酒糟-粉煤灰协同赤泥的改良试验研究

Experimental study on soil treatment of red mud with distillers'grains and fly ash

将酸性酒糟废渣和粉煤灰作为脱碱和改良材料对赤泥进行协同改良,通过比较赤泥基质的物理性状、营养物质质量比及重金属存在形态,并结合盆栽试验为赤泥堆场的生态修复提供依据。结果显示:酒糟能够降低赤泥碱度,促进赤泥基质团聚体的形成,改善基质的物理结构,提高基质营养物质质量比,有效固定基质重金属并降低重金属在植物体内的积累;粉煤灰可有效增加赤泥基质孔隙度,促进基质团聚体形成;两者联合添加时赤泥土壤化效果更为显著,基质各项理化指标较单独施用改善更为明显,添加质量分数为20%粉煤灰和质量分数为20%酒糟的基质碱蓬草发芽率达93.33%。通过测定基质浸出液代表性重金属的质量比,采用内梅罗综合污染指数法评估利用酒糟与粉煤灰改良赤泥的方案污染程度为清洁级水平。

This research attempts to use the acid liquor residue and fly ash of the lees as dealkalising and improvement materials,and by setting up different proportions of red mud and waste residue,a comparative study on the physical properties,nutrient content,and the present pattern of heavy metals in the red mud substrate was conducted to provide a basis for the ecological restoration and treatment of red mud dumps through potting tests.The results show that:(1)wine lees can reduce the alkalinity of red mud,promote the formation of red mud substrate agglomerates,improve the physical structure of red mud substrate,increase the nutrient content of the substrate,effectively fix the heavy metals in the substrate and reduce the accumulation of heavy metals in plants.After the addition of 20%wine lees,the pH of red mud substrate decreased from 12.3 to 8.1,the proportion of large agglomerates larger than 2 mm increased from 1.21%to 27.97%,the bulk weight decreased from 1.87 g/cm to 1.42 g/cm²,and the organic matter content increased from 5.01 g/kg to 36.43 g/kg.(2)The addition of fly ash can effectively increase the porosity of red mud substrate and promote Red mud matrix agglomerate formation.After the addition of 20%fly ash,the percentage of agglomerates less than 0.25 mm in the red mud substrate decreased from 59.43%to 24.02%,and the percentage of 1-2 mm agglomerates increased from 6.19%to 12.67%.(3)The effect of red mud soil improvement is more significant when the two are added together,and the physical and chemical indexes of the red mud substrate are significantly improved,with 93%germination of alkali poncho in a substrate with 20%fly ash and 20%wine lees.(4)The level of contamination of this soil chemical program was assessed as clean by measuring the content of Cd,Pb,Cr,Ni,Zn,and Cu in the leachate of the substrate using the Nemerow integrated contamination index method.