title: Agricultural by-products as low-cost sorbents for the removal of heavy metals from dilute wastewaters.
abstract: n the last years, much attention has been focused on the use of low-cost adsorbents for the removal of Cu(II) and Zn(II) from contaminated waters. In this context, we studied the sorption performances of two kinds of by-products resulted from the agriculture: soy bran and mustard husk. The effects of contact time, the initial metal ion concentration, pH, sorbent mass, and temperature on the adsorption capacity of the agricultural by-products as sorbents were investigated. The thermodynamic parameters associated with the adsorption process indicated that the process is spontaneous and endothermic. Modeling of experimental adsorption isotherm data showed that non-linear Langmuir isotherm fits better than other isotherms. The obtained values for the separation factor, R L were less than one which supports that the adsorption process was favorable. The obtained results indicated that the soy bran has a higher sorption capacity toward zinc ions (74.02 mg g(-1)) than mustard husk (63.69 mg g(-1)). Therefore, there is a great requirement for the search of biomaterials that are cheap and easily available for the removal of heavy metal ions from wastewater. The studied sorbents have the advantage of very low cost and great availability for simple operational experiments.
authors.affiliation: "Al. I. Cuza" University of Iasi, Faculty of Chemistry, Bd. Carol I, Nr. 11, 700506, Iasi, Romania, doinah@uaic.ro.
authors.forename: D
authors.initials: D
authors.lastname: Humelnicu
authors.forename: M
authors.initials: M
authors.lastname: Ignat
authors.forename: F
authors.initials: F
authors.lastname: Doroftei
mesh_terms: D000327:Adsorption; D000383:Agriculture; D004784:Environmental Monitoring; D006863:Hydrogen-Ion Concentration; D019216:Metals, Heavy / Q000032:analysis* / Q000737:chemistry; D013696:Temperature; D013816:Thermodynamics; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry; D015032:Zinc
chemical_list: D019216:Metals, Heavy; D062065:Wastewater; D014874:Water Pollutants, Chemical; D015032:Zinc
references.citation: Bioresour Technol. 2007 Dec;98(17):3344-53
references.pmid: 17624771
references.citation: J Hazard Mater. 2003 Feb 28;97(1-3):219-43
references.pmid: 12573840
references.citation: J Environ Sci (China). 2007;19(12):1436-41
references.pmid: 18277646
references.citation: J Hazard Mater. 2006 Aug 25;136(3):911-6
references.pmid: 16490303
references.citation: J Hazard Mater. 2009 Sep 15;168(2-3):813-9
references.pmid: 19297088
references.citation: J Hazard Mater. 2005 Jun 30;122(1-2):31-6
references.pmid: 15908112
references.citation: Water Res. 2009 Aug;43(15):3659-72
references.pmid: 19576609
references.citation: J Environ Manage. 2009 Aug;90(11):3485-9
references.pmid: 19576679