Heavy Metal Contamination in Farmland Soil and Bioremediation Measures: A Case Study of the Mining Area in Shaoguan

With the rapid development of mining,the soil heavy metal contamination is increasingly serious in Shaoguan,directly affecting the production of crops. This paper analyzes the farmland soil heavy metal contamination in the mining area of Shaoguan and the causes of heavy metal contamination in recent years,brings forward the bioremediation measures to control soil heavy metal contamination,and points out the development direction of bioremediation in farmland soil heavy metal contamination in the mining area.

Effects of heavy metal pollution on farmland soils and crops:A case study of the Xiaoqinling Gold Belt,China

This paper focuses on the heavy metal enrichment and heavy metal pollution degree associated with mining activities in some crops and the soils of different parent materials in the Xiaoqinling Gold Belt.According to the geochemical analysis results of the soils observed in the gold belt,the soils are most highly enriched in Pb,followed by Cr,Cu,and Zn.Furthermore,they are relatively poor in Hg,Cd,and As.It is also shown that the heavy metals in all kinds of soils have the same geochemical characteristics in the gold belt.As for the crops(such as corn and wheat)in the gold belt,Zn and Cu are the most abundant elements,followed by Pb and Cr.Meanwhile,Hg,Cd,and As were found to have relatively low concentrations in the crops.The heavy metals in wheat and corn have the same geochemical characteristics in the gold belt in general.Compared to the aeolian loess soils and the crops therein,heavy metals are more enriched in diluvial and alluvial soils and the crops therein.As shown by relevant studies,the Hg,Pb,Cd,Cu,and Zn pollution are mainly caused by mining activities.Corn and wheat in the gold belt have a high tendency of risk exposure to heavy metal pollution since they are mostly affected by mining activities and feature high background values of heavy metal concentrations.Furthermore,wheat is more liable to be enriched in heavy metals than corn is grown in all types of soils.The Hg pollution in soils leads to Hg accumulation,increasing the risk of Hg uptake in crops,and further affecting human health.This study will provide a scientific basis for the control and management of heavy metals in farmland soils of mining areas.

Contamination and risk assessment of heavy metals in farmland soils of Baghrash County, Xinjiang, Northwest China

Soil pollution significantly reduces environmental quality.In this study,farmland soil samples were collected from 25 sites in Baghrash County,Northwest China;and the concentrations of eight heavy-metal elements(arsenic,As;cadmium,Cd;chromium,Cr;copper,Cu;manganese,Mn;nickel,Ni;lead,Pb;zinc,Zn)were determined by standard methods.The spatial distribution,contamination level,and ecological risk stature of heavy metals were analyzed based on GIS technology,the Geo-accumulation Index(Igeo),the Pollution Load Index(PLI),and the Potential Ecological Risk Index(RI).Results indicated that(1)The average concentrations of Cd exceeded 12.12 times the allowed national standard for soil environmental quality of China.The average concentrations of Cd,Cr,Ni,Pb,and Zn exceeded the background values of irrigation soils in Xinjiang by 60.58,1.25,1.50,4.95,and 5.10 times,respectively.(2)The pollution order of the average value of Igeo for heavy metals was ranked as Cd>Zn>Pb>Ni>Cr>Cu>As>Mn.The individual potential ecological risk index for heavy metals was ranked in the order of Cd>As>Ni>Cu>Pb>Cr>Zn.The average PLI for the study area showed a heavy pollution level,while the average RI showed a considerable ecological risk stature,as compared to the classification standard.(3)The spatial distribution patterns of eight heavy metal elements were substantially heterogeneous.The moderately polluted areas with moderate potential ecological risks were distributed in the southern parts of the study area,whereas the heavily polluted areas with considerable potential ecological risks were distributed in the northern parts.Overall,it was observed that Cd contributed most to the PLI and RI of the farmland soils in Baghrash County.The pollution risk of Cd should be a major concern,and human activities in the region should be cautious.

Advances in Cotton Tolerance to Heavy Metal Stress and Applications to Remediate Heavy Metal-Contaminated Farmland Soil

Heavy metal-contaminated soil is one of the major environmental pollution problems of agricultural production and human health in the world.Remediation of heavy metals in soil is one of the most popular research subjects.Different remediation strategies have been reported to remove heavy metals from contaminated soil,among which phytoremediation is the most important one.Compared with other major crops,cotton shows the strongest and most widespread resistance to abiotic stresses,such as heavy metals.Although heavy metal stress adversely affects the growth and development of cotton,cotton possesses a set of sophisticated stress-resistance strategies.As the main product of cotton is nonedible fibers,which have a large biomass and strong heavy metal absorption and enrichment capacities,cotton is an ideal crop to restore heavy metal-contaminated soils and has unique advantages in terms of both ecological and economic benefits,with great application prospects.In this review,based on domestic and foreign research results in recent years,the effects of heavy metals on cotton growth and product quality were analyzed,the heavy metal absorption,accumulation,translocation and enrichment characteristics of cotton plants were summarized,and the adaptation and tolerance mechanisms of cotton to heavy metals were explored.Furthermore,the view that cotton is an effective crop to remediate heavy metal pollution in farmland soil has been proposed,and popularization and application suggestions for planting cotton to repair heavy metal pollution have been put forward to provide a reference for the comprehensive evaluation of the economic feasibility of cotton to repair heavy metal pollution in farmland soil.

Preliminary Study on Heavy Metal Pollution Status of Farmland Soil at Two Sides of Cheng-Guan Expressway

The heavy metal content of the farmland soil at two sides of Cheng-Guan Expressway is measured to make a preliminary evaluation on its heavy metal pollution status.After digestion and volume fixation of the soil samples collected,measure the Cu,Zn,Cd,Pb and Cr content with atomic absorption spectrophotometry and evaluate the measured data according to Level Two of National Soil Environmental Quality Standard to obtain the contamination status.Cu,Zn and Cd content of the farmland soil for sections of Cheng-Guan Expressway goes beyond Level Two of National Soil Environmental Quality Standard,while the Pb and Cr content meets Level Two of National Soil Environmental Quality Standard.Pb and Cr content of the farmland soil at two sides of Cheng-Guan Expressway is in safe state,while the Cu,Zn and Cd content is in a mild contamination state.Cu,Zn and Cd are the main pollution elements.

丹江口库区沿岸农田土壤重金属分布与来源解析

丹江口水库作为南水北调中线水源地,库区沿岸土壤重金属分布特征直接影响水库水质安全。为研究丹江口水库沿岸农田土壤重金属的污染特征及来源,测定了As、Cd、Cu、Pb、Hg、Ni、Zn和Cr等8种重金属。采用地质累积指数和富集因子对土壤污染状况进行评价,并运用相关性分析及主成分分析展开溯源。结果表明:研究区8种重金属(除2个样品的总As浓度外),其他样品重金属浓度均未超过《土壤环境质量农用地土壤污染风险管控标准(试行):GB 15618—2018》筛选值。Hg富集程度最高,均有4%采样点处于中度富集状态(1<I_(geo)≤2)和重度富集状态(2<I_(geo)≤3)。整个库区农田土壤重金属As、Cd、Cu、Pb、Hg、Ni、Zn和Cr的无污染至轻微污染区均>92%,As、Cd、Hg和Cr的中度以上污染区分别为4%、4%、6%和4%,仅Hg有2%区域属重度污染。空间上,8种重金属分布差异显著,库区农田土壤呈轻度富集趋势。来源解析发现,As、Cu、Ni和Zn主要受生活污染源和工业污染的混合影响,Pb以交通源为主,Cd主要来源于农业污染源,Hg受大气沉降源的污染,而Cr主要来源为成土母质自然源输入,其贡献率分别为44.655%、15.376%、13.093%、11.178%、8.386%。

基于波谱响应特征的雄安新区农田土壤重金属含量反演

分析并监测雄安新区农田土壤污染状况,对于保障粮食安全、建设绿色雄安具有重要意义。该研究以雄安新区为研究区,基于多源遥感数据珠海一号(Zhuhai-1)OHS数据、哨兵二号(Sentinel-2)L2A级数据的波谱响应特征及实地测得的农田土壤重金属含量数据,在对土壤重金属含量单因子与多因子污染评价的基础上,筛选出3种超标的农田重金属元素铅(Pb)、铜(Cu)、锌(Zn),采用偏最小二乘回归方法(partial least squares regression,PLSR)建立农田土壤重金属含量反演模型。利用Zhuhai-1提取土壤样本点的原始光谱反射率以及4种变换后的光谱反射率,Sentinel-2提取7种对重金属胁迫敏感的植被指数,将其与3种土壤重金属含量作相关性分析,筛选出敏感波段与植被指数,即波谱响应特征,构建土壤重金属含量反演模型。结果表明,3种模型整体反演精度较为优良,Pb含量反演模型决定系数(determination coefficient,R^(2))为0.490,均方根误差(root mean squared error,RMSE)为4.66 mg/kg,平均绝对值误差(mean absolute error,MAE)为1.92 mg/kg;Cu含量反演模型R^(2)为0.491,RMSE为16.85 mg/kg,MAE为3.69 mg/kg;Zn含量反演模型R^(2)为0.664,RMSE为20.63 mg/kg,MAE为9.36 mg/kg。将该模型应用于雄安新区农田区域,得到大部分农田土壤中Pb含量均未超过风险筛选标准,在研究区西南部、西部部分区域Cu含量超过土壤污染风险筛选值,同时在研究区西部、西南部Zn污染较严重,雄安新区东南部部分农田有Zn零星分布,其他区域Cu和Zn含量未超过国家土壤污染风险管控值。因此,利用多源遥感数据波谱响应特征反演土壤重金属Pb、Cu和Zn含量,能够快速准确地实现对雄安新区土壤重金属污染情况的调查,同时为大面积土壤重金属含量监测提供解决方案。

农田土壤重金属污染现状与安全利用技术研究进展

重金属污染农田直接影响粮食安全和农业可持续发展。安全利用技术主要通过降低土壤中重金属的生物有效性,以减少作物对重金属的吸收累积和消减重金属进入食物链的风险,其对解决我国重金属污染农田有效利用和保障粮食安全生产具有重要意义。因此,本文首先分析了农田土壤重金属污染成因与现状,然后综述了不同安全利用技术,如农艺调控措施(包括低累积作物品种筛选、水肥管理及间作或轮作耕作方式)、原位钝化改良和叶面阻控技术的研究进展,最后提出了强化重金属污染农田土壤安全利用研究及应用的对策。

铜选冶厂周边农田土壤重金属污染特征及来源解析

为分析云南某铜选冶厂周边农田土壤重金属污染特征及来源,通过测定农田土壤中重金属(Cu、Zn、Cr、Ni、Pb、Cd、As、Hg)的含量,采用污染负荷指数、地累积指数及潜在生态危害指数法评价农田土壤重金属污染特征,并结合相关性分析和PMF模型对土壤重金属来源进行分析.结果表明:研究区土壤中Cr、As、Pb、Hg 4种重金属元素的平均含量均高于云南省土壤背景值;污染负荷指数处于轻微污染;地累积指数中As(0.92)>Hg(-0.05)>Cr(-0.41)>Pb(-0.52)>Cu(-1.05)>Zn(-1.20)>Ni(-1.21)>Cd(-3.23),As元素属于轻度累积,其余重金属均为无累积;潜在生态风险单项指数中除Hg元素达到中等生态风险,其余7种重金属元素均为轻微生态风险,研究区整体处于轻微生态风险.土壤重金属来源分析中PMF模型解析5个因子,贡献率分别为14.8%、16.1%、15.3%、26.6%和27.2%.其中As元素主要为工业活动源,Cu、Zn、Cr、Ni元素主要为土壤成土母质源、Cd元素主要为农业活动源、Pb元素主要为交通源、Hg元素主要为化石燃料源.

朔州东部农田土壤–农作物重金属富集及健康风险评价

为研究重金属在农田土壤-作物之间的累积性及人群健康风险,采用富集因子(EF)、地累积指数(I_(geo))和潜在生态危害指数(RI)等指标对山西省朔州市东部三县市(山阴县、应县、怀仁市)131个样点农田土壤-作物系统(玉米、高粱和大豆)中重金属的含量、来源及富集程度进行调查,并采用EPA推荐的风险评估模型对人群健康风险进行了评估.结果表明:1)研究区土壤中8种重金属(Cd、Cr、As、Hg、Pb、Cu、Zn、Ni)含量均未超过《土壤环境质量农用地土壤污染风险管控标准(试行)》(GB 15618—2018)中农用地土壤污染风险筛选值;而Cr、Hg、Pb的平均含量分别是研究区背景值的1.20倍、6.26倍和1.33倍.2)研究区土壤中Hg元素为显著富集,其余重金属无富集.地累积指数分级结果表明,土壤中Hg呈中度污染,其余为无污染.潜在生态危害指数结果表明研究区为中度污染水平.3)主成分分析结果表明,研究区Ni、Cr、Zn、Cu主要来源于“自然来源”,Hg主要来源于“直接工业源”,As、Pb主要来源于“大气沉降-工业源”,而Cd主要来自“农业来源”.4)8种重金属对儿童的非致癌风险高于成人.研究区Pb对儿童和成人均无致癌风险,Cd和As对儿童和成人的致癌风险均处于可接受范围内,而Cr、Ni是主要致癌风险因子.

农田土壤重金属外源识别及安全利用技术筛选——以宜宾市筠连县部分区域为例

【目的】基于农田土壤重金属污染外部来源途径的识别结果,筛选出钝化剂-低积累作物品种耦合的镉污染农田绿色修复与安全利用技术,以期为农田土壤重金属污染防控提供参考依据。【方法】以四川南部宜宾市筠连县部分乡镇为研究区域,监测该区域内大气沉降、肥料使用、灌溉水及底泥中重金属含量从而计算不同途径的农田土壤重金属输入通量,并选择具有代表性的JL镇利用大田试验开展钝化剂、重金属镉低积累蔬菜和水稻品种筛选。【结果】2019—2020年研究区域农田土壤中汞、砷、铅和锌的主要输入途径为大气沉降,所占比例分别为99.99%、75.88%、90.57%和84.82%;镉、铬和镍的主要输入途径为肥料,所占比例均为100.00%;铜的主要输入途径为灌溉水,所占比例为93.66%。JL镇镉污染农田土壤中施用铁锰肥钝化剂(硫酸亚铁750 kg/hm^(2)+硫酸锰75 kg/hm^(2))对降低水稻籽粒中镉的效果最佳,归因于土壤微量元素的补充对肥力的改善作用,而钝化剂复配(3000 kg/hm^(2))处理下水稻籽粒中镉含量最高。镉低积累蔬菜和水稻品种筛选结果表明九斤萝卜和川康优6276是该地区最适宜种植的蔬菜和水稻品种,收获后可食用部分重金属镉含量均符合食品安全国家标准。【结论】在研究区域除应选用符合国家标准的肥料并注意防控大气沉降污染外,同时建议推广使用铁锰肥、腐殖酸和磷肥钝化材料,并种植九斤萝卜蔬菜和川康优6276水稻品种以保障农产品质量安全。

自然复合污染条件下小白菜对镉汞吸收的品种差异研究

为探明自然轻度镉(Cd)、汞(Hg)复合污染对不同品种小白菜生长及重金属吸收的影响,采用盆栽和田间试验,测定小白菜可食部的生物量、维生素C含量、可溶性蛋白含量和Cd、Hg含量。结果表明,所测指标在21个品种间均存在显著差异,Cd含量为0.185~1.25 mg/(kg·DW),Hg含量为8.56~238µg/(kg·DW)。在盆栽和田间条件下,2个品种Cd富集系数小于1,而所有品种Hg富集系数均小于1。相关性分析显示,可食部生物量、可溶性蛋白含量、Cd含量以及Hg含量之间均无显著相关关系。供试21个品种在该轻度复合污染农田种植不存在安全风险,其中‘奶油小白菜’是安全性最高的品种。

平原河网地区农田土壤重金属污染特征及来源解析

为实现对平原河网地区农田土壤重金属的精准管控,保障农产品的质量安全,本研究以典型平原河网地区——嘉兴市为例,通过采集表层(0~20 cm)土壤样品(n=40),分析土壤中重金属的含量水平与分布特征,利用地累积指数法和潜在生态风险指数法,评价重金属的污染风险,并结合相关性分析、绝对主成分得分-多元线性回归(APCS-MLR)和正定矩阵因子分解模型(PMF),定量解析重金属的污染来源。结果显示:土壤中铜(Cu)、镍(Ni)、铬(Cr)、锌(Zn)、铅(Pb)、镉(Cd)、砷(As)和汞(Hg)的含量分别为(28.8±3.73)、(36.5±5.98)、(60.7±5.38)、(70.5±8.04)、(33.2±6.25)、(0.08±0.04)、(7.30±1.52)mg·kg^(-1)和(0.31±0.15)mg·kg^(-1)。其中,部分点位Hg含量超过农用地土壤风险筛选值(超标率为12.5%)。研究区域主要污染元素为Hg,其地累积指数(Igeo)为(0.20±0.77),呈轻微至轻度污染(67.5%);综合潜在生态风险(RI)为(122±39.8),属于中度风险,Hg是主要风险因子(64.4%)。源解析结果表明,农田土壤重金属的来源为工业源(32.0%)、自然源(28.2%)、农业源(25.8%)和交通源(14.0%),其中Hg主要来源于农业源(62.9%)和工业源(37.1%)。未来可加强对农业投入品及工业三废的管控,降低农田土壤中Hg的输入,保障农田土壤的安全利用及农产品的质量安全。

阳新县浮屠镇农田土壤重金属含量评价

阳新县浮屠镇矿产资源丰富,近年来当地快速发展工矿业,矿产资源的开采势必会增加农田土壤重金属污染的风险,因此了解当地农田土壤的重金属含量对于污染防治具有重大意义。根据《土壤环境质量农用地土壤污染风险管控标准(试行)》(GB 15618—2018),利用国家监控的10个农田点位,采集土壤表层样品,测定土壤pH值和8项重金属(Hg、Cr、Ni、Cd、Cu、As、Pb、Zn)全量,综合利用地积累指数法、潜在生态风险指数法和空间插值法,评价农田土壤重金属含量和潜在生态风险。结果表明:1)阳新县浮屠镇农田土壤中除Cu以外,其他重金属含量均未超过农用地土壤分析筛选值;2)从地积累指数评价结果来看,Cu和Cd属于轻微污染水平,其他重金属均属于无污染水平;3)潜在生态风险指数为159.41,整体处于中等风险水平,主要贡献元素为Hg和Cd;4)依据主成分分析结合空间分析,Cd、Pb、As、Cu、Zn、Ni主要来源于工矿业的开采影响。Cr和Hg受到人为影响很小。综上,阳新县农用地土壤污染风险低,适合农业生产,但Cu和Cd的潜在风险需关注。

重金属污染田的小麦安全生产策略

农田土壤重金属污染严重威胁着粮食安全和人类健康.小麦作为主粮作物是人类摄入重金属的主要膳食来源之一,如何在重金属污染农田实现小麦的安全生产是当前农业生产中亟待解决的问题.论文综述了我国小麦生产中重金属的污染概况、土壤重金属污染防治的措施、小麦重金属的耐受和吸收转运机制、重金属低积累小麦种质筛选、基因发掘及品种选育技术的研究进展.研究认为种植重金属低积累品种并搭配适宜的农艺措施是现阶段小麦重金属污染防治的最有效措施;低积累种质筛选、优异基因挖掘与分子标记开发是现阶段小麦重金属低积累研究的主要任务.随着实用分子标记的不断开发,分子标记辅助选择的常规育种技术将成为未来一段时期小麦重金属低积累品种选育的有效手段.

“PRF+”模式新技术对农田重金属污染修复治理的应用

我国耕地重金属污染严重,已严重威胁我国农产品和粮食安全,针对农田重金属污染问题,本文首次提出“PRF+”农田重金属污染修复治理模式新技术,该模式从源头水源智能监控净化、农田重金属污染治理、地力提升与作物增产到秸秆离田再利用,实现边生产边修复,保障粮食安全。

我国农田土壤重金属污染现状及治理研究进展

农田土壤重金属污染导致农作物重金属含量超标,这些重金属随食物链进入人体,对人体健康造成危害。了解农田土壤重金属污染现状、重金属污染对农作物的危害以及污染农田的治理方法,对保障饮食安全具有重要意义。本文综述了我国农田土壤重金属污染现状,阐述了农田土壤重金属污染可能对农作物造成的影响,概括了目前农田土壤重金属污染的主要治理方式,分析了这些治理方式的差异性和优缺点,并对未来农田土壤重金属污染治理的方向进行了展望,以期为我国农田土壤重金属污染治理的进一步研究提供参考。

耕地重金属污染与安全利用综述

耕地土壤是人类赖以生存的重要资源之一,为农作物生长提供必要的养分和物质基础。然而,随着工业化和农业现代化的快速发展,重金属污染耕地土壤的问题日益严重。重金属污染不仅影响农产品质量安全,还会通过食物链危害人类健康。本文简要介绍了耕地土壤重金属污染情况,详细阐述了重金属污染对土壤、植物环境和人类健康的影响,总结了重金属污染耕地的安全利用措施,以期为耕地土壤重金属污染治理修复和安全利用提供参考。

植物修复技术在农田土壤污染治理中的应用与效果验证

本研究探讨了植物修复技术在农田土壤污染治理中的应用与效果验证。通过实地调查和实验室分析,我们评估了不同植物种类对重金属污染土壤的修复效果。结果表明,植物修复技术可以显著降低土壤中的重金属含量,并提高土壤的生物活性和养分含量。

云南省农田表土重金属分布特征与污染评价

为了解云南省农田表土中重金属含量的分布特征和污染情况,在全省范围内农田设立了113个具有代表性的表土采样点,测定了样品中Cu、Pb、Cr、Zn含量。采用单因子指数法、内梅罗综合污染指数法、地统计学分析及Pearson相关性分析对表土重金属污染进行了评价,结果表明:Cu、Pb、Cr、Zn四种重金属含量均值分别是云南省背景值的1.87、1.52、1.92、1.39倍;Cu、Cr、Zn含量的空间分布大体呈东高西低,Pb含量呈从西南到东北逐渐降低的趋势,综合污染指数分布与重金属含量分布较为一致;相关性分析中Pb、Zn与有机质呈显著正相关,Cu、Cr与砂粒呈正相关。Cu、Cr、Zn在空间分布和相关性分析中均显示其有相似的来源,推测为有机肥料。整体上,云南省农田污染属于轻微污染。