农业环境科学学报
農業環境科學學報
농업배경과학학보
Journal of Agro-Environment Science
2015年
9期
1665-1673
,共9页
水分管理%氧化铁%原位分析%有效性
水分管理%氧化鐵%原位分析%有效性
수분관리%양화철%원위분석%유효성
water management%Fe-oxides%in-situ analysis%availability
结合传统的化学消化法、原位微束X射线荧光扫描图谱(μ-XRF)和微束X射线近边结构分析(μ-XANES)等技术,分析了湖南锡矿山地区高砷(As)/锑(Sb)污染土壤中As和Sb的形态;结合室内培养和传统离位化学提取法研究了淹水和干湿交替处理对该土壤As和Sb形态及有效性的影响,并对其作用机制进行了阐述。结果表明:供试污染土壤中As主要以As(Ⅴ)价态存在,且土壤中As的元素分布与铁(Fe)、钙(Ca)、硫(S)的分布呈显著正相关(相关系数r分别为0.15、0.32、0.38,P<0.05);与干湿交替处理相比,淹水处理使得土壤溶液中As和Sb浓度分别提高了71.7%~4409%和3.53%~77.1%;土壤中无定形铁氧化物含量增加了13.8%,Fe结合态As和Sb含量分别增加了17.6%和32.33%,无定形铁氧化物含量与Fe结合态As和Sb含量呈显著正相关(决定系数r2分别为0.75、0.70,P<0.05)。尽管淹水处理下土壤中无定形氧化铁对As和Sb有较强的吸附作用,能增加As和Sb的固定,但铁锰氧化物的还原溶解而释放As、Sb对土壤溶液中As、Sb的含量影响更大,因此淹水较干湿交替提高了As、Sb的移动性和有效性。
結閤傳統的化學消化法、原位微束X射線熒光掃描圖譜(μ-XRF)和微束X射線近邊結構分析(μ-XANES)等技術,分析瞭湖南錫礦山地區高砷(As)/銻(Sb)汙染土壤中As和Sb的形態;結閤室內培養和傳統離位化學提取法研究瞭淹水和榦濕交替處理對該土壤As和Sb形態及有效性的影響,併對其作用機製進行瞭闡述。結果錶明:供試汙染土壤中As主要以As(Ⅴ)價態存在,且土壤中As的元素分佈與鐵(Fe)、鈣(Ca)、硫(S)的分佈呈顯著正相關(相關繫數r分彆為0.15、0.32、0.38,P<0.05);與榦濕交替處理相比,淹水處理使得土壤溶液中As和Sb濃度分彆提高瞭71.7%~4409%和3.53%~77.1%;土壤中無定形鐵氧化物含量增加瞭13.8%,Fe結閤態As和Sb含量分彆增加瞭17.6%和32.33%,無定形鐵氧化物含量與Fe結閤態As和Sb含量呈顯著正相關(決定繫數r2分彆為0.75、0.70,P<0.05)。儘管淹水處理下土壤中無定形氧化鐵對As和Sb有較彊的吸附作用,能增加As和Sb的固定,但鐵錳氧化物的還原溶解而釋放As、Sb對土壤溶液中As、Sb的含量影響更大,因此淹水較榦濕交替提高瞭As、Sb的移動性和有效性。
결합전통적화학소화법、원위미속X사선형광소묘도보(μ-XRF)화미속X사선근변결구분석(μ-XANES)등기술,분석료호남석광산지구고신(As)/제(Sb)오염토양중As화Sb적형태;결합실내배양화전통리위화학제취법연구료엄수화간습교체처리대해토양As화Sb형태급유효성적영향,병대기작용궤제진행료천술。결과표명:공시오염토양중As주요이As(Ⅴ)개태존재,차토양중As적원소분포여철(Fe)、개(Ca)、류(S)적분포정현저정상관(상관계수r분별위0.15、0.32、0.38,P<0.05);여간습교체처리상비,엄수처리사득토양용액중As화Sb농도분별제고료71.7%~4409%화3.53%~77.1%;토양중무정형철양화물함량증가료13.8%,Fe결합태As화Sb함량분별증가료17.6%화32.33%,무정형철양화물함량여Fe결합태As화Sb함량정현저정상관(결정계수r2분별위0.75、0.70,P<0.05)。진관엄수처리하토양중무정형양화철대As화Sb유교강적흡부작용,능증가As화Sb적고정,단철맹양화물적환원용해이석방As、Sb대토양용액중As、Sb적함량영향경대,인차엄수교간습교체제고료As、Sb적이동성화유효성。
Xikuangshan is the world′s largest antimony(Sb)mine and the surrounding soils are heavily contaminated with Sb, usually along with arsenic(As)as an associated pollutant. In this study, traditional chemical extraction methods and in- situ synchrotron-based tech-niques such asμ-XRF andμ-XANES were used to reveal forms and availability of As and Sb in the soil from Xikuangshan area. An indoor experiment was also conducted to investigate the effects of water managements(flooding and wetting-drying)on forms and availability of As and Sb.μ-XRF andμ-XANES analyses indicated that in the tested soil, arsenic mainly existed in penta-valent form and the As distribu-tion was significantly correlated with soil Fe, Ca, and S(correlation coefficients being 0.15, 0.32, and 0.38, respectively, P<0.05). Com-pared with alternative wetting-drying, flooding treatment resulted in a large amount of As and Sb release to soil solutions, with 71.7%~4409%increase of As and 3.53%~77.1%rise of Sb in the soil solutions, respectively. Furthermore, flooding treatment caused non-crys-talline Fe oxides to increase by 13.8%, leading to increases in content of As and Sb associated with Fe oxides by 17.6%and 32.33%, re-spectively. A linear correlation was found of Fe-As and Fe-Sb with non-crystalline Fe oxides(r2=0.75 and r2=0.70, respectively, P<0.05), indicating a stronger influence of non-crystalline Fe oxides on As and Sb adsorption. Increased surface areas during transition from crys-talline Fe oxides to non-crystalline Fe oxides promoted adsorption, and thus reduced the mobility and availability of As and Sb. However, enhancement of reductive dissolution of Fe/Mn oxides under flooding condition resulted in more As and Sb released to solution. Therefore, alternative wetting-drying treatment increased the adsorption and fixation of As and Sb, while flooding treatment generally increased their mobility and availability.