A review of applications and performance of algal sorbents in bioremediation of heavy Metals

Human activities have put a lot of pressure on the environment, which is caused by the production of large amounts of toxic effluents containing heavy metals, metalloids, radionuclides and various organic pollutants. The purpose of industrial treatment methods is to prevent or limit toxic emissions to the environment. Biological, physicochemical and green chemistry processes proposed and used to remove pollutants from industrial wastewater, before discharging into the environment. Biosorption is a physicochemical process that is carried out by various biological sorbents including microorganisms such as; algae, bacteria, fungi, yeast and waste materials derived from agricultural and food industries; concentrate on removal or retrieval of organic and inorganic materials from aqueous solutions and wastewater. Algae act well among microorganisms as bioactive sorbents. Different genus of macroalgae such as Sargassum, Cystoseria, Padina,Laminaria and Microalgae such as Nostoc, Chlamydomonas, Chlorella, Spirulina, Cladophora and Chaetophora, have undergone various experiments in the biosorption process of metals such as mercury, lead, cadmium, copper, chromium, nickel, cobalt and radionuclides such as uranium, cesium and strontium, and the maximum metal adsorption capacity was reported. Among different algae, Padinasp. and Cystoseriaindica with maximum adsorption capacity of 438.8 mg / g and 560 mg / g for uraniumhas been recognized as one of the best sorbents for uranium and candidates to heavy metals removal.