title: Copper, lead and zinc removal from metal-contaminated wastewater by adsorption onto agricultural wastes.
abstract: The use of agricultural wastes (groundnut shell, orange and banana peel, rice husk, coconut husk and Wawa tree saw dust) as potential cost-effective adsorbent for heavy metal removal from wastewater was evaluated. The effect of pH (2.0-6.0), adsorbent dosage (0.6-2.2 g), contact time (10-130 min) and initial concentration (Pb: 5-105 mg/L, Cu and Zn: 2.5-52.7 mg/L) on the metal removal efficiency and uptake capacity were investigated using response surface methodology to optimize the process conditions. Groundnut shell showed a high potential to remove Cu, Pb and Zn from synthetic wastewater. The highest removal efficiencies with groundnut as the adsorbent were 85% at pH 5.0 for Cu and 98% at pH 3.0 for Pb and Zn. The optimum conditions obtained were 2.5 g adsorbent with 40.7 mg/L Cu at pH 4.4 and 64 min contact time, 2.5 g adsorbent with 196.1 mg/L Pb at pH 5.6 and 60 min contact time and 3.1 g adsorbent with 70.2 mg/L Zn at pH 4.3 and 50 min contact time, for Cu, Pb and Zn, respectively. The regeneration of the groundnut shell was possible for a maximum of three cycles using 0.2 M HCl as the desorbing solution without any significant change in the adsorbing efficiency.
authors.affiliation: a Department of Environmental Engineering and Water Technology , UNESCO-IHE Institute for Water Education , Westvest 7, 2611 AX Delft , The Netherlands.
authors.forename: Suthee
authors.initials: S
authors.lastname: Janyasuthiwong
authors.affiliation: a Department of Environmental Engineering and Water Technology , UNESCO-IHE Institute for Water Education , Westvest 7, 2611 AX Delft , The Netherlands.
authors.forename: Sheila M
authors.initials: SM
authors.lastname: Phiri
authors.affiliation: a Department of Environmental Engineering and Water Technology , UNESCO-IHE Institute for Water Education , Westvest 7, 2611 AX Delft , The Netherlands.|b Department of Environmental Engineering, Faculty of Engineering , Chiang Mai University , Chiang Mai 50200 , Thailand.
authors.forename: Pimluck
authors.initials: P
authors.lastname: Kijjanapanich
authors.affiliation: a Department of Environmental Engineering and Water Technology , UNESCO-IHE Institute for Water Education , Westvest 7, 2611 AX Delft , The Netherlands.
authors.forename: Eldon R
authors.initials: ER
authors.lastname: Rene
authors.affiliation: c Department of Civil and Mechanical Engineering , University of Cassino and Southern Lazio , Via Di Biasio, 43, Cassino , FR 03043 , Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Esposito
authors.affiliation: a Department of Environmental Engineering and Water Technology , UNESCO-IHE Institute for Water Education , Westvest 7, 2611 AX Delft , The Netherlands.
authors.forename: Piet N L
authors.initials: PN
authors.lastname: Lens
mesh_terms: D000327:Adsorption; D000383:Agriculture; D003300:Copper / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007854:Lead / Q000737:chemistry*; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000191:economics / Q000379:methods*; D014866:Waste Products; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry*
chemical_list: D003300:Copper; D007854:Lead; D014866:Waste Products; D062065:Wastewater; D014874:Water Pollutants, Chemical; D015032:Zinc
keywords: adsorption; agricultural wastes; heavy metals; metal uptake capacity; response surface optimization