Correlations between estrogenic activity and DOC/UV260 ratio in wastewater treatment processes were investigated to propose a simple, reliable and comprehensive indicator for the presence of estrogenic substances. Con...Correlations between estrogenic activity and DOC/UV260 ratio in wastewater treatment processes were investigated to propose a simple, reliable and comprehensive indicator for the presence of estrogenic substances. Contrary to this, when short-term bioassays such as the E-SCREEN, receptor binding and reporter gene expression assays are used for detecting estrogenic activity in the wastewater sample, they require a long time, at least a few days. The major factors contributing to the estrogenic activity were found to be 17β-estradiol （E2） and estrone （El）. A good relationship between the DOC/ UV260 ratio and the concentration of estrogens （El and E2） in the effluent of the activated sludge process was found： the E2 concentration increased as the DOC/UV260 ratio increased while the E1 concentration decreased. The relative estrogenic activity and DOC/UV260 ratio showed a good correlation （R^2 = 0.84） for all sewage samples except the ozonized samples in the sewage treatment plants. This study shows that the estrogenic compounds are hard to be mineralized by the conventional biological processes. Advanced oxidation processes are required to further remove estrogenic substances in the secondary effluent. By analysis of DOC and UV260, the estrogenic activity in the wastewater can be rapidly estimated.展开更多
Phase change material microcapsules (MicroPCMs) with nano composite structures (NC-MicroPCMs) were fabricated to meet higher demand of thermal stability and hold core better. Degree of crystallinity (DOC) of the NC-Mi...Phase change material microcapsules (MicroPCMs) with nano composite structures (NC-MicroPCMs) were fabricated to meet higher demand of thermal stability and hold core better. Degree of crystallinity (DOC) of the NC-MicroPCMs was evaluated by the differential scanning calorimeter (DSC). The effectiveness of some processing variables, in terms of formaldehyde and melamine molar ratio F/M, weight ratio of core and shell material C/S, and the dosage of silver nano particles D(%), were analyzed statistically. It was found that: (1) DOC was dependent on these processing variables; (2) doping silver nano particles was beneficial to the formation of shell crystallite structure; and (3) higher F/M was helpful in getting a higher DOC for both NC-MicroPCMs and MicroPCMs. Also, DOC was found to be associated with thermal stability and the two features were confirmed, which showed a closely positive correlation.展开更多
文摘Correlations between estrogenic activity and DOC/UV260 ratio in wastewater treatment processes were investigated to propose a simple, reliable and comprehensive indicator for the presence of estrogenic substances. Contrary to this, when short-term bioassays such as the E-SCREEN, receptor binding and reporter gene expression assays are used for detecting estrogenic activity in the wastewater sample, they require a long time, at least a few days. The major factors contributing to the estrogenic activity were found to be 17β-estradiol （E2） and estrone （El）. A good relationship between the DOC/ UV260 ratio and the concentration of estrogens （El and E2） in the effluent of the activated sludge process was found： the E2 concentration increased as the DOC/UV260 ratio increased while the E1 concentration decreased. The relative estrogenic activity and DOC/UV260 ratio showed a good correlation （R^2 = 0.84） for all sewage samples except the ozonized samples in the sewage treatment plants. This study shows that the estrogenic compounds are hard to be mineralized by the conventional biological processes. Advanced oxidation processes are required to further remove estrogenic substances in the secondary effluent. By analysis of DOC and UV260, the estrogenic activity in the wastewater can be rapidly estimated.
基金Education Commission of Shaanxi Province for Providing Funding Support,China ( No. 2010JS006)
文摘Phase change material microcapsules (MicroPCMs) with nano composite structures (NC-MicroPCMs) were fabricated to meet higher demand of thermal stability and hold core better. Degree of crystallinity (DOC) of the NC-MicroPCMs was evaluated by the differential scanning calorimeter (DSC). The effectiveness of some processing variables, in terms of formaldehyde and melamine molar ratio F/M, weight ratio of core and shell material C/S, and the dosage of silver nano particles D(%), were analyzed statistically. It was found that: (1) DOC was dependent on these processing variables; (2) doping silver nano particles was beneficial to the formation of shell crystallite structure; and (3) higher F/M was helpful in getting a higher DOC for both NC-MicroPCMs and MicroPCMs. Also, DOC was found to be associated with thermal stability and the two features were confirmed, which showed a closely positive correlation.
