Persimmon tannin-based new sorption material for resource recycling and recovery of precious metals

Tannin-based biosorbents for environmental applications – A review

“…One of the modifications reported in literature is then the amine-functionalization of tannin-resins [40]. Fig.…”

Hydrometallurgical Recovery of Precious Metals and Removal of Hazardous Metals Using Persimmon Tannin and Persimmon Wastes

“…Although, as mentioned earlier, CPT and PP gels were found to exhibit extraordinary high selectivity for gold(III), we further attempted to enhance the affinity also for platinum(IV) and palladium [35][36][37][38][39][40]. It is easy to chemically modify persimmon tannin extract and persimmon waste including persimmon peel by immobilizing a variety of functional groups which exhibit special affinities for some metal ions onto their surface similar to other biomass wastes [41,42].…”

“…In our research works, persimmon waste was chemically modified by immobilizing functional group of dimethylamine (DMA) to prepare the adsorption gel functioning as a typical weak base type of anion exchange material and investigated its adsorption behavior for some precious and base metals from hydrochloric acid solutions [35,36]. Further, a variety of adsorption gels were prepared from persimmon tannin extract powder by the chemical modifications immobilizing other functional groups such as tertiary amine where the immobilized tertiary amine groups function as quaternary ammonium compounds (QA) [37], a typical strong base, as well as tetraethylenepentamine (TEPA) [38], glycidyltrimethyl ammonium (GTA), aminoguanidine (AG) [40], and bisthiourea (BTU) [41]. These are abbreviated as DMA-PW gel and QAPT, BTU-PT, AG-PT, TEPA-PT and GTA-PT gels, respectively, hereafter.…”

Selective Adsorption of AuIII from Aqueous Solution Using 2,5‑Dimercapto‑1,3,4‑thiadiazole Modified Persimmon Tannin

“…3 Over the past decade, persimmon peels and residues, whose main composition is persimmon tannin (PT), 4 have attracted a great deal of attention among waste agricultural byproducts because of the plentiful resources and moderate conditions for chemical modification. 4 Relevant work has mainly focused on grafting amine-and thiourea (TU)-based modifiers on the PT matrix [5][6][7] to improve both adsorption capacity and selectivity for precious metals. It is imperative to develop new modifiers to provide more choices for modifying biosorbents for various purposes.…”