Isotherm and kinetics modeling of Pb(II) and Cd(II) adsorptive uptake from aqueous solution by chemically modified green algal biomass

Abstract

In this study, the adsorption efficiency of epichlorohydrin modified fresh water green algal biomass was assessed for Pb(II) and Cd(II) uptake from aqueous solution. The process parameters such as contact time, dose, initial metal concentration, solution pH and temperature were optimized. The Langmuir, Freundlich, Temkin and Dubnin-Redushkevich isotherm model was applied to the equilibrium data, which best fitted the Langmuir isotherm indicating homogenous distribution of adsorption sites. The monolayer adsorption capacity was 100.00 for Pb (II) and 72.46 mg/g for Cd(II) adsorption. The kinetic data was best described by pseudo-second order model, with intraparticle and liquid film diffusion controlled mechanism. The negative values of Gibbs free energy change (ΔG º ) and positive enthalpy change (ΔH º ) showed that adsorption process was spontaneous and endothermic. The functional groups, surface morphology and elemental composition of adsorbent, before and after adsorption, was evaluated using FTIR spectra, SEM and EDS studies. The study revealed that the modified algal biomass can effectively and efficiently remove the title metal ions from aqueous solution.

Diffusive Properties of Alginate Biosorbents

“…Once again, biosorption has appeared to be an efficacious though low-cost solution for the recovery of heavy metals. For the above reasons, sorption on materials of natural origin has become the subject of extensive studies (described, for instance, in [8][9][10][11][12][13][14][15][16][17][18][19][20][21]). The studies have demonstrated that marine algae, which are acquired at a rather low cost, have a considerable sorption capacity.…”

Uptake of Cu2+and Zn2+from simulated wastewater using muskmelon peel biochar: Isotherm and kinetic studies

“…Several techniques available for heavy metals removal from wastewater such as reverse osmosis [1], electrocoagulation [2], ultrafiltration [3], dialysis/electrodialysis [4], and solvent extraction [5] are either costly or less effective due to their own limitations. However, the treatment of aqueous effluents using adsorption of metals onto low cost adsorbents [6][7][8][9][10][11][12] is regarded as an efficient and economical alternative. Biosorption using many agricultural biomass has attracted recent attention because of various functional groups available on the surface of biosorbents for the removal of heavy metals/dyes even at very low concentration from aqueous system [13,14].…”

Determination of Sorption Properties of Heavy Metals in Various Biosorbents

“…The preparation of biological material usually consisted of separating it from mechanical impurities, sometimes rinsing with water and drying into a solid mass in the process of thermal vaporisation of water from, e.g. algae [27], or in the process of lyophilisation [32]. Cleaned and dried samples were stored in paper containers or tightly closed plastic containers [3].…”

“…: Na + , K + , Ca 2+ and Mg 2+ . Also, other authors report the limited heavy metal sorption by cations which are naturally present in the environment [15,27].…”

“…The kinetics of sorption taking place due to ion-exchange is described by the pseudo-first order rate equation and more frequently by the pseudo-second order rate equation [21,[26][27][28]. These models are used to determine the constants of the reaction rate.…”