A Study On The Remediation Technology Of Soil Contaminated By Typical Organic Pollutants

With the rapid development of e of modern industry, agriculture, and animal husbandry, the soil pollution resulted from organic contaminants has aggravated in these days. The organic pollutants generated in the process of industrial production diffuse through soil and then accumulate around food chains, which in turn will jeopardize human health. Thus, the research of the remediation technology on contaminated soil polluted by organic contaminates has been made a research hotspot recently.The author designed the remediation and control of PAHs and sulfonamides contaminated soil and further studied the removal of PAHs and the migration inhibitation of sulfonamides. By characterizing biochars, removing PAHs and controlling the migration of sulfonamides, the author analyzed the remediation effect of organic contaminated soil. The main contents and results are as follows:First, In the experiments, biochar(BC), lignocellulose(LS), biochar associated with lignocellulose(BC+LS), and biochar associated with lignocellulose and Brij-30(BC+LS+BR) were added into soil respectively as planed to remediate phenanthrene(PHE) and benzo[a]pyrene(Ba P) contaminated soil. It was found the ranks of the removal rate for PHE and Ba P were LS > BC > BC + LS > BC + LS + BR and BC >LS > BC + LS + BR > BC + LS, respectively in PAHs-contaminated soil after 56days' incubation. The removal rate of PHE was inhibited regardless of the addition of surfactants in biochars amendment, while the removal rate of Bap in biochars contained soil was higher than that in cellulose contained soil. Besides, the dehydrogenase(DH) activities under different amendments ranked as LS > LS + BC+ BR > LS + BC > C > BC. Thus, the activity of dehydrogenase was inhibited by biochars. However, by adding cellulose the activity in soil was increased. Overall, the polyphenoloxidase(PPO) activity increased with time before day 42. The activity of PPO followed the order of BC + LS + BR > BC + LS > BC > LS > C under the different amendments over the process of a 56-day experiment. The PPO activity wasenhanced by cellulose and biochars. In the remediation process, it was not the species of bacteria in soil but the relative abundance of them changed. Meanwhile, it is found that the relative abundance of bacterium 109 bp and bacterium 442 bp were more than50% after adding LS. And bacterium 109 bp, 442 bp and 468 bp outranked other 8detected bacteria in all processes on the 56 th day. Changes in the relative abundance of bacteria manifested that the structure of bacterium community could be changed in the soil with additives. Shannon wiener index peaked on the 28 th day and decreased after adding additives. On the 56 th day, the Shannon wiener indexes in the four experimental groups were closer to or higher than that in the control group. Such was the case of evenness.Secondly, It was found in the experiment of limiting the migration of sulfonamides that for the control group the adsorption rates for sulfamerazine(SMZ)in the samples with the initial concentration of 20, 40, 60, 80 and 100 ?g/m L was8.7%, 7.5%, 9.1%, 8.75% and 12.5% after 72 hours adsorption; the desorption rates were 98.66%, 94.96%, 92.3%, 85.27% and 86.38%. However, after adding 0.03 g biochar, adsorption rates turned out to be 98.7%, 86.3%, 67.2%, 61% and 48.9%;desorption rates were 11.9%, 16.6%, and 23.14%. The adsorption rates for sulfapyridine(SPY) were 23%, 22%, 20%, 17.7% and 15.7%; the desorption rates were 44.5%, 42.5%, 45.6%, 50% and 56.7%. However, after adding 0.03 g biochar,the adsorption rates turned out to be 99.7%, 97.6%, 89.8%, 68.8% and 71.8%; the desorption rates were 0.3%, 1.6%, 4.7%, 13.2% and 10.5%. Thus it could be inferred that biochar is highly effective in restricting the migration of sulfonamides. The adsorption-desorption isothermals is achieved by Freundlick equation fitting and we found that the desoption rate in biochar added soil was very low, which manifested that biochars had a immobilization effect on sulfonamides and the sulfonamides in soil could be desorbed. Desorption of sulfonamides had a delayed adsorption While the soil biochar did not add in the soil..