The feasibility to recover indium (In) from discarded liquid crystal display (LCDs) panels by solvent extraction (SX) and a hollow fiber supported liquid membrane with strip dispersion (SLM-SD) system was investigated in this study. Di-(2-ethylhexyl)phosphoric acid (D 2 EHPA) was used as the extractant and the mobile carrier in SX and SLM-SD. The effect of different parameters such as pH, concentration of D 2 EHPA and stripping agents has been investigated for indium extraction. The average amount of indium in LCD screen was found to be 330 mg/kg and 70% of this indium was easily leached out by 3 M HCl in 30 min. An increase in the D 2 EHPA concentration from 0.025 to 0.25 M increased the extraction of indium and 79% of indium can be recovered by back-extraction with 2 M hydrochloric acid. For the SLM-SD system, more than 94% of indium can be recovered within 20 min under the same operating conditions. This indicates that the SLM-SD was more efficient for indium extraction than SX. However, a poor separation of iron and indium resulted on increasing the extraction time. Hence, process optimization for iron removal must be explored in a future work.

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Novel ternary nanocomposite photocatalysts based on g-C3N4/Bi2MoO6/TiO2 nanotube were synthesized using simple solid combustion, hydrothermal and wetness impregnation methods. The structural and morphological properties of the synthesized photocatalysts were systematically characterized using powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy and scanning electron microscopy (SEM). The crystal structure and phase purity of unitary, binary, and ternary photocatalysts were confirmed by XRD analysis. The SEM analysis reveals the tubular morphology of the TiO2 nanotube, and the presence of Ti, C, N, Bi, Mo, O, C, and N in the ternary composites was confirmed by EDX analysis. The photocatalytic decolorization efficiency of the ternary composites was evaluated by monitoring the decolorization of reactive black 5 and methylene blue dyes under visible light and direct sunlight irradiation, and these ternary composites were compared with binary composites and unitary photocatalysts in terms of the decolorization efficiency. After five cycles of adsorption and decolorization reactions, it was confirmed that the ternary composite photocatalysts were highly stable and reusable. From the results, we conclude that ternary composites (g-C3N4/Bi2MoO6/TiO2 nanotube) are efficient photocatalysts for the decolorization of dyes.