The inactivation of microorganisms by pulsed magnetic field was studied. It was improved that the application of electromagnetic pulses evidently causes a lethal effect on E. coli cells suspended in phosphate buffer s...The inactivation of microorganisms by pulsed magnetic field was studied. It was improved that the application of electromagnetic pulses evidently causes a lethal effect on E. coli cells suspended in phosphate buffer solution Na 2HPO 4/NaH 2PO 4(0 334/0 867 mmol/L). Experimental results indicated that the survivability(N/N 0; where N 0 and N are the number of cells survived per mill il iter before and after electromagnetic pulses application, respectively) of E. coli decreased with magnetic field intensity B and treatment time t. It was also found that the medium temperatures, the frequencies of pulse f, and the initial bacterial cell concentrations have determinate influences in destruction of E. coli cells by the application of magnetic pulses. The application of an magnetic intensity B=160 mT at pulses frequency f=62 kHz and treatment time t=16 h result in a considerable destruction levels of E. coli cells (N/N 0=10 -4 ). Possible mechanisms involved in sterilization of the magnetic field treatment were discussed. In order to shorten the treatment time, many groups of parallel inductive coil were used. The practicability test showed that the treatment time was shortened to 4 h with the application of three groups of parallel coil when the survivability of E.coli cells was less than 0 01%; and the power consumption was about 0 2 kWh /m 3.展开更多
The degradation of water source environment becomes serious problems accompanying with rapid urbanization in China. Ecological engineering provides ecologically sound and cost effective solution to solving this proble...The degradation of water source environment becomes serious problems accompanying with rapid urbanization in China. Ecological engineering provides ecologically sound and cost effective solution to solving this problem. As a case study, a 15 hm 2 ecological water storage basin for a water plant was designed and constructed on the TEDA area in Tianjin City. Located on saline, the construction of this project has to face serious difficulties, such as high salinity, scarce seed banks of macrophytes, and strong winds. Freshwater replacement, soil amendation and macrophytes planting at the basinshore, wooden water breaker and plastic membrane installation and other measures were conducted for the assistance of plant community establishment. The result showed that the chloride concentration in the basin water decreased from 11600 mg/L to less than 100 mg/L, and the chloride content in the basin sediment decreased from 2 1% to 0 35% after freshwater soaking. The introduced macrophytes of 8 species all survived and 11 other macrophytes species were occurred in the basin. A new ecosystem was created with increased biological diversity in the original saline, and the water quality was improved. This ecological water storage basin also provided a pleasing landscape for local people.展开更多
文摘The inactivation of microorganisms by pulsed magnetic field was studied. It was improved that the application of electromagnetic pulses evidently causes a lethal effect on E. coli cells suspended in phosphate buffer solution Na 2HPO 4/NaH 2PO 4(0 334/0 867 mmol/L). Experimental results indicated that the survivability(N/N 0; where N 0 and N are the number of cells survived per mill il iter before and after electromagnetic pulses application, respectively) of E. coli decreased with magnetic field intensity B and treatment time t. It was also found that the medium temperatures, the frequencies of pulse f, and the initial bacterial cell concentrations have determinate influences in destruction of E. coli cells by the application of magnetic pulses. The application of an magnetic intensity B=160 mT at pulses frequency f=62 kHz and treatment time t=16 h result in a considerable destruction levels of E. coli cells (N/N 0=10 -4 ). Possible mechanisms involved in sterilization of the magnetic field treatment were discussed. In order to shorten the treatment time, many groups of parallel inductive coil were used. The practicability test showed that the treatment time was shortened to 4 h with the application of three groups of parallel coil when the survivability of E.coli cells was less than 0 01%; and the power consumption was about 0 2 kWh /m 3.
文摘The degradation of water source environment becomes serious problems accompanying with rapid urbanization in China. Ecological engineering provides ecologically sound and cost effective solution to solving this problem. As a case study, a 15 hm 2 ecological water storage basin for a water plant was designed and constructed on the TEDA area in Tianjin City. Located on saline, the construction of this project has to face serious difficulties, such as high salinity, scarce seed banks of macrophytes, and strong winds. Freshwater replacement, soil amendation and macrophytes planting at the basinshore, wooden water breaker and plastic membrane installation and other measures were conducted for the assistance of plant community establishment. The result showed that the chloride concentration in the basin water decreased from 11600 mg/L to less than 100 mg/L, and the chloride content in the basin sediment decreased from 2 1% to 0 35% after freshwater soaking. The introduced macrophytes of 8 species all survived and 11 other macrophytes species were occurred in the basin. A new ecosystem was created with increased biological diversity in the original saline, and the water quality was improved. This ecological water storage basin also provided a pleasing landscape for local people.
