Preparation and coagulation efficiency of polyaluminium ferric silicate chloride composite coagulant from wastewater of high-purity graphite production

The aim of the present work was to produce a polyaluminium ferric silicate chloride （PAFSiC） coagulant from acidic and alkaline wastewater of purifying graphite by roasting, and subsequently to evaluate coagulation efficiency of the reagent by treating surface water from the Yellow River as well as municipal wastewater in comparison with the conventional coagulant polyaluminium chloride （PAC）. The PAFSiC coagulant was prepared by co-polymerization. The effects of （Al＋Fe）/Si molar ratio, OH/（Al＋Fe） molar ratio （i.e., γ value）, coagulant dosage and pH value of test suspension on the coagulation behavior of FAFSiC and the stability of the PAFSiC were also examined. Results showed that PAFSiC performed more efficiently than PAC in removing turbidity, chemical oxygen demand （COD）, and total phosphate （TP）. The PAFSiC with a γ value of 2.0 and （Al＋Fe）/Si ratio of 5 （PAFSiC 2.0/5） showed excellent coagulation effect for both turbidity and COD, while PAFSiC 1.0/5 was the best for TP. The optimum coagulation pH range of PAFSiC 2.0/5 was 5.0–9.0, slightly wider than that of PAC （6.0–8.0）. The process can be easily incorporated into high-purity graphite production plants, thereby reducing wastewater pollution and producing a valuable coagulant.

Synthesis,crystal structures and characterization of a pair of Tb~Ⅲ-based enantiomers

A pair of novel Tb^III-based enantiomers, [Tb（dbm）·Lss] （1） and [Tb（dbm）3.LRR] （2） （where Lss=（＋）-4,5-pinene bipyridine, LRR= （-）-4,5-pinene bipyridine, dbm=dibenzoylmethanate）, were synthesized and characterized based on single crystal X-ray diffi＇action, elemental analysis, FT-IR, TG and CD spectra. X-ray diffraction analysis showed that both the complexes crystallized in monoclinic crystal system with P21 chiral space group. The Tb^III ion was eight-coordinated by six O atoms of three dbm ligands and two N atoms fi-om one chiral ligand Lss or LRR. The CD spectra revealed that complexes 1 and 2 were enantiomers. Thermogravimetric analysis results indicated that 1 and 2 were thermally stable up to 246 ℃.

Recent progresses on alloy-based anodes for potassium-ion batteries

Potassium-ion batteries(KIBs)are one of the most promising large-scale electric energy storage systems due to the high abundance and low redox potential of K.As the key component,anode determines their energy density and safety.Alloy-based anodes,such as P,Sn,Sb,and Bi,have attracted extensive attention due to their abundant resources,suitable working potentials,and large theoretical capacities.However,the dramatic volume variation upon(de)potassiation results in pulverization of particles and their detaching from the current collector accompanied with performance decay.Various strategies,including designing micro-/nanostructures,introducing carbon substrates,and optimizing electrode/electrolyte interface,have been demonstrated to effectively alleviate these issues.Herein,we summarize the recent research progresses on alloy-based materials in KIBs.The synthesis methods,electrochemical performance,reaction mechanisms,and structure-activity relationships of these materials are considered,and challenges and perspectives are provided.This review provides new insight into designing of high-activity electrode materials for KIBs and beyond.