Wenzhong Zhang

Bio: Wenzhong Zhang is an academic researcher from University of Helsinki. The author has contributed to research in topics: Xanthan gum & Ion exchange. The author has an hindex of 10, co-authored 34 publications receiving 389 citations. Previous affiliations of Wenzhong Zhang include Shanghai Jiao Tong University.

Efficient and Selective Recovery of Trace Scandium by Inorganic Titanium Phosphate Ion-Exchangers from Leachates of Waste Bauxite Residue

Abstract: Bauxite residue (BR) is an inevitable industrial waste generated through the classic Bayer extraction of alumina from bauxite minerals. It contains relatively significant amount of valuable rare earth elements, including scandium, and therefore, we explored the suitability of trace scandium recovery from BR acid leachate by titanium phosphate (TiP) ion exchangers. Three kinds of TiP materials (amorphous TiP, α-TiP, and γ-TiP) were synthesized through fluorine-free precursors and characterized by chemical analysis, X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared (FTIR), ultraviolet/visible (UV/vis) diffuse reflectance spectrometry, 31P magic angle spinning (MAS) nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), and potentiometric titration. The Sc3+ exchange capacities were determined as 1.74, 0.55, and 0.22 mequiv g–1 for amorphous, α-, and γ-TiP, respectively. Competition of major elements (Fe, Al, Ca) in BR leachate with Sc upta...

Magnetic adsorbents for the treatment of water/wastewater—A review

Abstract: In recent years, adsorption has displayed promising and effective results as a treatment technology for water and wastewater by industries. In the process, a number of adsorbents have been synthesized and applied for the treatment of pollutants such as metals, dyes, pharmaceutical products in solutions. However, for adsorption to be unconditionally adopted by industries, a few obstacles such as high capital cost, difficult segregation of adsorbent from solution, and complex synthesis processes need to be addressed. The removal of suspend adsorbents in wastewater from a continuous flow system is a challenge which if addressed properly would enable us to recover the spent adsorbent efficiently. The spent adsorbents can then be regenerated and used again by the industries thereby leading to reduced capital investment. Therefore, studies have been carried out aiming at the incorporation of magnetism in such adsorbents to aid their removal from wastewater. This review aims to comprehensively list and discuss adsorbents which exhibit magnetic properties and their adsorption behaviour under diverse conditions. The literature survey presented in this paper renders evidence to the good potential of magnetic adsorbents to remove various pollutants from wastewater. However, the practical utility of such adsorbents needs to be explored before they can be commercially applied.

Rare earth elements: Mendeleev's bane, modern marvels.

Abstract: The rare earths (REs) are a family of 17 elements that exhibit pronounced chemical similarities as a group, while individually expressing distinctive and varied electronic properties. These atomistic electronic properties are extraordinarily useful and motivate the application of REs in many technologies and devices. From their discovery to the present day, a major challenge faced by chemists has been the separation of RE elements, which has evolved from tedious crystallization to highly engineered solvent extraction schemes. The increasing incorporation and dependence of REs in technology have raised concerns about their sustainability and motivated recent studies for improved separations to achieve a circular RE economy.