外文文獻翻譯---砷在環(huán)境中的生化特性

1、<p><b>　　本科畢業(yè)論文</b></p><p><b>　　外文文獻及譯文</b></p><p>　　文獻、資料題目：Arsenic in the environment: </p><p>　　Biology and Chemistry </p><p>　　文獻、資料來

2、源： 網(wǎng)絡</p><p>　　文獻、資料發(fā)表（出版）日期：2007.4.16</p><p>　　院 （部）：化學化工系</p><p>　　專 業(yè)：化學工程與工藝</p><p>　　班 級：四 班</p><p>　　姓 名：韓 其 成</p><p>　　學 號：

3、 200809011407</p><p><b>　　指導教師：張慧敏</b></p><p>　　翻譯日期：2012.3.2.</p><p><b>　　外文文獻：　</b></p><p>　　Arsenic in the environment: Biology and Chemistry

4、</p><p><b>　　Abstract：</b></p><p>　　Arsenic (As) distribution and toxicology in the environment is a serious issue, with millions of individuals worldwide being affected by As toxico

5、sis. Sources of As contamination are both natural and anthropogenic and the scale of contamination ranges from local to regional.There are many areas of research that are being actively pursued to address the As contamin

6、ation problem. These include new methods of screening for As in the field, determining the epidemiology of As in humans, and identifyi</p><p>　　In 2005, a conference was convened to bring together scientists

7、 involved in many of the different areas of As research. In this paper, we present a synthesis of the As issues in the light of long-standing research and with regards to the new findings presented at this conference. Th

8、is contribution provides a backdrop to the issues raised at the conference together with an overview of contemporary and historical issues of As contamination and health impacts.Crown Copyright . 2007 Published by Els<

9、;/p><p>　　1. Introduction</p><p>　　1.1. Location and scale of problem</p><p>　　Arsenic (As) has been detected in groundwater in several countries of the world, with concentration level

10、s exceeding the WHO drinking water guideline value of 10 μg/L (WHO, 2001) as well as the national regulatory standards (e.g. 50 μg/L in India and Bangladesh, Ahmedet al., 2004; Mukherjee et al., 2006). Arsenic in groundw

11、ater is often associated with geologic sources, but in some locations anthropogenic inputs can be extremely important. Ingestion of geogenic As from groundwater sources is man</p><p>　　1.2. Field screening f

12、or arsenic</p><p>　　Following the discovery of As in the Bengal Basin, there is now an urgent need to address the public health implications due to exposure from drinking water sources. In order to do this a

13、nd initiate appropriate mitigation measures, there is an urgent need to identify the As-contaminated tubewells (TW) that supply most of this drinking water (Chowdhury and Jakariya, 1999). This involves screening of water

14、 in millions of TW, and raising community awareness about the health problems related to chro</p><p>　　1.3. Epidemiology</p><p>　　Ingestion of groundwater with elevated As concentrations and the

15、 associated human health effects are prevalent in several regions across the world. Arsenic toxicity and chronic arsenicosis is of an alarming magnitude particularly in South Asia and is a major environmental health disa

16、ster (Chakraborti et al., 2004;</p><p>　　Kapaj et al., 2006). Arsenic is perhaps the only human carcinogen for which there is adequate evidence ofcarcinogenic risk by both inhalation and ingestion (Centeno e

17、t al., 2002; Chen and Ahsan, 2004). Most ofthe ingested As is rapidly excreted via the kidney within a few days (Tam et al., 1979; Buchet et al., 1981; Vahter, 1994). However, high levels of As are retained for longer pe

18、riods of time in the bone, skin, hair, and nails of exposed humans (Karagas et al., 2000; Mandal et al., 2003). St</p><p>　　1.4. Agriculture</p><p>　　The adverse effects of As in groundwater use

19、d for irrigation water on crops and aquatic ecosystems is also of major concern. In addition to potential human health impacts caused by ingestion of food containing As, thep otential for reduced crop yield due to its bu

20、ild-up in the soil is an active area of research. The fate of As in agricultural soils is often less well studied compared to groundwater, and in general has been studied in the context of As uptake by different plants (

21、Huq et al., 2001</p><p>　　1.5. Anthropogenic arsenic</p><p>　　Large quantities of As are released into the environment through industrial activities, which can be dispersed widely and as such pl

22、ay an important role in the contamination of soils, waters, and air (Nriagu,</p><p>　　1989; Jacks and Bhattacharya, 1998; Juillot et al., 1999; Matschullat, 2000; Pacyna and Pacyna, 2001). Elevated concentra

23、tions of As in soils occur only locally, but in areas of former industrial areas it may cause environmental concern (Nriagu, 1994; Smith et al., 1998; Kabata-Pendias and Pendias, 2001). Although many minerals contain As

24、compounds, the anthropogenic contribution to the environment in the past accounted for 82,000 metric tons/year worldwide (Nriagu and Pacyna, 1988). Inorganic A</p><p>　　The possible mobilization of As in the

25、 soils, and subsequent leaching into ground or surface water or entry into the human food chain, should always be considered as a serious hazard. Detailed investigations are therefore necessary to estimate the total conc

26、entrations of As in soils in such areas, its chemical fractionation, and potential solubility to evaluate the potential risks from As mobilization.</p><p>　　1.6. Microbial transformations of arsenic</p>

27、;<p>　　Mobilization of As in natural ecosystems is predominantly driven by microbially mediated biogeochemical interactions. Microbial reduction of As(V) to the more toxic and mobile As(III) species occurs via det

28、oxification (Cervantes et al., 1994) or respiration processes (Ahmann et al., 1994). The genes that encode the proteins involved in As resistance are either plasmid or chromosomally borne, and have been best studied in E

29、scherichia coli. Plasmid R773 comprises of five genes arsRDABC organized i</p><p>　　1.7. Remediation</p><p>　　Several technologies are currently available for As removal, ranging from simple and

30、 effective coagulation– flocculation, to sophisticated technologies such as ion exchange and reverse osmosis (Naidu and Bhattacharya, 2006). In addition, low-cost remediation methods, such as auto-attenuation and the use

31、 of geological material as natural sorbents for As (e.g. laterite, bauxsols, natural red earth or Fe-rich oxisols) have emerged as possible alternatives for the removal of As from groundwater in t</p><p>　　1

32、.8. Current research</p><p>　　Research on As is currently very active and includes assessment of interactions at scales ranging from molecular bonding to sub-continental, As speciation in inorganic and organ

33、ic materials through a wide variety of chemical and spectroscopic approaches, and an emerging understanding of the role of microbes and other biota in As cycling. A recent review on health impacts of As resulted in drink

34、ing water standards of 10 μg/L or even lower in some countries (Kapaj et al., 2006). These lowered stan</p><p>　　2. Theme of the Special Symposium</p><p>　　The Special Symposium (SYP-4) “Arsenic

35、 in the Environment: Biology and Chemistry” was organized as part of the 8th International Conference on Biogeochemistry of Trace Elements (ICOBTE) in Adelaide, Australia during April 2005. This Special Symposium attract

36、ed a wide range of contributions from a large number of multidisciplinary As researchers, that covered major themes, such as: 1) sources and characterization of As in groundwater environment; 2) processes that control mo

37、bility and speciation </p><p>　　Key research contributions from several international teams of scientists working on As in the environment, groundwater in the Bengal Delta Plain and elsewhere in the world we

38、re presented and discussed during the symposium and are amalgamated in this Special Issue of The Science of the Total Environment.</p><p>　　3. Layout and summary of the articles</p><p>　　This sp

39、ecial issue comprises 14 articles and 1 short communication, grouped into four sections. 1) Arsenic in the groundwater environment; 2) arsenic in agricultural soils and mining environment; 3) biogeochemistry of As and to

40、xicity, and 4) remediation of Ascontaminated soils and sediments.</p><p>　　3.1. Arsenic in the groundwater environment</p><p>　　This section has five articles. The first two contributions deal w

41、ith the specific issues related to the occurrence of geogenic As in the alluvial aquifers of Bangladesh. The first paper (von Brömssen et al., 2007-this volume) targets low-arsenic aquifers in areas with high concen

42、trations of geogenic As in groundwater with a case study from Matlab Upazila in Southeastern Bangladesh. The local drillers are constructing deeper tubewells than in the recent past (60 m instead of 30 m), primarily bec&

43、lt;/p><p>　　The problem of geogenic As is not only restricted to the Bengal Basin and its surrounding region. DissolvedAs in groundwaters from coastal aquifers used extensively for human consumption has led to

44、widespread concern in eastern Australia. In the next paper O'Shea et al. (2007-this volume), discuss about the source of naturally occurring As in a coastal sand aquifer of eastern Australia. The study suggests that

45、As is regionally derived from erosion of As-rich stibnite(Sb2S3) mineralisation presen</p><p>　　In the next paper (Jakariya et al., 2007-this volume) analytical results of field test kits and laboratory meas

46、urements by AAS as a “gold standard” for As in water for 12,532 TWs in Matlab Upazila in Bangladesh were compared. The study indicated that the field kit correctly determined the status of 87% of the As levels compared t

47、o the Bangladesh Drinking Water Standard (BDWS) of 50 μg/L, and 91% of the WHO guideline value of 10 μg/L. However, due to analytical and human errors during the determi</p><p>　　The concluding short contrib

48、ution in this section (Vuki et al., 2007-this volume) deals with a study on the speciation of As in spring waters located along Tumon Bay in the small island of Guam in Western Pacific Ocean. Earlier investigation conduc

49、ted by the Guam Environmental Protection Agency (GEPA, 2002) on total concentrations of As in groundwater springs and seepages at Guam indicated concerns over As contamination resulting predominantly from anthropogenic s

50、ources. Although more detailed s</p><p>　　3.2. Arsenic in agricultural soils and miningenvironment</p><p>　　The first article in this section (Saha and Ali, 2007- this volume) deals with the dyn

51、amics of arsenic in agricultural soils irrigated with As-contaminated groundwater in Bangladesh. Arsenic concentrations in the soil layers of 12 rice fields located in four Asaffected areas and two unaffected areas in Ba

52、ngladesh were monitored systematically. This study clearly shows enrichment of As in the top soil of rice fields irrigated with As-contaminated groundwater (79–436 μg/L), compared to areas where</p><p>　　The

53、re are several hot spots in Poland where soils have very high concentrations of As, caused both by natural geochemical enrichment and long-lasting ore mining and processing operations (Karczewska et al., 2004, 2005). Det

54、ailed investigations are therefore necessary to estimate the total concentrations of As in soils in such hot-spot-areas, its chemical fractionation, and potential solubility to evaluate the risks for mobilization of As.

55、In the second article in this section (Krysiak and Karcze</p><p>　　The last paper in this section (Eapaea et al., 2007-this volume) discusses the dynamics of As in the mining sites of Pine Creek Geosyncline

56、of Northern Territory of Australia. This study examined the mobility and retention of As in soil and sediments from five mine sites in the region, based on measuring the operationally- defined forms of As in soils and ot

57、her sediments using a modified sequential extraction procedure. The study revealed that As was present both in soluble and loosely bound for</p><p>　　3.3. Biogeochemistry of arsenic</p><p>　　Thi

58、s section contains three articles describing the aspects of biogeochemical interactions of As and toxicology. The first article deals with Arsenicicoccus bolidensis, a novel As-reducing actinomycete in contaminated sedim

59、ents near the Adak mine (Routh et al., 2007). At Adak, a small mining town in the Västerbotten district of Northern Sweden, high-As concentrations are encountered in surface and groundwater, sediments, and soil. In

60、spite of the oxic conditions, As-rich surface and ground water</p><p>　　The third article in this section (Krishnamohan et al., 2007-this volume) deals with the systematic study of the urinary As methylation

61、 and porphyrin profile of C57Bl/6J mice chronically exposed to sodium arsenate. The results indicate that As interferes with the function of enzymes responsible for haem biosynthesis leading to alteration in the porphyri

62、n profile. The levels of total As were significantly related to dose. No significant differences in the urinary As methylation pattern between co</p><p>　　3.4. Remediation of arsenic contaminated water, soil

63、s and sediments</p><p>　　This section contains three articles and one short communication that discuss aspects of remediation of As-contaminated water, spoils and sediments. The first article (Vithanage et a

64、l., 2007-this volume) examines Natural Red Earth (NRE) as a novel adsorbent for retention of As(III) and As(V) from aqueous solution. Results of laboratory experiments show that As(V) has a strong affinity for NRE surfac

65、e sites compared to As (III). With an increase in the initial loading, As(V) adsorption deviated f</p><p>　　The second article in this section (Aldrich et al., 2007-this volume) deals with the uptake of As(I

66、II) and As(V) by the desert plant species Mesquite (Prosopis spp.) and its potential application for phytoremediation of As-contaminated soils. Seedlings were grown in agarbased medium containing 5 mg/L of either As(III)

67、 or As (V). Results showed that the As concentrations from As (V) were significantly higher than the As concentrations from As(III) in all portions of the plant. X-ray absorption sp</p><p>　　There are few pu

68、blished accounts of As uptake by natural vegetation growing on As-polluted soils (Environment Agency, 2002). In the third article in this section, Madejón and Lepp (2007-this volume) investigated the distribution of

69、 arsenic in soils and plants of woodland regenerated on As-contaminated soils that exceeded the UK guidelines for ‘safe’ soil As concentrations (50 mg/ kg; MAFF, 1993). Each site had a different source of soil As, but al

70、l had either been spontaneously colonized by nati</p><p>　　The last contribution to this section is a short communication (Anderson andWalsh, 2007-this volume) that examines As uptake by the common marsh fer

71、n Thelypteris palustris and its potential use for phytoremediation. The wide range of habitat and ease of cultivation of the marsh fern would make it an ideal plant for remediation in many environments. Hydroponic and so

72、il cultivations of T. palustris, revealed As accumulations in both roots and fronds of the plant. The levels of As were up to 100 ti</p><p>　　4. Conclusions</p><p>　　Arsenic contamination of wat

73、er supplies is a problem on a global scale. Past anthropogenic practices have released large amounts of As into the environment and caused contamination of groundwater resources, usually at relatively small scales. In ma

74、ny areas of the world, biogeochemical processes have resulted in a release of naturally occurring As into groundwater; in some cases, large regions are affected. The adverse impact of As on human health has been document

75、ed, and there are now indication</p><p>　　We sincerely hope that these articles are of considerable interest to the readers. They reflect the latest state of the art on our understanding of various inter-dis

76、ciplinary facets of the problem of arsenic in environmental realm, mechanisms of mobilization in groundwater, fate of arsenic in the agricultural systems, biogeochemical interactions and the measure for remediation. We b

77、elieve that discussions during the symposium significantly improved our understanding of the global problem of As i</p><p>　　Acknowledgements</p><p>　　This special issue would remain incomplete

78、without expressing our sincere and deep sense of gratitude to the International Society of Trace Element Biogeochemistry (ISTEB) and the organizers of the 8th International Conference on the Biogeochemistry of Trace Elem

79、ents (ICOBTE) who have considered the Special Symposium (SYM-4) on “Arsenic in the Environment: Biology and Chemistry” for initial phases of planning, organization and sponsor for this important platform for the scientif

80、ic discussions on</p><p><b>　　中文譯文：</b></p><p>　　砷在環(huán)境中的生化特性</p><p><b>　　摘要</b></p><p>　　砷在環(huán)境中的分布和毒性是一個嚴重的問題，世界上有上百萬的人在遭受砷毒性的危害。砷污染的來源有自然方面和人類活動，

81、還有污染的規(guī)模使一個小區(qū)域的污染影響整個區(qū)域，有許多地方的研究發(fā)現(xiàn)了砷污染的這一問題。這些因素使得對于砷污染去除的方法有了新的方法，研究出了砷對人類的傳染病學，還有研究出了在農(nóng)業(yè)中植物對砷吸收后的產(chǎn)生的危害影響。對于受到砷污染過的給水處理是重要的，而且這一研究意味著評估自然恢復和植物修復的潛力，在砷環(huán)境中另一有效的研究領域就是對于微生物的新陳代謝和生物地球化學之間的作用。</p><p>　　在2005年，召開一

82、個會議，參加者來自不同地區(qū)的對于砷研究科學家。在這篇文獻中，呈現(xiàn)了這次會議中對于長期從事砷問題研究的綜述還有新的發(fā)現(xiàn)。這一會議的貢獻提供了對于砷問題研究的一次交流機會，還有對于砷對于人類健康影響和砷污染的當前過去的評價。</p><p>　　關鍵詞：砷；污染；地下水；管井式井泵篩選；現(xiàn)場檢測組件；健康；安全水體；農(nóng)業(yè)；土壤；礦場環(huán)境；植物修復；吸附；修復</p><p><b>

83、　　1 引言</b></p><p>　　1．1 砷污染的地理位置和污染規(guī)模</p><p>　　砷已經(jīng)被世界上許多國家的地下水中檢測到，砷的濃度超過了WHO對于飲用水（10µg/l）和自然水源砷濃度（50µg/l）的標準。地下水中的砷通常聯(lián)系到地質原因，但是在一些地區(qū)人為排放的砷對于地下水的危害也是極大的，從地下水中攝入的砷已經(jīng)被證明對身體造成慢性的健康

84、紊亂。研究者檢測到許多地方的地下水中含有砷，這些地方亞洲尤甚。澳大利亞的地下水中葉發(fā)現(xiàn)到砷，而且砷濃度超過了其本國對于飲用水中含砷的濃度標準7µg/l），除此之外，地下水中砷的來源是人為原因的也被報道過。</p><p><b>　　1．2砷的檢測</b></p><p>　　目前，在孟加拉國，對于由飲用砷污染水而造成的公共健康影響需要迫切的研究，為了解決這

85、個問題和采取適當?shù)木徍痛胧?，孟加拉的采取的措施，是一種對于大多數(shù)飲用水輸送設備叫做管井的識別確定，這牽扯到上百萬這樣的管井中水的檢測，并且也對居民對于飲用砷污染水帶來健康問題的認識有一定的提高，這樣的措施因此需要經(jīng)濟可行性的方法。對于砷污染的水井的檢測、評估和監(jiān)控，考慮到時間框架和經(jīng)濟來源可利用行，現(xiàn)場測試裝置比實驗室措施更實用，它對于水井的水的檢測快速，而且簡單、成本低。但是現(xiàn)場測試裝置它的正確率低下，它所提供的半定量的結果和可依賴型

86、受到質疑。因而，在這一檢測裝置在孟加拉國和世界上其他地方被推薦大規(guī)模使用之前，需要對這一裝置的檢測結果做進一步的評估。</p><p>　　1．3砷毒性所產(chǎn)生的流行病學</p><p>　　世界上多個區(qū)域的居民飲用高砷污染水使他們的健康受到影響這一現(xiàn)象是普遍的，砷的毒性 長期暴露在砷條件下是令人擔憂的，尤其是在南亞。砷可能是唯一的被足夠證據(jù)證明出來的致癌物質。攝取的砷大部分通過腎臟排出體外

87、，但是，高濃度的砷會在骨骼、皮膚、頭發(fā)和指甲存留很長時間。在對暴露人體的尿液中砷的形態(tài)研究表明代謝物組成10-15%是無機砷和一甲基砷酸，還有大部分60-80%的二甲基砷酸。最近的研究已經(jīng)發(fā)現(xiàn)了一甲基砷酸和二甲基砷酸在人體尿液的蹤跡。此外，一甲基砷酸比三價砷和五價砷更具毒性。</p><p>　　1．4砷在農(nóng)業(yè)方面產(chǎn)生的影響</p><p>　　用含砷的地下水對于農(nóng)作物和水生生態(tài)系統(tǒng)的灌溉

88、所產(chǎn)生的副作用也是一個令人關心的重要問題，除此之外還有由于攝取含有砷的食物而造成的對人類健康的影響，由于砷在土壤的逐漸積累使得農(nóng)作物產(chǎn)量減產(chǎn)的可能性，這些方面都是研究的熱點。相比于地下水中的砷和不同植物吸收砷方面，在農(nóng)業(yè)土壤方面，砷的影響沒有很好的研究。農(nóng)作物質量和砷對于農(nóng)作物質量和產(chǎn)量方面產(chǎn)生的影響已經(jīng)變的越來越令人關心的問題了，尤其那些使用地下水灌溉水稻的南亞國家，大米是這些國家的主要產(chǎn)品。研究表明，土壤中砷的濃度在25mg/kg時

89、大米將減產(chǎn)10%。一項在溫室內(nèi)做的研究表明，用砷濃度為0.2-8mg/L時，使用的是一種叫做BR-Ⅱ型的大米。砷在大米中的積累和通過攝入大米進入食物鏈這兩個方面是一個令人關心的問題。</p><p>　　1．5人為原因產(chǎn)生的砷</p><p>　　工業(yè)活動產(chǎn)生的大量的砷廣泛的釋放到環(huán)境中，這對于土壤、水體和空氣的污染起著重要的作用。礦場含有砷的礦物質，但是全球的人類活動在過去每年產(chǎn)生砷總共

90、有82000噸。無機砷物質像砷酸鈣、砷酸鉛、砷酸鈉和許多其他物質，這些物質被用來作為殺蟲劑、除草劑大量使用。在過去，水溶性的保護劑，像砷酸銅還有以砷為化合物質的化學品已經(jīng)在土壤中導致大范圍的金屬污染，但是由于對砷的毒性、食物安全和環(huán)境污染的理解，無機砷物質在農(nóng)業(yè)的使用的大量減少是在20世紀60年代。此外，制作含有砷的殺蟲劑和除草劑的工場，會向附近釋放污染物和負載砷的物質，這可能回污染土壤和水體。</p><p>

91、　　全球有許多地方由于地理地質因素富含高濃度的砷，例如波蘭，此外還有制作含砷工業(yè)產(chǎn)生的礦渣、垃圾和尾料也含有大量的砷。對于全球工業(yè)區(qū)域的陸地環(huán)境中的砷的生物可利用性是一個廣泛關注的問題，大部分砷污染的土壤能夠恢復到先前砷排放時候法定標準。研究表明，農(nóng)村區(qū)域溶解性的砷濃度平均在0.6-0.9mg/L，而被工業(yè)水釋放影響的河流砷濃度平均在3.2-5.6mg/L，但是懸浮性的砷相對于溶解性的砷是十分低的，農(nóng)村區(qū)域和工業(yè)河流的懸浮性砷濃度分別為

92、0.1-0.2mg/L、0.2-0.8mg/L。但是，對于工業(yè)河流，溶解性的砷濃度能夠達到25.6mg/L。</p><p>　　土壤中砷的遷移，可能隨后進入陸地或者水體表面或者進入人類食物鏈，這些被看作是一個危害嚴重的問題，因此有必要對這些區(qū)域土壤中的砷濃度做一個細節(jié)調(diào)查，還有它的化學特性、溶解性，以此來評估砷遷移所帶來的潛在危害。</p><p>　　1．6微生物對砷的轉移作用<

93、/p><p>　　自然生態(tài)系統(tǒng)的砷的遷移主要通過微生物新陳代謝在生物地球化學方面作用使砷發(fā)生遷移，微生物五價砷還原到更具毒性和遷移性的三價砷是通過解毒作用或者呼吸作用發(fā)生的，只有一小部分微生物具有通過呼吸作用把五價砷還原為三價砷。研究表明，微生物參與的把五價砷還原為三價砷的過程比通過使用無機的化學轉化作用快許多倍，因此，微生物對于地下土壤中砷的循環(huán)起著一個重要的作用。</p><p><

94、b>　　1．7修復作用</b></p><p>　　目前有多種可利用性除砷技術，簡單有效的如混凝沉淀技術，精細技術如離子交換技術和反滲透技術。除此之外，低成本的修復技術，如稀釋，還有在發(fā)展中國家對于來自地下水中砷的去除方法，通過使用地質材料作為自然吸附劑除砷已經(jīng)被認作相對可能的技術，但是，現(xiàn)在迫切的需要研究出一種低成本有效率的除砷技術。</p><p>　　利用植物修復技

95、術來除砷這一觀點已經(jīng)提出了20多年，植物修復技術與以往的砷污染土壤的修復術如掩埋和化學穩(wěn)定有許多優(yōu)點，具有成本低、環(huán)境污染小的優(yōu)點。研究表明，一些熱帶和溫帶植物種類能夠對于無機砷和有機砷很好的忍受和積累。豆科灌木是一種能夠在潮濕或者干旱環(huán)境中很好生存的植物，研究發(fā)現(xiàn)它能夠吸附鉻和其他金屬像鉛，它能夠把六價鉻還原為毒性較小的三價鉻，但是目前，還沒有發(fā)現(xiàn)沙漠的植物能夠吸收砷或者其他毒性元素。</p><p><

96、b>　　1．8目前除砷技術</b></p><p>　　目前對于砷的研究是十分積極的，包括在反應規(guī)模上、砷的形態(tài)包括無機砷和有機砷通過各種化學和光譜實驗轉化評估，還有一種新興的評估就是砷在微生物和生物之間的循環(huán)的評估。當前的研究認為飲用水的砷濃度不能高于10ug/L，這也使得供水成本增加，還讓人們意識到人類的健康和生態(tài)系統(tǒng)聯(lián)系，刺激了對于除砷技術進一步研究。</p><p&g

97、t;　　考慮到砷的危害性，一個兩天的關于砷污染問題的會議召開，下面就是介紹了會議的主題和會后刊發(fā)的文件。</p><p><b>　　2 會議主題</b></p><p>　　這次特殊的會議是在澳大利亞2005年4月舉行的，主題是“砷在環(huán)境中的生化特性”，此次的會議的舉辦作為第八屆關于微量元素的生物地球化學特性國際會議的一部分。這次會議的主要主題為：</p>

98、;<p>　?。?）地下水環(huán)境中砷的來源和特性</p><p>　?。?）砷在土壤、水體和生物體的遷移和形態(tài)過程</p><p>　?。?）在自然環(huán)境中砷在地球化學、水文學和生態(tài)學的轉變方面的對含量的預測</p><p>　?。?）砷的分析技術和形態(tài)研究</p><p>　?。?）對于受到砷污染的土壤和地下水的恢復和管理<

99、/p><p>　?。?）砷對于農(nóng)業(yè)和供水管理的影響。</p><p>　　除此之外，基于對砷遷移過程基礎的理解，這次會議還討論了各種化學方面和光譜學方面的實驗，并且更加重視微生物和植物對于砷循環(huán)的重要性，這次會議重要的研究都在這次會議的期刊刊發(fā)出來。</p><p><b>　　3研究文獻的綜述</b></p><p>