soil per year were then calculated when metals contaminated organic fertilizers were applied, and its effects on soil environmental qualitv were further evaluated.