Sewage Sludge Biochar As Persulfate Activator For Remediation Of Anthracene Contaminated Soil

With the rapid development of urbanization and industrialization in China,the disordered emission of living waste and industrial wastes has caused serious soil pollution.As one of the comman organic pollutants,polycyclic aromatic hydrocarbons(PAHs)are strongly poisonous,carcinogenic,and environmentally persistent which represents significant risk to the surrounding ecological environment and to human health.The chemical oxidation technology based on the iron species activation can effectively degrade the PAH pollutants in groundwater and soil.But there still exist some problems,comman ferrous compounds such as Fe(II)ion,iron minerals,zero-valent nanometer iron which have low oxidant utilization rate and were sensitive to environmental factors,easily to be corroded,secondary-pollution etc.In this paper,the soil contaminated with anthracene was checked.We studied the optimal conditions of the anthracene degradation of chelating agent/Fe(II)/PS system and iron-containing sewage sludge biochar/PS system,the effect environmental factors and the reaction mechanism of mentioned materials.As following:In the second chapter,the degradation effect of Fe(II)activated persulfate in soil was investigated.It was found that after 3 days the degradition of anthracene showed better performance which can reach 74.4% when the dosage of persulfate and ferrous ion were 1.2 mmol,0.24 mmol respectively;the study of p H effect also showed that the anthracene degradation rate under acidic condition was significantly higher than that of neutral and alkaline conditions;chelating agent such as citric acid can significantly influence anthracene degradition in PS/Fe2+ system,the removal efficiency can reach 71.9%.In the third chapter,a series of sewage sludge biochar was successfully prepared by high temperature calcination in inert atmosphere,furthermore,preliminary biochar was modified to achieve larger specific surface area and high ion content materials to activate PS for degrading anthracene in soil.It was found that sewage sludge biochar showed better activation than traditional ion minerals.SSB,SSBZn,and SSBFe showed better performance over a wide initial p H range(3.0 –11.0).The excellent stability of SSBFe was also studied by thrice loop operations after fifth run test and low ion leaching of SSBFe.EPR experiment showed that sulfate radical and hydroxy radical were active radical in biochar/PS system.