復合礦化穩(wěn)定劑對砷污染土壤穩(wěn)定效果及機理的研究
發(fā)布時間：2018-07-18 14:38
【摘要】：本課題以人工砷污染土壤為研究對象,選用含鐵材料、含鋁材料、含錳材料、含硫材料、堿性材料、粘土礦物、有機質(zhì)等穩(wěn)定藥劑對砷污染土壤進行穩(wěn)定化處理,篩選出效果較優(yōu)的幾種穩(wěn)定藥劑,再進行復配實驗,確定最佳配比；然后對土壤含水量、土壤pH、競爭性離子、反應(yīng)時間、污染初始濃度等穩(wěn)定效果影響因素進行研究；接著運用生物有效性、浸出毒性、賦存形態(tài)及物相分析等方法,闡述添加穩(wěn)定藥劑處理后砷的遷移性、毒性、賦存形態(tài)及物相成分；最后,對穩(wěn)定處理后的砷污染土壤進行模擬酸雨淋溶實驗,為實際應(yīng)用提供理論依據(jù)。實驗結(jié)果表明：(1)穩(wěn)定藥劑的篩選與組配實驗結(jié)果表明：砷污染土壤的最佳穩(wěn)定藥劑種類及配比為：主要穩(wěn)定藥劑FeS,投加量為Fe/As=15:1;pH調(diào)節(jié)劑電石渣,投加量為0.5%；土壤改良劑菌渣,投加量為6%；穩(wěn)定處理后土壤砷的穩(wěn)定效率達到90.53%,砷的浸出濃度為2.09 mg·L-1,低于《危險廢物鑒別標準浸出毒性鑒別》GB 5085.3-2007標準值5 mg·L-。(2)土壤砷穩(wěn)定效果影響因素實驗結(jié)果表明：①土壤含水率以30%為宜,含水率太低,影響土壤和藥劑之間的充分反應(yīng)；含水率太高,砷的毒性和移動性加強,修復成本提高。②土壤pH偏酸性和中性有利于砷的穩(wěn)定,堿性則有利于砷的溶出,其中pH在2.20-9.85時土壤砷的穩(wěn)定效率變化不大,pH=6左右時砷的穩(wěn)定效果最好,pH在9.85-12.01時土壤砷的穩(wěn)定效率明顯降低。③競爭性陰離子對土壤砷穩(wěn)定效率的抑制作用表現(xiàn)為PO43-SO42-≈ NO3-Cl-,其中P043-的加入會明顯降低土壤砷的穩(wěn)定效率,8042-和N03-對砷的穩(wěn)定效果有輕微的抑制作用,Cl-對砷穩(wěn)定效率的影響很小。④隨著反應(yīng)時間的加長,土壤砷的穩(wěn)定效率呈現(xiàn)先上升后平緩的趨勢,反應(yīng)時間15天時,砷的穩(wěn)定效率為升至93.28%,持續(xù)增加反應(yīng)時間至120天,砷的穩(wěn)定效率變化不大。⑤土壤砷的穩(wěn)定效率隨著砷污染濃度的升高而降低,當砷污染濃度分別506 mg·kg-1和833 mg·kg-1時,砷的穩(wěn)定效率分別為92.36%和90.53%,對砷的穩(wěn)定處理效果良好；當砷污染濃度分別為2951 mg·kg-1 5290 mg·kg-1時,砷的穩(wěn)定效率分別為55.57%和47.54%,對砷的穩(wěn)定處理能力有限。(3)生物有效性分析結(jié)果表明：利用化學提取法和生理原理提取法浸提污染土壤,3組處理土壤的有效態(tài)砷和有機體內(nèi)砷的可給量高低順序為污染原土去離子水》穩(wěn)定藥劑,穩(wěn)定處理能夠明顯降低土壤中砷的生物有效性,大幅度降低土壤有效態(tài)砷和有機體內(nèi)砷的可給量。(4)浸出毒性分析結(jié)果表明：利用國標法(HJ/T299-2007)和TCLP法浸提污染土壤,3組處理土壤砷的浸出濃度高低順序為污染原土去離子水》穩(wěn)定藥劑,穩(wěn)定處理能夠顯著穩(wěn)定和吸持土壤中的砷,大幅度降低砷的毒性浸出濃度。(5)賦存形態(tài)分析結(jié)果表明：穩(wěn)定處理后的污染土壤中易溶態(tài)砷含量降低18.61%,鐵型砷升高10.36%,鈣型砷升高5.81%,穩(wěn)定處理能有效將土壤中易溶態(tài)砷轉(zhuǎn)化為鐵型砷和鈣型砷。(6)物相分析結(jié)果表明：穩(wěn)定處理后的污染土壤新增了CaAl2Si2O8·4H20(斜方鈣沸石)、Ca3Fe4+3(AsO4)4(OH)8·3H2O(：菱砷鐵礦)、Fe2(AsO4)(SO4)OH · 5H2O(砷鐵礬礦)、(Al,Fe+3)3AsO4(OH)8·5H2O(砷鐵鋁礦)四種礦物,穩(wěn)定處理能促使土壤中的砷向礦物態(tài)砷轉(zhuǎn)化。(7)模擬酸雨實驗表明：①穩(wěn)定處理土壤砷的淋出濃度隨著淋洗時間延長維持在0.88mg·L-1～1.01 mg·L-1之間,遠低于污染土壤中砷的淋出濃度17.79 mg.L-1～7.31mg·L-,穩(wěn)定處理可以有效控制砷的溶出。②穩(wěn)定處理土壤中砷的總量降低為9.63%,遠低于污染原土的28.93%,主要由于穩(wěn)定處理使土壤中的砷生成難溶性鐵型砷和鈣型砷,同時添加的菌渣增加了土壤緩沖能力,從而有效抵抗酸雨的沖刷。
[Abstract]:This subject takes artificial arsenic contaminated soil as the research object, selects the iron containing material, the aluminum containing material, the manganese bearing material, the sulfur bearing material, the alkaline material, the clay mineral, the organic matter and so on stabilizing agent to the arsenic contaminated soil, and selects several stable reagents which have the better effect, then the compound experiment is carried out to determine the optimum ratio; then the soil is determined. The influence factors such as water content, soil pH, competitive ion, reaction time, initial concentration of pollution and other factors are studied. Then, biological availability, leaching toxicity, occurrence form and phase analysis are used to explain the mobility, toxicity, occurrence form and phase composition of arsenic after the addition of stable agents. Finally, after stable treatment, it is treated steadily. The leaching experiment of simulated acid rain in arsenic contaminated soil provides theoretical basis for practical application. The experimental results show that: (1) the results of the selection of stable agents and the experimental results show that the best stable agent type and proportion of arsenic contaminated soil are the main stable agent FeS, the dosage of Fe/As=15:1, the calcium carbide slag of pH regulator, and the dosage of 0.5% The soil improvement agent residue was 6%, the stable efficiency of soil arsenic was 90.53% after stable treatment, and the leaching concentration of arsenic was 2.09 mg. L-1, which was lower than that of >GB 5085.3-2007 standard value 5 mg. L-. (2) for soil arsenic stability. The water content is too low to affect the full reaction between the soil and the medicament; the water content is too high, the toxicity and mobility of arsenic are strengthened and the repair cost is increased. The soil pH partial acid and neutrality is beneficial to the stability of arsenic, and the alkalinity is beneficial to the dissolution of arsenic. In the case of pH, the stability efficiency of the arsenic in soil changes little, and the stability of arsenic at about pH=6 is stable. The efficiency of soil arsenic stability decreased obviously when pH was at 9.85-12.01. (3) the inhibitory effect of competitive anions on soil arsenic stability was PO43-SO42- NO3-Cl-. The addition of P043- would obviously reduce the stability of arsenic in soil. 8042- and N03- have a slight inhibition effect on the stability of arsenic, and Cl- for arsenic stability efficiency. As the reaction time increased, the stability efficiency of soil arsenic increased first and then slowed down, and the stability efficiency of arsenic increased to 93.28% when the reaction time was 15 days, and the stability efficiency of arsenic was increased to 120 days, and the stability efficiency of arsenic changed little. The stable efficiency of arsenic was 92.36% and 90.53% respectively when the concentration was 506 mg. Kg-1 and 833 mg. Kg-1 respectively. When the arsenic pollution concentration was 2951 mg. Kg-1 5290 mg. Kg-1, the stability efficiency of arsenic was 55.57% and 47.54% respectively. The stability treatment ability of arsenic was limited. (3) bioavailability analysis showed that: Using chemical extraction method and physiological principle extraction method to extract contaminated soil, 3 groups of Available Arsenic in soil and the amount of arsenic in the body are in the order of contaminated soil deionized water > stable agent. Stable treatment can obviously reduce the bioavailability of arsenic in soil, greatly reduce the available arsenic in soil and the arsenic in the body. (4) the results of leaching toxicity analysis showed that the leaching concentration of soil arsenic in 3 groups was contaminated by the national standard method (HJ/T299-2007) and TCLP method. The order of the leaching concentration of arsenic in the soil was contaminated soil deionized water > stable reagent, stable treatment could stabilize and absorb arsenic in soil, and greatly reduced the toxic leaching concentration of arsenic. (5) occurrence form. The results showed that the content of easily soluble arsenic in contaminated soil was reduced by 18.61%, iron type arsenic increased by 10.36% and calcium type arsenic increased by 5.81%. Stable treatment could effectively transform the soluble arsenic in soil into iron type arsenic and calcium type arsenic. (6) the result of phase analysis showed that CaAl2Si2O8. 4H20 (trapezoid calcium boiling) was added to the contaminated soil after stable treatment. Stone), Ca3Fe4+3 (AsO4) 4 (OH) 8. 3H2O (: siderite), Fe2 (AsO4) (SO4) OH. 5H2O (arsenite), (Al, Fe+3) 3AsO4 (arsenopyrite) four minerals, stable treatment can promote the transformation of arsenic in the soil to mineral arsenic. (7) simulated acid rain experiment showed: (1) stable treatment of soil arsenic leaching concentration prolonged with leaching time to maintain Between 0.88mg, L-1 and 1.01 mg / L-1, the concentration of arsenic in contaminated soil is 17.79 mg.L-1 to 7.31mg L-. Stable treatment can effectively control the dissolution of arsenic. 2. The total arsenic in soil is reduced to 9.63%, which is much lower than that of contaminated soil, which is mainly due to the stable treatment of arsenic in soil to produce refractory iron type arsenic and the arsenic in soil. Calcium based arsenic also increased soil buffering capacity and effectively resisted acid rain scouring.
【學位授予單位】：廣西大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：X53
本文編號：2132217
[Abstract]:This subject takes artificial arsenic contaminated soil as the research object, selects the iron containing material, the aluminum containing material, the manganese bearing material, the sulfur bearing material, the alkaline material, the clay mineral, the organic matter and so on stabilizing agent to the arsenic contaminated soil, and selects several stable reagents which have the better effect, then the compound experiment is carried out to determine the optimum ratio; then the soil is determined. The influence factors such as water content, soil pH, competitive ion, reaction time, initial concentration of pollution and other factors are studied. Then, biological availability, leaching toxicity, occurrence form and phase analysis are used to explain the mobility, toxicity, occurrence form and phase composition of arsenic after the addition of stable agents. Finally, after stable treatment, it is treated steadily. The leaching experiment of simulated acid rain in arsenic contaminated soil provides theoretical basis for practical application. The experimental results show that: (1) the results of the selection of stable agents and the experimental results show that the best stable agent type and proportion of arsenic contaminated soil are the main stable agent FeS, the dosage of Fe/As=15:1, the calcium carbide slag of pH regulator, and the dosage of 0.5% The soil improvement agent residue was 6%, the stable efficiency of soil arsenic was 90.53% after stable treatment, and the leaching concentration of arsenic was 2.09 mg. L-1, which was lower than that of >GB 5085.3-2007 standard value 5 mg. L-. (2) for soil arsenic stability. The water content is too low to affect the full reaction between the soil and the medicament; the water content is too high, the toxicity and mobility of arsenic are strengthened and the repair cost is increased. The soil pH partial acid and neutrality is beneficial to the stability of arsenic, and the alkalinity is beneficial to the dissolution of arsenic. In the case of pH, the stability efficiency of the arsenic in soil changes little, and the stability of arsenic at about pH=6 is stable. The efficiency of soil arsenic stability decreased obviously when pH was at 9.85-12.01. (3) the inhibitory effect of competitive anions on soil arsenic stability was PO43-SO42- NO3-Cl-. The addition of P043- would obviously reduce the stability of arsenic in soil. 8042- and N03- have a slight inhibition effect on the stability of arsenic, and Cl- for arsenic stability efficiency. As the reaction time increased, the stability efficiency of soil arsenic increased first and then slowed down, and the stability efficiency of arsenic increased to 93.28% when the reaction time was 15 days, and the stability efficiency of arsenic was increased to 120 days, and the stability efficiency of arsenic changed little. The stable efficiency of arsenic was 92.36% and 90.53% respectively when the concentration was 506 mg. Kg-1 and 833 mg. Kg-1 respectively. When the arsenic pollution concentration was 2951 mg. Kg-1 5290 mg. Kg-1, the stability efficiency of arsenic was 55.57% and 47.54% respectively. The stability treatment ability of arsenic was limited. (3) bioavailability analysis showed that: Using chemical extraction method and physiological principle extraction method to extract contaminated soil, 3 groups of Available Arsenic in soil and the amount of arsenic in the body are in the order of contaminated soil deionized water > stable agent. Stable treatment can obviously reduce the bioavailability of arsenic in soil, greatly reduce the available arsenic in soil and the arsenic in the body. (4) the results of leaching toxicity analysis showed that the leaching concentration of soil arsenic in 3 groups was contaminated by the national standard method (HJ/T299-2007) and TCLP method. The order of the leaching concentration of arsenic in the soil was contaminated soil deionized water > stable reagent, stable treatment could stabilize and absorb arsenic in soil, and greatly reduced the toxic leaching concentration of arsenic. (5) occurrence form. The results showed that the content of easily soluble arsenic in contaminated soil was reduced by 18.61%, iron type arsenic increased by 10.36% and calcium type arsenic increased by 5.81%. Stable treatment could effectively transform the soluble arsenic in soil into iron type arsenic and calcium type arsenic. (6) the result of phase analysis showed that CaAl2Si2O8. 4H20 (trapezoid calcium boiling) was added to the contaminated soil after stable treatment. Stone), Ca3Fe4+3 (AsO4) 4 (OH) 8. 3H2O (: siderite), Fe2 (AsO4) (SO4) OH. 5H2O (arsenite), (Al, Fe+3) 3AsO4 (arsenopyrite) four minerals, stable treatment can promote the transformation of arsenic in the soil to mineral arsenic. (7) simulated acid rain experiment showed: (1) stable treatment of soil arsenic leaching concentration prolonged with leaching time to maintain Between 0.88mg, L-1 and 1.01 mg / L-1, the concentration of arsenic in contaminated soil is 17.79 mg.L-1 to 7.31mg L-. Stable treatment can effectively control the dissolution of arsenic. 2. The total arsenic in soil is reduced to 9.63%, which is much lower than that of contaminated soil, which is mainly due to the stable treatment of arsenic in soil to produce refractory iron type arsenic and the arsenic in soil. Calcium based arsenic also increased soil buffering capacity and effectively resisted acid rain scouring.
【學位授予單位】：廣西大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：X53
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