【摘要】：在巖溶地區(qū)煤礦山污染修復(fù)過程中,鈣鹽在風(fēng)化的酸性煤矸石污染物質(zhì)控制方面發(fā)揮著至關(guān)重要的作用,為評價不同類型伴隨陰離子鈣鹽對風(fēng)化煤矸石中特征污染組分釋放影響,通過在風(fēng)化煤矸石中添加等摩爾比(以鈣計)的CaCO_3、Ca_3(PO_4)_2、CaC_2O_4、CaSO_4、CaCl_2、Ca(NO_3)26種鈣鹽并穩(wěn)定7 d后,考察了浸出液的pH、EC、Eh及Fe、Mn、Cu、Zn和SO_4~(2-)等特征污染物。結(jié)果表明:CaCO_3、Ca_3(PO_4)_2能有效緩沖煤矸石的酸度,明顯提高了體系的pH,極顯著(p0.001)抑制風(fēng)化煤矸石中特征污染組分的溶出釋放;CaC_2O_4能顯著提高煤矸石浸出液的pH,降低浸出液EC、Eh及Mn、Cu、Zn和SO_4~(2-)的含量,但草酸根的存在明顯促進(jìn)亞鐵和總鐵的釋放;CaSO_4一定程度上會抑制Fe、Mn、Cu的釋放,但會提高浸出液中Zn、SO_4~(2-)的含量,總體上對各污染組分的影響作用不顯著;呈中性的強(qiáng)酸強(qiáng)堿鹽CaCl_2、Ca(NO_3)_2由于離子競爭作用及Ca~(2+)形成復(fù)合物-石膏沉淀作用能顯著(p0.05)抑制SO_4~(2-)的溶出,但在一定程度上可降低浸出液的pH、提高浸出液的EC及Zn離子濃度,而對其他污染組分影響作用相對較小,故建議在煤礦山污染修復(fù)過程中需謹(jǐn)慎使用或引入此類物質(zhì)。綜上,不同類型伴隨陰離子的鈣鹽對風(fēng)化煤矸石中pH、EC、Fe、Mn、SO_4~(2-)及重金屬等多種特征污染組分的釋放存在顯著差異,影響著風(fēng)化煤矸石在環(huán)境中的潛在污染風(fēng)險和修復(fù)材料的污染控制效果。
[Abstract]:In the process of remediation of coal mine pollution in karst area, calcium salt plays an important role in the control of weathered acidic coal gangue pollutants. In order to evaluate the effect of different types of anionic calcium salts on the release of characteristic contaminants from weathered gangue, 26 calcium salts were added to weathered gangue by adding CaCO_3,Ca_3 (PO_4) of equal molar ratio (in calcium) to the weathered gangue. After 7 days of stabilization, 26 calcium salts were added to the weathered gangue. The characteristic pollutants such as pH,EC,Eh, Fe,Mn,Cu,Zn and SO_4~ (2 -) in the leachate were investigated. The results showed that PO_4 could effectively buffer the acidity of coal gangue, and the pH, of the system could significantly inhibit the dissolution and release of characteristic pollutants in weathered gangue. CaC2O4 could significantly increase the contents of pH, Mn,Cu,Zn and SO_4~ (2-) in the leachate of coal gangue. However, the presence of oxalate can obviously promote the release of ferrous and total iron. CaSO4 can inhibit the release of Fe,Mn,Cu to some extent, but increase the content of Zn,SO_4~ (2-) in the leachate. CaCl_2,Ca (NO_3) 2, a neutral strong acid and strong base salt, could significantly inhibit the dissolution of SO_4~ (2-) because of the action of ion competition and Ca~ (2) formation complex-gypsum precipitation, but to a certain extent, it could decrease the pH, of leaching solution and increase the concentration of EC and Zn ions. However, the effect on other pollution components is relatively small, so it is suggested that this kind of substances should be used or introduced carefully in the process of pollution remediation in coal mines. In conclusion, there are significant differences in the release of pH,EC,Fe,Mn,SO_4~ _ (2-) and heavy metals in the weathered coal gangue by different types of calcium salts accompanied by anions. It affects the potential pollution risk of weathered coal gangue in the environment and the pollution control effect of remediation materials.
【作者單位】： 貴州大學(xué)資源與環(huán)境工程學(xué)院;貴州大學(xué)應(yīng)用生態(tài)研究所;貴州大學(xué)新農(nóng)村發(fā)展研究院;
【基金】：國家自然科學(xué)基金資助項(xiàng)目(41663009) 貴州省教育廳自然科學(xué)研究項(xiàng)目(黔教合KY字[2016]011);貴州省教育廳研究生教育創(chuàng)新計劃項(xiàng)目(黔教研合GZZ字[2016]07) 貴陽國家高新區(qū)高層次人才創(chuàng)新創(chuàng)業(yè)項(xiàng)目(GYGC(2015)-0035)
【分類號】：X752
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本文編號：2225076