Biosorption and separation behaviour of Sr(II) and Y(III) using Aspergillus terreus: isolation, characterization, batch and column studies

In this study, Aspergillus terreus was isolated from liquid radioactive waste and used as a dead biosorbent material to separate Y(III) from a solution containing both Sr(II) and Y(III). Fourier transform infrared spectroscopy, energy dispersive X-ray analysis, scanning electron microscope, and thermogravimetric analysis were also used to characterize the produced biosorbent fungus. A batch technique was conducted to study the biosorption behavior of A. terreus toward Sr(II) and Y(III) ions. The distribution behavior of Sr(II) and Y(III) as a function of pH in the range 1–5 has been studied. Y(III) from Sr(II) can be separated at all the pH ranges examined. The biosorption process was performed at different adsorption parameters such as pH, biosorbent weight, agitation time, and initial adsorbate concentration to get maximum removal of Sr(II) and Y(III) ions. After 30 min, both ions have reached equilibrium. The uptake percentage of Sr(II) and Y(III) increased with increasing pH value with a removal percentage of 9.5 and 99.5%, respectively, and was achieved at pH 5.00. The thermodynamic analyses revealed that the biosorption process was endothermic, spontaneous, and regulated mainly by physical biosorption. Nitric acid is the best desorbing agent among different eluting agents used. 0.1 M from HNO₃ is sufficient to eliminate about 76.65 and 81.10% of Sr(II) and Y(III), respectively, where A. terreus may be regenerated for reuse efficiently. The separation of Y(III) from a solution including Sr(II) has been established by a column technique with a breakthrough capacity of 1.43 mg/g for Sr(II) and 63.00 mg/g for Y(III). The results indicate that the A. terreus biosorbent is highly efficient in separating Y(III) from Sr(II).