Fine Fibrous Amidoxime Adsorbent Synthesized by Grafting and Uranium Adsorption–Elution Cyclic Test with Seawater

Abstract

Fibrous amidoxime adsorbents were prepared by radiation-induced co-grafting of acrylonitrile (AN) and methacrylic acid (MAA) and subsequent amidoximation. Adsorption of uranium in seawater was evaluated by pumping seawater into the adsorbent column. The best monomer ratio of AN and MAA was 7 : 3 for continual usage of uranium adsorption. Though hydrochloric acid is an effective eluting agent for the metals adsorbed on the adsorbent, amidoxime groups were simultaneously damaged after five cycles of adsorption -desorption. This deterioration was reduced by an alkaline treatment of the adsorbents after each elution. Furthermore, various organic acids were examined as elution agents. It was found that the 80% of adsorption activity was still maintained after five cycles of adsorption -desorption when tartaric acid was used for eluting agent.

Recovery of uranyl from aqueous solutions using amidoximated polyacrylonitrile/exfoliated Na-montmorillonite composite

“…Five regents were chosen based on the literature related to uranyl elution [4,13], and the result is shown in Fig. 8.…”

“…Among these methods, adsorption by inorganic clay minerals [9], natural organic matters including organism [12], or artificial synthetic materials [10,13] has been proved to be a promising technology and has been studied extensively, because it is simple to operate, easy to modify and friendly to the environment. Generally, natural materials have the merits of low cost and wide adaptability; however, poor selectivity and low adsorption capacity have severely restricted its real application.…”

Effect of hydrophilic and hydrophobic monomers grafting on microbial poly(3-hydroxybutyrate)

“…Another application of radiation graft polymerization is developmental research into the separation and refinement of proteins to separate functional materials (Miyoshi et al, 2005). For environmental reasons, materials are being developed as graft adsorbents to remove toxic metals from industrial waste waters and the harmful constituents of the atmosphere (Seko et al, , 2004Shiraishi et al, 2003). Research into the recovery of useful rare metals from seawater and hot springs is currently being undertaken (Seko et al, 2005).…”

Extraction of uranium from seawater : design and testing of a symbiotic system

“…After this elution, the adsorbent is washed in a solution of KOH to regenerate the active functional groups for reuse (T. Suzuki and Oguma; Seko et al, 2004). In this method, however, this acidic elution process leads to significant degradation of the adsorbent with each reuse due to the deterioration of the sorbent caused by acid hydrolysis.…”