Remediation Of Contaminated Soil By Using Fenton Pre-oxidation Combined Bioremediation

Fenton's pre-oxidation with hydroxyl radicals of short persistent time and great instantaneous strength can avoid the impact to indigenous bacteria significantly and release a lot of nutrition.In bioremediation process,matching the number of residual indigenous bacteria and nutrient levels can promote the fluidity of nutrient,high activity of indigenous bacteria and bioremediation of TPH.First of all,this study explored the effects of different hydroxyl radicals pre-oxidation on the subsequent bioremediation of TPH.Based on these effects,the relationship between the nutritional level and the quantityr of residual indigenous bacteria was studied for subsequent bioremediation.Then the effects of different hydroxyl radicals on soil SOM oxidation were studied.Finally obtain the efficient pre-oxidation and efficient follow-up bioremediation conditions.The conclusions of experiments as below:?1?When the maximum instantaneous intensity of hydroxyl radicals is the same and the level of nutrient is basically the same,the longer the duration of hydroxyl radicals is,the greater the damage to indigenous.?2?When the duration of hydroxyl radicals is consistent,the lower the instantaneous intensity,the lower the degree of nutrient level and the residual number of indigenous bacteria,the nutrient flow and the activity of indigenous bacteria was limited and the removal of TPH is only 15%.?3?Under the low nutrient level,the amount of excess or less residual indigenous bacteria is not conducive to nutrition flow,bioremediation of TPH was limited.When the residual indigenous bacteria matched with low nutrient level,the nutrient flow was smooth?DOC=78%,ammonia nitrogen =89%?and the degradation rate of TPH was 39%.?4?Under the condition of moderate nutrient level,the higher the residual soil number and the more nutrient level,the better the nutrient flow?DOC = 97%,ammonia nitrogen = 92%?.The effect of TPH on subsequent bioremediation was significant?59%?,Especially for medium to long chain hydrocarbons(C₁₇-C₂₆).?5?The oxidation of fulvic acid into small molecule organic matter or carbon dioxide and water is related to the instantaneous strength and duration of hydroxyl radicals produced by Fenton,where instantaneous intensity is particularly important.