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1.
陈世俭 《生态环境》2000,9(3):183-185
试验研究了泥炭和堆肥对铜污染土壤盆栽黑麦草生物量的影响。结果表明,在未添加有机物质的情况下,随着污染土壤铜含量的增加,黑麦草生物量呈明显减少的趋势(呈显著负相关),地下部分对铜毒害的反应比地上部分更敏感;导致黑麦草生物量减产20%的土壤铜含量在200~400 mg/kg之间。添加有机物质能显著促进黑麦草尤其是其地下部分的生长,使中度、重度铜污染土壤上的三茬黑麦草生物量平均增加80%~200%,并提高了导致黑麦草严重减产的土壤铜临界浓度。堆肥的增产效果好于泥炭。在试验的9个月内,有机物质仍能维持对受铜污染的土壤上的黑麦草生长的促进作用。  相似文献   

2.
重金属进入土壤后难以被降解,并通过食物链在生物体内富集,长此以往会导致中毒、癌症、畸形、突变,严重影响了人类生产活动及地球生态系统的稳定。植物修复技术是一种经济有效的重金属污染修复技术,其依靠超富集植物强大的自身抗性机制,从土壤中提取或稳定重金属,达到污染治理的目的。然而修复土壤重金属污染的超富集植物通常生长缓慢、生物量低,其抗性机制也会受到植物本身对重金属胁迫的阈值限制,当胁迫超过这个阈值,植物修复的效率就会大大降低甚至失去修复功能。文章在解析植物重金属相互作用机制的基础上,综述了添加外源物质对重金属毒害植物的缓解效应以及其在强化植物修复土壤重金属污染中的应用研究进展;介绍了应用外源物质调控植物吸收转运重金属的3种途径,分别为提高土壤重金属生物利用度、促进植物生长以及增强植物耐性。提出了应用外源物质作为强化植物修复措施的潜力及今后的研究方向,其未来的研究应着重于以下方面:明确外源物质的应用浓度、时期、方式与植物吸收转运重金属之间的关系;从植物内源激素及信号分子间的互作、抗逆基因表达、内生及根际微生物等不同层面上揭示外源物质对植物积累重金属的调控机理;开展外源物质与其他植物修复强化技术的联合应用研究。这些研究可为土壤重金属污染的植物修复技术及其强化措施研究提供科学依据,同时也对植物修复工程技术的发展实践具有一定的指导意义。  相似文献   

3.
分析了泥炭和堆肥两种有机物质的添加量水平对冶炼厂附近污染土壤中铜形态及其活性的影响。结果表明, 添加土重2 . 5 % 有机物质就对土壤铜化学形态与活性产生显著的影响, 使氧化锰结合态和松结合有机态铜等向紧结合有机态铜转化, 使土壤化学活性铜 (2 . 5 % 醋酸提取) 降低约20 % ; 添加量增加到5 . 0 % , 控制作用有明显加强的趋势; 添加量再增至10 . 0 % , 单位添加量有机物质的控制作用明显减弱。  相似文献   

4.
吴海珍  韦朝海  周盛 《生态环境》2012,21(1):166-171
生物吸附与降解是解决持久性有机污染物(POPs)最有潜力的方法之一,有必要介绍利用微生物把目标污染物转化为易降解的物质甚至矿化的POPs修复原理及其技术。对此,概述了近年来国内外基于微生物通过膜融合、胞质融合和核融合形成能够降解POPs的杂种细胞的细胞融合技术;基于降解性质粒的相容性,把能够降解不同污染物的质粒组合到一个菌种中,形成多质粒的新菌种,使微生物由于代谢途径的改变能够矿化POPs的基因工程菌构建技术;基于通过某些载体把酶固定于其中实现活性稳定、可以回收及可重复利用的酶固定化技术,以及基于降解菌活性酶分子亚基置换、降解菌活性酶的定点突变、降解酶的体外定向进化这几方面的酶构建技术;进一步分析基于分子生物学提高POPs生物修复能力的原理,指出经生物技术改造的工程菌和固定化酶未能进入实际应用的障碍所在。以多溴联苯醚(PBDEs)的微生物细胞吸收和降解机理作为典型POPs生物修复的案例,强调生物降解的过程强化需要建立多尺度上功能方面的适合;提出了分子生物学与基因工程学的结合在解决POPs环境污染方面未来的基础科学问题与研究思路。综合上述,典型POPs的生物修复技术的构建需要考虑宏观污染物协同降解的工艺理论,在基因水平、分子水平、反应器水平及工程水平上追求更高功能方面的适合。  相似文献   

5.
持久性有机污染物(POPs)由于具有致癌性、致畸性和致突变效应的"三致性",近年来已经越来越受到人们的关注.本文综合分析了有机氯农药(OCPs)、多氯联苯(PCBs)、二英类(PCDD/Fs)、多环芳烃(PAHs)及多溴联苯醚(PBDEs)等几种典型土壤持久性有机污染物的空间分布特征.同时,对土壤POPs的挥发作用、吸附/解吸、迁移、生物降解、化学降解等环境行为进行了深入分析,并指出了这些环境行为的影响因素,包括POPs的物质属性、土壤理化性质及周围环境等共性影响因素及其它因素.此外,针对国内外研究现状中存在的问题,提出了相关建议,指出控制土壤POPs污染的根本手段在于管理措施的完善.  相似文献   

6.
For the duration of the war accident in former Yugoslavia, several industrial and military targets were burnt and damaged, resulting in a significant release of persistent organic pollutants. Locations heavily targeted in the attacks were later defined by UNEP as four “hot spots”: Kragujevac, Novi Sad, Pancevo and Bor. We analyzed concentration levels of pollutants collected in 2004 and 2005 in air samples from the city of Kragujevac, Serbia, following the war accident of 1999. Pollutants included polycyclic aromatic hydrocarbons (PAHs), hexachlorocyclohexane (HCH), dichloro-diphenyl-trichloroethane (DDT), dichloro-diphenyl-dichloroethylene (DDE), dichloro-diphenyl-dichloroethane (DDD) and polychlorinated biphenyls (PCBs). We present results obtained during air sampling campaign conducted in July 2004 by the active sampling method; and during September 2004–June 2005 by the passive sampling method. Our findings show the occurrence of residual quantities of DDT, HCH, PCBs and PAHs in air samples. High levels of PCBs are probably due to the destruction of transformers during the war accident.  相似文献   

7.
Persistent organic pollutants (POP) in human milk originating from various sources are used as environmental exposure markers. Further, mothersmilk is a predominant pathway for human exposure for suckling infants to POP. The aim of present study was to provide baseline and time trend information on human milk POP concentrations in the Republic of Moldova. A pooled sample of breast milk was analyzed in 2009 and 2015 and health risk evaluated by comparing reference values of humans' daily intake with estimated daily intake (EDI). Results showed decreases for concentrations of dichlorodiphenyltrichloroethane, hexachlorobenzene, dieldrin, heptachlor, α and β-hexachlorocyclohexane, polychlorinated biphenyls, dioxin-like polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins and dibenzofurans between sampling periods. Regardless of the decrease, EDI was higher than reference values for dioxins toxic equivalents, polychlorinated biphenyls and β-hexachlorocyclohexane in both phases. However, increased levels were detected for polybrominated diphenyl ethers (twofold) and hexabromocyclododecane (threefold) from 2009 to 2015, but the EDI in both phases is much lower than the reference. The decline in certain POP levels may be attributed to coordinated efforts undertaken by national and international entities to regulate these compounds. The basis for the elevated levels of polybrominated diphenyl ethers and hexabromocyclododecane remains unknown but raises concerns regarding lactational exposure.  相似文献   

8.
饲料是养殖动物的主要食物来源,饲料中的持久性有机污染物(POPs)能够在养殖动物体内蓄积,从而影响动物源性食品安全,对人体健康构成潜在的危害.目前有关饲料中二英类等传统POPs的研究已较为深入,而饲料中新型POPs的污染也逐渐引起人们的关注.本文综述了现有文献关于饲料中多溴二苯醚(PBDEs)、六溴环十二烷(HBCD...  相似文献   

9.
Persistent organic pollutants (POPs) were recorded in sediment and fish samples collected from the western coast of Alexandria. Total hydrocarbons (aliphatic+PAHs ) in sediment ranged from 683.8 to 34670.1 ng g ?1 with an average of 9286.9 ng g ?1. The sum of C16–C34 of aliphatic fractions was<4000?ng g;?1, indicating the presence of a fresh petroleum source. For all sediments, the anthracene/phenanthrene ratio was>0.1, suggesting the dominance of a pyrolytic source. Total aliphatics in different fish species ranged from 253 to 11?132 ng g;?1, while total PAHs ranged from 3862 to 35?746 ng g;?1 wet weight. Benzo[a]pyrene was the most dominant PAH fraction ranged from 1902.7 to 32 905.5 with an average of 9464.5?ng g;?1 wet weight in all fish species. Concentrations of polychlorinated biphenyls (PCBs) ranged from 0.79 to 64.9?ng g;?1 with an average 12.14?ng g;?1 wet weight. The concentrations of organochlorines in fish species (Euthynnus alleferatus, Scomberomorus commerson, Sphyraena Sphyraena, Diplodus vulgaris, and Alepes djedaba) decreased following the order: PCBs>DDTs>HCHs>total cyclodienes. Concentrations of DDTs in fish tissues ranged from 4.89 to 36.37 ng g?1 with an average of 16.4?ng g;?1 wet weight. The concentrations of total HCHs ranged from 0.3 to 65.7?ng g;?1 with an average of 16.35?ng g;?1. The present study indicates: (1) fresh petroleum input where Pr/Ph>1; (2) PAHs in sediment<4000 ng g ?1; (3) BaP concentration exceeded the permissible levels in Alepes djedaba species; (4) DDTs in sediment were below the effective range low level; (5) PCBs>effective range low and相似文献   

10.
珠三角地区POPs农药的污染现状及控制对策   总被引:23,自引:2,他引:23  
概述了中国及国际社会对持久性有机污染物(Persistent Organic Pollutants,POPs)的关注情况。并通过对POPs农药在珠江三角洲地区(Pearl River Delta Area,PRD)使用情况的调查,以及对珠江三角洲地区POPs农药在各环境介质中的污染现状的文献综述,结合环境污染数据以及POPs农药污染调查工作中得到的数据和信息,对该地区POPs污染的可能原因和环境中可能存在的新近污染源进行了初步探讨。同时也指出了当前珠江三角洲地区在POPs农药削减与淘汰工作中所遭遇到的缺乏完善的管理体系等困难,并针对问题提出了包括加大科研投入,加强基础研究,掌握污染物来源和去向,加强替代药物的研究,建立和实施更严格的环境法规以及标准,加强环境监测能力建设,建立POPs农药污染的信息公开机制等一系列的控制对策。  相似文献   

11.
从广东省西江流域三个饮用水源地采集三个样品,分别分析其中两类持久性有机污染物—有机氯农药和多环芳烃的含量以及来源,从这两类污染物对水环境污染的角度初步判断饮用水源的安全性。首先采用液液萃取的方法对样品进行前处理,然后分别用GC.ECD和GC—MS测定有机氯农药和多环芳烃的含量。实验发现有机氯农药质量浓度在水相中为1.99ng·L^-1~ 4.76ng·L^-1,在颗粒相中为0.36ng·L^-1~0.68ng·L^-1;多环芳烃质量浓度在水相中为73.40ng·L^-1~865.89ng·L^-1,在颗粒相中为16.76ng·L^-1~19.31ng·L^-1。结果表明,六六六和滴滴涕质量浓度低于国标《生活饮用水水源水质标准》(CJ3020.93)的规定,同时苯并[a]芘也低于世界卫生组织《饮用水水质标准》的规定,而其它物质标准中均无规定。由此说明,就有机氯农药和多环芳烃这两类污染物在水中的含量来说,广东西江领域饮用水源是相对安全的。但是由于这两类污染物都具有很强的生物富集性,因此它们在水环境中的存在和作用也是不容忽视的。  相似文献   

12.
农药和化肥对无尾两栖类蝌蚪的毒性效应研究进展   总被引:4,自引:0,他引:4  
以两栖动物研究环境污染物的毒性效应进而监测环境的变化,已成为国内外的研究热点.两栖类的胚胎发育和变态过程对水的依赖性极强,而且鳃和皮肤有很强的渗透性,当其受到污染胁迫时,在细胞、组织及生理生化水平上都会发生显著变化,进而会影响其存活和生长发育.在总结国内外相关研究基础上,综述和分析了农药、化肥(氮肥)对无尾两栖类蝌蚪的行为表现、生长发育、组织结构和生理生化变化等方面的毒性效应,以期为农药、化肥的水环境监测及合理使用提供全面的科学依据.  相似文献   

13.
Samples of groundwater, river water, river sediment, paddy soil, rice seeds, hen eggs, fish, umbilical cord blood, and newborn meconium were collected from October 2002 to October 2003 near a large site in China used for the disassembly of obsolete transformers and other electronic or electrical waste. Six indicator PCB congeners, three non-ortho dioxin-like PCB congeners, and six organochlorine pesticides were determined in the samples by GC with electron capture detector. The results demonstrated that the local environment and edible foods had been seriously polluted by toxic PCBs and organochlorine pesticides. The actual daily intakes (ADIs) of these pollutants were estimated for local residents living in the area. The intake data showed that the contents of PCBs in these local residents were substantial, as the ADI estimates greatly exceed the reference doses set by the World Health Organization and the United States Agency for Toxic Substances and Disease Registry. The presence of the indicator PCB congeners in the cord blood and the meconium samples, as well as significant correlations (r 2 > 0.80, p < 0.05) between these levels, suggests a potential biotransfer of these indicators from mothers to their newborns. This preliminary study showed that obsolete transformers and other electronic or electrical waste can be an important source for the emission of persistent organic pollutants into the local environment, such as through leakage, evaporation, runoff, and leaching. Contamination from this source appears to have reached the level considered to be a serious threat to environmental and human health around the disassembly site.  相似文献   

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