陈年垃圾腐殖土理化性质及无侧限抗压强度研究

Study on the Physical-chemical Properties and Unconfined Compressive Strength of Aged Garbage Humus

以吉水县某高龄期填埋场腐殖土为研究对象,探究其理化性质及浸出液性质并为其资源化利用提供有效途径。研究表明,垃圾腐殖土中灰土及砖石组分含量高达93.62%,玻璃、塑料等组分含量为6.38%。腐殖土为砂质土,热稳定性良好;XRD及EDS结果显示其主要化学成分为SiO_(2)、Al_(2)O_(3)、FeO、CaCO_(3),主要矿物成分为石英、方解石等;腐殖土有机质组分含量为15.4%,存在Cr、Zn、As这3项重金属全量超标,且存在As、Pb浸出浓度不同程度超标。腐殖土经熟石灰-水泥固化后pH>12,有利于加速有机质的分解,无侧限抗压强度达1.7~3.1 MPa,熟石灰与水泥总掺量>10%可满足JTG D50—2017公路沥青路面设计规范二级及二级以下公路中等、轻交通底基层的填筑要求,具备作为道路填筑材料的潜质。

The humus soil of an aged landfill in Jishui county was taken as the research object to explore the physicschemistry properties and leaching solution,in order to provide an effective way for its resource utilization.The results showed that the content of lime soil,brick and stone components in waste humus was as high as 93.62%,and the content of glass and plastic was 6.38%.The humus was sandy soil with good thermal stability.The results of XRD and EDS showed that the main chemical components were SiO_(2),Al_(2)O_(3),FeO and CaCO_(3),while the main mineral components were quartz,calcite and so on.The content of organic matter in humus was 15.4%.Heavy metals including chromium,zinc and arsenic exceeded the standard,and the leaching concentration of arsenic and plumbum also exceeded the standard in different degrees.The pH of humus after curing by lime-cement was greater than 12,which was beneficial to accelerate the decomposition of organic matter.Its unconfined compressive strength was 1.7-3.1 MPa,while the total content of lime and cement more than 10%could meet the filling requirements of JTG D50—2017 Specifications for Design of Highway Asphalt Pavement for medium and light traffic base and subbase of secondary and below secondary roads,which had the potential to be used as road filling materials.