查看更多>>摘要：The separation of water from oily wastewater by using membranes is a big challenge because of serious membrane fouling and low separation efficiency. So, for the first time, Nylon 6 (N6) membranes blended with ZnO nanoparticles with a N6 support layer by the electrospinning technique were fabricated, where the N6 layer enhanced the mechanical strength and ZnO NPs formed a strong barrier on the N6 membrane to reduce membrane pore-clogging. The micron pore size membranes created by hydrophilic ZnO NPs on electrospun Nylon 6 fiber-matrix structures contributed to the hydrophilicity and fouling resistance of the membranes. The optimal quantities of ZnO NPs and N6 in the electrospun membranes were 2.5 and 40 w.t%, respectively, for achieving the desired specific flux of 215.14 LMH/bar over 3 h when using a 0.1% v/v oil/water influent. Up to 90% of oil, chemical oxygen demand, turbidity, total dissolved solids, and total suspended solids were removed to fulfill discharge requirements. The presence of ZnO NPs in the N6 membrane also exhibited excellent anti-fouling properties with the flux recovery ratio of 52.5 % and water flux of 405.6 LMH/bar, which was much better than those of a pristine N6 membrane, indicating the microfiltration membranes developed in this study were reasonably resistant to fouling to ensure high effluent water quality and the fabricated N6/ZnO NPs membrane is feasible in treating oil-containing wastewater.
查看更多>>摘要：In order to meet the growing demand for phosphate rock and sludge treatment, this study developed a hydrothermal oxidation-precipitation method for efficiently recovering phosphorus from dewatered sludge. The method could recover almost 90% of the phosphorus in sludge and acquire solid recyclate with a phosphorus content of 9.47%±0.21%. Oxidation, acidification, and complexation during the hydrothermal oxidation process contributed releasing the majority of phosphorus into liquid products. The newly formed flocs between humic substances and scarcely-soluble phosphate became final recyclate during recovery stage.
查看更多>>摘要：The development of solid oxide electrochemical cells (SOC's) coincides with the policy of emission peak and carbon neutrality, and possesses significant commercial prospects in the future energy market. Developing perovskite oxides with mixed oxygen ionic and electronic conductivity is an effective approach to alleviate the issues caused by lowering the operating temperature and the utilization of hydrocarbon fuel. Recently, Sr2Fe_(1.5)Mo_(0.5)O_(6-δ) with double perovskite structure exhibits high conductivity, excellent redox stability and catalytic activity in both air and hydrogen environments, and presents broad application prospects in SOC's. Surface modification and element doping further enhance the electro -catalytic activity of the Sr2Fe_(1.5)Mo_(0.5)O_(6-δ)_(6-δ) electrode, enabling a broader application prospect in SOC's. This review summarizes the structures, properties, applications, shortcomings, and optimizations of the Sr2Fe_(1.5)Mo_(0.5)O_(6-δ)-based oxides in detail. The research and development of the Sr2Fe_(1.5)Mo_(0.5)O_(6-δ)-based oxides have specific guidance and assistance for the progress of intermediate temperature SOC's.
查看更多>>摘要：Developing a highly efficient, cost-effective, and stable bifunctional electrode for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is still a major challenge. This work reports on a novel method for fabricating TiN ceramic membrane supported nitrogen-incorporating NiCo2 nanowires (NiCo2-N/TiN) as a bifunctional electrode. Owing to its unique structure, the ample reaction sites available, and the enhanced mass/charge transport ability, the NiCo2-N/TiN electrode exhibits efficient catalytic performance both in HER and OER, with overpotentials of 131 mV at 20 mA· cm~(-2) for HER and 330 mV at 20 mA·cm~(-2) for OER, together with excellent stability in alkaline solution. The NiCo2-N/TiN electrode only requires a cell voltage of 1.71 V to drive the current density of 20 mA · cm~(-2) for overall water splitting, which exhibits excellent stability for more than 100000 s. Accordingly, the produced ceramic membrane electrode has a great potential for application in industrial hydrogen production.
查看更多>>摘要：Direct air capture (DAC), as a typical technology of negative emission technologies, is indispensable to neutralizing mobile carbon emissions. The polyamine-loaded adsorbent with high CO2 capacities at extremely low CO2 concentration while maintaining mild regeneration conditions is a promising choice for actual DAC systems. This work comprehensively investigated the effect of oxygen in the air on the selectivity of polyamine-functionalized adsorbents towards CO2 in the adsorption process and the oxidative stability in the desorption process. Results indicate high selectivity toward CO2 and oxidative resistance of adsorbents can be realized by accurately controlling the operating temperature. The oxidation of supported polyamine follows a three-phase mechanism. The oxidative stability of adsorbents varied at oxidation phases distinguished by different operating temperatures. Instructed by that three-phase oxidation mechanism, the optimal regeneration temperature of 80 °C was suggested for supported PEI and TEPA adsorbents. This optimal regeneration temperature can achieve favorable CO2 capture performance and maintain superior oxidative stability. Based on these findings, an air-assisted temperature swing adsorption DAC system was proposed to collect CO2 from the air for agricultural greenhouse.
查看更多>>摘要：Membrane separation technology is a potential low-cost flue gas CO2 capture technology to cope with increasing CO2 content in the atmosphere. This paper analyzes the effects of different driving force generation strategies, membrane separation performance and water vapor on operating energy consumption and CO2 capture cost. Then membrane processes are optimized and designed under a wide range of separation requirements. The energy consumption of feed compression combined with permeate vacuum is the lowest when the stage cut is larger than 33.8%, but from the perspective of CO2 capture cost, the vacuum operation is suitable for membranes with high CO2 permeance and moderate selectivity, such as the CO2 permeance above 4000 GPU and the CO2/N2 selectivity below 100, to reduce the investment cost of membrane-related equipment. Since only improving the CO2/N2 selectivity results in an enlarged membrane area and consequently limits the reduction of CO2 capture cost, the development trend of CO2 permeance with increasing CO2/N2 selectivity is proposed to restrain the expansion of membrane area. The water vapor in flue gas can improve the mass transport driving force of CO2 and reduce the membrane area and the capture cost. For water-facilitated membranes, it is recommended to use segmented humidification to replenish the water vapor content of the residue side, especially for the membrane process with a high stage cut, such as the first stage of a two-stage membrane process. Finally, the optimal membrane process and operating pressure under different separation targets, specifically 50-95% dry basis CO2 purity and 50-90% CO2 recovery rate, are obtained by the techno-economic analyses.
查看更多>>摘要：Phosphorus removal and recovery are important because phosphorus is both a water contaminant and present in chemicals used in agriculture and various industries. As an extremely effective approach to achieve this objective, chemisorption has been identified as a suitable technology. Herein, the adsorption materials La-doped powdered activated carbon and granular activated carbon (La-PAC (D), La-GAC (D)) were prepared by a one-pot hydrothermal process. The strategy behind the adsorbents was based on the ability of La to compensate for the electronegativity and poor selectivity of the activated carbon matrix. Furthermore, the mass transfer rate was enhanced through the formation of vacancies in the structure of the doped material resulting in larger pore sizes, more adsorption sites, and contributions to the diffusion of phosphate molecules to the interior. The phosphate adsorption capacities of La-PAC (D) and La-GAC (D) were 202.43 mg g~(-1) and 181.82 mg g~(-1), respectively, which were superior to most adsorbents. The excellent properties could be maintained at low phosphorus concentrations in actual wastewater. The employed characterization methods combined with density functional theory calculations revealed that AC, La, and the doping structure improved the adsorption performance, and the main adsorption pathways of phosphate were electrostatic attraction and complexation. La-AC (D) could accelerate the development of adsorption materials for water pollution remediation.
查看更多>>摘要：As natural resources become more and more limited, it is exceptionally essential to decrease energy consumption in membrane separation processes, which makes membranes with ultra-high water permeance increasingly expected. Graphene oxide (GO) membranes have exhibited an unsurpassed future for wastewater purification. However, it is two key challenges to greatly increase the water permeance while retaining the removal efficiency of contaminants and improve the enduring stability of membranes in aqueous solution. In this work, the membranes with ultrafast water permeability were prepared by self-assembly vacuum filtration method using carbohydrazide (CHZ) as reducing and cross-linking agent. The obtained lamellar rGO/CHZ nanofiltration membranes exhibited water permeance bigger than 1600 L m~(-2)h~(-1) bar~(-1), and outstanding separation efficiency, e.g., Congo Red (CR), Malachite Green (MG), and Crystal Violet (CV) removal rate of 99%. More importantly, the composite membrane exhibited efficiently selective separation of various mixed dyes. Such as binary mixed dyes of MG/MO, the removal rate of MG is 99%, while the removal rate of MO is merely 23%. In addition, the membrane still showed excellent stability after long-term immersion in solutions of various pH values. The separation performance in terms of complete rejection of single dyes and selective filtration of mixed dyes makes them one of the promising materials for dye separation, purification, and reuse.
查看更多>>摘要：Herein, we presented a ferrate-enhanced electrocoagulation/ultrafiltration (fECUF) system with three pathways of contaminants removal during the oxidation of Fe(II), realizing superior water production, excellent fouling control, and outstanding environmental risk reduction in municipal wastewater reuse. The system addressed the issue of the rapid inorganic membrane fouling caused by the traditional electrocoagulation processes. The formation of a unique cake layer with a bilayer structure in fECUF was favored to decrease the accumulation of organics and inorganics in membrane pores and maintain the membrane flux. Compared with the UF control system, the fECUF system decreased the transmembrane pressure by 63.13%. Redundancy analysis confirmed that oxidation dominated the removal of humic-like substances and UV_(254), while oxidation and coagulation synergistically promoted the reduction of DOC, protein-like substances, and trace organics. Also, coagulation contributed to the removal of antibiotics resistance genes (ARGs), which reduced their ability to be widely transmuted by a horizontal gene transfer mechanism. Compared to the UF control system, 4.48-39.76 times higher reduction of four ARGs were obtained in fECUF. Overall, this study has verified the potential advantages of the fECUF system in membrane fouling control and contaminants reduction for water reclamation.
查看更多>>摘要：Among many photo catalysts, metal phthalocyanine-sensitized semiconductor material has become a research hotspot as an efficient deep desulfurization catalyst. In this work, three series modified phthalocyanine, under nitro, amino and carboxyl as substituted groups, have been obtained firstly and named MTNPc, MTAPc, and MTcPc (M = Mn (II), Fe (II), Co (II), Ni (II), Cu (II)). The corresponding metal phthalocyanine/La_(0.8)Ce_(0.2)NiO3 composite catalysts have been successfully synthesized by impregnation method. Through the study on the photocatalytic oxidation desulfurization of DBTs under simulated sunlight, it was found the effect of central metal ions on the catalyst activity is related to their valence electron configuration, while the substituted groups are attributed to their own properties. For the further research, the kinetic study has been introduced to restore the actual reaction process, finding it conformed to the quasi-first reactions and the order of desulfurization degree of the catalysts with the same central metal ions and different peripheral substituted groups is MTcPc/La_(0.8)Ce_(0.2)NiO3 > MTNPc/La_(0.8)Ce_(0.2)NiO3 > MTAPc/La_(0.8)Ce_(0.2)NiO3. Besides, the CoTcPc/La_(0.8)Ce_(0.2)NiO3 with the best desulfurization performance shows t_(1/2) = 74 min and the reused experiment has been done to study their actual use value.
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