Natrolite proved to be an effective adsorbent for the adsorptive removal of lead and chromium ions from aqueous solutions. Adsorption parameters such as pH, adsorbent dose, temperature, and contact time were optimized. For the determination of rate of metal adsorption by natrolite from 50 mL (20 mg L-1), the supernatant was analyzed for residual metals after the contact period of 10-120 min. The effect of pH on metal adsorption by natrolite was determined at values pH 2-8 and the effect of different doses of natrolite from 0.1 to 0.6 was determined, as well as to what extent the adsorption data obey Langmuir and Freundlich adsorption isotherms were also investigated. Thermodynamic studies shows the negative values of ∆G0
at all the temperature indicates the spontaneous nature of Pb(II) and Cr(VI) ions on natural mineral natrolite. Natrolite has shown good results ans exhibits that the pH plays an important role in adsorption of metal ions.
Key words: natrolite; adsorption; isotherm models; wastewater
|
