A hydrophilic hyper-cross-linked polymer resin NDA-150 was developed to remove 1-naphthol from the contaminated waters. The sorption performance of 1-naphthol on NDA-150 was explored and compared with that on the commercial hydrophobic resin XAD-4. The sorption rates of 1-naphthol onto both of the two resins obey the pseudo-second-order kinetics, and are limited by the successive steps of film diffusion and intraparticle diffusion. The greater sorption rate on XAD-4 than NDA-150 is probably due to the larger average pore diameter of XAD-4. All the adsorption isotherms can be represented by Langmuir equation. The larger capacity and stronger affinity ofNDA-150 than XAD-4 probably result fromthe abundant microporous structure and polar groups of NDA-150. In aqueous phase hydrophobic XAD-4 adsorbs 1-naphthol driven principally by enthalpy change, while the adsorption onto hydrophilic NDA-150 driven mainly by entropy change. The breakthrough and the total sorption capacity of NDA-150 to 1-naphthol were obtained to be 1.10 and 1.58mmolmL−1 resin at 293K, respectively. Nearly 100% regeneration efficiency for the resin was achieved by ethanol at 313K.

The current study reports a potential process to selectively separate and preconcentrate tartaric acid from its simulated industrial effluent. It was achieved by sorption onto a tailored polymeric ligand exchanger. The polymeric ligand exchanger is essentially a copper(II)-bound specialty chelating polymer (denoted D-Cu). Effect of solution pH and competing sulfate on tartaric acid sorption onto D-Cu was also included in the study. Compared to a weakly basic anion exchanger D-301, D-Cu exhibits more favorable sorption of tartaric acid from aqueous media coexisting with Na2SO4 at a high level. The exhausted D-Cu was amenable to an entire regeneration by the diluted NaCl solution. Results of column sorption tests further demonstrated the feasibility of D-Cu for selective separation and preconcentration of tartaric acid from the simulated wastewater for its further recovery.

The present study reported synthesis of a new inorganic exchanger, i.e., zirconium hydrogen monothiophosphate [Zr(HPO3S)2, denoted ZrPS] and its selective sorption toward Pb(II), Cd(II) and Zn(II) ions. ZrPS sorption toward all the three metals is dependent upon solution pH due to the ion-exchange nature. As compared to another inorganic exchanger zirconium phosphate [Zr(HPO4)2, denoted ZrP], ZrPS exhibits highly selective sorption toward these toxic metals from the background of calcium ions at great levels. Such sorption preference is mainly attributed to the presence of-SH group in ZrPS, as further demonstrated by FT-IR analysis and XPS study. Moreover, ZrPS particles preloaded with heavy metals could be efficiently regenerated with 6M HCl for multiple use without any noticeable capacity loss. All the experimental results indicated that ZrPS is a promising sorbent for enhanced heavy metals removal from contaminated water.

Sorption of aromatic sulfonates onto two aminated polystyrene sorbents with different pore structures (M-101 and D-301) was investigated for optimization of their potential application in chemical wastewater treatment. Sodium benzenesulfonate (BS), sodium 2-naphthalene sulfonate (2-NS) and disodium 2,6-naphthalene disulfonate (2,6-NDS) were selected as reference solutes and sodium sulfate was as a competitive inorganic salt. Sorption selectivity of both sorbents is dependent upon the concentration levels of aromatic sulfonates in solution coexisting with sodium sulfate at a high level. However, both sorbents exhibit different characters. D-301 presents more favorable sorption for the solutes at relatively high levels (e.g., higher than 5 mM for BS, 0.7mM for 2-NS and 0.05mM for 2,6-NS), while M-101 removes aromatic sulfonates more completely when the solute concentration kept at relatively low levels. Based on the experimental results, we proposed an integral process of sorption onto D-301 followed by secondary-sorption onto M-101 to remove aromatic sulfonates from industrial wastewater completely and economically. Furthermore, the satisfactory performance revealed from large-scale application further demonstrated the feasibility of extending this process to dispose of other associated chemical wastewaters.

In the present study a novel technique was proposed to prepare a polymer-supported hydrated ferric oxide (D201-HFO) based on Donnan membrane effect by using a strongly basic anion exchanger D201 as the host material and FeCl3-HCl-NaCl solution as the reaction environment. D201-HFO was found to exhibit higher capacity for arsenic removal than a commercial sorbent Purolite ArsenX. Furthermore, it presents favorable adsorption selectivity for arsenic removal from aqueous solution, as well as satisfactory kinetics. Fixed-bed column experiments showed that arsenic sorption on D201-HFO could result in concentration of this toxic metalloid element below 10 μg/L, which was the new maximum concentration limit set recently by the European Commission and imposed by the US EPA and China. Also, the spent D201-HFO is amenable to efficient regeneration by NaOH-NaCl solution.