| Fenton oxidation process in treating organic sewage is advanced, especially coupled with flocculation. The strong oxidizing property of Fenton, adsorption effect of Fe(OH)3 and flocculation of polymeric flocculant can greatly reduce toxic and harmful organic pollutants.The article was based on treating sewage with PFOS and harmful hydroquinone in it. The organic waste water was processed with Fenton and sedimentation. Different factors were tested in the process of reducing pollutants, such as reaction time, temperature, initial pH value, input amount of H2O2, initial concentration of Fe2+ , salinity and flocculant added. Conclusions are listed as follows:1. Fenton had no oxidization effect on PFOS. If base was added, the reaction product Fe(OH)3 could adsorb PFOS, whose concentration would be reduced to 0.807mg·L-1 and reduction rate was almost 60%. High salinity could promote the adsorption effect. Flocculant CPAM could not eliminate PFOS and accelerate flocculation.2. The best operating condition for Fenton to oxidize hydroquinone were: Concentration of H2O2 was 9.794 mmol·L-1. Initial concentration of Fe2+ was 2.4485 mmol·L-1. Initial pH value was 3.5. The reaction time was 45min. High salinity would result in low reduction rate of TOC. If flocculation PDADMAC was added, the reduction rate was 54.68% which was not quite satisfactory and needed improving.The research was also put into treating secondary sedimentation tank sewage from a certain chemical park plant. The best operating condition were: Concentration of H2O2 was 7.346 mmol·L-1. Initial concentration of Fe2+ was 0.9182 mmol·L-1. The reaction time was 90min. Under the optimal condition, reduction rate of TOC was 45.64%. Compared with CPAM, PDADMAC had the advantage of less amount used and a higher TOC reduction rate. So PDADMAC was selected. The optimal input for PDADMAC was 2mg·L-1. And reduction rate of TOC was 54.68%. After the treatment, the water could strictly meet the requirement of effluent standard of level 2. |
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