Considering the advantages of hollow fiber supported liquid membrane (HFSLM), it has been applied for extraction of Co(II) with a motivation to extract cobalt from various waste resources. Extraction efficiency and transport behavior of Co(II) through HFSLM containing Cyanex 272 diluted in kerosene were investigated. Experiments were performed as a function of aqueous feed solution velocity (1000 mL/min) for both feed and strip, pH of feed solution in the range of 4.00-6.75, the carrier concentration of 25-1000 mol/m3, and acid concentration in strip solution of 1-500 mol/m3on. The mass transfer rate or flux JCo(II), which is a function of metal concentration, volume of solution, and membrane area were analyzed. The optimum condition for extraction of Co(II) was pH of 6.00, Cyanex 272 concentration of 500 mol/m3 and H2SO4 concentration of 100 mol/m3.

In this study, cobalt oxide (Co3O4) powder was prepared by simple precipitation and heat-treatment process of cobalt sulfate that is recovered from waste lithium-ion batteries (LIBs), and the effect of heat-treatment on surface properties of as-synthesized Co(OH)2 powder was systematically investigated. With different heat-treatment conditions, a phase of Co(OH)2 is transformed into CoOOH and Co3O4. The result showed that the porous and large BET surface area (ca. 116 m2/g) of Co3O4 powder was prepared at 200°C for 12 h. In addition, the lithium electroactivity of Co3O4 powder was investigated. When evaluated as an anode material for LIB, it exhibited good electrochemical performance with a specific capacity of about 500 mAh g–1 at a current density of C/5 after 50 cycles, which indicates better than those of commercial graphite anode material.

Zeolites, minerals with the formula Mx/n[AlO2]x(SiO2)y] zH2O, are environmentally friendly materials used as water treatment adsorbents, gas adsorbents, and petrochemical catalysts. This study used a mixture of aluminum black dross and waste glass to synthesize zeolites via a hydrothermal synthesis and analyzed the effects of varying reaction time on phase changes under different synthesis conditions. With increased reaction times, a phase change from zeolite Na-P1 to analcime was observed; on employing hydrothermal synthesis at 150°C for 96 h, the majority of the crystalline structures changed into analcime. Heavy metal cation adsorption was tested to assess the applicability of the synthesized analcime to water treatment. Zeolite adsorption of at least 95% was observed for both Pd and Cd ions. Although a higher level of adsorption was observed for Pb ion than Cd ion, Cd ion was demonstrated to undergo relatively faster adsorption when tested under optimal pulp density at the same level of adsorption (95%).