High strength refractory organic stream is produced during the production of 2-phenylamino-3-methyl-6-di-n-butylaminofluoran （One Dye Black 2, abbr. ODB 2）, a novel heat-sensitive material with a promising market. I...High strength refractory organic stream is produced during the production of 2-phenylamino-3-methyl-6-di-n-butylaminofluoran （One Dye Black 2, abbr. ODB 2）, a novel heat-sensitive material with a promising market. In this study, a combination of acidificationprecipitation, primary biological treatment, Fenton＇s oxidation and another biological treatment was successfully used for the removal of COD from 18000-25000 mg/L to below 200 mg/L from the ODB 2 production wastewater in a pilot experiment. A COD removal of 70%-80% was achieved by acidification-precipitation under a pH of 2.5-3.0. The first step biodegradafion permitted an average COD removal of 70% under an hydraulic residence time （HRT） of 30 h. By batch tests, the optimum conditions of Fenton＇s oxidation were acquired as： Fe^2＋ dose 6.0 mmol/L; H2O2 dose 3000 mg/L; and reaction time 6 h. The second step biological treatment could ensure an effluent COD below 200 mg/L under an HRT of 10 h following the Fenton＇s treatment.展开更多
Fenton’s oxidation method was successfully used to synthesize an ideal titania film in situ on NiTi shape memory alloy(SMA) for medical applications. Characterized with scanning electron microscopy, X-ray photoelectr...Fenton’s oxidation method was successfully used to synthesize an ideal titania film in situ on NiTi shape memory alloy(SMA) for medical applications. Characterized with scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffractometry, inductively coupled plasma mass spectrometry and electrochemical tests, it is found that the titania film produced by Fenton’s oxidation method on NiTi SMA is nanostructured and has a Ni-free zone near its top surface, which results in a notable improvement in corrosion resistance and a remarkable decrease in leaching of harmful Ni ions from NiTi SMA in simulated body fluids. The improvement of effectiveness to corrosion resistance and the reduction in Ni release of NiTi SMA by Fenton’s oxidation method are comparable to those by oxygen plasma immersion ion implantation reported earlier.展开更多
Graded modified Fenton’s （MF） oxidation is a strategy in which H 2 O 2 is added intermittently to prevent a sharp temperature increase and undesired soil sterilization at soil circumneutral pH versus adding the sam...Graded modified Fenton’s （MF） oxidation is a strategy in which H 2 O 2 is added intermittently to prevent a sharp temperature increase and undesired soil sterilization at soil circumneutral pH versus adding the same amount of H 2 O 2 continuously.The primary objective of the present study was to investigate whether a mild MF pre-oxidation such as a stepwise addition of H 2 O 2 can prevent sterilization and achieve a maximum degradation of tank oil in soil.Optimization experiments of graded MF oxidation were conducted using citric acid,oxalic acid and SOLV-X as iron chelators under different frequencies of H 2 O 2 addition.The results indicated that the activity order of iron chelates decreased as：citric acid （51%） SOLV-X （44%） oxalic acid （9%）,and citric acid was found to be an optimized iron chelating agent of graded MF oxidation.Three-time addition of H 2 O 2 was found to be favorable and economical due to decreasing total petroleum hydrocarbon removal from three time addition （51%） to five time addition （59%）.Biological experiments were conducted after graded MF oxidation of tank oil completed under optimum conditions mentioned above.After graded oxidation,substantially higher increase （31%） in microbial activity was observed with excessive H 2 O 2 （1470 mmol/L,the mol ratio of H 2 O 2：Fe 2＋ was 210：1） than that of non-oxidized soil.Removal efficiency of tank oil was up to 93% after four weeks.Especially,the oil fraction （C 10 –C 40 ） became more biodagradable after graded MF oxidation than its absence.Therefore,graded MF oxidation is a mild pretreatment to achieve an effective bioremediation of oil contaminated soil.展开更多
基金Project supported by the National Natural Science Foundation of China (No.50525824)Natural Science Fund of Xinjiang Province of China (No.200432109).
文摘High strength refractory organic stream is produced during the production of 2-phenylamino-3-methyl-6-di-n-butylaminofluoran （One Dye Black 2, abbr. ODB 2）, a novel heat-sensitive material with a promising market. In this study, a combination of acidificationprecipitation, primary biological treatment, Fenton＇s oxidation and another biological treatment was successfully used for the removal of COD from 18000-25000 mg/L to below 200 mg/L from the ODB 2 production wastewater in a pilot experiment. A COD removal of 70%-80% was achieved by acidification-precipitation under a pH of 2.5-3.0. The first step biodegradafion permitted an average COD removal of 70% under an hydraulic residence time （HRT） of 30 h. By batch tests, the optimum conditions of Fenton＇s oxidation were acquired as： Fe^2＋ dose 6.0 mmol/L; H2O2 dose 3000 mg/L; and reaction time 6 h. The second step biological treatment could ensure an effluent COD below 200 mg/L under an HRT of 10 h following the Fenton＇s treatment.
基金Project supported by Program for New Century Excellent Talents(NCET) in University of Ministry of Education of ChinaProject(50501007) supported by the National Natural Science Foundation of China+1 种基金Project(BK2007515) supported by the Natural Science Foundation of Jiangsu Province, ChinaProject(7001999) supported by SRG Grant from the Research Committee of the CityU of HK
文摘Fenton’s oxidation method was successfully used to synthesize an ideal titania film in situ on NiTi shape memory alloy(SMA) for medical applications. Characterized with scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffractometry, inductively coupled plasma mass spectrometry and electrochemical tests, it is found that the titania film produced by Fenton’s oxidation method on NiTi SMA is nanostructured and has a Ni-free zone near its top surface, which results in a notable improvement in corrosion resistance and a remarkable decrease in leaching of harmful Ni ions from NiTi SMA in simulated body fluids. The improvement of effectiveness to corrosion resistance and the reduction in Ni release of NiTi SMA by Fenton’s oxidation method are comparable to those by oxygen plasma immersion ion implantation reported earlier.
基金supported by the Program of In-ternational S&T Cooperation(No.2010 DFA 94550,2010KW-24-1)the National Natural Science Founda-tion of China(No.50830303)+1 种基金the Major Science and Technology Program for Water Pollution Control and Treatment(No.2009ZX07317-007-001)the Program for Changjiang Scholars and Innovative Research Team in University(No.IRT0853)
文摘Graded modified Fenton’s （MF） oxidation is a strategy in which H 2 O 2 is added intermittently to prevent a sharp temperature increase and undesired soil sterilization at soil circumneutral pH versus adding the same amount of H 2 O 2 continuously.The primary objective of the present study was to investigate whether a mild MF pre-oxidation such as a stepwise addition of H 2 O 2 can prevent sterilization and achieve a maximum degradation of tank oil in soil.Optimization experiments of graded MF oxidation were conducted using citric acid,oxalic acid and SOLV-X as iron chelators under different frequencies of H 2 O 2 addition.The results indicated that the activity order of iron chelates decreased as：citric acid （51%） SOLV-X （44%） oxalic acid （9%）,and citric acid was found to be an optimized iron chelating agent of graded MF oxidation.Three-time addition of H 2 O 2 was found to be favorable and economical due to decreasing total petroleum hydrocarbon removal from three time addition （51%） to five time addition （59%）.Biological experiments were conducted after graded MF oxidation of tank oil completed under optimum conditions mentioned above.After graded oxidation,substantially higher increase （31%） in microbial activity was observed with excessive H 2 O 2 （1470 mmol/L,the mol ratio of H 2 O 2：Fe 2＋ was 210：1） than that of non-oxidized soil.Removal efficiency of tank oil was up to 93% after four weeks.Especially,the oil fraction （C 10 –C 40 ） became more biodagradable after graded MF oxidation than its absence.Therefore,graded MF oxidation is a mild pretreatment to achieve an effective bioremediation of oil contaminated soil.
