Title: Chemically activated phosphate slime as adsorbent for heavy metals removal from polluted water

Authors: Mohamed Nageeb Rashed; Aiman Rashed Mohamed; Mohamed Ahmed Awadallah

Addresses: Faculty of Science, Aswan University, 81528 Aswan, Egypt ' EL Nasr Mining Company, Edfo, Aswan, Egypt ' EL Nasr Mining Company, Edfo, Aswan, Egypt

Abstract: Phosphate slime was activated by chemical activators (0.5 M HNO3, 1 M HNO3, 2MHNO3, 0.5MHNO3: 0.5M NaOH, 1MHNO3: 1M NaOH, and 2MHNO3: 2M NaOH) to use as a cost-effective adsorbent for removal of heavy metals (Pb, Ni, Cd, Zn and Cu) from solution. The influence of pH, adsorbent dosage, contact time, initial metal concentration, and temperature on metals adsorption were investigated. Results revealed that slime phosphate activated by 2MHNO3 was an effective adsorbent for the removal of all metals from aqueous solution. Metal removal was affected by pH, adsorption dosage, initial metal concentration and solution temperature, while it shows less significant for effect of contact time. Metal adsorption was in a good correspondence with the Langmuir isotherm. The order for the maximum adsorption using the adsorbent was Zn (43.47 mg/g) > Cu (38.46 mg/g) > Ni (34.47 mg/g) > Pb (33.3 mg/g) > Cd (26.31 mg/g).

Keywords: metals adsorption; heavy metals; phosphate slime; treatment; water pollution; adsorbents; chemical activators; metal removal; pH; adsorbent dosage; contact time; metal concentration; solution temperature; initial concentration; zinc; copper; nickel; lead; cadmium.

DOI: 10.1504/IJEWM.2015.071289

International Journal of Environment and Waste Management, 2015 Vol.16 No.2, pp.145 - 165

Received: 24 Jul 2014
Accepted: 11 Mar 2015

Published online: 19 Aug 2015 *

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