不同有机物料对风化煤矸石污染释放及介质养分的影响

Effects of Organic Materials on the Release of Contaminant and Nutrient from the Weathering Coal Gangue

为评价常见不同有机物料添加对风化煤矸石污染物释放及介质养分的影响,分别在风化的富硫煤矸石介质中添加质量比为1%的腐殖酸、牛粪、沼渣、剩余污泥和空白煤矸石5个处理,稳定7 d后测定煤矸石浸出液的酸度、铁、锰、硫酸根等特征污染组分及氮、磷素等介质养分指标。结果表明:风化煤矸石浸出液具有较强的酸度(p H=2.4),较高的氧化还原电位(Eh=403 m V)、电导率(EC=3 653μS/cm),并含有较高浓度的铁、锰、硫酸根(总Fe=483 mg/L,Mn=4.58 mg/L,SO42-=3 005 mg/L)及多种重金属离子(Cu=1.33 mg/L,Zn=0.75 mg/L)。少量腐殖酸的存在,在一定程度上能降低风化煤矸石浸出液的p H、明显提高盐度,但对Eh、铁、锰、硫酸根及有害金属离子含量影响不明显,同时能有效提高煤矸石介质中有效磷的含量。少量沼渣、牛粪、剩余污泥的添加都能有效提高风化煤矸石的p H,降低盐度、Eh、总铁及硫酸根含量,特别是污泥、牛粪表现出相对较好的污染控制效果;同时,沼渣、牛粪、剩余污泥的添加均显著(p<0.05)改善风化煤矸石介质中全氮、全磷含量,且能够极显著(p<0.01)改善介质有效氮、有效磷等矿物养分的含量,但在一定程度上能促进Mn、Cu、Pb、Zn、F-多种有害离子的溶出,剩余污泥的添加能明显增加煤矸石浸出液中Zn的溶出,在施用中应注意防范。

In order to evaluate the effects of different organic materials on the release of pollutants and nutrients in weathered coal gangue, l%（mass ratio） of humic acid, cow dung, biogas residue, sludge were added in weathered sulfur- rich gangue. After 7 days, the characteristics of pollution components including acidity, iron, manganese, sulfate radical and phosphorus, nitrogen were determined. Results showed that the leachate of weathering gangue had a strong acidity（pH=2.4 ）, high electrical conductivity （EC = 3 653 μS/cm） and redox potential （Eh--403 mV）. Iron, manganese, sulfate with total Fe 483 mg/L, Mn 4.58 mg/L, SO4 2-- 3005 mg/L and heavy metal ions concentration such as Cu 1.33 mg/L, Zn 0.75 mg/L were higher. A small amount of humic acid could significantly reduce pH of the leachate, but increase its salinity; while the effects on Eh, iron, manganese, sulfate and harmful metal ions were not obvious, the content of phosphorus increased effectively. Few additions of cow dung, biogas residue and sludge could effectively improve pH, reduce salinity, Eh, total iron and sulfate, especially cow dung and sludge. Meanwhile, cow dung; biogas residue and sludge could improve the content of nitrogen and phosphorus in weathered coal gangue significantly （p〈0.05）, the available nitrogen and available phosphorus were improved significantly （p〈0.01）, but it could promote dissolution of a variety of harmful ions such as Mn, Cu, Pb, Zn and F, significantly increase Zn. So these organic materials should be paid attentions in application.