Engineering application of recyclable guanidine hydrochloride-hexamethylenediamine phytic acid polydopamine supported melamine sponge for the efficient elimination of europium and chromium from industrial wastewater

Synthesis and application of recyclable adsorbents with many available active sites and high adsorption capacity for accomplishing quick kinetics and high removal proportion have been become significant challenges in the purified fields of radionuclides and heavy metals contamination. Herein, regenerative ploy (guanidine hydrochloride hexamethylenediamine-phytic acid)-polydopamine decorated melamine sponges (PGH/HDPA/PDA/MS) were successfully synthesized using melted polymerization approach to remove Eu(III) and Cr(VI). The sorption behaviors and interactive mechanisms of Eu(III) and Cr(VI) by PGH/HDPA/PDA/MS were obtained via macroscopical experiments under various water chemistry factors conditions. The findings of our experimental studies demonstrated that specific sorption performances of Eu(III) and Cr(VI) onto PGH/HDPA/PDA/MS hybrids could achieve equilibrium within 3 h. The maximum adsorption capacities were respectively 2.43 × 10−3 mol/g and 6.75 × 10−3 mol/g for Eu(III) and Cr(VI), which were higher than large numbers of adsorbents reported among the anterior literatures. The interactive mechanism between PGH/HDPA/PDA/MS hybrids and Eu(III) and Cr(VI) was displayed through electrostatic attraction, cation exchange, surface complexation. Besides, the partially trivalent Cr(III) was also adhered to PGH/HDPA/PDA/MS surfaces through reductive reaction. According to our studies, the PGH/HDPA/PDA/MS hybrids are regarded as feasible adsorbents for highly effective purification of trivalent lanthanides and heavy metal ions pollutions from industrial wastewater.