Jian-Guang Yang

BACKGROUND: A new membrane electro‐deposition based process for tin recovery from stannous solid waste was introduced. Linear sweep voltammetry (LSV), cyclic voltammetry (CV) and chronoamperometry (CHR) was applied to investigate the electrodeposition of tin(II) from a stannous chloride acid electrolyte containing an amine non‐ionic surfactant by using a membrane cell.RESULTS: Electrochemical mechanism analysis results showed that 0.3% vol. amine non‐ionic surfactant facilitated ions diffusion by increasing the diffusion coefficient from 8.32E‐12 m² s⁻¹ to 2.85E‐11 m² s⁻¹, and inhibited tin(II) ions reduction as well as tin nucleation and hydrogen evolution. The applied ionic membrane did not hinder tin electrodeposition, while tin(II) ions reduction and hydrogen evolution was weakened with increasing HCl concentration from 1.5 to 4.5 mol L⁻¹ and Sn²⁺ concentration increased from 20 to 80 g L⁻¹.CONCLUSIONS: The tin(II) reduction process is proved to be irreversible and diffusion‐controlled, while the nucleation and growth of tin was involved in the process of diffusion for the proton reduction occuring in parallel with tin electrodeposition, and the process follows the mechanism of three‐dimensional instantaneous nucleation and subsequent grain growth limited by diffusion. © 2016 Society of Chemical Industry

The main aim of this study was to separate heavy metals and yield crude bio-oil from a heavy metals hyperaccumulator harvest, Sedum plumbizincicola, through hydrothermal upgrading process. Parameters such as granularity, temperature, pressure, and duration were examined for their effect on the removal efficiency of heavy metals and upgrading efficacy of crude bio-oil. Maximum heavy metal removal efficiency of >99% and crude bio-oil upgrading efficiency of >63% were attained with an 18 mesh (1 mm) granularity, and 22.1 MPa at 370 degrees C in the presence of 10 mg/L additives for 60 s. Under these optimized conditions, an oil phase (mostly composed of phenolic hydrocarbons and derivatives), a water phase raffinate containing Zn2+ (0.39 g/L), Pb2+ (0.10 g/L), Cu2+ (0.16 g/L), and a solid phase (the hydrothermal upgrading residue, which completely satisfies the limit set by China legislation related to biosolids disposal, were obtained).