This paper presents the effect of reaction factors on wet air oxidation(WAO) of H acid wastewater. Higher COD Cr removal were observed at low initial pH, high reaction temperature and no addition of Na 2SO 4. I...This paper presents the effect of reaction factors on wet air oxidation(WAO) of H acid wastewater. Higher COD Cr removal were observed at low initial pH, high reaction temperature and no addition of Na 2SO 4. Initial oxygen pressure P O 2 should be consistent with the initial H acid concentration. The changes of some indexes were also studied. A significant initial (about 10 min) rapid reduction in COD Cr was observed at 200℃ and 250℃. The decline of pH and the increase of SO 2- 4 concentration were found in all the experiments. Some formic acid and large amount of acetic acid were detected in the treated solution in this study. The analysis of off gas indicated undetectable amount of SO 2 and nitrogen oxides. The biodegradability of H acid solution was greatly improved after WAO treatment. The ratio of BOD 5/COD Cr increased from initial 3 4% to 33 3% after one hour reaction at 160℃ and 3 MPa initial oxygen pressure(initial H acid concentration:10 g/L, mixing speed:300 r/min). The result of WAO of H acid production wastewater was similar to that of WAO of H acid pure compound in distilled water.展开更多
文摘This paper presents the effect of reaction factors on wet air oxidation(WAO) of H acid wastewater. Higher COD Cr removal were observed at low initial pH, high reaction temperature and no addition of Na 2SO 4. Initial oxygen pressure P O 2 should be consistent with the initial H acid concentration. The changes of some indexes were also studied. A significant initial (about 10 min) rapid reduction in COD Cr was observed at 200℃ and 250℃. The decline of pH and the increase of SO 2- 4 concentration were found in all the experiments. Some formic acid and large amount of acetic acid were detected in the treated solution in this study. The analysis of off gas indicated undetectable amount of SO 2 and nitrogen oxides. The biodegradability of H acid solution was greatly improved after WAO treatment. The ratio of BOD 5/COD Cr increased from initial 3 4% to 33 3% after one hour reaction at 160℃ and 3 MPa initial oxygen pressure(initial H acid concentration:10 g/L, mixing speed:300 r/min). The result of WAO of H acid production wastewater was similar to that of WAO of H acid pure compound in distilled water.
