Research On Fenton Oxidation Of Wastewater From Low Temperature Pyrolysis Of Contaminated Soil

Remediation of soil mercury pollution has become one of the hot topics in the field of environmental remediation,and the methods to deal with conventional mercury contaminated soils include physical remediation,chemical remediation,bioremediation,etc.Low temperature pyrolysis technology for remediation of mercury contaminated soil has high removal efficiency and Recyclable mercury and maintain soil fertility and other advantages,this technology has been applied in Qingzhen City in an organic chemical plant contaminated soil,and get good results.In addition to the mercury pollution in soil complex organic pollutants,contaminants continue to accumulate in the soil,in the use of low temperature pyrolysis process produces a lot of deep color,the pungent smell of wastewater,especially COD concentration,ammonia concentration is far more than the "sewage comprehensive discharge standard"(GB 8978-1996)three emission standard.Therefore,it is not possible to evaluate the water quality of conventional chemical wastewater.In order to improve the low temperature pyrolysis process and ensure the harmless treatment technology,it is necessary to study the process water and put forward the feasible scheme:The first stage is the analysis of the characteristics of water quality to determine the type of wastewater,the wastewater GC/MS scanning,found that there are benzene,phenol and polycyclic aromatichydrocarbons;In wastewater COD,ammonia nitrogen,volatile phenol and other pollutants were detected COD concentration up to 15000mg/L~20000 mg/L,2000 mg/L in ammonia nitrogen,volatile phenol also seriously exceed the standard,calculation of B/C is about 0.14~0.18,the wastewater belongs to high concentration organic wastewater degradation.The second stage is to treat wastewater by Fenton oxidation,the removal rate of COD to get the best experimental conditions of Fenton oxidation wastewater treatment as the indexes,including pH=3~4,FeSO4·7H2O initial reaction dosage of 13.9 g/L,H2O2 dosage is three times 84 ml/L,reaction time 40 min,repeated oxidation;finally COD the removal rate reached 83%.The third stage evaluation method of Fenton oxidation on the comprehensive effect of wastewater treatment,under the optimal conditions,the wastewater treatment after the concentration of COD,ammonia nitrogen,volatile phenol and other pollutants in the treatment after the removal rates were 83%?42.55%?80%,biochemical indicators of B/C wastewater increased from 0.18 to 0.36,the biodegradability increased by 100%.The fourth phase contrast pyrolysis wastewater of different concentration gradient and wastewater treatment Fenton oxidation of other types,to verify the effectiveness of Fenton oxidation of highconcentration organic wastewater,reflects the complexity of pyrolysis and refractory wastewater.The pyrolysis process of organic wastewater is a high concentration of wastewater,the Fenton oxidation of wastewater treatment has a good effect,the biochemistry is obviously improved,provides a good basis for subsequent biochemical treatment or other treatment technology,to improve the system of low temperature pyrolysis technology provides technical support.