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SO4 −-based oxidation technologies have been considered as key solution in polycyclic aromatic hydrocarbons (PAHs) degradation. This study constructed Fe2+-activated persulfate oxidation to degrade pyrene in water and soil by using batch and column experiments. Pyrene degradation kinetic in polluted water and effects of soil background electrolytes (Cl−, HCO3− and humic acid) on pyrene degradation were both investigated. The variation of soil properties during pyrene degradation in soil was evaluated. Polluted water remediation results showed that approximately 93.2 % of pyrene was degraded by 65 mM of persulfate with Fe2+/persulfate molar ratio of 0.25. In soil, 88.5 % of pyrene was degraded under the same persulfate concentration and Fe2+/persulfate molar ratio, and there was a slight decrease of soil pH (from 6.7 to 5.4). Cl−, HCO3− and humic acid in soil brought an adverse effect to pyrene degradation through scavenging SO4 −. Column study of soil remediation proved the superiority of Fe2+ in activating persulfate, whose application in soil remediation can finally reduce soil pollution and simultaneously avoid the excessive soil acidification in in-situ remediation. In addition, by evaluating the soil organic matter and total organic carbon during the remediation process, it was found that the soil properties have been improved. Therefore, Fe2+-activated persulfate oxidation would be a feasible way to remediate pyrene polluted water/soil.

This study prepared a biosurfactant by using piggery wastewater to enhance ethylbenzene removal from contaminated gas in a biotrickling filter (BTF). Experiments were conducted to investigate the enhancement of ethylbenzene removal and the biofilm characteristics in present of the biosurfactant. Results demonstrated that the optimal biosurfactant concentration was 0.1 CMC and the corresponding ethylbenzene removal rate was 87.2%, much higher than that (68.9%) achieved in free of biosurfactant. The inlet ethylbenzene concentration and the empty bed residence time (EBRT) affected ethylbenzene removal as well. In present of 0.1 CMC of biosurfactant, ethylbenzene removal rate decreased from 87.2% to 72.2% with the increasing inlet ethylbenzene from 1000 to 2200 mg/m3, and decreased from 91.1% to 42.7% with the EBRT shorten from 30 to 7.5 s. For the enhancement mechanisms of ethylbenzene removal in BTF, the biosurfactant changed the contents of extracellular polymers (EPS) and decreased negative surface charge of the biofilm in the BTF, which improved the mass transfer of ethylbenzene to biofilm and facilitated the aggregation of microbes, and further improved the removal of ethylbenzene. All in all, the biosurfactant would be a feasible way to enhance the removal of ethylbenzene by the BTF.