High-performance,stable CoNi LDH@Ni foam composite membrane with innovative peroxymonosulfate activation for 2,4-dichlorophenol destruction

In this study,the cobalt-nickel layered double hydroxides(CoNi LDH)were synthesized with a variety of Co/Ni mass ratio,as CoxNiyLDHs.In comparison,Co1Ni3LDH presented the best peroxymonosulfate(PMS)activation efficiency for 2,4-dichlorophenol removal.Meanwhile,CoNi LDH@Nickel foam(CoNi LDH@NF)composite membrane was constructed for enhancing the stability of catalytic performance.Herein,CoNi LDH@NF-PMS system exerted high degradation efficiency of 99.22%within 90 min for 2,4-DCP when[PMS]_(0)=0.4 g/L,Co^(1)Ni^(3)LDH@NF=2 cm×2 cm(0.2 g/L),reaction temperature=298 K.For the surface morphology and structure of the catalyst,it was demonstrated that the CoNi LDH@NF composite membrane possessed abundant cavity structure,good specific surface area and sufficient active sites.Importantly,·OH,SO_(4)·^(-)and^(1)O_(2)played the primary role in the CoNi LDH@NF-PMS system for 2,4-DCP decomposition,which revealed the PMS activation mechanism in CoNi LDH@NF-PMS system.Hence,this study eliminated the stability and adaptability of CoNi LDH@NF composite membrane,proposing a new theoretical basis of PMS heterogeneous catalysts selection.

Degradation of Rhodamine B by MnFe-LDH/PMS/O_(3) three-phase catalytic system: performance, mechanism and ecotoxicity studies

This study developed a novel MnFe-LDH/PMS/O3 three-phase catalytic system to degrade the organic dye RhB, which was used to address the drawbacks of persulfate oxidation and ozonation techniques. The structure, ionic and elemental composition, specific surface area, and magnetic properties of the LDHs were investigated using a variety of physicochemical characterization tools. The results showed that MnFe-LDH had a large specific surface area, a rich crystalline phase composition, and a functional group structure. The RhB degradation rate of MnFe-LDH/PMS/O3 was 0.34 min−1, which was much higher than that of other comparative systems. RhB could be completely degraded in 10 min after optimization and had a significant effect on TOC removal. The system was found to be effective over a wide pH range. Common anions were largely unaffected and humic acid acted as an inhibitor. At the same time, the system had generally effective degradation performance for different dyes. Combined with quenching experiments and EPR, it was found that SO4•−, •OH, O_(2)•−, and 1O_(2) all participated in the reaction, and •OH contributed more. The degradation pathway of RhB was derived by LC-MS, and the T.E.S.T. evaluation found that the toxicity of the intermediate product was significantly reduced. Finally, the stability and availability of LDHs were verified using cycling experiments and metal ion leaching. This work provides a theoretical basis and data support for the synergistic catalysis of PMS/O3 and the deep treatment of dye wastewater.

Efficient degradation of sulfacetamide by CoFe PBAs and PBA@PVDF composite membrane activating peroxymonosulfate

More and more antibiotics that are difficult to biodegrade have been detected in water environments threatening ecosystems and human health.Therefore,it is urgent to develop efficient water treatment methods to degrade antibiotics.In this work,Co-Fe Prussian blue analogues(PBAs)with different molar ratios were synthesized for peroxymonosulfate(PMS)activation to degrade sulfacetamide(SAM,10 mg/L).By increasing Co molar ratio,the PMS activation capability and electrochemical properties of PBAs were enhanced.Due to its excellent reactivity(degradation efficiency of 84.2%and mineralization efficiency of 52.79%),cost benefit(electrical energy per order,0.01019 k Wh/L)and lower metal leaching([Co]=0.259 mg/L,[Fe]=0.128 mg/L),PBA-1,the as-prepared catalyst with a molar ratio of cobalt to iron of 1:1,was selected for further study.The radical scavenging experiments and an electron paramagnetic resonance(EPR)trapping experiments were performed and revealed that PBA-1 addition was required to produced·OH and SO_(4)^(·-)from PMS activation.Accordingly,we proposed a PMS activation mechanism and SAM decomposition pathways for PBA-1/PMS reaction system.Besides,a PBA-1@polyvinylidene fluoride(PVDF)catalytic membrane was further prepared to expand the application potential of PBA nanoparticles.The PBA-1@PVDF catalytic membrane was highly effective and exhibited a great reusability;thus,it could be considered for applications in actual water treatment processes.

Application of metal sulfides in energy conversion and storage

Sulfides refer to a category of compounds formed by strong electro-positivity metal or non-metal combine with sulfur.Owing to its tunable stoichiometric composition,unique crystal structure,abundant redox centers,the synergy between transition metal ions,and strong corrosion resistance in alkaline environments[1-4],metal sulfides receive increasing attention in different fields such as batteries,capacitors,adsorption,catalysis/photocatalysis.

Reservoir accumulation conditions and key exploration&development technologies for Keshen gas field in Tarim Basin

The Keshen gas field is located in the central part of Kuqa foreland thrust belt in Tarim Basin,and is another large gas field discovered in Kuqa depression after Kela 2 gas field.Since the breakthrough in 2008,a number of large and medium scale gas reservoirs including Keshen 2,Keshen 5 and Keshen 8 have been discovered,that are characterized by ultra depth,ultra-high pressure,ultra-low porosity,ultra-low permeability,high temperature and high pressure.With natural gas geological reserves of nearly trillion cubic meters and production capacity of nearly 5.5 billion cubic meters,the Keshen gas field is the main natural gas producing area in Tarim Oilfield.The Keshen gas field is located in a series of thrusting imbrication structures in the Kelasu structural belt of Kuqa foreland thrust belt.The salt roof structure,plastic rheology of salt beds and pre-salt faulted anticlinal structure constitute the large wedge-shaped thrust body.The thick delta sandstone of the Cretaceous Bashijike Formation is widely distributed,and it forms the superior reservoir-caprock combination with overlying Paleogene thick gypsum-salt bed.The deep Jurassic-Triassic oil and gas migrate vertically along fault system formed in Late Himalaya,break through the thick Cretaceous mudstone and move laterally along the fracture system of the pre-salt reservoirs,to form anticline and fault anticline high pressure reservoir groups.Through near ten years of studies,the three-dimensional seismic acquisition and processing technology for complex mountainous areas,extrusion salt-related structural modeling technology and fractured low-porosity sandstone reservoir evaluation technology have been established,which lay a foundation for realization of oil and gas exploration objectives.Logging acquisition and evaluation technology for high temperature,high pressure,ultra-deep and low-porosity sandstone gas reservoirs,and efficient development technology for fractured tight sandstone gas reservoirs have been developed,which provide a technical support for efficient exploration&development and rapid production of the Keshen gas field.