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To achieve a fast adsorption rate and a high adsorption capacity in the selective adsorption of Cr(vi) from wastewater, a novel Cr(vi) ion imprinted polymer (Cr(vi)-IIP) was synthesized by bulk polymerization with 4-vinyl pyridine (4-VP) as a functional monomer.

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An extractive desulfurization method was developed with 1,8-diazabicyclo[5.4.0]­undec-7-ene Im ([DBU]­[Im]) and 1,1,3,3-tetramethylguanidine Im ([TMG]­[Im]) as extractants. Effects of extraction time, ionic liquid (IL):model fuel mass ratio, ILs species, initial concentration of sulfur, and temperature on removal efficiency of sulfur compound were investigated. The removal efficiencies of dibenzothiophene, 4,6-dimethyldibenzothiophene, and benzothiophene with [DBU]­[Im]/[TMG]­[Im] as extractants were 79.2%/69.4%, 68.4%/57.7%, and 61.2%/54.4%, respectively. The interaction between [DBU]­[Im] and sulfur compounds could be enhanced by extra heterocyclic aromatic ring in DBU cation and imidazolium ring in Im anion. Both extraction processes with these two ILs as extractants were fast (extraction equilibrium was reached within 10 min). The reusability of prepared ILs was studied, and the multistage cross-current extraction experiments were performed. Moreover, the characterization methods of nuclear magnetic resonance hydrogen spectrum and Fourier transform infrared spectroscopy and the calculation methods of optimized geometry and interaction energy between sulfur compounds and extractants by Gaussian 09 software were used for the study of extraction mechanism. Furthermore, the oxidative–extractive method was used for deep desulfurization of model fuel and real diesel fuel.

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Extraction equilibria of copper(II) from aqueous acetate buffer solutions with di-(2-ethylhexyl)phosphoric acid (D2EHPA) dissolved in kerosene and the stripping equilibria were investigated. Results showed that acetate ions can greatly improve the copper(II) extraction efficiency. The distribution coefficients were significantly dependent on the concentration of acetate ions and the pH value in the aqueous phase because of various mechanisms of extraction and complex formation in the organic phase. With the initial pH value of 4.44 and the acetate ion concentration of 0.18 mol·L-1, the maximum distribution coefficient was observed. In addition, mechanisms of copper(II) extraction in acetate buffer media were established. In the stripping process, the ability to back-extract copper(II) from the organic phase is HCl > H2SO4 > H3PO4.

A novel magnetic copper imprinted chitosan/ graphene oxide composite biomaterial was prepared by the combination of ion imprinting and inverse suspension crosslinking for selective adsorption of Cu(II) from aqueous solution. High adsorption capacity for copper was obtained with a low level cross-linking and the addition of graphene oxide and triglycine in the preparing process. The prepared ion-imprinted magnetic chitosan polymer microsphere (CS-IIP) was characterized by FT-IR, TGA, SEM, and EDX. The results indicated that the CS-IIP was prepared successfully and showed good thermostability. Effects of different experimental conditions like pH value, contact time, and Cu(II) concentration on the adsorption capacity were investigated. The adsorption process follows the Freundlich isotherm equation and the pseudo-second-order kinetic model. The highest adsorption capacity of CS-IIP was 132 mg g −1 . The calculation of selective factors and relative selectivity factors of CS-IIP for Cu 2+ /M 2+ (M = Zn, Ni, Co, or Cd) was studied. Moreover, the reusability and stability of CS-IIP were investigated too.

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