The new adsorbent was prepared by mixing cellulose with dicyclohexyl-18- crown-6 via microwave irradiation method and it was used to remove lead ions from aqueous solution. In contrast to the traditional way (in which grafted polymers are produced by using chemical-free radical producers), this method is rapid, reproducible, and gives a high quality product. Different physicochemical techniques such as FTIR, SEM, and XRD and TGA were used for the characterization of the produced adsorbent. Based on the ANOVA statistical value, the adsorption of Pb²⁺ ion onto grafted cellulose has been found to be significant, with very low probability (p) values (<0.001). The pH and initial concentration were observed to be the most significant factors that affected the Pb²⁺ ion removal from the analysis of variance. Pseudo-second-order and Langmuir equations were applied to the adsorption of Pb²⁺ ion and under the optimized conditions, the maximum absorption capacity in modified cellulose of Pb²⁺ was 58.3 mg/g. Various factors which affect metal ion adsorption, including temperature, power of hydrogen, shaking time, adsorbent quantity, and metal ions concentration were studied. More importantly, the adsorbent could be reused by using 0.1 M nitric acid. GRAPHICAL ABSTRACT

The aim of this study was to prepare novel supramolecular hybrid nanoparticles (HNPs) that can selectively separate and recover scandium metal ions, Sc(III), from an aqueous phase based on molecular recognition technology (MRT). Moreover, this approach is fully compatible with green chemistry principles. In this work, natural amorphous silica (SiO₂) nanoparticles were prepared by a precipitation method from Iraqi rice husk (RH) followed by surface modification with 3-amino-propyl triethoxysilane (APTES) as coupling agent and Kryptofix 2.2.2 (K2.2.2) as polycyclic ligand. To evaluate the potential of the hybrid nanoparticles, the prepared HNPs were used for the solid–liquid extraction of scandium, Sc(III), ions from model solutions due to the fact that K2.2.2 are polycyclic molecules. These polycyclic molecules are able to encapsulate cations according to the corresponding cavity size with the ionic radius of metal by providing a higher protection due their cage-like structures. Moreover, the authors set the objectives to design a high-technology process using these HNPs and to develop a Sc recovery method from the aqueous model solution prior to employing it in industrial applications, e.g., for Sc recovery from red mud leachate. The concentrations of Sc model solutions were investigated using the UV-Vis spectrophotometer technique. Different characterization techniques were used including scanning electron microscope (SEM), atomic force microscopy (AFM), Brunauer–Emmett–Teller (BET), X-ray diffraction (XRD), X-ray fluorescence (XRF), and Fourier transform infrared (FTIR). The extraction efficiency of Sc varied from 81.3% to 96.7%. Moreover, the complexed Sc ions were efficiently recovered by HCl with 0.1 mol/L concentration. The stripping ratios of Sc obtained ranged from 93.1% to 97.8%.

In this research, the traditional version of the phase inversion method was used to fabricate a flat sheet of a blended membrane. The method was involved using a polymer that blends polyether sulfone (PES) varied proportions (0,3,4 and 5 wt.%), and polyphenyl sulfone (PPSU) was 20wt%. It was found that with the addition of PES, the membrane properties increased, the best properties were with 4%wt. The ratio was chosen PES 4wt% to study the effect of time, temperature, and pressure on the rejection of heavy and radioactive elements. The increase in the porosity was with the addition of 4% PES. The rejection of heavy and radioactive elements for thUF membrane increases with increasing of the operating pressure and time. While by increasing the temperature, the rejection of heavy and radioactive elements for thUF membrane decreased. The rejection of K, Th, and Pb are higher than other elements, the order of the rejection is K˃Th˃Pb˃U˃Cd˃Zn˃Cu>Ni.

Three mesoporous silica with different functional group were prepared by one-step synthesis based on the simultaneous hydrolysis and condensation of sodium silicate with organo - silane in the presence of template surfactant polydimethylsiloxane - polyethyleneoxide (PDMS - PEO). The prepared materials were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), atomic force microscopy (AFM) and nitrogen adsorption/desorption experiments. The results indicate that the preparation of methyl and phenyl functionalized silica were successful and the mass of methyl and phenyl groups bonded to the silica structure are 15, 38 mmol per gram silica. The average diameter of the silica particles are 103.51, 167.25 , and 86.41 nm while the average pore diameter are 6.7, 16.4, and 2.7 nm for unfunctionalized, methyl, and phenyl functionalized silica respectively.

Trails were performed for the recovery of group trace elements, including the radioactive elements, partitioned with the phosphogypsum (PG) stockpiled in around 12 million tones at Al-Qaim in Akashat Phosphate Fertilizer State Company. The method utilizes the concept of the preferential solubility of phosphogypsum in water over other metal sulfates, phosphates, silicates and others may exist with phosphogypsum. At the limit of PG solubility a colloid is formed due to the in-soluble and partially soluble constituents including various trace elements which are settled down after 20-45 minutes. Shorter time settlement was achieved in the presence of polyacrylamide as coagulant. The dissolution process of PG in water has been studied using conductivity technique. De-ionized water show better solvation power for PG and better separation properties compared with potable water. The efficiency of separation and settling of the suspended colloidal particles was studied as function of pH, temperature, time and the presence of flocculent polyvinyl acrylamide. The abundance of the trace elements in PG was determined using x-ray fluorescence, atomic absorption and induced plasma emission spectroscopy. Radioactivity accumulated by the 238U and 232Th decay schemes were measured for 226Ra-228Ra and 222Rn gamma and Alfa spectrometry. Due to their low solubility, it is anticipated that appreciable percentage recovery for the alkaline earth elements Sr, Ba and 226Ra,228Ra, while partial recovery is expected for the other elements i.e., Cu, Zn, Pb, Fe, R.E, uranium and thorium. Phospgogypsum was finally purified with acceptable properties for industrial and agricultural applications.