Removal of chromium ions from polluted water via goethite and/or zeolite modified by TiO2

Shehata, Mohamed; Sherif, Abd El-Hamid; Hassien, Saraha Hamada

doi:10.21608/gjsr.2024.277683.1016

Removal of chromium ions from polluted water via goethite and/or zeolite modified by TiO2

Articles in Press

Document Type : Original Article

Authors

¹ Department of Chemistry, Faculty of Science, Cairo University

² Envier. Res. Dept. Soils, Water and Envier. Res. Institute, Agric. Res. Center

³ Envier. Res. Dept. Soils, Water and Envier. Res. Institute Agriculture Research Center

10.21608/gjsr.2024.277683.1016

Abstract

The study investigates the efficacy of Goethite, Zeolite, and modified synthetic counterparts with titanium oxide, in eliminating chromium ions, from aqueous solutions. Objectives encompass exploring the impact of material dosage variation on adsorption at constant pH and concentration, assessing adsorption isotherms on different materials at fixed pH and dosage for various Cr(VI) concentrations. Studying adsorption kinetics over time at constant pH and dosage, and examining the influence of pH on Cr(VI) adsorption by different materials. Removal efficiency decreases at higher concentrations, with GZTi>ZTi>Z>G Goethite clay mineral (G), zeolite clay mineral (Z), modified goethite + zeolite +titanium oxide mineral (GZTi) and modified zeolite mixed with titanium oxide (ZTi) demonstrates higher removal efficiency than G at lower Cr(VI) concentrations. Langmuir and Freundlich adsorption isotherms were applied to synthetic Cr(VI) solutions using various clayey minerals, yielding R2 values ranging from 0.6768 to 0.9535 for Langmuir and 0.90 to 0.99 for Freundlich. Different clay adsorbent dosages showed increased adsorption % with higher dosages, resulting in removal efficiencies of 79 to 99.3% for Cr(VI) in the order GZTi>ZTi>Z>G. Higher sorbent weights increased removal efficiency, with Langmuir and Freundlich's equations fitting well (R2 values of 0.9896 to 0.9977 for Langmuir and 0.7849 to 0.9977 for Freundlich). The contact time study revealed optimal removal efficiency for Cr(VI) at 120 minutes, declining at 240 minutes, with GZTi>ZTi>Z>G showing values ranging from 7.5 to 25%. Adsorption envelopes for Cr(VI) at different pH levels indicated varying removal efficiencies, with GZTi>ZTi>Z>G achieving 44-95% removal, particularly at low pH values for Cr(VI).

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