High-capacity, nanofiber-based ion-exchange membranes for the selective recovery of heavy metals from impaired waters

Abstract

This contribution describes the development, performance evaluation and modeling of polyelectrolyte-modified nanofiber membranes for heavy metal recovery from impaired water. High-capacity membranes were prepared by grafting poly(acrylic acid) (PAA) and poly(itaconic acid) (PIA) to cellulose nanofiber mats. The success of polymer grafting was confirmed by attenuated total reflectance Fourier-transform infrared spectroscopy. Membrane permeabilities for a series of polymer grafted nanofiber membranes were measured by direct-flow filtration. Single-component ion-exchange isotherms were measured at constant pH for cadmium, nickel, and calcium ions. The higher metal-polymer complex stability of Cd-PIA over Cd-PAA was found to be an impact factor for achieving high Cd binding capacities. Single-component ionexchange isotherms were well described by the Langmuir model, with maximum capacities of PIA-modified membranes that exceeded 220 mg Cd/g, comparable to traditional resin-based ionexchange media. Moreover, membranes were selective for Cd over Ni and Ca because of different hydration energies and ionization potentials. Competitive ion-exchange measurements were made using environmentally relevant concentrations of these ions to determine the selectivity of the membranes for cadmium ion. Experimental isotherms for Cd-Ca and Cd-Ni were compared to model predictions from the competitive Langmuir model with Langmuir

Heavy metal adsorption ability of a new composite material based on starch strengthened with chemically modified cellulose

“…There are many well-known processes regarding the treatments of contaminated wastewaters like membrane filtration, 1-4 chemical precipitation, [5][6][7] electrocoagulation, [8][9][10][11][12] reverse osmosis, [13][14][15] adsorbtion, [16][17][18][19][20][21][22][23][24] ion exchange, [25][26][27] etc., all of them with their inherent advantages and disadvantages. At the same time, most of them are not suitable for developing countries due to huge cost investment in terms of use of chemicals, infrastructure, and operation.…”

Synthesis of Zeolite A from Metakaolin and Its Application in the Adsorption of Cationic Dyes

“…Removing these contaminants from industrial wastewaters before effluents are discharged into the aquatic environment is obviously necessary. Various methods, such as biological processes [2], ultrasound [3], active carbon adsorption [4], ozone treatment [5], coagulation/flocculation [6], and ion exchange resin [7,8] and ion exchange membrane adsorption methods [9], have been investigated in an attempt to remediate dye-containing wastewaters. However, these methods are not always efficient and economical enough, so new alternative technologies that rely on low-cost materials are mandatory to solve the issues related to dye-containing wastewaters [10].…”

Removal of cadmium(II) cations from an aqueous solution with aminothiourea chitosan strengthened magnetic biochar

“…5 Until now, many technologies have been adopted for Cd(II) decontamination from wastewater discharge. [6][7][8][9][10][11][12] Among these technologies, adsorption is the most used method because of its flexibility in design and operation, efficiency, and economy in practice. 13 Consequently, the use of an economical adsorbent is a crucial issue for the development of the adsorption method.…”