O-nitro-phenol wastewater which contains refractory organic matters can not be degraded by conventional biological methods. In this work, o-nitro-phenol wastewater was effectively treated using magnetization-enhanced ...O-nitro-phenol wastewater which contains refractory organic matters can not be degraded by conventional biological methods. In this work, o-nitro-phenol wastewater was effectively treated using magnetization-enhanced oxidation by NaCIO solutions. The pollutant concentrations in wastewater were 250 mg/L o-nitro-phenol, 2,000 mg/L CODcr and 150 times color. The experimental results show that, using the method in this work, 94.4% o-nitro-phenol, 94.2% CODCr and 100% color can be removed at pH 6, 200 mg charcoal, 8 mL oxidizer, 5 min reaction time in 1000 mL wastewater. The treatment can be enhanced under magnetic field. CODCr and o-nitro-phenol removal can keep unchanged while the reaction time can be reduced to 3 min when the intensity of magnetic field was 60 mT.展开更多
This study compared the effects of chemical aging on the polyvinylidene fluoride（PVDF）membranes fabricated with the methods of non-solvent induced phase separation（NIPS）（named NIPS-PVDF） and thermally induced ph...This study compared the effects of chemical aging on the polyvinylidene fluoride（PVDF）membranes fabricated with the methods of non-solvent induced phase separation（NIPS）（named NIPS-PVDF） and thermally induced phase separation（TIPS）（named TIPS-PVDF）. The chemical solutions of sodium hypochlorite（NaClO） and sodium hydroxide（NaOH） were chosen at the concentration of 5000 mg/L. The equivalence of 5 and 10 years was respectively selected as the time of aging. The physicochemical evolutions of membrane aging are characterized on the base of morphology analysis, chemical components, permeation ability and mechanical properties. The aging of NIPS-PVDF membrane led to the elimination of surface hydrophilic additives, while NaO H focused on the dehydrofluorination process resulting in the formation of conjugated chains of polyene on the skeleton structure. The chemical components of the surface of TIPS-PVDF membrane were removed continuously during the aging processes of both NaClO and NaOH, which was caused by the saponification of surface additives and the chain scissions of skeleton structure, but without producing any obvious conjugated chains of polyene. All the aging processes led to the increase of contact angle and the decrease of mechanical properties, and the permeability was reduced first and increased later due to the enlargement of surface membrane pores and membrane block. With the influence of membrane aging, selectivity of membrane was decreased（except coliform bacteria）. At the beginning of filtration, the turbidity and particle count were at relatively high levels and declined with the filtration process.展开更多
The effects of various parameters on the removal rate of CN were discussed in the paper. The results showed that under the conditions of 30℃ pH = 3.0, Fe2＋ dosage was 80 mg/L, the NaCIO concentration of 0.10 mol/L, ...The effects of various parameters on the removal rate of CN were discussed in the paper. The results showed that under the conditions of 30℃ pH = 3.0, Fe2＋ dosage was 80 mg/L, the NaCIO concentration of 0.10 mol/L, reaction time in 60 min, Fe2＋ has a satisfactory catalytic activation, and the removal rate of CN was about 37.89%.展开更多
文摘O-nitro-phenol wastewater which contains refractory organic matters can not be degraded by conventional biological methods. In this work, o-nitro-phenol wastewater was effectively treated using magnetization-enhanced oxidation by NaCIO solutions. The pollutant concentrations in wastewater were 250 mg/L o-nitro-phenol, 2,000 mg/L CODcr and 150 times color. The experimental results show that, using the method in this work, 94.4% o-nitro-phenol, 94.2% CODCr and 100% color can be removed at pH 6, 200 mg charcoal, 8 mL oxidizer, 5 min reaction time in 1000 mL wastewater. The treatment can be enhanced under magnetic field. CODCr and o-nitro-phenol removal can keep unchanged while the reaction time can be reduced to 3 min when the intensity of magnetic field was 60 mT.
文摘This study compared the effects of chemical aging on the polyvinylidene fluoride（PVDF）membranes fabricated with the methods of non-solvent induced phase separation（NIPS）（named NIPS-PVDF） and thermally induced phase separation（TIPS）（named TIPS-PVDF）. The chemical solutions of sodium hypochlorite（NaClO） and sodium hydroxide（NaOH） were chosen at the concentration of 5000 mg/L. The equivalence of 5 and 10 years was respectively selected as the time of aging. The physicochemical evolutions of membrane aging are characterized on the base of morphology analysis, chemical components, permeation ability and mechanical properties. The aging of NIPS-PVDF membrane led to the elimination of surface hydrophilic additives, while NaO H focused on the dehydrofluorination process resulting in the formation of conjugated chains of polyene on the skeleton structure. The chemical components of the surface of TIPS-PVDF membrane were removed continuously during the aging processes of both NaClO and NaOH, which was caused by the saponification of surface additives and the chain scissions of skeleton structure, but without producing any obvious conjugated chains of polyene. All the aging processes led to the increase of contact angle and the decrease of mechanical properties, and the permeability was reduced first and increased later due to the enlargement of surface membrane pores and membrane block. With the influence of membrane aging, selectivity of membrane was decreased（except coliform bacteria）. At the beginning of filtration, the turbidity and particle count were at relatively high levels and declined with the filtration process.
文摘The effects of various parameters on the removal rate of CN were discussed in the paper. The results showed that under the conditions of 30℃ pH = 3.0, Fe2＋ dosage was 80 mg/L, the NaCIO concentration of 0.10 mol/L, reaction time in 60 min, Fe2＋ has a satisfactory catalytic activation, and the removal rate of CN was about 37.89%.
