Selective Capacitive Recovery of Rare-Earth Ions from Wastewater over Phosphorus-Modified TiO Cathodes via an Electro-Adsorption Process.

Large amounts of wastewater containing low-concentration (<10 ppm) rare-earth ions (REIs) are discharged annually in China's rare-earth mining and processing industry, resulting in severe environmental pollution and economic losses. Hence, achieving efficient selective recovery of low-concentration REIs from REIs-containing wastewater is essential for environmental protection and resource recovery. In this study, a pseudocapacitance system was designed for highly efficient capacitive selective recovery of REIs from wastewater using the titanium dioxide/P/C (TiO/P/C) composite electrode, which exhibited over 99% recovery efficiency for REIs, such as Eu, Dy, Tb, and Lu in mixed solution.

One-step removal of high-concentration arsenic from wastewater to form Johnbaumite using arsenic-bearing gypsum.

High-level arsenic-containing wastewater (HAW) causes serious environmental pollution. Chemical precipitation is the most widely used technology for treating HAW. However, chemical precipitation generates huge amounts of hazardous solid wastes, which leads to secondary pollution.