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In this paper, Ag/Zn-MIP-TiO 2 was prepared by sol-gel method, and the imprinted molecule was ethyl p-hydroxybenzoate. To study the properties of the Ag/Zn-MIP-TiO 2 on the photocatalytic activity, these factors were investigated: the effects of the dosage of Ag and Zn, the amount of imprinted molecules, the calcination temperature and time, then the capture of active substances. Besides, the selectivity of Ag/Zn-MIP-TiO 2 was investigated in three aspects: UV-vis multi-wavelength spectral integral area change, specific group absorbance change and traditional reaction kinetic parameter change. The selectivity coefficients of the three angles are 8.55, 1.47 and 6.77. And the selectivity factors are 4.12, 1.02 and 4.81, indicating that Ag/Zn-MIP-TiO 2 has high selectivity. Furthermore, its selectivity is not only for the specific characteristic groups on the target pollutants, but for the integrated target pollutants. From the perspective of materials, Ag/Zn-MIP-TiO 2 is 100% anatase with a lower band gap and a larger specific surface area. As a molecularly imprinted polymer, the active sites on the surface make it have selective recognition function. The results of photocatalytic experiments are as follows: the optimum Ag and Zn ratio is Ti:Ag:Zn = 100:1:0.75 (molar ratio); the best molecular weight of imprint is Ti:MIP = 5:1; the finest calcination temperature is 500 °C; the optimum calcination time is 2 h; the removal rate of ethyl p-hydroxybenzoate degraded by photocatalysis for 2 h is 99.1%; the main active substance of the photocatalytic reaction is •OH., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Rising atmospheric carbon dioxide (CO 2 ) may stimulate the proliferation of cyanobacteria. To investigate the possible physiological responses of cyanobacteria to elevated CO 2 at different nutrient levels, Microcystis aeruginosa were exposed to different concentrations of CO 2 (400, 1100, and 2200 ppm) under two nutrient regimes (i.e., in nutrient-rich and nutrient-poor media). The results indicated that M. aeruginosa differed in its responses to elevated atmospheric CO 2 at different nutrient levels. The light utilization efficiency and photoprotection of photosystem II were improved by elevated CO 2 , particularly when cells were supplied with abundant nutrients. In nutrient-poor media, both total organic carbon and the polysaccharide/protein ratio of the extracellular polymeric substance increased with elevated CO 2 , accompanied by high cellular carbon/nitrogen ratios. Besides, cells growing with fewer nutrients were more prone to suffer intracellular acidification with elevated CO 2 than those growing with abundant nutrients. Nonetheless, alkaline phosphate activity of cyanobacteria was improved by high CO 2 , provided that reduced pH was in the optimum range for alkaline phosphate activity. Nitrate reductase activity was inhibited by elevated CO 2 regardless of nutrient levels, leading to a reduced nitrate uptake. These changes indicate that the biogeochemical cycling of nutrients would be affected by higher atmospheric CO 2 conditions. Overall, cyanobacteria in eutrophic waters may benefit more than in oligotrophic waters from rising atmospheric CO 2 concentrations, and evaluations of the influence of rising atmospheric CO 2 on algae should account for the nutrient level of the ecosystem., (Copyright © 2019 Elsevier B.V. All rights reserved.)