Agricultural by-products as low-cost sorbents for the removal of heavy metals from dilute wastewaters
- 297 Downloads
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.
KeywordsHeavy metal Adsorption By-products Langmuir isotherm Freundlich isotherm
One of the authors (D. Humelnicu) would like to thank Dr. Mirela Suchea for her help in the SEM images discussions.
- Banu, I. (2008). Potential of maize cobs for removal Zn(II) and Ni(II) in aqueous system. Revista de Chimie Bucharest, 59, 1375–1377.Google Scholar
- Das, Nilanjana, Karthika, P., Vimala, R., Vinodhini, V. (2008). Use of natural products as biosorbent of heavy metals. An overview. Natural Product Radiance, 7, 133–138.Google Scholar
- Everett, A. J. (1998). Adsorption of metals by geomedia. California: Academic.Google Scholar
- Oliveira, L.S., Franca, A.S. (2008). Low-cost adsorbents from agri-food wastes. Food Science and Technology New Research, 171–209.Google Scholar