Adsorption of Zinc and Copper Heavy Metal Ions from Smelting Wastewater Using Modified Lava Particles

摘要

This paper investigated the ability of modified lava particles (MLP), a kind of modified surface media from volcanic eruption, to remove Cu(II) and Zn(II) from simulated smelting wastewater. The equilibrium adsorptive quantity was determined as a function of the initial pH, temperature, MLP dosage, and contact time in a batch test. The results showed that the metal ions uptake by MLP was rapid, and the equilibrium time was 8 h at 25℃ and pH 6, especially within 5-60 min, 80% equilibrium quantity was obtained. With the increase of initial pH value (from 3 to 6), the removal efficiency of Cu(II) and Zn(II) was also increase to 85.31% and 58.21%, respectively, but when pH was more than 6, sedimentation was found. Temperature and thermody-namic studies for the present adsorption process were performed at 15, 20, 25, 30, and 35℃ by determining the values of AG° and AH°, and it was confirmed that the adsorption process is endothermic and spontaneous. And the optimal MLP dosage of 10 g/L and 6 g/L were obtained for Cu(II) and Zn(II) removal, respectively. The mechanism of these two metal ions sorped by MLP was inferred that the hydroxide micro-precipitation and surface hydroxyl complex were predominant.