Performance and applications of ZnO/pyrolusite composite particle electrode.

In this research, we employed a synergistic three-dimensional (3D)-electrode technology in combination with a photocatalytic method to effectively treat wastewater containing chlorine derived from sulfonated phenolic resin (SMP). To modulate the band gap of single ZnO through semiconductor compounding, we successfully synthesized a ZnO/pyrolusite composite particle electrode on the surface of a pyrolusite particle electrode via a hydrothermal method. By incorporating MnO2 into pyrolusite, the ZnO band gap was modified, leading to a reduction in bandwidth of approximately 1.21 eV compared to pristine ZnO. Consequently, the light absorption range of the material was significantly broadened. Through the synergistic effect of photocatalysis, we achieved an impressive 96.45% removal rate of chemical oxygen demand (COD) in SMP wastewater, which effectively enhanced the photocatalytic performance of the material. Furthermore, our quenching experimental study confirmed the involvement of active chlorine species (ACl: Cl2, HClO, and ClO-), OH, h+, and O2- in the degradation process of SMP within the photocatalytic system constructed by the ZnO/pyrolusite composite particle electrode. The relative contributions were ranked as follows: ACl > h+ > ·OH > ·O2-.

Performance analysis of a half-batch multi-cell three-dimensional electrode reactor for drilling wastewater: COD removal, energy consumption and hydrodynamic characteristic.

Although a three-dimensional electrode system (3DES) has made remarkable achievements in improving the property of electrodes and investigating pollutant degradation mechanism, the design of an electrochemical reactor for application in drilling wastewater has not been reported yet. In this study, a novel half-batch multi-cell 3DES reactor was constructed by us to degrade organic compounds from drilling wastewater. The separate effect of electrolysis time, current density, the configuration of granular activated carbon (GAC) electrodes, aeration rate and volumetric recirculation flow on chemical oxygen demand (COD) removal and energy consumption of the half-batch reactor were analyzed, and further optimization via response surface methodology (RSM). Results showed that the optimal operation conditions for the reactor included electrolysis time of 100 min, a current density of 9.2 mA/cm2, GAC electrode vertical configuration, an aeration rate of 2.67 L/min and a volumetric recirculation flow of 100 mL/min. Under these conditions, the maximum percentage COD removal was found to be 97.39% with an energy consumption of 77.89 kWh(kg COD)-1. The residence time distribution (RTD) method was carried out in continuous flow pattern to investigate the hydrodynamic characteristics of the reactor. Results showed that flow rate was the most dominant factor for the flow pattern of the reactor, followed by the aeration rate and current density. The low dispersion number and the percentage of dead volume are 0.214 and 3.87% when the flow rate of 100 mL/min, respectively, which indicates that there is an intermediate flow pattern existing in between plug-flow ideal and complete mixing flow, furthermore, it is close to the plug-flow ideal.

Structural diversity directed by switchable coordination of substitute groups in a ternary Cu(II)-triazole-sulfoisophthalate self-assembly system: synthesis, crystal structures and magnetic behavior.

Four magnetic samples with different building blocks and dimensionalities, {[Cu(4)(atr)(2)(µ(3)-OH)(2)(sip)(2)]·4H(2)O}(n) (1), {[Cu(4)(atr)(2)(H(2)O)(8)(µ-OH)(2)(sip)(2)]·1.3CH(3)OH·0.7H(2)O}(n) (2), {[Cu(3)(atr)(4)(H(2)O)(2)(sip)(2)]·4H(2)O}(n) (3) and {[Cu(3)(atr)(4)(H(2)O)(2)(µ(3)-OH)(sip)(Hsip)]·2CH(3)OH·2.75H(2)O}(n) (4) (atr = 4-amino-1,2,4-triazole and sip(3-) = 5-sulfoisophthalate), were obtained and characterized structurally and magnetically. Complex 1 exhibits a three-dimensional (3D) robust framework with butterfly-like Cu(II)(4) clusters periodically extended by tetratopic sip(3-) connectors. Complex 2 possesses a 2D layer with alternating Cu(II)(3) + Cu(II)(1) chains crosslinked by pairs of ditopic sip(3-) linkers. By contrast, the latter two entities feature 1D broad ribbons with linear (for 3) and triangular Cu(II)(3) cores (for 4) propagated by bidirectional sip(3-) connectors. Structural analysis reveals that the diverse building blocks and dimensionalities of 1-4 are significantly dominated by the tunable coordination of exocyclic amino- and/or sulfonate-group of the mixed ligands. Magnetically, antiferromagnetic interactions with variable strength transmitted by -NN- moiety of atr and hydroxyl mediators result in overall S = 0 (for 1) and 1/2 (for 3 and 4) spin ground states. These interesting results indicate that coordinative side group in the ternary metal ion-azolate-carboxylate system can be utilized to generate aesthetically pleasing building units and variably polytopic connectors, leading to differently extended superstructures and magnetic behavior.

Benzimidazolium 3,5-dicarb-oxy-benzoate trihydrate.

Cocrystallization of benzimidazole with benzene 1,3,5-tricarb-oxy-lic acid in slightly basic medium afforded the title compound, C(7)H(7)N(2) (+)·C(9)H(5)O(6) (-)·3H(2)O, in which one of the imidazole N atom is protonated and one carb-oxy-lic group of aromatic acid is deprotonated. In the crystal structure, inter-molecular N-H⋯O hydrogen-bonding connects the two organic components into dimers, which are further linked into a three-dimensional network by O-H⋯O and N-H⋯O inter-actions between the water mol-ecules and the dimers.