北京园林绿地6种树木的叶片和一年生枝中5种重金属含量比较

为了解不同园林树木对重金属的吸收情况,以北京市陶然亭公园、紫竹院公园、中科院植物园、马甸公园、皇城根遗址公园和营城建都滨水绿道不同环境绿地为样地,选择样地间共有的园林树木,采用ICP光谱仪测定了6种树木叶片和一年生枝条中重金属锌(Zn)、铬(Cr)、镍(Ni)、砷(As)和汞(Hg)的含量,以此为基础,采用隶属函数法将6种树木单位重量对5种重金属的综合富集能力进行排序,并对同树种叶片与当年生枝、5种重金属吸收量分别进行相关分析。结果表明：1)不同树种叶片和一年生生枝条单位重量中重金属含量有显著差异,且因重金属种类而异。Zn、As含量最高的为金银木,Cr、Ni、Hg含量最高的依次为圆柏、侧柏、丁香;丁香富集Zn、Cr、As的能力最低,白皮松富集Ni能力最低,侧柏富集Hg能力最低。2)树木叶片和当年生枝单位重量对5种重金属综合富集能力排序为：金银木＞侧柏＞圆柏＞油松＞丁香＞白皮松。其中,针叶树种中圆柏、侧柏、油松富集5种重金属的综合能力显著高于白皮松(P＜0.01),阔叶树种中金银木吸收重金属的能力显著高于丁香(P＜0.01)。3)树木不同器官中重金属含量也不同,不同树种间叶片与枝条中仅Cr含量具有显著相关性,相关系数为0.461(P＜0.01),其他4种元素均未达到显著水平。4)同树种叶片和当年生枝Cr和Ni吸收呈极显著相关性(P＜0.01),其他元素吸收之间未呈现相关性。本研究结果对北     

磷石膏堆场对周围农田土壤重金属含量的影响

对什邡市两家磷化工厂的磷石膏和磷石膏堆周围土壤中Zn、Cd、As、Cu、Pb、Hg和U的含量及空间分布特征进行了检测和分析,根据重金属含量对土壤环境质量进行评价,并结合研究区地形地貌、气候特征研究重金属分布和来源。结果表明：磷石膏中重金属的含量较高,磷石膏的堆放使得磷石膏中的重金属在周边耕作层土壤中形成了较大的累积;9个土样中,各元素的检出率均为100%,Cd、Cu、Zn和Pb的含量最高,Cd的最高含量超土壤三级标准近3倍,Cu和Zn平均含量超过了土壤二级标准;磷石膏堆周围土壤中重金属含量在平面上与磷石膏堆距离成负相关,在纵向剖面上,重金属含量也基本上随着深度的增加而降低,各元素含量下降的程度不一样,Cd和Pb的下降程度最大。     

土壤pH和有机质含量对重金属可利用性的影响

以昆明市内28个作物种植点为例,对土壤重金属镉(Cd)、铜(Cu)、锰(Mn)、镍(Ni)、铅(Pb)及锌(Zn) 6种元素全量、有效态含量和相关土壤因子进行了测定.统计分析表明:土壤pH与Cd、Cu、Ni、Pb及Zn有效态含量呈显著的二次函数关系,当pH值在6.5左右时,重金属有效态含量较高,而随着土壤pH的进一步提高,其有效态含量显著降低.土壤有机质与Cd、Mn、Ni、Pb和Zn有效态含量呈显著正相关.因此,适当调节土壤pH至中性或弱碱性,科学合理地施用有机肥料,可有效降低耕地红壤重金属的生物可利用性,消减重金属污染问题.     

甘肃省白银市冶炼厂周围土壤中Cd、Cu、Pb、Zn的富集分布

对白银冶炼厂周围东、南、西、西北、西南、东南不同方向土壤中重金属Cd、Cu、Pb、Zn的富集分布进行研究,结果表明冶炼厂周围土壤存在不同程度的污染,其中以东侧污染最为严重,其次为东南侧,西南侧土壤污染相对较轻。整个区域土壤存在严重的Cd污染,Cd平均含量15.93mg/kg,最高达99.13mg/kg;相关性分析表明Cd与Pb、Zn之间有很好的相关性(r=0.897和r=0.969),表明Cd的分布与Zn、Pb相关;Cd、Cu、Pb、Zn与不同方向之间的负相关性表明,随距离冶炼厂越来越远,重金属的含量逐渐降低,说明冶炼烟尘沉降是引起土壤污染的重要原因。     

平顶山市白鹭洲城市湿地公园土壤重金属元素特征及评价

以平顶山市白鹭洲城市湿地公园表层土壤中重金属元素为研究对象,通过统计分析、空间插值分析、指数评价和聚类分析等手段,研究并评价了研究区土壤重金属元素特征。结果显示,研究区土壤中Cr、Co、Ni、Cu、Hg、Cd、Pb、As等元素含量均低于《土壤环境质量建设用地土壤污染风险管控标准(试行)》中第一类用地筛选值,但区域分布差异性较大。综合研究认为,局部地区个别重金属元素表现为中度污染,这些元素主要为Cd和Hg等,且毒性强度大。Hg和Cd元素同为亲硫元素,二者呈正相关,且含量和空间分布均具有相似性,可能属于同一物源。本研究结果为研究区及类似矿山生态重建和废弃地治理提供依据和参考。     

城市攀缘植物对大气颗粒物的吸附效果及重金属累积研究

城市攀缘植物具有吸附颗粒物及累积重金属的作用,能够有效改善城市生态环境。通过对6种攀缘植物叶片单位面积吸附不同粒径颗粒物、叶面颗粒物及叶片中重金属含量进行研究得出：五叶地锦(Parthenocissus quinquefolia)单位面积吸附总颗粒物量最大(12.56mg/cm2),七姊妹(Rose multiflora)和金银花(Lonicera japonica)较小。凌霄(Campsis grandiflora)吸附大颗粒物能力最强,木通(Akebia quinata)吸附粗颗粒物和细颗粒物能力最强。植物叶面颗粒物及叶片中重金属含量具有显著差异,地锦(Parthenocissus tricuspidata)叶面颗粒物中Cr含量最大,木通叶面颗粒物中Cu含量最大,五叶地锦叶面颗粒物中Pb,Zn和Cd含量最大。地锦叶片对Cr和Pb的富集能力最强,五叶地锦叶片对Zn和Cd的富集能力最强,凌霄叶片对Cu的富集能力最强。通过计算相关系数表明,除Cu之外,叶面颗粒物中4种重金属均与不同粒径颗粒物表现出正相关关系,其中Cr、Pb和Zn与细颗粒物的相关系数分别为0.760,0.759和0.813。植物叶片中重金属Cr与细颗粒物呈极显著正相关,相关系数为0.787。叶片中各重金属含量受到叶面颗粒物中各重金属含量的显著影响,叶面颗粒物中Cu-Pb、Pb-Zn、Cd-Cr呈极显著正相关,叶片中Zn-Pb、Cd-Cr、Cd-Pb、Cd-Zn呈极显著正相关,表明大部分重金属具有同源性。     

天津市环城四区绿地重金属含量特征及生态风险评价

绿地土壤是城市生态系统的重要组成部分,随着城市化进程的加快,绿地中的重金属污染问题日益引起人们的重视。为查明天津市环城四区绿地重金属含量特征、空间变异特征及潜在生态风险,本文以环城四区200件绿地土壤样品为基础,对Cr、Ni、Cu、Zn、Pb、As、Hg、Cd等8项重金属指标进行测定,应用统计分析、对比分析及Hankanson生态风险指数法等进行探讨,结果表明：①绿地土壤中Hg和Cd的变异程度最高,与人类活动关系密切;Cu、Zn、As具有较大的变异性;Pb、Ni、Cr在土壤中分布均匀。②与天津市表层土壤背景值相比,Hg、Cd和Zn这3种元素明显富集,Cu、Pb、As、Ni与土壤背景值相差不大,Cr低于土壤背景值。③单一重金属的潜在生态因子Hg为强烈生态风险,Cd为中等生态风险。④潜在生态危害指数RI=241.42为中等生态风险,居住绿地的土壤重金属生态风险相对较高,Hg和Cd为主要的影响因素,贡献率分别为为65.79%和21.68%,须注意管控和生态保护。     

甜瓜各器官6种重金属元素富集及转运能力差异的比较分析

为比较6种重金属元素在甜瓜植株各器官中富集及转运能力的差异,于果实成熟期采集土壤、根、茎、叶、果实并测定其中的Cr、Cu、As、Ni、Pb和Cd 6种重金属元素,在此基础上,通过富集系数、转运系数,评估了植株不同器官中重金属元素富集能力的差异,比较了各迁移阶段6种重金属元素转运能力的差异。结果显示,各器官中,根富集重金属元素的能力最强,较其他受试重金属元素,Cd和Cu更易在甜瓜植株中富集;迁移各阶段中,Cr、Ni、As、Pb 4种重金属元素由茎转运至果实和叶片的能力相对较强,Cd由根转运至茎的转运能力更强;重金属元素Cu由茎转运至叶片的能力相对较弱。不同重金属元素在甜瓜植株各器官中的富集、转运能力有所差异,宜根据目标调控重金属元素种类,开展对应主要转运阶段阻滞技术的研究与探讨。     

胶州湾沿岸土壤重金属元素分布特征及其生态风险评价

为探究胶州湾沿岸土壤重金属元素分布特征并对其进行生态风险评价,2019年5月采集胶州湾沿岸表层土壤样品34个、5个不同类型剖面土壤样品37个,运用富集系数、因子分析、潜在生态风险指数(potential ecological risk index,RI)等方法对其进行分析。结果表明:除As外,表层土壤重金属元素的平均含量均高于青岛市土壤背景值;表层土壤重金属元素空间分布不均匀,其中黄岛区As高,青岛市、黄岛区、城阳区Cd高,胶州经济技术开发区Cr、Ni高,Cu、Pb、Zn高值区主要位于青岛市和黄岛区,青岛市Hg高;剖面土壤重金属元素差异较大,农田、湿地和工业区附近的剖面所有土壤重金属元素均受到明显影响,而河畔和轮渡附近的剖面则仅部分重金属元素受到影响;表层土壤重金属元素As、Cd、Cu、Hg、Pb、Zn受到人为因素的明显影响,而Cr、Ni则主要来源于自然来源;表层土壤重金属元素Cd、Cu、Hg的潜在生态风险较高,其多种重金属元素的综合潜在生态风险也高,因此应加强土壤生态的污染控制和治理,防止土壤生态进一步恶化。     

开封市化肥河污灌区土壤蔬菜中Cd、V、Co和Cu污染评价

通过对开封市东郊污灌区土壤及蔬菜中重金属污染现状进行调查研究,分别测定重金属Cd、V、Co和Cu含量。研究结果表明,以《国家土壤环境质量标准》进行评价土壤样品受到不同程度的重金属污染,主要为Cd污染,超标率为48%,即近一半采样点土壤Cd含量超出国家土壤环境质量二级标准。Cd含量分布明显受与化肥河距离的影响,即距化肥河越近Cd含量越高,反之越低;V、Co和Cu的含量分布没有呈现出明显规律。蔬菜中重金属含量与国家食品安全卫生标准对比得到,蔬菜样品受到不同程度的重金属污染,主要为Cd和Cu污染,超标率分别为100%和13%。总体表现为叶菜类重金属含量高于根茎类蔬菜。     

Heavy metal contents in horticultural crops of a representative area of the European Mediterranean region

Heavy metal content (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn) was analysed in the edible parts of two types of horticultural crops (leaf and inflorescence crops) from 30 agricultural fields in Castellón (Spain), a representative area of the European Mediterranean region. Selected soil properties relevant to control the mobility and bioavaibility of heavy metals were analysed for the general characterisation of these agricultural soils. The levels of clay, high percentages of organic matter and the presence of carbonate seem to suggest an important retention of heavy metals by these components in most of these soils. However, the high salinity in some fields (>4 dS/m) seems to facilitate the mobility of some heavy metals (e.g. Cu). The mean values of total contents of heavy metals in soils were similar to values obtained in other works on Spanish agricultural soils. However, there were some fields with a metal content (particularly Cu, Pb or Zn) higher than these works, reflecting an important anthropogenic source. In seven fields, the crop contents of Cd and/or Pb were higher than the maximum levels established by the Commission Regulation no. 466/2001 for horticultural crops. Heavy metal contents in leaf crops were higher than in inflorescence crops, except for Zn. The differences for Cd, Cr, Cu, Fe and Mn contents between these two types of crops were statistically significant. The analysis of crop heavy metal contents showed a higher absorption and/or accumulation of heavy metals in leaf crops than in inflorescence crops. Differences in crop characteristics seem to be responsible for the differential accumulation of heavy metals. Furthermore, agronomic practices and other sources of heavy metals (e.g. atmospheric deposition for Cd and Pb) may also have some influence on crop accumulation. Given the relevance of horticultural crops in the Mediterranean diet, it is highly necessary to extend the experience of this work to other areas of the European Mediterranean region.     

北京市下沉广场地表灰尘重金属污染 特征及健康风险评价

通过采集下沉广场的地表灰尘样品，测定其中重金 属的含量，分析不同元素之间的相关性，探讨环境因素对重 金属含量的影响，采用健康风险评价模型评价相关风险。结 果表明，北京10座下沉广场地表灰尘中Cd、Pb、Cr、Cu、 Zn和Ni的平均含量分别为0.87、45.30、84.88、52.41、 167.47、24.03mg/kg，除Ni外，依次超过了北京土壤背景值 的3.28、0.84、1.85、1.80、1.91倍。灰尘中的Pb、Cu、 Zn含量具有显著正相关关系，人流密度对Cu含量有显著正相 关影响。下沉广场地表灰尘重金属引起的健康风险处于较低水 平。研究结果为下沉广场的设计和养护管理提供了科学依据。     

Cellulose/chitin beads for adsorption of heavy metals in aqueous solution

We successfully prepared the biodegradable cellulose/chitin beads by coagulating a blend of cellulose and chitin in 6 wt% NaOH/5 wt% thiourea aqueous solution with 5% H2SO4 as coagulant, and investigated the adsorption of heavy metals (Pb2+, Cd2+, Cu2+) from an aqueous solution on the beads by atomic absorption spectrophotometer. Batch adsorption experiments were carried out as a function of ion concentrations, initial pH, ionic strength, temperature, adsorption time and desorption time. The results revealed that the cellulose/chitin beads could adsorb effectively Pb2+, Cd2+ and Cu2+ ions, and the uptakes of Pb2+, Cd2+ and Cu2+ ions on cellulose/chitin beads were 0.33 mmol/g at pH0 4, 0.32 mmol/g at pH0 5 and 0.30 mmol/g at pH0 4, respectively. Experimental results also showed that the adsorption of these heavy metals was selective to be in the order of Pb2+ > Cd2+ > Cu2+ in a low ion concentration solution. The adsorption equilibrium time of these heavy metals on beads was 4-5 h, but the desorption time was 5-15 min. Moreover, these beads could be regenerated up to about 98% by treating with 1 mol/L HCl aqueous solution. The mechanisms for the removal of free heavy metal ions by cellulose/chitin beads was based on mainly complexation adsorption model, as well as a affinity of hydroxyl groups of the materials on metals. Therefore, we developed new environment-friendly beads prepared by a simple produce process for removal and recovery of heavy metals.     

Heavy metal pollution in the Chao Phraya River estuary, Thailand

A study on heavy metal pollution in the Chao Phraya River estuary indicated that the accumulation of Cd, Cu, Cr and Pb in water in the river mouth vicinity was significant, which may have a long term impact on the aquatic environment through precipitation of heavy metals to the bottom sediments and bio-accumulation and bio-magnification of heavy metals in various food chains. Although the seasonal and spatial variations of heavy metals in the sediments and fish did not conform to a definite pattern, the heavy metal contents of samples were higher than those previously reported in the area and in some cases were higher than the mean world concentrations. Thus, Thai people may ingest Hg and Pb in fish in the Chao Phraya River estuary at quantities more than those reported for other countries.     

Physiological and biochemical markers in the process of resistance and/or tolerance of heavy metals in the abandoned mining area of Sidi Kamber,Skikda, Algeria

This paper reports the biomonitoring of metallic pollution in the mine of Sidi Kamber Skikda town, to determine the resistance and/or tolerance to Zn, Pb, Cd and Cu in metalliferous plants. During the period of March–May, 2015, soil and plants samples were collected from three different stations in the study area. The total heavy metal fraction was determined by ICP/MS, whereas biochemical markers were determined by spectrophotometric techniques. The results obtained showed high levels of heavy metals in soil and plants compared to international standards. The translocation factor revealed that the studied plants can transfer and/or accumulate metals in their roots or their aerial parts as a function of characteristics of each metal, soil contents and physiological role in the plant. The contents of chlorophyll, proline, total sugars and total proteins are directly influenced by changes in bioavailable contents of heavy metals. It has been found that the plants studied and biomarkers are better suited for phytoremediation and biomonitoring of heavy metals pollution.     

Health risk assessment of heavy metal exposure to street dust in the zinc smelting district, Northeast of China

Heavy metal contamination in the street dust due to metal smelting in the industrial district of Huludao city was investigated. Spatial distribution of Hg, Pb, Cd, Zn and Cu in the street dust was elucidated. Meanwhile, noncancer effect and cancer effect of children and adults due to exposure to the street dust were estimated. The maximum Hg, Pb, Cd, Zn and Cu contents in the street dust are 5.212, 3903, 726.2, 79,869, and 1532 mg kg^− 1, and respectively 141, 181, 6724, 1257 and 77.4 times as high as the background values in soil. The trends for Hg, Pb, Cd, Zn and Cu are similar with higher concentrations trending Huludao zinc plant (HZP). The exponential equation fits quite well for the variations of Pb, Cd, Zn and Cu contents with distance from the pollution sources, but not for Hg. The biggest contribution to street dust is atmospheric deposition due to metal smelting, but traffic density makes slight contribution to heavy metal contamination. According to the calculation on Hazard Index (HI), in the case of noncancer effect, the ingestion of dust particles of children and adults in Huludao city appears to be the route of exposure to street dust that results in a higher risk for heavy metals, followed by dermal contact. The inhalation of resuspended particles through the mouth and nose is almost negligible. The inhalation of Hg vapour as the fourth exposure pathway to street dust is accounting for the main exposure. Children are experiencing the potential health risk due to HI for Pb larger than safe level (1) and Cd close to 1. Besides, cancer risk of Cd due to inhalation exposure is low.     

Deposition of airborne elements from Sembule steel mill surveyed by moss analysis

The local contamination of airborne elements caused by the Sembule steel works was studied by the analysis of Mg, Ca, Fe, Ni, Pb and Cd accumulated in transplanted moss. The concentrations of heavy metals (Fe, Ni, Pb, Cd) and other elements (Mg, Ca) were determined in soil, moss and water collected in the vicinity of Sembule steel mill. Comparison of elemental ratios indicate that there is contamination by heavy metals around this area. Accumulation coefficients have been applied to moss, soil and water data in an attempt to work out the contribution of these elements to water via soil and air. In evaluating Fe, Ni, Pb and Cd contents of river water and soil, a distinction was made between the amounts which are taken up from soil and those reaching the water as air depositions (as measured by use of moss). The calculations indicate that soil contributes 79.4, 96.3, 23.3, 0.50, 14.6 and 30.6 percent of Mg, Ca, Cd, Pb, Ni and Fe, respectively, whereas air deposition contributes 20.6, 3.73, 76.7, 99.5, 85.4 and 69.4 percent, respectively.     

北京市土壤重金属污染研究

为调查研究北京市一些重点功能区的土壤重金属污染状况,在朝阳、海淀、石景山、通州、怀柔、顺义区等典型的耕地、林地、菜地、工业区、交通区、旅游区选择采集了10个土壤样本。对各样点土壤的pH值、有机质含量、速效P、速效K、全N、全P、全K以及重金属元素Cr、Cd、Pb、Zn的含量进行了测定。采用单项污染指数法和内梅罗综合污染指数法来评价土壤重金属污染程度,并针对北京市不同功能区的土壤重金属污染状况,提出了相应的防治措施与对策。