Bioremediation In Nuclear Industry by Seaweeds Biomass and Cyanobacteria

Biological and Biotechnological processes such as biosorption and phytoremediation as bioremediation techniques along with physical and chemical methods in the nuclear waste management process have been promising in recent years. A lot of research has been done on the use of different types of seaweeds, cyanobacteria and other microorganisms for the adsorption of radionuclides and heavy and toxic metals due to their high adsorption capacity and economy. Among the studied bioremediation methods, brown algae biomass is one of the main alternatives for the adsorption of radionuclides and heavy metals in the management of nuclear waste and other industries.BACKGROUND AND OBJECTIVESThe effluent released from the nuclear industry, uranium mining, power plant effluents, medical research laboratories and nuclear incidents is more harmful to the environment as well as to humans directly due to emissions. In order to deal with the harmful effects of radioactive waste, waste management is done with special physical, chemical, and biological methods[۱-۵].Bioremediation and phytoremediation are the two main techniques of using microorganisms and plants to remove radioactive and heavy metals pollution. The use of dried biomass of seaweeds has been interesting due to its abundance, economic aspects and effectiveness in the treatment of radioactive liquid waste. Based on the blooming of cyanobacteria phenomenon due to the production of a high volume of biomass and their resistance to environmental unfavorable conditions is a suitable alternative for adsorbing radioactive pollution[۶-۱۲]. The objective of this lecture is to introduce some advances in nuclear wastes management to radionuclide removal by seaweeds and cyanobacteria as a biological method.MATERIALS AND METHODSIn order to investigate the performance of algae, cyanobacteria or microorganisms in the adsorption or bioaccumulation and removal of radionuclides, brown algae, and cyanobacteria biomass is placed in contact with the pollutant. Effective parameters such as pH, pollutant concentration, amount of adsorbent and contact time are studied to determine the optimal conditions of adsorption. Biosorption is investigated during two processes, including investigation in a batch system and an adsorbent column.RESULTS AND DISCUSSIONThe obtained results show the high efficiency of brown algae biomass in adsorbing and removing radionuclides. Cyanobacteria have also shown an expected performance in adsorbing radionuclides. The research results showed the efficiency of algae in adsorbing uranium from ۱۵۰ to ۳۱۸ mg/L and other radionuclides depending on the type of biomass and operational conditions[۹, ۱۳-۱۸]. Cyanobacteria provide the possibility of adsorption of radionuclides in the aquatic environment in the form of biological adsorption and bioaccumulation[۶, ۷, ۱۲]. Reducing the volume of solid cellulose waste is also one of the cases that provides the possibility of using it with the help of microorganisms to biodegrade organic materials[۳, ۱۹-۲۴]. ۱۵CONCLUSIONBiotechnological processes or biosorption are proposed as effective and in many cases cost-effective options for the treatment of radioactive wastes and the removal of heavy metals. In the nuclear waste management process, brown algae have shown better performance in the adsorbent columns. It is possible to use algae and other microorganisms and plants in the bioremediation process in order to remove nuclear pollution and treat solid and liquid waste.

کلیدواژه ها:

Biosorption ، Adsorption ، Radionuclides ، Bioremediation ، Removal