本文選題：砷　切入點(diǎn)：銻　出處：《貴州大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：本文以黔西南州晴隆銻礦周邊土壤為研究對象,采集21個表層土壤樣品,分析測定了As和Sb的含量、賦存形態(tài)及生物有效性。以貴州省土壤背景值和國家土壤環(huán)境質(zhì)量標(biāo)準(zhǔn)為依據(jù),利用單因子污染指數(shù)法評價了土壤As和Sb的污染特征,并借助Hakanson潛在生態(tài)危害指數(shù)法評價As、Sb污染程度及環(huán)境風(fēng)險(xiǎn)。采用實(shí)地調(diào)查和模擬試驗(yàn)相結(jié)合的研究方法,在實(shí)驗(yàn)室模擬研究干濕條件下土壤As、Sb及氧化鐵的變化特征。土壤樣品As和Sb含量分析采用微波消解-氫化物發(fā)生-原子熒光光譜法,As和Sb形態(tài)特征分析使用“土壤和沉積物13個微量元素形態(tài)順序提取程序”國家標(biāo)準(zhǔn)方法(GB/T25282-2010)。結(jié)果表明:(1)研究區(qū)土壤As、Sb污染嚴(yán)重,尤以Sb更甚。土壤As含量范圍在12.38-127.85 mg·kg-1,高于背景值0.61-6.39倍;土壤As的均值為43.52 mg·kg-1,高于國家土壤環(huán)境質(zhì)量二級標(biāo)準(zhǔn)30 mg·kg-1,超過貴州省土壤背景值20 mg·kg-1。土壤Sb含量范圍在171.9-603.8 mg·kg-1,高于背景值76.75-269.54倍;均值為267.5 mg·kg-1,高于背景值119.42倍。經(jīng)單因子污染指數(shù)分析,As和Sb單項(xiàng)污染指數(shù)Pi范圍分別為:Pi(As)0.62-6.39,Pi(Sb)76.8-269.5,As屬中度污染和輕度污染,而Sb屬于重度污染,土壤的污染程度SbAs。經(jīng)Hakanson潛在生態(tài)風(fēng)險(xiǎn)評價,研究區(qū)重金屬的總潛在生態(tài)風(fēng)險(xiǎn)值很高,33.33%的土壤樣品生態(tài)風(fēng)險(xiǎn)很強(qiáng),67.67%的土壤樣品生態(tài)風(fēng)險(xiǎn)極強(qiáng),即生態(tài)危害程度總體為強(qiáng);從單元素角度分析可知:Sb的潛在生態(tài)危害程度高于As。(2)研究區(qū)土壤As和Sb的存在形態(tài)均以殘?jiān)鼞B(tài)為主,分別占總量的52.87%-87.58%、76.30%-91.47%。其次是可還原態(tài)和可氧化態(tài),弱酸提取態(tài)含量較低,水溶態(tài)含量最低。土壤中As的可還原態(tài)、可氧化態(tài)、弱酸提取態(tài)、水溶態(tài)分別占總量的2.49%-19.59%、3.68%-20.46%、0.16%-3.86%和0.02%-0.77%;土壤中Sb的可還原態(tài)、可氧化態(tài)、弱酸提取態(tài)、水溶態(tài)分別占總量的0.58%-7.16%、0.77%-7.34%、0.05%-1.51%和0.01%-1.10%。經(jīng)相關(guān)性分析,土壤As不同形態(tài)之間、Sb不同形態(tài)之間、甚至As和Sb部分形態(tài)之間均呈顯著的線性相關(guān)關(guān)系。經(jīng)初步分析,土壤中生物可利用態(tài)銻含量為0.15-14.60 mg·kg-1,占總量的0.05%-2.46%,而土壤中生物可利用態(tài)砷含量為0.12-2.94 mg·kg-1,占總量的0.21%-4.37%。(3)持續(xù)淹水期間,水溶液中As、Sb含量都隨淹水天數(shù)遞增而呈先快速增加后保持平穩(wěn)的趨勢,水溶液中三價砷占總砷及三價銻占總銻的比例亦呈相同變化趨勢。淹水后,污染程度不同的3種處理土壤(TH-CF、TM-CF、TL-CF)Sb的水溶態(tài)、弱酸提取態(tài)、可還原態(tài)和可氧化態(tài)的比重都增加了,殘?jiān)鼞B(tài)Sb的比重降低了;土壤As各形態(tài)(水溶態(tài)、弱酸提取態(tài)、可還原態(tài)、可氧化態(tài)和殘?jiān)鼞B(tài))的比重有增有減,且增減幅度有所不同。持續(xù)淹水期間,土壤As不同形態(tài)之間、土壤Sb不同形態(tài)之間都存在顯著的線性相關(guān)關(guān)系。(4)持續(xù)淹水期間,土壤無定形氧化鐵的含量隨著淹水時間的延長而增加,土壤結(jié)晶態(tài)氧化鐵含量則隨淹水時間的延長而減少。在污染程度不同的3種處理(TH-CF、TM-CF、TL-CF)土壤中,土壤無定形氧化鐵含量具有相同的變化趨勢,淹水84 d后分別較淹水前增加了133.42%、137.79%、326.5%;土壤氧化鐵活化度亦隨著淹水時間的延長而增大,變化趨勢基本相同,但TL-CF土壤中活化度增幅最明顯。持續(xù)淹水期間,土壤結(jié)晶態(tài)氧化鐵含量逐漸減少,淹水初期(0-7 d)的變化最為劇烈,到淹水末期(84 d),3種處理(TH-CF、TM-CF、TL-CF)土壤結(jié)晶態(tài)氧化鐵含量降幅分別為36.46%、43.57%、51.89%。(5)干濕交替過程中,土壤Sb和As各形態(tài)含量都隨周期性干濕交替而呈波動變化,土壤不同形態(tài)As(Ⅲ)及Sb(Ⅲ)含量也隨著周期性干濕交替呈波動變化。污染程度不同的3種處理土壤(TH-DW、TM-DW、TL-DW),淹水時,除殘?jiān)鼞B(tài)外,土壤中其它形態(tài)的As和Sb含量都隨淹水天數(shù)遞增而遞減,遞減幅度大小為:水溶態(tài)弱酸提取態(tài)可還原態(tài)和可氧化態(tài);落干時,土壤As和Sb各形態(tài)的含量呈波動變化,水溶態(tài)、弱酸提取態(tài)微減,殘?jiān)鼞B(tài)微增,可還原態(tài)和可氧化態(tài)有增有減,但各形態(tài)之和基本相等。污染程度不同的3種處理土壤(TH-DW、TM-DW、TL-DW),淹水時,土壤As(Ⅲ)及Sb(Ⅲ)含量增加,As(Ⅲ)及Sb(Ⅲ)占各自總的比例也增加;落干時,土壤As(Ⅲ)及Sb(Ⅲ)含量略微減小,As(Ⅲ)及Sb(Ⅲ)占各自總的比例也略微減小。干濕交替過程中,土壤As不同形態(tài)之間、土壤Sb不同形態(tài)之間均存在顯著的線性相關(guān)關(guān)系。(6)干濕交替過程中,土壤無定形氧化鐵和結(jié)晶態(tài)氧化鐵的含量都隨周期性干濕交替而呈波動變化,且各自變化趨勢基本相同。污染程度不同的3種處理土壤(TH-DW、TM-DW、TL-DW),淹水時,土壤無定形氧化鐵含量增加,土壤結(jié)晶態(tài)氧化鐵含量減少;落干時,土壤無定形氧化鐵含量減少,土壤中結(jié)晶態(tài)氧化鐵含量增加,但增減幅度各略有不同。
[Abstract]:This paper takes Qianxi Prefecture in Qinglong antimony mine surrounding soil as the research object, collected 21 surface soil samples, the contents of As and Sb were analysed, speciation and bioavailability. The background values of soils in Guizhou province and the state soil environment quality standard as the basis, using the method of single factor pollution index to evaluate the soil pollution of As and Sb and with the help of the Hakanson potential ecological risk index method in the evaluation of As, Sb pollution and environmental risk. Adopting the research method of field investigation and simulation test of the combination, in the laboratory simulation of soil As, Sb variation and oxidation of iron. By microwave digestion hydride generation atomic fluorescence spectrometry analysis of soil samples As and the content of Sb, As and Sb analysis of morphological characteristics using the "program" national standard method for extraction of soil and sediment of 13 trace elements form sequence (GB/T25282-2010). The results showed that: (1). The study area of soil As, Sb pollution is serious, especially Sb. Soil As content in the range of 12.38-127.85 mg, kg-1, 0.61-6.39 times higher than the background value; the mean soil As was 43.52 mg kg-1, higher than the two level of the national soil environmental quality standard of 30 mg / kg-1, exceed the background values of soils in Guizhou province 20 mg kg-1. the content of soil Sb in the range of 171.9-603.8 mg, kg-1, 76.75-269.54 times higher than the background value; the mean value of 267.5 Mg - kg-1, 119.42 times higher than the background value. By the analysis of single factor pollution index, As and Sb single pollution index of Pi were Pi (As) 0.62-6.39, Pi (Sb) 76.8-269.5, As and moderate pollution light pollution, and Sb pollution is severe, the soil pollution degree of SbAs. by Hakanson potential ecological risk assessment, the total potential ecological risk of heavy metals in value is very high, the ecological risk of 33.33% soil samples is very strong, the ecological risk of 67.67% soil samples is extremely strong, namely ecological hazard The overall degree is strong; the analysis from the angle of single element: the degree of potential ecological risk of Sb is higher than As. (2) forms of soil As and Sb were mainly in residual form, accounting for the total 52.87%-87.58%, 76.30%-91.47%. followed by the reducible and oxidizable state, weak acid extraction low content water the lowest content of soluble As in the soil. The reducible, oxidizable, acid extractable state, water soluble and accounted for 2.49%-19.59%, 3.68%-20.46%, 0.16%-3.86% and 0.02%-0.77%; Sb in soil reducible, oxidizable, acid extractable state, water soluble and accounted for 0.58%-7.16%, 0.77%-7.34%, 0.05%-1.51% 0.01%-1.10%. and the correlation analysis between soil As of different forms, between different forms of Sb, and showed a significant linear relationship between As and Sb form. After preliminary analysis, bio available in soil by state of antimony content was 0.15-14.60 mg Kg-1, accounting for 0.05%-2.46% of the total, while soil bioavailable arsenic content is 0.12-2.94 mg kg-1, accounting for 0.21%-4.37%. of the total (3) sustained during the flooding in aqueous solution As, Sb content with the increasing number of water flooded and has maintained a steady trend after the first rapid increase, water soluble trivalent arsenic solution the total arsenic and trivalent antimony accounted for the proportion of antimony was also the same trend. After flooding, 3 kinds of soil with different pollution levels (TH-CF, TM-CF, TL-CF) Sb water soluble, acid extractable, reducible and oxidizable proportion has increased, the proportion of reducing residual Sb; various forms of soil As (water soluble, acid extractable, reducible, oxidizable and residual) proportion increases and decreases, and the changes are different. The continuous flooding period, soil As of different forms of soil, Sb there is a significant linear relationship between different forms (4. Continuous flooding) During the period, the content of soil amorphous iron oxides increased with the flooding time, soil crystalline iron oxide content decreased with prolonged inundation. In 3 kinds of different pollution levels (TH-CF, TM-CF, TL-CF) in soil, soil amorphous iron oxide containing gauge has the same change trend, flooding after 84 D compared with before flooding increased by 133.42%, 137.79%, 326.5%; the activation degree of soil iron oxide with prolonged inundation and the increasing trend is basically the same, but the TL-CF in soil salinity increase. Live the most obvious sustained during the flooding of the soil crystalline iron oxide content decreased gradually, and waterlogging (0-7 d) was the most severe changes to the end, flooding (84 d), 3 (TH-CF, TM-CF, TL-CF treatment) by soil crystallization ferric oxide content were 36.46%, 43.57%, 51.89%. (5) alternate process, various forms of soil Sb and As content with periodic 騫叉箍浜ゆ浛鑰屽憟娉㈠姩鍙樺寲,鍦熷￥涓嶅悓褰㈡，

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