Synthesis and Application of Eco-Friendlyred Onion Skins Azo Dyes for The Removal of Cobalt from Aqueous Media
- August 17, 2021
- Posted by: rsispostadmin
- Categories: Chemistry, IJRIAS
International Journal of Research and Innovation in Applied Science (IJRIAS) | Volume VI, Issue VII, July 2021|ISSN 2454-6194
Gervais Manizabayo 1*, Aimable Niyomugabo2, Dr. Uche John Chukwu3
1 Chemistry Department, College of Science and Technology, University of Rwanda, Rwanda
2Chemical Engineering Department, African Center of Excellence for Sustainable Mining, Copperbelt University, Zambia
3Pure and Industrial Chemistry Department, University of Port Harcourt, Nigeria
Abstract: The present study investigated the synthesis of low cost and environmental friendly red onion skins azo dyes derivatives and their application as ligands for the extraction of cobalt (II) ions from aqueous media. The effect of pH, agitation time, ligand concentration, and metal ion concentration on Co2+ ions removal efficiency as well as the stoichiometric coefficients were examined. The study revealed that the azo dyes were effective in removing Co2+ ion from aqueous solution. The highest removal efficiencies were obtained within the pH ranges 6-7. The results also showed that the % extraction (% E) of Co2+ions increased with agitation time and concentration of the ligand. The slope analysis carried out on the experimental data demonstrated that Co2+ions reacted with the ligands in 1:2 metals to ligand ratio.
Keywords: Extraction, red onion skin, azo dyes, quercetin, Co2+ ions.
I. INTRODUCTION
Cobalt ion (Co2+) is among inorganic compounds formed from metals known as transitional metals. Like other heavy metals, most of cobalt ions find their way into the environment through waste waters discharged from nuclear power plants as well as mining, electroplating, pigment, metallurgical, electronic and paint industries[1], [2]. While cobalt ions are biologically necessary and an essential component vitamin B12 and cobalamins which play role in red blood cells production[3], the exposure to high level of (Co2+)has been reported to cause various health effects such vomiting, nausea, paralysis, vision problem, lung irritation, sterility, hair loss, thyroid, low blood pressure, bone defects and diarrhea [1], [2]. Therefore, it is important to detect and remove cobalt (II) ions from wastewater prior to their discharge into the environment.
Over the years, different methods including chemical precipitation, membrane separation, ion exchange, adsorption and many others has been used in the recovery of in trace of heavy metals from aqueous media [4]–[10]. However, it has been reported that these methods are very expensive and consume a lot of energy [11]. On the other hand, studies have revealed that solvent extraction could contribute to energy saving in extraction of valuable materials from waste sludge (Mansur, Marcelo Borges., 2011). On the other hand, solvent extraction presents downsides which include the emulsion formation, dissolving of unwanted materials and loss of some compounds. The successful application of solvent extraction for the extraction of heavy metals for aqueous media requires the use of ligands that can interact with the metal ions to form insoluble compounds.
