Application of Saccharomyces cerevisiae/Calcium Alginate Composite Beads for Cephalexin Antibiotic Biosorption from Aqueous Solutions

Abstract

Cephalexin (CPX) is recognized as a water pollutant, and it has been listed in a number of countries with a risk factor greater than one. Herein, the present work focused on the synthesis, characterization and biosorption capacity evaluation of Saccharomyces cerevisiae immobilized in calcium alginate as a biosorbent to remove CPX from aqueous solutions. Biosorbent was characterized by SEM and FTIR techniques. Batch biosorption experiments were conducted in order to evaluate the effect of the initial pH, biosorbent dose and CPX initial concentration. The removal efficiency, in considered optimal conditions (pH = 4, CPX initial concentration = 30 mg/L, biosorbent dose = 1 g/L) was 86.23%. CPX biosorption was found to follow the pseudo–second-order kinetics. The equilibrium biosorption data were a good fit for the Langmuir model with correlation coefficient of 0.9814 and maximum biosorption capacity was 94.34 mg/g. This study showed that the synthesized biosorbent by immobilization technique is a low-cost one, easy to obtain and handle, eco-friendly, with high feasibility to remove CPX antibiotic from aqueous solution. The findings of this study indicate that the biosorbents based on microorganisms immobilized on natural polymers have the potential to be applied in the treatment of wastewater.

Encapsulation of Saccharomyces pastorianus Residual Biomass in Calcium Alginate Matrix with Insights in Ethacridine Lactate Biosorption

“…The viscous suspension obtained by mixing sodium alginate with biomass was forced to pass through the encapsulator small diameter nozzles under high pressure. As consequence, the resulted beads ( Figure 2 ) have an irregular and elongated shape and not the spherical and regular one attained, for example, when the immobilization procedure is applied [ 24 ]. The beads dimensions were between 1.89 mm ± 0.13 mm.…”

“…The free cells encapsulation or immobilization in a fixed matrix constitute a solution to this problem, offering at the same time a series of advantages such as: easy solid–liquid separation, control of the size, design of different type of biosorbents and possibility of use in continuous flow systems [ 17 , 18 , 23 , 24 , 25 , 26 ].…”

“…Among the natural polymers, the most used for biosorbents obtaining is the alginate due to its good chemical stability, non-toxicity, biocompatibility, incorporation efficiency and low cost [ 24 , 29 ].…”

“…Among the most extensively researched microorganisms are the yeasts from Saccha-romyces genus, especially Saccharomyces cerevisiae , which have been noted as efficient biosorbents for heavy metals, dyes and drugs [ 17 , 18 , 19 , 20 , 23 , 24 , 29 , 30 ].…”

Biosorptive Removal of Ethacridine Lactate from Aqueous Solutions by Saccharomyces pastorianus Residual Biomass/Calcium Alginate Composite Beads: Fixed-Bed Column Study

“…Various techniques, such as adsorption, biosorption, membrane separation, advanced oxidation processes, electrocoagulation, etc., are increasingly used to eliminate drugs from water [5,[8][9][10][11][12][13].…”