Citric Acid Enhanced Copper Removal by a Novel Multi-amines Decorated Resin

Abstract

Cu removal by a novel multi-amines decorated resin (PAMD) from wastewater in the absence or presence of citric acid (CA) was examined. Adsorption capacity of Cu onto PAMD markedly increased by 186% to 5.07 mmol/g in the presence of CA, up to 7 times of that onto four commercial resins under the same conditions. Preloaded and kinetic studies demonstrated adsorption of [Cu-CA] complex instead of CA site-bridging and variations of adsorbate species were qualitatively illustrated. The interaction configuration was further studied with ESI-MS, FTIR, XPS and XANES characterizations. The large enhancement of Cu adsorption in Cu-CA bi-solutes systems was attributed to mechanism change from single-site to dual-sites interaction in which cationic or neutral Cu species (Cu2+ and CuHL0) coordinated with neutral amine sites and anionic complex species (CuL− and Cu2L22−) directly interacted with protonated amine sites via electrostatic attraction, and the ratio of the two interactions was approximately 0.5 for the equimolar bi-solutes system. Moreover, commonly coexisting ions in wastewaters had no obvious effect on the superior performance of PAMD. Also, Cu and CA could be recovered completely with HCl. Therefore, PAMD has a great potential to efficiently remove heavy metal ions from wastewaters in the presence of organic acids.

Solvent-assisted synthesis of potassium copper hexacyanoferrate embedded 3D-interconnected porous hydrogel for highly selective and rapid cesium ion removal

“…For the HPC, the peak appearance at 1597 and 1416 cm -1 is due to COO -antisymmetric and symmetric stretching, respectively, suggesting the binding of potassium with COO - [41,42]. The functional group of COO -K + could be originated from the carboxylate of citric acid coordinated to Cu after the formation of KCuHCF, and the presence of Cu-CA complex in the CPC is confirmed by the shoulder peak at 1621 cm -1 [43]. In addition, the distinct bands at 2089, 586, and 478 cm -1 in the HPC clearly demonstrate the existence of KCuHCF, where the shift of C N stretching compared to that of the bulk KCuHCF is related to the internal strain in the film matrix [44].…”

Immobilizing Laccase on Different Species Wood Biochar to Remove the Chlorinated Biphenyl in Wastewater

“…The biochar is chemically stable and has a highly porous structure 15 . According to previous research, biochar is very suitable as adsorbents in environment management over adsorption processes 16 , 17 ; and has been used for the removal of pollutants from soil or water for decades. However, the studies about immobilizing laccase on biochar have been seldom reported.…”

Carbon Fibers Obtained from Flax and Their Adsorption Performance in the Removal of Cu(II) and Co(II) from Aqueous Solutions

“…The ion exchange resins, which are widely‐used for the removal of heavy metal ions from water. Their adsorption capacity of Cu II is reported to be between 100 and 200 mg g ‐1 ,‐ whilst for the case of Co II the values range between 40 and 90 mg g ‐1 ,. Various surface oxidized carbon materials are also known as adsorbents of copper ions.…”