Experimental Study On Lime Solidification/Stabilization Process Refinery Waste Contaminated Soil

As technology advanced, people's dependence on petroleum and its derivatives is growing, while the oil and its derivatives environmental pollution have become increasingly serious. Zhong Chuan railway Jiuhe Yi tunnel is located in jiuhe town, Gaolan County, Lanzhou City, Gansu Province. Site excavation mileage to HK6 + 405 at the tunnel face sustained abnormal smell of gas and a small amount of seepage. To ensure construction safety, construction program of the open-cut excavation to be recognized as refinery waste that contaminated soil excavation. To ensure the safety of construction and operation when Jiuhe Yi No. tunnel came cross portion containing refinery waste and contaminated soil contamination impact, we need to take solidification / stabilization process technology. In this paper, compressive strength test, TCLP test and scanning electron microscopy were conducted by using non-side in both directions from the macro and micro analysis of the curing agent for lime solidification / stabilization treatment to get the impact of waste contaminated soil in physical and chemical aspect. Through test data analysis, conclusion could be drawn as the following:? Under the same curing period, unconfined compressive strength of dark-colored soil samples cured increases with growing content of lime, while unconfined compressive strength of light-colored soil samples increase with the growing dosage of lime in a certain range, and then reduced;? With the same lime content, unconfined compressive strength raised firstly slow and increased greatly later. Besides, unconfined compressive strength of light-colored soil unconfined compressive strength is proportional to its curing period.? Under the same curing period, with the increase of cured lime content, benzene, chromium, cadmium, lead concentration and organic content seeped from dark and light soil specimen decreased, but concentrated content of phenol and sulfide has increased; with the same lime content, the curing period hardly affected the benzene, cadmium content leaching from the dark soil and light soil specimens. While content of heavy metals lead(Pb) and chromium(the concentration of Cr) and sulphide increases with the curing period but below the national emission standards.? Curing lime agent could increase p H value of wasted refinery contaminated soil and could effectively reduce the COD value and BOD value which both were lower than the national secondary standard.? With the increase of curing period and lime content, dark and light contaminated soil had increased chemical reaction with hardened lime, which could develop the number of rod-like structure, lower the porosity as well as dense structure. With the same curing period and the same lime content, combination degree of light contaminated soil was superior to dark contaminated soil. Additional, the former structure was denser than the latter.