Cyanobacterial Biomass as a Potential Biosorbent for the Removal of Recalcitrant Dyes from Water

Carlos Diaz-Uribe,Eduardo Schott,Arnold R Romero Bohórquez,Ximena Zarate,William Vallejo,Barni Angulo,Karen Patiño,Euler Gallego-Cartagena,Vincent Hernández

doi:10.3390/w13223176

Abstract

The accumulation of cyanobacteria produced due to eutrophication processes and the increment of different pollutants in water as a result of industrial processes affects aquatic environments such as the ocean, rivers, and swamps. In this work, cyanobacterial biomass was used as a biosorbent for the removal of a commercial dye, methylene blue (MB). Thus, MB was removed from biomass obtained from cyanobacterial samples collected from the swamp located in the Colombian Caribbean. Spectroscopical techniques such as FTIR, SEM, EDX measurements were used for the physico-chemical characterization of the bio-adsorbent material. Furthermore, we present the effect of various adsorption parameters such as pH, MB dose, time, and adsorbent concentration on the adsorbent equilibrium process. Three different isotherm models were used to model the MB adsorption on biomass. The functional groups identified on biomass suggest that these models are suitable for the characterization of the sorption of cationic dyes on the surfaces of the biomass; in addition, an SEM assay showed the heterogeneous surface of the biomass’ morphology. The equilibrium tests suggested a multilayer type adsorption of MB on the biomass surface. The kinetics results show that a pseudo-second order kinetic model was suitable to describe the MB adsorption on the biomass surface. Finally, the herein obtained results give an alternative to resolve the eutrophication problems generated by cyanobacterial growth in the swamp “Ciénaga de Malambo”.

Highlights

Yang et al, reported a KF = 1.71 for Cr removal from sugarcane pulp residue and biosorbent [53], Kilic et al, reported a KF = 9.30 for Ni removal from almond shells and biosorbent [54], and Amouei et al, reported a KF = 5.28 for Cd removal from canola residue [55]. Compared to these previously reported studies, our results show the potential of cyanobacterial biomass for methylene blue (MB) removal
The MB removal on biomass obtained from cyanobacterial cultures was shown
Model was suitable to describe the adsorption kinetic data indicating chemisorption, which could be the major interaction during MB adsorption on the biomass’ surface

Summary

Introduction

Water is a critical resource for all living beings on earth; we face a great ecological challenge today, due to rapid urbanization and human anthropogenic activities [1] Contaminants such as organic and inorganic pollutants are delivered into the water affluents (e.g., ponds, lakes, streams, rivers, and oceans). Climate change indicators demonstrate the challenge that humanity is facing (e.g., CO2 atmosphere level, earth temperature, ocean temperature, glaciers and sea ice melting, global sea level, ocean acidification, and extreme climate) [4,5]. Among these indicators, the ocean’s acidification is increasing due to eutrophication [6], where an accumulation of plants and cyanobacteria is produced

Methods

Results

Conclusion