劉秋龍,楊 昱,夏 甫,賈永鋒,廉新穎,徐祥健,馮 帆,張 妍,姜永海*

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地下水中陰離子對(duì)球磨零價(jià)鐵除砷影響

劉秋龍1,2,楊 昱1,夏 甫1,賈永鋒1,廉新穎1,徐祥健1,馮 帆1,張 妍1,姜永海1*

(1.中國(guó)環(huán)境科學(xué)研究院水環(huán)境研究所,北京 100012；2.上海大學(xué)環(huán)境與化學(xué)工程學(xué)院,上海 200444)

研究了不同濃度下幾種陰離子(NO3?、SO42?、H2PO4?、SiO32?)對(duì)球磨零價(jià)鐵(BZVI)除砷規(guī)律的影響,探討了上述陰離子對(duì)BZVI氧化As(III)能力的影響,三價(jià)砷及五價(jià)砷的轉(zhuǎn)化機(jī)制,及BZVI腐蝕產(chǎn)物.研究證實(shí),不同濃度的NO3?和SO42?對(duì)砷去除效率影響不顯著,但是隨著H2PO4?和SiO32?濃度升高,溶液中As(V)分別由25.1%上升到83.6%和下降到3.8%;通過SEM和拉曼光譜分析發(fā)現(xiàn),H2PO4?促進(jìn)BZVI的腐蝕,導(dǎo)致As(III)氧化能力增強(qiáng);而鐵表面形成二氧化硅聚合物或非晶固相則是SiO32?降低BZVI對(duì)砷氧化和吸附能力的主要機(jī)制.

地下水；砷污染；球磨零價(jià)鐵(BZVI)；陰離子

高砷地下水廣泛存在于我國(guó)以及世界各地,給飲用水安全帶來了嚴(yán)峻的挑戰(zhàn)[1-3].零價(jià)鐵(ZVI) 作為一種來源豐富、價(jià)格低廉的水處理材料,近年來在含砷(As)地下水處理中得到了廣泛的研究和應(yīng)用[4-6].有文獻(xiàn)報(bào)道,零價(jià)鐵對(duì)三價(jià)砷具有氧化、吸附和共沉淀作用,去除砷的效率達(dá)到90%以上[7-8].但是,大量的實(shí)驗(yàn)證明,零價(jià)鐵顆粒太小,容易團(tuán)聚,從而降低了其對(duì)砷等污染物的去除能力[9-13].

眾多學(xué)者利用超聲、酸洗、雙金屬、合成鐵基負(fù)載和球磨等方法改性零價(jià)鐵,以提高其性能[14-20].機(jī)械球磨改性零價(jià)鐵具有操作簡(jiǎn)單、成本低的特點(diǎn),從而逐漸受到廣泛關(guān)注[21].有研究表明,通過球磨改性的ZVI降解DDT和苯酚,去除效果均顯著提高[22-23].

利用零價(jià)鐵去除地下水中的砷技術(shù)應(yīng)用中,處理效果受地下水中常見的一些陰離子影響[24-25],有研究證實(shí),NO3-和SO42-等對(duì)零價(jià)鐵去除總砷影響不明顯,H2PO4-和SiO32-等對(duì)去除總砷有明顯抑制作用[26-27].此外,ZVI由于表面活性高,容易與水和溶解氧反應(yīng)生成中間活性產(chǎn)物,這些活性中間產(chǎn)物將毒性遷移性強(qiáng)的As(III)氧化為As(V)[28],同時(shí)ZVI通過類芬頓反應(yīng)生成鐵的氧化物或者氫氧化物,對(duì)溶液中的砷具有很強(qiáng)的吸附能力[29].

然而,有關(guān)地下水中H2PO4-和SiO32?存在下,零價(jià)鐵通過球磨改性去除As(III)及過程中砷價(jià)態(tài)變化研究很少,尤其是反應(yīng)過程中,氧化能力的變化及機(jī)理也不明確.基于此,本文在研究SO42-、NO3-、H2PO4-、及SiO32?對(duì)球磨零價(jià)鐵(BZVI)除砷影響的規(guī)律基礎(chǔ)上,探討上述離子對(duì)BZVI氧化能力的影響,三價(jià)砷及五價(jià)砷的轉(zhuǎn)化機(jī)制,及BZVI腐蝕產(chǎn)物,提升改性零價(jià)鐵去除地下水中砷污染性能.

1 材料與方法

1.1 儀器與試劑

Fe0粉末(100目,上海阿拉丁生化科技股份有限公司),亞砷酸鈉、硫酸鈉、硝酸鈉、氫氧化鈉、磷酸二氫鈉、硅酸鈉等均為分析級(jí),鹽酸和硼氫化鉀為優(yōu)級(jí)純(均購(gòu)自上海強(qiáng)順化學(xué)試劑公司).

主要設(shè)備:行星球磨機(jī)(QM 1SP2,南京大學(xué)儀器學(xué)院,中國(guó)), 多參數(shù)便攜式儀器(HQ30D,HACH,美國(guó)),立式數(shù)顯全溫振蕩培養(yǎng)箱(HZQ-F160, 常州迅生儀器有限公司),原子熒光光譜儀(PSA 10.055Millennium Excalibur AFS, 英國(guó)),冷場(chǎng)發(fā)射掃描電子顯微鏡SEM(Hitachi SU-8010,日立高科), 顯微激光拉曼光譜儀(JY HR-800, Horiba)等.

1.2 改性零價(jià)鐵制備

本實(shí)驗(yàn)采用球磨法改性零價(jià)鐵(BZVI):將3g Fe0粉末和30個(gè)球(5.5mm)置于行星球磨機(jī)中,在轉(zhuǎn)速為500r/min,空氣接觸條件下,持續(xù)時(shí)間1h.多次制備BZVI材料,儲(chǔ)存在厭氧培養(yǎng)箱中.

1.3 試驗(yàn)方法

批處理實(shí)驗(yàn)的溶液中含有2mg/L As(Ⅲ), 0.03mol/L NaCl電解質(zhì)溶液,初始BZVI鐵投加量為2.5g/L.為了確定陰離子對(duì)As(III)氧化吸附的影響,將NO3?、SO42?、H2PO4?、SiO32?分別加入到溶液中,通過改變陰離子用量,使得初始條件下上述4種陰離子濃度分別為0,10,50,250,1000mg/L,并進(jìn)行了一系列批次實(shí)驗(yàn).所有反應(yīng)器(100mL錐形燒瓶)均為含有50mL溶液的完全混合間歇反應(yīng)器系統(tǒng).將反應(yīng)器在恒溫(25±1)℃200r/min搖床中攪拌,分別在0, 2,5,10,20, 30,60min取樣.在實(shí)驗(yàn)中,用注射器按上述取樣時(shí)間周期性地從每個(gè)反應(yīng)器中取出2mL溶液樣品,然后通過0.22μm的膜過濾,立即分析溶液中砷價(jià)態(tài)及含量;反應(yīng)后樣品離心(6000r/min),冷凍真空處理24h待測(cè).

1.4 分析方法

原子熒光法測(cè)定溶液中的砷:將反應(yīng)過程中特定時(shí)間段取出的樣品用0.22mm濾膜過濾,用去離子水進(jìn)行稀釋,用高效液相色譜與原子熒光聯(lián)用儀(HPLC-AFS)測(cè)定As(III)和As(V)濃度.

固體樣品分析:將反應(yīng)前后的固體樣品,經(jīng)冷凍真空處理后,通過SEM,拉曼等表征分析樣品.

2 結(jié)果與討論

2.1 NO3?和SO42?對(duì)As去除效率的影響

(a)總砷的去除率;(b)As(V)變化;不同初始SO42-濃度下(c)總砷的去除率;(d)As(V)變化

如圖1所示,初始濃度不同的NO3?和SO42?條件下,BZVI去除砷的反應(yīng)時(shí)間均在20min內(nèi)完成,且在實(shí)驗(yàn)條件下,其去降砷效率相近,可見2種陰離子在不同濃度條件下,對(duì)BZVI去除砷的反應(yīng)時(shí)間和去除效率影響不明顯.

2.2 H2PO4?對(duì)As去除效率的影響

圖2 不同H2PO4-濃度對(duì)As去除效率的影響

(a)總砷的去除率; (b)As(V)的去除率

如圖2所示,在實(shí)驗(yàn)條件下,隨著時(shí)間的增加,不同初始濃度的H2PO4?對(duì)BZVI去除砷效率影響較大,如10,250mg/L的H2PO4?,在反應(yīng)進(jìn)行20min時(shí),去除效率分別為97.45%和23.20%,相差74.25%,這一現(xiàn)象與Su等[30]研究基本一致,說明較高濃度的H2PO4?對(duì)BZVI去除總砷有明顯的抑制作用;為了研究H2PO4?對(duì)BZVI氧化砷能力的影響,分析了溶液中As(V) 的濃度,結(jié)果如圖2中(b)所示,高濃度H2PO4?促進(jìn)了BZVI將As(III) 氧化成As(V)的能力,在反應(yīng)進(jìn)行5min時(shí),10,250mg/L的H2PO4?,溶液中As(V)的濃度分別是846.84,1405.96μg/L,相差559.12 μg/L,在反應(yīng)進(jìn)行20min時(shí),溶液中As(V)的濃度分別是46.12,1532.96μg/L,相差1486.84 μg/L,這說明隨著H2PO4?濃度的增大,溶液中As(V)的濃度增多,反應(yīng)體系中氧化能力增強(qiáng),同時(shí)發(fā)現(xiàn)高濃度的H2PO4?減弱了對(duì)溶液中As(V)的吸附能力.綜上所述,高濃度的H2PO4?加強(qiáng)了BZVI氧化As(III)轉(zhuǎn)化為As(V)的能力,但同時(shí)抑制了對(duì)As(V)的吸附能力.

2.3 SiO32?對(duì)砷去除效率的影響

(a)總砷的去除率;(b)(30min)總砷變化;(c)As(V)的去除率;(d) As(V)(10min和30min)濃度變化

如圖3所示,隨著反應(yīng)時(shí)間的進(jìn)行,不同初始SiO32?濃度對(duì)零價(jià)鐵去除砷的效果有顯著差異(圖3(a)、(b)),反應(yīng)進(jìn)行30min時(shí),總砷濃度基本達(dá)到平衡,如10,250mg/L的SiO32?,去除效率分別為97.78%與15.60%,相差82.18%,說明較高濃度下的SiO32?對(duì)BZVI去除總砷效果有明顯的抑制作用;為了研究SiO32?對(duì)BZVI氧化砷能力的影響,分析了溶液中As(V) 的濃度,如圖3(c)、(d)所示,較高濃度的SiO32?抑制了BZVI氧化As(III)的能力,在反應(yīng)進(jìn)行10min時(shí),10,250mg/L的SiO32?溶液中As(V)的濃度分別是474.36,195.52μg/L,相差278.84μg/L,反應(yīng)進(jìn)行30min時(shí),溶液中As(V)的濃度分別是22.08, 264.72μg/L,相差242.64μg/L,說明隨著SiO32?濃度增大,As(III)氧化為As(V)的能力逐漸減弱,同時(shí)吸附砷的能力也減弱,當(dāng)SiO32?濃度增加到250mg/L,已經(jīng)基本抑制As(V)的吸附.(達(dá)到一個(gè)吸附飽和的臨界點(diǎn).1000mg/L氧化能力弱于250mg/L,2者吸附能力基本一致,所以展現(xiàn)出As(V)1000mg/L低于As(V)250mg/L).

2.4 H2PO4?和SiO32?影響As去除的機(jī)理

由圖2(b)和圖3(c)可知,隨著H2PO4-和SiO32-濃度升高、溶液中As(V)分別由25.1%上升到83.6%和下降到13.8%.在H2PO4-和SiO32?分別存在于BZVI去除As的反應(yīng)體系中,為了進(jìn)一步了解其影響除砷機(jī)制,對(duì)本試驗(yàn)反應(yīng)前后的BZVI進(jìn)行SEM(圖4)及拉曼光譜分析(圖5).

如圖4(a)、(g)所示,原始BZVI的圖像顯示了相對(duì)干凈和光滑的表面,這可能是一層氧化物涂層. 如圖4(b)、(h)所示, 反應(yīng)后的零價(jià)鐵顆粒表面出現(xiàn)了碎片狀的物質(zhì),變得粗糙和多孔,說明零價(jià)鐵有明顯腐蝕的現(xiàn)象.如圖4(c)~(f)發(fā)現(xiàn),隨著H2PO4?濃度逐漸增大,零價(jià)鐵與砷溶液反應(yīng)后,BZVI表面上觀察到扁平球狀的腐蝕產(chǎn)物逐漸增多,表明H2PO4-促進(jìn)鐵的腐蝕,致使氧化As(III)的能力增強(qiáng).在無H2PO4?條件下形成的腐蝕產(chǎn)物具有雜亂的片狀結(jié)構(gòu),而富H2PO4-條件下形成的腐蝕產(chǎn)物則是規(guī)則薄片圓球狀的結(jié)構(gòu). BZVI顆粒球狀表面突起的方形可能是BZVI對(duì)H2PO4?的吸附作用引起,以及不規(guī)則顆粒可能是與鐵的氫氧化物共沉淀作用所致. 如圖4(i)~(l)所示,隨著SiO32?濃度的增加,零價(jià)鐵與砷溶液反應(yīng)后,觀察到BZVI表面上逐漸變光滑,說明零價(jià)鐵腐蝕程度逐漸降低.

如圖5(a)所示,隨著H2PO4-濃度的增加,當(dāng)濃度達(dá)到50mg/L時(shí),Fe2O3特征峰減弱,并且發(fā)現(xiàn)原來1350,1610cm?1Fe2O3的特征峰位置出現(xiàn)偏移,這是由于零價(jià)鐵對(duì)H2PO4?的吸附作用引起,該偏移峰仍為Fe2O3.由于H2PO4?的濃度增大,導(dǎo)致溶液中pH值降低,促進(jìn)BZVI的腐蝕,導(dǎo)致As(III)氧化能力增強(qiáng),而H2PO4?在ZVI表面上的吸附沉積顯著抑制As(V)的去除,這是由于BZVI表面反應(yīng)位點(diǎn)的顯著競(jìng)爭(zhēng)[31],同樣的效果其他學(xué)者也有報(bào)道[32].

如圖5(b)所示,當(dāng)SiO32?離子濃度達(dá)到10mg/L時(shí),在1350,1610cm?1Fe2O3的特征峰消失,隨著濃度增大,1450,1550cm?1處看到尖銳的峰并且峰值逐步增強(qiáng),該峰的產(chǎn)生表明了樣品中含有二氧化硅,但是相對(duì)于標(biāo)準(zhǔn)的二氧化硅特征峰來說,發(fā)生了相對(duì)位移,這是因?yàn)殍F氧化物與SiO2復(fù)合物聚集小尺寸效應(yīng),導(dǎo)致了在拉曼表征過程中檢測(cè)到散射,從而發(fā)現(xiàn)二氧化硅特征峰位移的現(xiàn)象,總體來說是BZVI表面產(chǎn)生了二氧化硅.其次,當(dāng)腐蝕開始時(shí),SiO32?可以吸附在少量腐蝕產(chǎn)物上作為屏障,并在BZVI表面上逐漸形成二氧化硅聚合物或無定形固相,抑制腐蝕的發(fā)生,前人的研究也證明這一點(diǎn)[33].

圖4 不同濃度陰離子存在下BZVI的SEM圖

(a)、(g)為未參與反應(yīng)的BZVI和與砷反應(yīng); (b)H2PO4-=0mg/L; (c)H2PO4-=10mg/L; (d)H2PO4-=50mg/L; (e)H2PO4-=250mg/L ; (f) H2PO4-= 1000mg/L; (h) SiO32-=0mg/L; (i) SiO32-=10mg/L; (j) SiO32-=50mg/L; (k) SiO32-=250mg/L ;(l) SiO32-=1000mg/L

(a)不同H2PO4-濃度下、(b)不同SiO32?濃度下

2.5 討論

依據(jù)前人研究及本文結(jié)論,在BZVI去除地下水中砷污染研究領(lǐng)域還存在以下幾點(diǎn)值得深入研究:

地下水成分復(fù)雜,陰離子通常不是單一存在,應(yīng)考慮繼續(xù)深入研究多種離子共存時(shí),BZVI對(duì)砷去除的影響.

地下水流速緩慢,應(yīng)考慮通過柱實(shí)驗(yàn)研究BZVI砷性能的穩(wěn)定性及長(zhǎng)效性能.

3 結(jié)論

3.1 初始濃度不同的NO3?和SO42?條件下,2種不同濃度離子對(duì)砷去除效率影響不顯著. H2PO4?可以促進(jìn)BZVI對(duì)As(III)的氧化,隨著H2PO4?的升高,溶液中As(V)由25.1%上升到83.6%,SiO32?可以降低BZVI對(duì)As(III)的氧化,溶液中As(V)由25.1%下降到3.8%.

3.2 高濃度H2PO4?存在下,反應(yīng)后的BZVI顆粒表面出現(xiàn)了碎片狀的物質(zhì),變得粗糙和多孔,而高濃度SiO32?存在下,表面上逐漸變光滑.

3.3 H2PO4-的添加導(dǎo)致溶液中pH值降低,促進(jìn)BZVI的腐蝕,導(dǎo)致As(III)氧化能力增強(qiáng),而H2PO4?在ZVI表面上的吸附沉積顯著抑制As(V)的去除,這是由于BZVI表面的反應(yīng)位點(diǎn)顯著競(jìng)爭(zhēng),SiO32?則在鐵表面形成二氧化硅聚合物或非晶固相,進(jìn)而降低BZVI與砷的氧化和吸附能力.

[1] Jia Y, XiB, Jiang Y, et al. Distribution, formation and human-induced evolution of geogenic contaminated groundwater in China: A review [J]. Science of the Total Environment, 2018,643:967-993.

[2] Wang Y, PiK, Fendorf S, et al. Sedimentogenesis and hydrobiogeochemistry of high arsenic Late Pleistocene-Holocene aquifer systems [J]. Earth-Science Reviews, 2017.

[3] 鄧安琪,董兆敏,高 群,等.中國(guó)地下水砷健康風(fēng)險(xiǎn)評(píng)價(jià) [J]. 中國(guó)環(huán)境科學(xué), 2017,37(9):3556-3565. Deng A Q, Dong Z M, Gao Q, et al. Health risk assessment of arsenic in groundwater across China [J]. China Environmental Science, 2017, 37(9):3556-3565.

[4] Cullen W R, K J Reimer. Arsenic speciation in the environment [J]. Chemical Reviews, 2010,89(4):713-764.

[5] Bang S, Johnson M D, Korfiatis G P, et al. Chemical reactions between arsenic and zero-valent iron in water [J]. Water Research, 2005,39(5):763-770.

[6] Bang S, Korfiatis G P, Meng X, Removal of arsenic from water by zero-valent iron [J]. Journal of Hazardous Materials, 2005,121(1): 61-67.

[7] Mohan D, Jr P C, Arsenic removal from water/wastewater using adsorbents--A critical review [J]. Journal of Hazardous Materials, 2007,142(1):1-53.

[8] 李鈺婷,張亞雷,代朝猛,等.納米零價(jià)鐵顆粒去除水中重金屬的研究進(jìn)展 [J]. 環(huán)境化學(xué), 2012, 31(9):1349-1354. Li Y T, Zhang Y L, Dai C M, et al. The advance on removal of heavy metals in water by nanoscale zero-valent iron [J]. Environmental Chemistry, 2012,31(9):1349-1354.

[9] Chutia P, Kato S, Kojima T, et al. Arsenic adsorption from aqueous solution on synthetic zeolites [J]. Journal of Hazardous Materials, 2009,162(1):440-447.

[10] Fu F, Dionysiou D D, Liu H. The use of zero-valent iron for groundwater remediation and wastewater treatment: A review [J]. Journal of Hazardous Materials, 2014,267(3):194-205.

[11] Yan W, Vasic R, Frenkel A I, et al. Intraparticle reduction of arsenite (As(III)) by nanoscale zerovalent iron (nZVI) investigated with In Situ X-ray absorption spectroscopy [J]. Environmental Science & Technology, 2012,46(13):7018-7026.

[12] ZhuH J, Jia Y F, Wu X, et al. Removal of arsenic from water by supported nano zero-valent iron on activated carbon [J]. Journal of Hazardous Materials, 2009,172(2):1591-1596.

[13] 鄭西來,唐鳳琳,辛 佳,等.污染地下水零價(jià)鐵原位反應(yīng)帶修復(fù)技術(shù):理論·應(yīng)用·展望 [J]. 環(huán)境科學(xué)研究, 2016,29(2):155-163. Zheng X L, Tang F L, Xin J, et al. Development of a Zero- Valent Iron-Based In-situ Reactive Zones Technique for Remediation of Contaminated Groudwater [J]. Research of Environmental Sciences, 2016,29(2):155-163.

[14] 張 瑾,魏才倢,白 鴿,等.多聚物吸附納米零價(jià)鐵在多孔介質(zhì)中的遷移 [J]. 中國(guó)環(huán)境科學(xué), 2018,38(10):3747-3754. Zhang J, We C J, Bai G, et al. Transport of PAA modified nanoscale zero-valent iron in water saturated porous media [J]. China Environmental Science, 2018,38(10):3747-3754.

[15] Harendra S, Vipulanandan C, Degradation of high concentrations of PCE solubilized in SDS and biosurfactant with Fe/Ni bi-metallic particles [J]. Colloids & Surfaces A Physicochemical & Engineering Aspects, 2008,322(1):6-13.

[16] Hung Hui-Ming, Hoffmann, Michael R, Kinetics and Mechanism of the Enhanced Reductive Degradation of CCl4by Elemental Iron in the Presence of Ultrasound [J]. Environmental Science & Technology, 2000,32(19):3011-3016.

[17] 田凱勛,楊 超,肖 泉,等.超聲強(qiáng)化零價(jià)鐵/過硫酸鉀體系降解2,4,6-三氯苯酚廢水 [J]. 中國(guó)環(huán)境科學(xué), 2017,37(10):3729-3734. Yang C, Xiao Q, Fu X T, et al. Degradation of 2,4,6- TCP in an ultrasound-enhanced zero-valent iron/potassium persulfate system [J]. China Environmental Science, 2017,37(10):3729-3734.

[18] Huang YH, Tang C, Zeng H, Removing molybdate from water using a hybridized zero-valent iron/magnetite/Fe(II) treatment system [J]. Chemical Engineering Journal, 2012,200-202(34):257-263.

[19] Notini L, Latta D E, Neumann A, et al. The Role of Defects in Fe(II)-Goethite Electron Transfer [J]. Environmental Science & Technology, 2018,52(5):2751.

[20] 趙雅光,萬俊鋒,劉奉濱,等.零價(jià)鐵(ZVI)治理水體砷污染研究進(jìn)展 [J]. 環(huán)境化學(xué), 2013,66(10):1943-1949. Zhao Y G, Wan J F, Liu F B, et al. Application of zero-valent iron (ZVI) technology for arsenic removal from aqueous environment [J]. Environmental Chemistry, 2013,66(10):1943-1949.

[21] Reardon E J. Anaerobic Corrosion of Granular Iron: Measurement and Interpretation of Hydrogen Evolution Rates [J]. Environmental Science & Technology, 1995,29(12):2936-2945.

[22] Kang S, Liu S, Wang H, et al. Enhanced degradation performances of plate-like micro/nanostructured zero valent iron to DDT [J]Journal of Hazardous Materials, 2016,307:145.

[23] Ambika S, Devasena M, Nambi I M, Synthesis, characterization and performance of high energy ball milled meso-scale zero valent iron in Fenton reaction [J]. Journal of Environmental Management, 2016,181: 847-855.

[24] Su C, Puls RW, In situ remediation of arsenic in simulated groundwater using zerovalent iron: laboratory column tests on combined effects of phosphate and silicate [J]. Environmental Science & Technology, 2003,37(11):2582-7.

[25] Sun H, Wang L, Zhang R, et al. Treatment of groundwater polluted by arsenic compounds by zero valent iron [J]. Journal of Hazardous Materials, 2006,129(1):297-303.

[26] Su C, Puls RW, Arsenate and arsenite removal by zerovalent iron: effects of phosphate, silicate, carbonate, borate, sulfate, chromate, molybdate, and nitrate, relative to chloride [J]. Environmental Science & Technology, 2001,35(22):4562-8.

[27] Tyruvola K, Nikolaidis N P, Veranis N, et al. Arsenic removal from geothermal waters with zero-valent iron--effect of temperature, phosphate and nitrate [J]. Water Research, 2006,40(12):2375-2386.

[28] Sun Y, Guan X, Wang J, et al. Effect of weak magnetic field on arsenate and arsenite removal from water by zerovalent iron: an XAFS investigation [J]. Environmental Science & Technology, 2014,48(12): 6850-8.

[29] Fu FL, Dionysiou DD, Liu H, The use of zero-valent iron for groundwater remediation and wastewater treatment: A review [J]. Journal of Hazardous Materials, 2014,267(3):194-205.

[30] Su C, Puls RW, Arsenate and arsenite removal by zerovalent iron: kinetics, redox transformation, and implications for in situ groundwater remediation [J]. Environmental Science & Technology, 2001,35(7):1487-92.

[31] Su C, Puls RW, Arsenate and arsenite removal by zerovalent iron: effects of phosphate, silicate, carbonate, borate, sulfate, chromate, molybdate, and nitrate, relative to chloride [J]. Environmental Science & Technology, 2001,35(22):4562-8.

[32] Yang Z, Xu H, Shan C, et al. Effects of brining on the corrosion of ZVI and its subsequent As(III/V) and Se(IV/VI) removal from water[J]. Chemosphere, 2017,170:251-259.

[33] Smith SD, Edwards M, The influence of silica and calcium on arsenate sorption to oxide surfaces [J]Journal of Water Supply: Research and Technology - AQUA, 2005,54(4):201-211.

Impact of groundwater anions on the arsenic remove by ball milling zero valent iron.

LIU Qiu-long1,2, YANG Yu1, XIA Fu1, JIA Yong-feng1, LIAN Xin-ying1, XU Xiang-jian1, FENG Fan1, ZHANG Yan1, JIANG Yong-hai1*

(1.Chinese Research Academy of Environmental Sciences, Beijing 100012, China；2.School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China)., 2019,39(5)：2028~2033

The effect of ball milled zero-valent iron (BZVI) on As remove was studied under different concentrations of NO3?, SO42?, H2PO4?and SiO32?. The oxidation capacity of BZVI on As(III), transformation between As(III) and As(V), and the corrosion products of BZVI affected by these anions were studied as well. Arsenic removal efficiency was not significantly changed under varied concentrations of NO3-and SO42-. However aqueous As (V) ratio increased from 25.1% to 83.6% accompanied by the increase of H2PO4?, while it decreased from 25.1% to 3.8% with the increase of SiO32?. Results of scanning electron microscopy images and raman spectroscopy showed that H2PO4?promoted the corrosion of BZVI, resulting in the enhanced As (III) oxidation capacity. Besides under aqueous SiO32-the formation of silica polymer or amorphous solid phase on iron surface mainly contributed to the weakened As oxidation and adsorption capacity by BZVI .

groundwater；arsenic pollution；ball milling zero valent iron；anion

X523

A

1000-6923(2019)05-2028-06

劉秋龍(1992-),男,山西大同人,上海大學(xué)環(huán)境學(xué)院碩士研究生,主要研究地下水污染修復(fù).

2018-09-20

國(guó)家水污染控制與治理科技重大專項(xiàng)(2018ZX07109-003)

*責(zé)任作者, 研究員, jyhai203@126.com