An eco‐friendly approach for copper (II) biosorption on alga Cystoseira indica and its characterization

Abstract

The alga Cystoseira indica was used for copper (II) removal from aqueous solutions. Effects of initial pH, ion concentration, contact time, and different pretreatments on biosorption were investigated. Potentiometric titration, chemical modification, FTIR and ICP analyses were performed to study the biosorption mechanism. Ho's pseudo‐second order model described kinetics data appropriately. Adsorption isotherm was fitted to Langmuir model with the maximum adsorption capacity of 72.1 mg g−1 at pH 4 and 25°C for 0.6 g l−1 of biomass. Strong, weak, and very weak acidities which were calculated from potentiometric titration were respectively 1.50, 1.49, and 0.67 me per g dry biomass. Sulfonate, carboxyl, and amine functional groups were involved in biosorption. Treatment with alkali and salt increased biosorption capacity, while acidic treatment decreased it. Ions of Na+, Sr2+, Ca2+, Zn2+, H+, and Mg2+ were released into the solution due to copper removal which indicated that ion exchange was a mechanism of biosorption. © 2018 American Institute of Chemical Engineers Environ Prog, 38: S323–S330, 2019

Removal of yttrium from rare-earth wastewater by Serratia marcescens: biosorption optimization and mechanisms studies

“…The negative shift of the peak from 1074 to 1064 cm −1 also indicated the involvement of C–OH. The result agrees with Roozegar and Behnam 45 , and they also found a negative shift of C–OH peak after alage biosorption of copper. The analysis of FTIR showed that the hydroxyl, amine, and carboxyl groups derived from proteins and polysaccharides might be involved in the S. marcescens biosorption of Y(III).…”

“…This peak overlapped stretching vibrations in the hydroxyl (–OH) and amine (–NH) groups derived from sugars and amino acids 43 , 44 . The distinguished asymmetric and symmetric stretching vibration peaks of carboxylate (–COO − ) were evidenced at 1649 and 1403 cm −1 45 . In addition, the peaks recorded at 1243 cm −1 and 1074 cm −1 were the characteristic peaks of carboxyl/carboxylate and stretching vibrations of C–OH, respectively 46 .…”

“…The shift of the BE of C=O and COO − to lower frequencies after biosorption of Y(III) indicated a decrease of electron density at the adjacent carbon atoms resulted from the donated of electrons oxygen atoms to Y(III) 54 . The replacement of H + by Y (III) should be responsible for the positive shift of C–O and O–C=O 45 . The results of C1s confirmed the involvement of (C–O) and COO − in the biosorption of Y(III).…”

Adsorption studies of hexavalent chromium ions on the dead biomass of Cystoseira indica

“…The weak band in the region of 1200-800 cm -1 is attributed to C-OH stretching vibrations of carboxylic acids, since the carboxylic group is the most abundant functional group in brown algae due to the presence of alginate polymer. The broad band below 1000 cm -1 results from long alkyl chains [22,23]. Figure 1b shows similar bands for acid-treated biomass but more intense compared to the natural one indica-ting the presence of enhanced quantity of surface functional groups that have high tendency to bind with metal ions and hence, play a vital role in defining the adsorption capacity of an adsorbent.…”