The photochemical degradation of p nitrophenol and 2,4 dinitrophenol in both natural seawater and artificial seawater was studied under the irradiation of mixed light sources(ultraviolet lamp/high pressure mercury lam...The photochemical degradation of p nitrophenol and 2,4 dinitrophenol in both natural seawater and artificial seawater was studied under the irradiation of mixed light sources(ultraviolet lamp/high pressure mercury lamp). The photolysis of the two nitrophenols was influenced by various factors including medium, heavy metal ions and photosensitizer. The photolysis of the two nitrophenols in natural seawater was faster than in artificial seawater, presumably due to the effect of inherent photosensitizers in natural seawater. The addition of Cu 2+ , Pb 2+ or Cd 2+ into the seawater solutions obviously increased the photolysis rate of the nitrophenols. Interestingly, we found that the presence of anthroquinone could accelerate the photolysis of p nitrophenol in natural seawater but had almost no impact on the photolysis of 2,4 dinitrophenol. The half lives of the photoreactions in natural seawater under our conditions were 40-54 min for p nitrophenol and 37-69 min for 2,4 dinitrophenol, respectively. Our study suggests that photochemical degradation is an important removal pathway for the nitrophenols in seawater.展开更多
A new type of amphiphilic derivative of carboxymethylchitosan(CMCHS) was prepared by reaction of CMCHS with p-nonylphenyl glycidyl ether. The structure of the resulting derivatives, i.e., (2-hydroxyl-3-p-nonylphenoxy)...A new type of amphiphilic derivative of carboxymethylchitosan(CMCHS) was prepared by reaction of CMCHS with p-nonylphenyl glycidyl ether. The structure of the resulting derivatives, i.e., (2-hydroxyl-3-p-nonylphenoxy) propyl-carboxy-methylchitosan(HNP-CMCHS) had been identified by UV and IR spectroscopy. They are water-soluble and have surface activity, which is related to the degree of substitution and the added electrolyte in the solution. In the presence of NaCl, two transitions appeared on the surface tension-concentration plots, that means the possibility of the formation of intramolecular micelle. It was also found that it need a long time for the surface tension of the derivative solutions to get a equilibrium value and the time is related to the derivative concentration, degree of substitution and added electrolyte of the solution.展开更多
文摘The photochemical degradation of p nitrophenol and 2,4 dinitrophenol in both natural seawater and artificial seawater was studied under the irradiation of mixed light sources(ultraviolet lamp/high pressure mercury lamp). The photolysis of the two nitrophenols was influenced by various factors including medium, heavy metal ions and photosensitizer. The photolysis of the two nitrophenols in natural seawater was faster than in artificial seawater, presumably due to the effect of inherent photosensitizers in natural seawater. The addition of Cu 2+ , Pb 2+ or Cd 2+ into the seawater solutions obviously increased the photolysis rate of the nitrophenols. Interestingly, we found that the presence of anthroquinone could accelerate the photolysis of p nitrophenol in natural seawater but had almost no impact on the photolysis of 2,4 dinitrophenol. The half lives of the photoreactions in natural seawater under our conditions were 40-54 min for p nitrophenol and 37-69 min for 2,4 dinitrophenol, respectively. Our study suggests that photochemical degradation is an important removal pathway for the nitrophenols in seawater.
文摘A new type of amphiphilic derivative of carboxymethylchitosan(CMCHS) was prepared by reaction of CMCHS with p-nonylphenyl glycidyl ether. The structure of the resulting derivatives, i.e., (2-hydroxyl-3-p-nonylphenoxy) propyl-carboxy-methylchitosan(HNP-CMCHS) had been identified by UV and IR spectroscopy. They are water-soluble and have surface activity, which is related to the degree of substitution and the added electrolyte in the solution. In the presence of NaCl, two transitions appeared on the surface tension-concentration plots, that means the possibility of the formation of intramolecular micelle. It was also found that it need a long time for the surface tension of the derivative solutions to get a equilibrium value and the time is related to the derivative concentration, degree of substitution and added electrolyte of the solution.
