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Ni-Mn@KL ozone catalyst was prepared for the efficient treatment of reverse osmosis membrane concentrates. The working conditions and reaction mechanism of the ozone-catalyzed oxidation by Ni-Mn@KL were systematically studied. Then, a comprehensive CRITIC weighting-coupling coordination evaluation model was established. Ni-Mn@KL was characterized by scanning electron microscopy, BET, X-ray diffraction, X-ray photoelectron spectroscopy, energy-dispersive spectrometry, and X-ray fluorescence spectrometry and found to have large specific surface area and homogeneous surface dispersion of striped particles. Under the optimum working conditions with an initial pH of 7.9 (raw water), a reaction height-to-diameter ratio of 10:1, an ozone-aeration intensity of 0.3 L/min, and a catalyst filling rate of 10%, the maximum COD removal rate was 60.5%. Free-radical quenching experiments showed that OH oxidation played a dominant role in the Ni-Mn@KL-catalyzed ozone-oxidation system, and the reaction system conformed to the second-order reaction kinetics law. Ni-Mn@KL catalysts were further confirmed to have good catalytic performance and mechanical performance after repeated utilization. PRACTITIONER POINTS: Ni-Mn@KL catalyst can achieve effective treatment of RO film concentrated liquid. High COD removal rate of RO membrane concentrated liquid was obtained at low cost. Ni-Mn@KL catalyst promotes ozone decomposition to produce ·OH and O 2 - · oxidized organic matter. The Ni-Mn@KL catalyst can maintain good stability after repeated use. A CRITIC weight-coupling coordination model was established to evaluate the catalytic ozonation., (© 2024 Water Environment Federation.)

In this work, a composite flocculant (polyferric titanium sulfate-polydimethyldiallylammonium chloride [PFTS-PDMDAAC]) with a rich spatial network structure was prepared for the treatment of simulated wastewater containing polystyrene (PS) micro-nanoparticles. Characterization results showed that the surface of the PFTS-PDMDAAC was a three-dimensional network polymer of chain molecules that exhibited good thermal stability and formed an amorphous polymer containing multiply hydroxyl-bridged titanium and iron. When n(OH - ) : n(Fe) = 1:2, n(PO 4 3- ) : n(Fe) = 0.35, n(Ti) : n(Fe) = 1:8, n(DMDAAC) : n(Fe) = 5:100, and the polymerization temperature is 60°C, the prepared composite flocculant has the best effect. The effects of dosage, pH, and agitation intensity on the flocculation properties of PFTS-PDMDAAC were also studied. The optimal removal rates of PS-μm and haze by PFTS-PDMDAAC were 85.60% and 90.10%, respectively, at a stirring intensity of 200 rpm, a pH of 9.0, and a PFTS-PDMDAAC dosage of 20 mg/L. The flocs produced by the PFTS-PDMDAAC flocculation were large and compact in structure, and the flocculation mechanism was mainly based on adsorption bridging. Kaolin played a promoting role in the process of PS-μm removal by PFTS-PDMDAAC floc and accelerated the formation of large and dense flocs. This study provided a reference for the coagulation method to remove micro-nanopollutants in the actual water treatment process. PRACTITIONER POINTS: A composite flocculant with rich spatial network structure (PFTS-PDMDAAC) was prepared. PFTS-PDMDAAC can effectively remove micro-nano polystyrene (PS) in wastewater. The floc produced by PFTS-PDMDAAC is large and compact in structure. The flocculation mechanism of PFTS-PDMDAAC is mainly adsorption bridging., (© 2023 Water Environment Federation.)

In this work, Ti-Sn-Sb/γ-Al 2 O 3 particle electrodes were prepared and employed for the degradation of oxytetracycline (OTC) by three-dimensional electrocatalytic technology. Factors associated with the preparation of Ti-Sn-Sb/γ-Al 2 O 3 particle electrodes were investigated. The effects of initial concentration, conductivity, pH value, aeration intensity, current density, plate spacing, and particle electrode dosage on OTC removal were studied. The removal rate of OTC and total organic carbon were achieved approximately 92.0% and 41.0% under the optimal operating condition, respectively. In addition, Ti-Sn-Sb/γ-Al 2 O 3 particle electrode was analyzed by Fourier Transform Infrared spectroscopy (FT-IR), scanning electron microscope (SEM), energy dispersive spectrum analysis (EDX), X-Ray Fluorescence Spectrometer (XRF), and X Ray Diffraction analysis (XRD), which indicated that a significant amount of TiO 2 , SnO 2 , and Sb 2 O 3 were formed on the surface of Ti-Sn-Sb/γ-Al 2 O 3 particle electrode. It was also observed that the primary function of Ti-Sn-Sb/γ-Al 2 O 3 particle electrode in the three-dimensional electrode electrolysis process is the strong oxidizing function of ·OH for degrading OTC. Consequently, the analysis of degradation products of oxytetracycline (OTC) demonstrates. In addition, the results and conclusions of this study provide a methodological basis and engineering practice basis for removing the low concentration of antibiotics in water., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

A Y-type zeolite was prepared from illite clay, which was activated and synthesized by a solid-phase alkali fusion technique with reduced reaction conditions and crystal methods. The optimal synthesis conditions were investigated using the Box-Behnken design for a NaOH/illite (mass ratio) of 1:2, an activation temperature of 185 °C, and an activation time of 2.7 h. The synthesized Y-type zeolites were characterized by various analytical techniques such as FT-IR, XRD, and SEM, and the results obtained show that small amounts of quartz and P-type zeolites are present in the synthesized products. The mixture was classified as a zeolitic mineral admixture (ZMA). The adsorption performance of ZMA on Pb(II) and Cu(II) in solution was evaluated by batch adsorption experiments. The results showed that ZMA had good adsorption performance for Pb(II) and Cu(II), with maximum adsorption amounts of 372.16 and 53.46 mg/g, respectively. From the investigation, it was concluded that the adsorption process is chemisorption occurring in monomolecular layers and relying on electrostatic adsorption, ion exchange and complexation of hydroxyl groups on the ZMA surface for heavy metal cations. The ZMA reusability result shows that sodium chloride has the ability to regenerate the active site by restoring the ion exchange capacity without significant loss of Pb(II) and Cu(II) adsorption. [ABSTRACT FROM AUTHOR]