Biosorption of amaranth red in aqueous solution onto treated and untreated lignocellulosic materials (pineapple peelings and coconut shells)

Abstract

The removal of amaranth red dye from aqueous solution by untreated and treated pineapple peelings and coconut shells with phosphoric acid was studied in batch mode at room temperature. The study highlighted several parameters such as the contact time, the mass of the adsorbent, the pH of the solution, and the initial concentration of the dye. The results showed that the removal of dyes by the bioadsorbents depended on the pH and the initial concentration of the adsorbate. The adsorption capacity increased with increasing amaranth red dye concentration and the mass of the bioadsorbent. It was also established that maximum adsorption took place at pH = 2 for different adsorbents. The treated raw materials have greater surface area than the untreated materials. In order to deduce the adsorption mechanism, four simplified kinetic models were investigated. The kinetic data were well represented by the pseudo second order kinetic model giving high correlation coefficients R² values for all the biosorbents suggesting that chemisorption was the rate determining step. An equilibrium study of the adsorption process also showed that the Langmuir model best described the adsorption on all the biosorbents. The values of energy obtained from the Temkin isothermare also positive, this shows that the adsorption process isexothermic. These results indicate that pineapple peelings and coconut shells have a high potential as adsorbents for removing amaranth red dye from aqueous solution

Kinetic, Isotherm and Thermodynamic Studies of the Adsorption of Thymol Blue onto Powdered Activated Carbons from <i>Garcinia cola Nut</i> Shells Impregnated with H<sub>3</sub>PO<sub>4</sub> and KOH: Non-Linear Regression Analysis

“…This is explained as follows: at the start of the adsorption process, all the vacant sites on the adsorbent were completely available and the thymol blue molecules were fast attached. The same tendency had been obtained by Ndifor-Angwa for and others when they adsorbed amaranth red onto treated and untreated lignocellulosic materials [1]. Thereafter, the rate of adsorption deceased gradually with the progress of adsorption within 5 to 60 minutes for the two adsorbents, and reached equilibrium in about 60 minutes.…”

“…The intensive industrialization considered as key to economic development, which started in the last century is at the origin of the proliferation of various pollutants in the environment, and most of them are difficult to eliminate [1].…”

“…The wastes resulting from industrial activities represent a danger to man and his environment, due to their very low biodegradability and the slowness of their elimination [1]. The global increase in water pollution has increased awareness among the public, and more attention is being focused on combating the problem [2].…”

“…Adsorption has proved to be a more effective and cheaper process, and its equipment is easy to implement [1]. However, the choice of adsorbent remains a major worry because most adsorbent materials such as alumina, zeolites, activated clays, and silica gels are also used as catalyst support materials [12].…”

Bioremediation of dyes using coconut parts via adsorption: a review

“…Coconut shell was the predominantly used part for the removal of dyes from the waste water. There are three ways to modify the coconut shell prior to the removal of dyes, namely activated carbon [39][40][41][42][43], acid or base treatment [44,45], and as immobilizer for the bacteria [46]. Table 1 summarizes the physical parameters, adsorption kinetic and equilibrium isotherm of the modified coconut shell.…”