| With the continuous progress of the social civilization and technology,Industrial production will be inevitably expanded. This may lead to an increasing scale of indu strial wastewater discharge, including a large number of hypersaline organic wastew ater. The climbing content of wastewater is mainly caused in two ways. One is from the chemical plant, and the other is from the extracted process of petroleum and natu ral gas. Numerous organic matter in the wastewater will directly reflect on the hardn ess and eutrophication of river water. The soil, surface water and groundwater, as a r esult, will be severely polluted. Also, the inhibition, which hypersaline organic waste water cause to the microorganism, will disturb the purification effect of biological tre atment system. Therefore, it is significant to find an effective treatment of hypersalin e organic wastewater.Our paper revolves around using Fenton oxidation to remove organic contaminants from high saline effluent by two technology. One method is combinations of absorption and two-staged Fenton oxidation, another one is accelerating the ferric system with hydroxylamine hydrochloride( HA) and benzoquinone(BQ). The details are summarized as follows:(1)Combination of activated carbon adsorption and two-staged Fenton oxidation was applied to treat high salinity p-aminophenol production wastewater. The results indicated that pH has rather limited effect on removal of organic substances by activated carbon adsorption. When dosage of activated carbon was 4g/L, 61% of TOC was removed. Organic removal efficiency of Fenton oxidation was greatly enhanced by two-staged reaction mode. TOC in effluent was reduced to below 150 mg/L, when reaction temperature, pH, 30% H2O2 dosage, Fe2+/H2O2 molar ratio were 25 oC, 3, 3%( v/v), 0.05 respectively. The particle size of Fenton sludge was approximately 4.5 μm and increased significantly after PAM flocculation. However, PAM flocculation process was strongly dependent on solution pH, and PAM didn’t work at pH above 10. Consequently, the solution pH needed to be prudently controlled in practical application.(2)Fenton oxidation is generally inhibited in the presence of a high concentration of chloride ions. This study investigated the feasibility of using benzoquinone(BQ) and hydroxylamine hydrochloride(HA) as Fenton enhancers for the removal of glycerin from saline water under ambient temperature by an accelerating the ferric system. It was found that organics removal was not obviously affected by chloride ions of low concentration(less than 0.1 M), while the mineralization rate was strongly inhibited in the presence of a large amount of chloride ions. In addition, ferric hydrolysis-precipitation was significantly alleviated in the presence of HA and BQ, and HA was more effective in reducing ferric ions into ferrous ions than BQ, while the H2O2 decomposition rate was higher in the BQ-Fenton system. Electron spin resonance(ESR) analysis revealed that hydroxyl radical() production was reduced in high salinity conditions, while it was enhanced after the addition of HA and BQ(especially HA). This study provided a possible solution to control and alleviate the inhibitory effect of chloride ions on the Fenton process for organics removal. |
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