Removal of radioactive material (Uranium-VI) from low level wastewaters and subsequent disposal of loaded biomass

Abstract

The concentration of radioactive material i.e., Uranium, when disposed from nuclear reactor as low-level wastewater is under the limit value of 10 mg/l and concentration from mine tailing wastes is in the order of 10–100 mg/l. Biosorption is very cost-effective adsorption mechanism, discussed in this paper for removal Uranium (VI) from LLW using nonviable fungus called Ganoderma lucidum. Non-viable fungus has its advantage over viable fungus like for viable fungus one has to maintain temperature, pH and nutrient level. In this paper, the fungus called Ganoderma lucidum (GL) was used for sequestering uranium (VI) followed by studying their equilibrium and kinetics. Results show sorption rate is satisfactory, and data fitted a model of second order. Also, GL to be very effective biosorbent with 70 % of the total sequestration took place during the first 5 min for pure uranyl solution the corresponding specific uranium uptake rates being 0.106 mg/g-min at equilibrium concentration of 10 mg/L (Uranium VI) and pH maintained is 5. In this paper effect of competing co-ions were also studied and it is found out that effect of iron on uranium uptake is quite significant whereas the effect of other co-ions is at best marginal. Thus, biosorption by GL fungus is energy efficient and cost-effective method for removal of radioactive material from low level wastewater.