Cadmium Removal by Two Strains of Desmodesmus pleiomorphus Cells

Abstract

The capacity of microalgae to accumulate heavy metals has been widely investigated for its potential applications in wastewater (bio)treatment. In this study, the ability of Desmodesmus pleiomorphus (strain L), a wild strain isolated from a polluted environment, to remove Cd from aqueous solutions was studied, by exposing its biomass to several Cd concentrations. Removal from solution reached a maximum of 61.2 mg Cd g −1 biomass by 1 day, at the highest initial supernatant concentration used (i.e., 5.0 mg Cd L −1 ), with most metal being adsorbed onto the cell surface. Metal removal by D. pleiomorphus (strain ACOI 561), a commercially available ecotype, was also assessed for comparative purposes; a removal of 76.4 mg Cd g −1 biomass was attained by 1 day for the same initial metal concentration. Assays for metal removal using thermally inactivated cells were also performed; the maximum removal extent observed was 47.1 mg Cd g −1 biomass, at the initial concentration of 5 mg Cd L −1 . In experiments conducted at various pH values, the highest removal was achieved at pH 4.0. Both microalga strains proved their feasibility as biotechnological tools to remove Cd from aqueous solution.

Preparation of a Composite Biosorbent Using Scenedesmus quadricauda Biomass and Alginate/Polyvinyl Alcohol for Removal of Cu(II) and Cd(II) Ions: Isotherms, Kinetics, and Thermodynamic Studies

“…The interaction of metal ions with algal biomass could be primarily with the carboxylic groups (pKa value in the range 3.5-5.0) of the cell wall components. Several researchers have investigated the effect of pH on biosorption of heavy metals by using different kinds of biomass, and similar findings were reported (Dwivedi et al 2010;Farooq et al 2010;Monteiro et al 2010). …”

“…Even small traces of the heavy metal ions can be harmful to mankind (Fagundes-Klen et al 2010;Monteiro et al 2010;Mashitah et al 2008;Bhat et al 2008;Bayramoglu et al 2003;Akar et al 2009;Xiao et al 2010). Among them, cadmium has attracted wide attention of environmentalists as one of the most toxic metals.…”

“…Therefore, there is a need for an alternative technique, which is efficient and cost-effective. Biosorption, based on living or nonliving microorganisms or plants, is a promising potential alternative to conventional processes for the removal of heavy metal ions (Guillen-Jimenez et al 2009;Monteiro et al 2009;Lourie et al 2010;Jalali et al 2002;Papageorgiou et al 2008;Akar and Tunali 2006;Vinod et al 2009;de-Bashan and Bashan 2010;Monteiro et al 2010).…”

Bioprocess considerations for microalgal-based wastewater treatment and biomass production

“…Furthermore, after uptake and accumulation by microalgae, valuable elements such as gold and silver can easily be recovered by treating the microalgae biomass [55]. The potential of accumulation of Hg, Cd, Zn, Au, Ag, Co, Mn, Cs, Ni, Fe, Cu and Cr by suspended or immobilized microalgae cells have been reported previously [55][56][57][58][59][60][61][62][63][64].…”

Non-linear Isotherm Models, Cadmium Kinetics, and Biosorption Thermodynamics of Dried Biomass of Native Aphanothece sp. in a Batch System

“…and Oedogonium sp., have successfully removed Cd ions from aqueous solutions [12][13][14]. However, the use of Aphanothece sp.…”