Biosorption of metals from contaminated water using seaweed

Abstract

Heavy metals are major pollutants in marine, lake and groundwaters as well as in industrial and even treated effluents. Biosorption, an inexpensive and reliable method to remove cadmium and lead ions from solution using dry seaweed biomass as adsorbents, was investigated. Sargassum wightii exhibited maximum metal uptake at pH 4–5 and the value ranged from 18% to 29% of dry biomass. The kinetics of metal adsorption was fast with 70–80% taking place within 30 min. Based on these results, a biobattery involving perforated columns packed with pulverized dry biomass of S. wightii was designed, which could remove metals in the range of 50–97% from a multi-metal ion solution within two and a half hours. The mechanism of metal sorption by seaweeds and the advantages of the present design of seaweed columns are discussed in the light of ecofriendly and cost-effective approach for effluent treatment.