Heavy metal sorption by marine algae and algal by‐products

Abstract

All the Oceans are plentiful with marine algae. Non-viable marine macroalgae are able to adsorb heavy metal ions. Compared with other biosorbents, such as fungi, bacteria, yeasts and microalgae, they have the advantage of being easily available, cheap and having high heavy metal sorption capacities. The by-products of marine phaeophyceae are even more cost-effective heavy metal biosorbers. Experiments of heavy metal sorption using non-viable F u c u vesiculosus, Ascophyllurn nodosum and algal by-products were carried out to investigate the factors influencing and optimizing the heavy metal biosorption. The pH value, biomass concentration, heavy metal concentration, heavy metal species, competing ions, algal varieties and time were the most decisive parameters. The sorption isotherms showed increasing sorption capacities and decreasing sorption efficiencies with an increase in the initial heavy metal concentration. Sorption kinetics of different metals were established. Biomass concentration influenced the sorption efficiencies very much, but reduced the sorption capacity per g biomass. The pH value controlled the sorption (pH 3-7) and desorption (pH 1-2) decisively. Beside heavy metal contaminated model waters, actual industrial effluents were treated successfully by algal sorhents in batch experiments and continuous column tests. Transmission electron micrographs of different contaminated and untreated algal specimens are available.

Metal sorption by algal biomass: From batch to continuous system

“…Likewise, for an Aeromonas hydrophila biomass packed bed, increase in breakthrough time from 13.5 to 18.3 h was noticed with increase in bed height from 7 to 13 cm [51]. Pradhan and Rai [100,101], Volesky and Prasetyo [131], Sandau et al [108] and several other workers had also made similar observations for the algal biomass packed column [115]. 7.3.1.2.…”

Heavy metal resistant Distigma proteus (Euglenophyta) isolated from industrial effluents and its possible role in bioremediation of contaminated wastewaters

“…Metal resistant algae reported in wastewaters and metalpolluted environments process and detoxify heavy metal ions usually through biosorption, adsorption and bioaccumulation (Verma and Singh 1995;Sandau et al 1996;Shakoori 2001, 2003;Gin et al 2002;Chojnacka et al 2004).…”

Bioactive compounds in seaweed: functional food applications and legislation

“…Not only desireable minerals but also metals in toxic concentrations, heavy metals and other compounds are concentrated in seaweed. For example, lead (Pb), mercury (Hg) cadmium (Cd), copper (Cu), manganese (Mn), zinc (Zn) and the explosive compound trinitrotoluene that may be present in the ambient environment (Besada et al 2009;Cruz-Uribe et al 2007;Greger et al 2007;Mehta and Gaur 2005;Ronnberg et al 1990;Sandau et al 1996). Concentration factors of 10 3 -10 4 for the above heavy metals and even up to 10 6 can be reached for chromium (Cr; references in Lobban and Harrison 1994).…”