Nickel (Ni+2) Adsorption on Borax Production Waste from Industrial Wastewater

Borax sludge was selected as the adsorbent due to its dolomite content to purify the industrial wastewater. Ni+2 concentration in the industrial wastewater was decreased with the adsorption on the borax production waste. To clarify the adsorption mechanism, various pH values, initial concentrations, and contact times were applied. The adsorption percentage increased with the increasing pH value because of the precipitation of metal ion. In the isothermal analyses, the best-fitted isotherms were in the order of Temkin> Freundlich> Langmuir> Harkins-Jura isotherms. The adsorption heat (BT) was determined as 277 kJ/mole in Temkin isotherm and n value of Freundlich was estimated as 1.3. In the kinetic analyses of Ni+2 adsorption, the pseudo-second-order was the best fitted kinetic method. The adsorbed amount value of Ni+2 per unit mass (qe) varied between 8.3682 and 40 mg/g. The estimated isothermal and kinetic results indicated that the sludge of borax production waste can be preferred as an alternative for the preparation of low-cost adsorbents.