Study on the mechanism of copper–ammonia complex decomposition in struvite formation process and enhanced ammonia and copper removal

Hydrothermal Treatment of Arsenic Sulfide Residues from Arsenic-Bearing Acid Wastewater

“…Moreover, wasted electrolyte with a high concentration of arsenic is produced abundantly in copper and lead-zinc electrolyte processes [ 8 , 9 ]. At present, there are many treatment methods for arsenic-containing wastewater, such as precipitation, adsorption, and biological methods [ 10 , 11 , 12 , 13 , 14 ]. However, such wastewater is usually treated with sodium sulfide, sodium hydrosulfide or hydrogen sulfide to precipitate arsenic, and the deposition of arsenic sulfide residue (ASR) is then engendered [ 15 , 16 ].…”

Novel Green Method for the Synthesis of Monoacetin over Bifunctional Cu–Cr Phosphates under the CO2 Atmosphere

“…XPS spectra of O 1s, Cu 2p, Cr 2p, and P 2p core levels of Cu–Cr phosphates and monometallic phosphates were obtained and are shown in Figure . The Cu 2p transition mainly exhibits XPS spectra corresponding to Cu 2p 3/2 at binding energies of 930–936 eV. , As shown in Figure A, the low-energy peaks of Cu 2p 3/2 at 934.4–934.7 eV are generally attributed to Cu 2+ in octahedral sites, while the high-energy peaks at 935.3–935.9 eV correlate with Cu 2+ in tetrahedral sites . The peaks at 931.9–932.6 eV can be attributed to the Cu + state. , Figure A shows that only eight-coordinated Cu 2+ can be observed on the CuP catalyst, while there are both eight-coordinated Cu 2+ and four-coordinated Cu 2+ on the bimetallic Cu–Cr catalysts, which suggests that the introduction of Cr species affects the coordination numbers of Cu species.…”

“…The Cu 2p transition mainly exhibits XPS spectra corresponding to Cu 2p 3/2 at binding energies of 930−936 eV. 28,29 As shown in Figure 4A, the low-energy peaks of Cu 2p 3/2 at 934.4−934.7 eV are generally attributed to Cu 2+ in octahedral sites, while the highenergy peaks at 935.3−935.9 eV correlate with Cu 2+ in tetrahedral sites. 30 The peaks at 931.9−932.6 eV can be attributed to the Cu + state.…”

Removal of ammonia from aqueous solutions by ligand exchange onto a Cu(ii)-loaded chelating resin: kinetics, equilibrium and thermodynamics

“…51,52 Many studies have proved the importance of solution pH as one of the critical control parameters in the adsorption process, especially in ammonia adsorption. [53][54][55][56] The solution pH had an important inuence on the equilibrium ammonia concentration and the ammonia removal efficiency. The effect of solution pH on the ammonia adsorption on AMAR were shown in Fig.…”