Biosorption of Cr(VI) by free and immobilized Pediastrum boryanum biomass: equilibrium, kinetic, and thermodynamic studies

Abstract

The thermodynamic studies indicated that the biosorption process was spontaneous and endothermic in nature under studied conditions. For all the tested biosorbents, biosorption kinetic was best described by the pseudo-second-order model.

Use of the Coenobial Green Algae Pseudopediastrum boryanum (Chlorophyceae) to Remove Hexavalent Chromium from Contaminated Aquatic Ecosystems and Industrial Wastewaters

“…When the pH of the solution gradually increases, the functional groups are deprotonated. The resultant surface charge on the microalgae cell wall becomes negative and the biosorption decreases [18]. Our observations regarding the pH influence coincide with the results presented by other authors who studied the sorption properties of other microalgae.…”

“…When the pH of the solution gradually increases, the functional groups are deprotonated. The resultant surface charge on the microalgae cell wall becomes negative and the biosorption decreases [18]. It was observed that, with the decreasing pH, the percentage of chromium removal increased.…”

“…The sorption capacity (q) determining the amount of chromium(VI) adsorbed in the dry matter of the biosorbent compared to the current concentration in aqueous solution was calculated as follows [18]:…”

“…This phenomenon is accounted for by the increase in both the protonation of the biomass function groups and the degree of dissociation of chromium ions. The functional groups are then positively charged, so they can strongly bind electrostatically with negatively charged chromium ions (HCrO 4− , Cr 2 O 7 2− , Cr 4 O 13 2− ) [18][19][20]. When the pH of the solution gradually increases, the functional groups are deprotonated.…”

Investigating the Effect of Different Growth Media on Biomass Production of Pseudopediastrum boryanum (Turpin) E. Hegewald Isolates

“…The algal species P. boryanum has beneficial attributes for wastewater treatment, particularly due to its high productivity and efficient removal by simple gravity sedimentation (Park et al 2014). A pilot Cr (VI) biosorption study was carried out with the P. boryanum strain that we had isolated and used in the present study and the result was successful (Baykal Ozer et al 2012). Microalgae P. boryanum was chosen as a subject for this research due to its potential uses of waste water treatment and biodiesel production.…”