In this study, we investigated the kinetics of arsenic removal from waste acid by the combination of zero-valent iron (ZVI) and CuSO4. ZVI samples were characterized by X-ray diffraction and scanning electron microscopy before and after arsenic removal; the results showed that after the arsenic removal reaction, As2O3 and magnetite phases were detected on the surface of these samples. Kinetic studies were carried out under different reaction temperatures, with different CuSO4 concentrations, and with different iron to arsenic molar ratios (Fe/As). The kinetic data of the arsenic removal were fitted to different kinetic models. The fitting results showed that the arsenic removal process could be described by the shrinking core model, controlled by residual layer diffusion. The apparent activation energy of the reaction was 9.0628 kJ/mol, the reaction order with the CuSO4 concentrations was −0.12681, and the reaction order with the molar ratio of iron to arsenic (Fe/As) was 3.152.

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Uranium plant wastewater was treated in laboratory scale experiments by employing zero valent iron powder. Batch experiments conducted by the response surface methodology (RSM) proved significant decrease in concentrations of uranium due to a decrease in an oxidation-reduction potential and an increase in pH relative to an application of zero valent iron powder. Results indicated that it is effective on the removal of uranium from uranium plant wastewater with the uranium concentration of 2772.23 μg/L due to the adding of zero valent iron powder. it was found that the scope of pH is widely from 3 to 5 from the experimental data obtained in this study. The predicted model obtained from response surface methodology is in accordance with experimental results.

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