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The heterogeneous and multifunctional charged polymers have broad application prospects in modern catalysis. One of the valid methods of synthesizing multifunctional charged polymers is incorporating metalloporphyrins with halide anions. Herein, a series of zinc(II)porphyrin-based porous ionic polymers [PIP-ZnTIPP/DVB (1:m) (m = 20, 40, 60, 80)] were synthesized by combining imidazolium-functionalized Zn-porphyrin (ZnTIPP) and divinylbenzene (DVB) through the free-radical copolymerization by a solvothermal method. The rigid PIPs have many physical advantages such as spatial separation of Zn-porphyrin sites, high thermal stability, hierarchical pore structures, high specific surface area, and abundant imidazolium (Br − ) group in the polymeric skeletons, which exhibit fantastic catalytic activity for the coupling reaction of epoxides and CO 2 without any solvent or cocatalyst. In particular, the catalyst PIP-ZnTIPP/DVB (1:20) displayed the highest catalytic activity with a yield of 99% and a turnover frequency (TOF) of 759 h −1 and could be recycled six times without the loss of activity. The excellent catalytic activity results from a synergistic effect between zinc sites and nucleophilic bromide anions.

Two carboxyl‐functional Mn (III)–porphyrins reacted with two metal nitrates (Cr (NO3)3·9H2O and Al (NO3)3·9H2O) via solvothermal method, respectively, to produce four metalloporphyrin‐based metal organic gels (MOGs). To remove unreacted metal salts and DMF, the gels were dealt with Soxhlet extraction and supercritical CO2. Finally, four desired porous coordination polymers (PCPs) were prepared. The newly synthesized PCPs were characterized by FT‐IR, UV–vis, SEM, and TEM. The contrast experiments show these PCPs possess good catalytic activities for the cycloaddition reactions of epoxide and CO2 under mild and solvent‐free conditions using tetrabutylammonium bromide (TBAB) as co‐catalyst.

The production of cyclic carbonates using CO 2 and epoxides has received great attention due to 100 % atom utilization. Herein, novel imidazolium-containing metalloporphyrins were synthesized as bifunctional catalysts for the cycloaddition reactions of epoxides and CO 2. The reaction conditions were optimized and analyzed with the response surface methodology. Under the optimum condition using Zn-porphyrin 1 as the catalyst, the turnover number (TON) and turnover number frequency (TOF) for the cycloaddition of CO 2 and ECH were 11,629 and 1,735, respectively. In addition, analysis of the RSM indicated that the CO 2 pressure had only a small impact on the yield. Based on this conclusion, the catalytic activity of 1 was further evaluated under mild conditions. Regardless of whether the CO 2 pressure is high or ambient, this Zn-porphyrin exhibited an excellent performance with a high turnover number frequency.

The function of sewer as reactors must rely on the biofilm in it. In this paper, the formation, structure, oxygen transfer, and activity of the biofilm under different hydraulic conditions were studied by the microelectrode technology, oxygen uptake rate (OUR) technology, and 454 high-throughput pyrosequencing technology. Results showed that when the wall-shear stresses were 1.12, 1.29, and 1.45 Pa, the porosity of the steady-state biofilm were 69.1, 64.4, and 55.1 %, respectively. The maximum values of OUR were 0.033, 0.027, and 0.022 mg/(L*s), respectively, and the COD removal efficiency in the sewers reached 40, 35, and 32 %, respectively. The research findings had an important significance on how to improve the treatment efficiency of the sewers. Fig. a Graphical Abstract.

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