Enhanced biosorption of europium and cesium ions from aqueous solution onto phalaris seed peel as environmental friendly biosorbent: Equilibrium and kinetic studies.

The sorption characteristics of Eu(III) and Cs(I) removal from aqueous solution were estimated using phalaris seeds peel powder (PSP), a novel biosorbent that is economical and low-cost. Batch equilibrium experiments were carried out to investigate the effects of contact time, initial metal concentration, media pH, and interference ions on the sorption of Eu(III) and Cs(I). PSP powder characterization via Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TG/DSC), X-ray diffraction (XRD), and scanning electron microscope (SEM) revealed some changes before and after the adsorption process. This indicates that most likely, adsorption has taken place between the metal ions and the adsorbents in the aqueous solution. The obtained results show that Eu(III) has a higher selectivity than Cs(I). The kinetics of the adsorption of Eu3+ and Cs+ have been discussed. It was shown that the second-order kinetic equation could describe the sorption and was found to be the best fitted model (R2 = 0.999) for two metal ions. Langmuir and, Dubinin-Radushkevich (D-R), isotherm were found to best fit (R2 = 0.99) in this study. The separation factor (RL) value of less than 1.0 indicates that the biosorption of both metal ions on PSP is favorable. Thermodynamic parameters, such as ΔHo, ΔGo, and ΔSo, have been calculated by using the thermodynamic equilibrium coefficient obtained at different temperatures. The obtained results indicated the endothermic nature of the sorption process for both metal ions onto PSP. PSP powder has the potential to be used as a low-cost biosorbent for the removal of Eu(III) and Cs(I) from wastewater, according to the findings.

Green approach for radium isotopes removal from TENORM waste using humic substances as environmental friendly.

Humic substances (HS) of the dark-colored are found in all soils and sediments as natural organic matter (NOM). HS has high affinity interacted with various organic and inorganic pollutants. Therefore, the HS were isolated from agriculture soil and their potential to remove radium species (226+228Ra) from TENORM scale waste produced from oil production was investigated. Different factors affecting on the efficient removal of radium species by natural humic and natural fulvic acids (NHA and NFA) were investigated by batch technique. These parameters include contact time, concentration of HS, pH, successive leaching as well as the influence of mixed ratio of NHA and NFA. The experimental results indicate that, higher pH and concentration of HS is capable of leaching out 95.2% and 90.2% from TENORM scale waste by the NHA and NFA, respectively, through 3 successive leaching process. Admixture of NHA and NFA solution has been removed 93% of 226+228Ra from scale waste. It is a novel approach for efficient removal Ra isotopes level from TENORM scale waste by economic and eco-friendly that could be help for design a semi-pilot plant for scale-up test in forthcoming study.