Water purification using different waste fruit cortexes for the removal of heavy metals

Abstract

The use of different cortex fruit wastes, including banana, kiwi and tangerine peels, for removing toxic and heavy element Cd +2 , Cr +3 and Zn +2 ions from aqueous solutions has been previously investigated. The ground material was powdered in a mortar and passed through a screen to obtain two different particle sizes, 1 and 2 mm, for all of the powders. In preliminary experiments using kiwi cortex, material with a 1-mm particle size showed a higher retention capability (up to 10-16% of Cd +2 , Zn +2 and Cr +3) than material with 2-mm particles. Considering these results, material with a 1-mm particle size was used in further experiments with the other waste materials. For Cd +2 , Zn +2 and Cr +3 removal, it was determined that kiwi and tangerine cortex showed better biosorption capability when compared with banana cortex (up to 35% more for Cd, 25% more for Zn and 35% more for Cr). The effects of the initial concentration (10-100 mg/l), pH (2-10), adsorbent dosage (0.1-2.0 g) and contact time (5-120 min) were studied at room temperature. A strong dependence of the adsorption capacity on the initial metal concentration was observed. The capacity increased as the initial concentrations decreased. A maximum removal was observed at an adsorbent dosage of 2.0 g and an initial concentration of 10 mg/l. The adsorption isotherms of the different cortex fruit wastes were determined. The equilibrium data were tested using a Langmuir isotherm model, and the kinetics conformed to the pseudo-second equation. The order of the maximum adsorption capacity of these metal ions on banana was Cr +3 < Cd +2 < Zn +2 , whereas it was Cd +2 < Cr +3 < Zn +2 for kiwi and tangerine. Complexation is proposed as the adsorption mechanism. The experimental results show that the natural biosorbent was effective for the removal of pollutants from an aqueous solution.

Adsorption of Chromium(VI) onto Freshwater Snail Shell-Derived Biosorbent from Aqueous Solutions: Equilibrium, Kinetics, and Thermodynamics

“…Biosorbents are adsorbents derived from various kinds of biomass, mainly industrial and agricultural by-products, such as clay, corncob, and fly ash [2,14,15], which are used for the removal of various contaminants from the water environment. Among them, a large number of low-cost biosorbents developed from different by-products, such as tamarind nut carbon [12], green coconut shell [3], sugarcane bagasse [4], coffee husk [5], rice husk [16], waste fruit cortexes [17], and mango kernel [18], had been used for aqueous Cr(VI) adsorption. Especially, the materials containing biogenic calcium carbonate (CaCO 3 ) have been attracting much attention from scholars.…”

Titanium Pyrophosphate for Removal of Trivalent Heavy Metals and Actinides Simulated by Retention of Europium

“…In that regard, several investigators have studied low cost materials such as biosorbents, in which there is the biomass of residues of vegetable or animal origin or bacteria and fungi [8, 26, 27]. These biosorbents have proven themselves efficient in the removal of metals in aqueous solutions.…”

Study of Wastewaters Contaminated with Heavy Metals in Bioethanol Production

“…The presence of heavy metals in aquatic systems has become a serious threat and has a great potential to cause environmental-derived cancer because these metals are non-biodegradable, and therefore persistent (2). Metals are mobilized and carried into the food web as a result of leaching from waste dumps, polluted soils and water (3).…”

“…These metals increase in concentration at every level of the food chain, and are passed onto the next higher level in a phenomenon called biomagnification (3).…”

“…Some investigations on the removal of heavy metal ions with agricultural by-products have been previously reported. Algae, fungi, bacteria, parts of some higher plants and yeasts have proven to be potential metal biosorbents (3).…”