Metal Distributions in Complexes with Chiarella vulgaris in Seawater and Wastewater

Abstract

Divalent cadmium (Cd), copper (Cu), iron (Fe), nickel (Ni), lead (Pb), and zinc (Zn) simultaneous complexes with an algal biomass Chiarella vulgaris were studied for bioremediation purposes in various aqueous media: distilled‐deionized water (DDIW), seawater, nuclear‐reactor pool water, and process wastewater. Reactions were monitored using various dry masses of algae (2 to 12 mg) at constant temperature (20 to 22 °C) and constant metal concentrations for reaction times ranging from 0 to 150 minutes. Complexes occurred within 30 minutes and reached a steady state after 80 to 120 minutes. Distribution constants (K'd) were calculated for the complexes and relative orders of K'd were reported. The K'd are used to evaluate relative efficiency of metal remediation from waters. Lead, Cu, and Ni complexes had the greatest K'd values and those metals were most efficiently removed from these waters. Zinc and Fe formed the most labile complexes. The order of Kd values for complexes in DDIW was Pb > Cu > Cd > Zn, then Cu > Cd > Zn in seawater, Cd > Cu > Zn in reactor pool water, and Ni > Cd > Cu > Zn > Fe in wastewater. C. vulgaris biomass may potentially be used as an alternative to traditional water treatment methods for simultaneous extraction of metals from seawater, process wastewater, or drinking water.