In order to synthesize an improved adsorbent for heavy metal ions,we studied the condensation reaction of chitosan with salicylaldehyde in ethanol to form a Schiff base.The effect irradiating the reaction using an ult...In order to synthesize an improved adsorbent for heavy metal ions,we studied the condensation reaction of chitosan with salicylaldehyde in ethanol to form a Schiff base.The effect irradiating the reaction using an ultrasonic liquid processor was contrasted with conventional methods.The IR spectra of condensed chitosan prepared by the two methods showed that their molecular structures were identical.The reaction conditions,including solvents,ultrasonic power density and irradiation time,pH,and reactant ratio,were optimized by orthogonal design.A shorter reaction time and a higher product yield were obtained using ultrasonic-assisted synthesis compared with the traditional method.A condensation degree of 89.63% was achieved using the optimized conditions:i.e.ultrasonic irradiation at 180 W for 60 min;95% ethanol as the solvent,pH 4.0,and salicylaldehyde:chitosan ratio of 6:1.展开更多
Ultrasonic and jet combined process was studied to remove determined by static experiments, and stability of this combined process algae in lake type raw water. The optimum reaction time was was checked by dynamic exp...Ultrasonic and jet combined process was studied to remove determined by static experiments, and stability of this combined process algae in lake type raw water. The optimum reaction time was was checked by dynamic experiments. The results was showed that ultrasonic/jet combined process has excellent removal efficiency on algae in lake type raw water, and it＇s a simple operation, and has no secondary pollution. When the pH, temperature, chlorophyll-a（Chl-a） and cell concentration（OD560） of raw water are 7.69, 25.8 ℃, 29.003 mg/m^3 and 0.091, the average removal efficiency on Chl-a and OD560 are 81.60% and 80.22%, respectively, which are stable by this combined process when it is operating in 36 hours, and samples are analyzed each 4 hours.展开更多
基金Supported by Doctoral Discipline Special Foundation,Education Ministry of China (No.20050561014)the National High Technology Research and Development Program of China (863 Program) (No.2007AA100405)
文摘In order to synthesize an improved adsorbent for heavy metal ions,we studied the condensation reaction of chitosan with salicylaldehyde in ethanol to form a Schiff base.The effect irradiating the reaction using an ultrasonic liquid processor was contrasted with conventional methods.The IR spectra of condensed chitosan prepared by the two methods showed that their molecular structures were identical.The reaction conditions,including solvents,ultrasonic power density and irradiation time,pH,and reactant ratio,were optimized by orthogonal design.A shorter reaction time and a higher product yield were obtained using ultrasonic-assisted synthesis compared with the traditional method.A condensation degree of 89.63% was achieved using the optimized conditions:i.e.ultrasonic irradiation at 180 W for 60 min;95% ethanol as the solvent,pH 4.0,and salicylaldehyde:chitosan ratio of 6:1.
文摘Ultrasonic and jet combined process was studied to remove determined by static experiments, and stability of this combined process algae in lake type raw water. The optimum reaction time was was checked by dynamic experiments. The results was showed that ultrasonic/jet combined process has excellent removal efficiency on algae in lake type raw water, and it＇s a simple operation, and has no secondary pollution. When the pH, temperature, chlorophyll-a（Chl-a） and cell concentration（OD560） of raw water are 7.69, 25.8 ℃, 29.003 mg/m^3 and 0.091, the average removal efficiency on Chl-a and OD560 are 81.60% and 80.22%, respectively, which are stable by this combined process when it is operating in 36 hours, and samples are analyzed each 4 hours.
