Biomass base membrane with phenol hydroxy-amino group for ultraselective adsorption of radioactive Co(II) in trace concentration

60 Co is widely utilized in industries and can emit high gamma energy. The removal radioactive   60 Co in trace concentration from wastewater is important for human health and environment protection. Here, we designed a biomass base   membrane with phenol hydroxyl-amino group for ultraselective enriching of trace concentration of Co 2+   from radioactive wastewater. This novel membrane adsorbent (PAM–PBWT), that is, the immobilized black wattle tannin (BWT) modified with polyethylenimine onto the polyamide microporous membrane (PAM), utilizes   phenolic hydroxyl and   amino group can form a coordinated coordination with Co 2+ , exhibiting high selectivity adsorption to Co 2+   even in the presence of other ions. A maximal adsorption capacity (0.39 mmol g −1 ) was reached at pH 8.0 and 323 K. The continuous adsorption experiments showed that the PAM–PBWT can enrich the trace concentration of Co 2+   (60 ng L −1 ) from radioactive wastewater in the presence of other coexisting ions (K + , Ca 2+ , Na + , Mg 2+ , Zn 2+ , Mn 2+ , Fe 3+ ). Moreover, the processing capacity of three-layer PAM–PBWT for simulated   60 Co-containing wastewater can reach 80 L m −2 . Notably, PAM–PBWT can be easily regenerated with 0.1 M HNO 3   without the loss of adsorption capacity. Our work might introduce a new strategy for realizing selectivity adsorption of trace concentration irradiation contaminants from   radioactive wastewater.