Alkali treatments with three concentrations were used to modify a microarc-oxidized(MAO) coating on titanium alloy surface in order to further improve its surface bioactivity. Morphology, chemical compositions and pha...Alkali treatments with three concentrations were used to modify a microarc-oxidized(MAO) coating on titanium alloy surface in order to further improve its surface bioactivity. Morphology, chemical compositions and phase constitues, roughness, contact angle and apatite induction of the alkali-treated coatings were studied and compared. Scanning electron microscope(SEM) was applied to observe the morphologies, X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS) were used to detect the phase constitutes and chemical compositions, a surface topography profilometer was used to analyze the surface roughness, and contact angle was measured by liquid drop method. Alkali treatements result in the formation of Na2Ti6O13 and Na2Ti3O7 phase on the MAO coating, which leads to the increase of surface roughness and the decrease of contact angle. Experimental results showed that the apatite induction of the alkali-treated coatings was dependent on the applied alkali concentrations during treatments, and Na+concentration can promote the formation of apatite phase.展开更多
Alkaline pretreatment is an effective technology to disintegrate sewage sludge, where alkali dosage and sludge concentration are two important factors. p H value or alkali concentration is usually adjusted in order to...Alkaline pretreatment is an effective technology to disintegrate sewage sludge, where alkali dosage and sludge concentration are two important factors. p H value or alkali concentration is usually adjusted in order to determine a proper dosage of alkali. Our work has found that this is not a good strategy. A new parameter, the ratio of alkali to sludge(Ra/s), is more sensitive in controlling the alkali dosage. The sludge concentration Csand retention time t are two other important factors to consider. The validity of these arguments is confirmed with modeling and experiments. The individual effect of Ra/s, Csand t was studied separately. Then the combined effect of these three factors was evaluated. The sludge disintegration degree of 44.7% was achieved with the optimized factors. Furthermore, an alkaline-microwave combined pretreatment process was carried out under these optimized conditions. A high disintegration degree of 62.3% was achieved while the energy consumption of microwave was much lower than previously reported.展开更多
[Objective] This paper aimed to study the treatment process of high con- centration wastewater from organic fungicide production by using Fenton oxidation. [Method] The alkali out pretreatment was used to investigate ...[Objective] This paper aimed to study the treatment process of high con- centration wastewater from organic fungicide production by using Fenton oxidation. [Method] The alkali out pretreatment was used to investigate the effects of NaOH concentration, molar ratio of H2O2 to Fe2＋ and H202 dosage on COD removal rate and decolourization ratio. [Result] The optimal operating conditions were determined as follows： pH=3.0, NaOH concentration of 15 g/L, n [H2O2]：n [Fe2＋] =4.20, reaction time of 30 min. [Conclmio.] The research provided scientific references for the treatment of high concentration wastewater from fungicide production.展开更多
基金Projects(51172050,51102060,51302050)supported by the National Natural Science Foundation of ChinaProject(HIT.ICRST.2010009)supported by the Fundamental Research Funds for Central Universities,ChinaProject(HIT.NSRIF.2014129)supported by the Natural Scientific Research Innovation Foundation in Harbin Institute of Technology,China
文摘Alkali treatments with three concentrations were used to modify a microarc-oxidized(MAO) coating on titanium alloy surface in order to further improve its surface bioactivity. Morphology, chemical compositions and phase constitues, roughness, contact angle and apatite induction of the alkali-treated coatings were studied and compared. Scanning electron microscope(SEM) was applied to observe the morphologies, X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS) were used to detect the phase constitutes and chemical compositions, a surface topography profilometer was used to analyze the surface roughness, and contact angle was measured by liquid drop method. Alkali treatements result in the formation of Na2Ti6O13 and Na2Ti3O7 phase on the MAO coating, which leads to the increase of surface roughness and the decrease of contact angle. Experimental results showed that the apatite induction of the alkali-treated coatings was dependent on the applied alkali concentrations during treatments, and Na+concentration can promote the formation of apatite phase.
基金the National Natural Science Foundation of China(51078234)Shenzhen R&D fund(JCYJ20140418193546101)Shenzhen University R&D fund(T201203)
文摘Alkaline pretreatment is an effective technology to disintegrate sewage sludge, where alkali dosage and sludge concentration are two important factors. p H value or alkali concentration is usually adjusted in order to determine a proper dosage of alkali. Our work has found that this is not a good strategy. A new parameter, the ratio of alkali to sludge(Ra/s), is more sensitive in controlling the alkali dosage. The sludge concentration Csand retention time t are two other important factors to consider. The validity of these arguments is confirmed with modeling and experiments. The individual effect of Ra/s, Csand t was studied separately. Then the combined effect of these three factors was evaluated. The sludge disintegration degree of 44.7% was achieved with the optimized factors. Furthermore, an alkaline-microwave combined pretreatment process was carried out under these optimized conditions. A high disintegration degree of 62.3% was achieved while the energy consumption of microwave was much lower than previously reported.
基金Supported by the Overall Strategic Cooperation Program of Chinese Academy of Sciences in Guangdong Province(2012B09040046)~~
文摘[Objective] This paper aimed to study the treatment process of high con- centration wastewater from organic fungicide production by using Fenton oxidation. [Method] The alkali out pretreatment was used to investigate the effects of NaOH concentration, molar ratio of H2O2 to Fe2＋ and H202 dosage on COD removal rate and decolourization ratio. [Result] The optimal operating conditions were determined as follows： pH=3.0, NaOH concentration of 15 g/L, n [H2O2]：n [Fe2＋] =4.20, reaction time of 30 min. [Conclmio.] The research provided scientific references for the treatment of high concentration wastewater from fungicide production.
