Evaluation of the excellent adsorption performance for lead ions of (sodium alginate/ waste para-aramid)-based polymer composite functionalized by ethylene diamine tetra (methylene phosphonic acid)

With the rapid development of industry, efficient removal of heavy metal ions such as lead ions in wastewater has been attracted much attention in the fields of water treatment and environmental remediation. Herein, a novel polymer composite adsorbent material EDTMPA-P/A has been successfully prepared through the combination of sodium alginate and waste para aramid using low-temperature esterification method, and the subsequent modification of EDTMPA (ethylene diamine tetra (methylene phosphonic acid)). The static saturation adsorption experiment verified that EDTMPA-P/A had significant adsorption performance for lead ions, hence, EDTMPA-P/A has been employed to adsorb lead ions from aqueous solutions, and the relevant adsorption behaviors of the polymer composite adsorbent for lead ions have been investigated in detail. The adsorption isotherm of EDTMPA-P/A was consistent with the Langmuir isotherm model, and the corresponding kinetics data were well fitted by the pseudo-second-order kinetic model. The maximum adsorption capacity of EDTMPA-P/A obtained by Langmuir isotherm for lead ions was 315.46 mg/g at 35 °C, which was much higher than other adsorbents reported in the literatures. Moreover, the adsorption thermodynamic parameters ΔG, ΔH and ΔS of EDTMPA-P/A for lead ions were 1.92 kJ mol⁻¹ (35 °C), 14.69 kJ mol⁻¹, and 41.74 J K⁻¹ mol⁻¹, respectively. The research results indicated that EDTMPA-P/A could be evaluated as a novel efficient adsorbent with high efficiency in wastewater treatment and removal of lead ions, and it is great application prospect that EDTMPA-P/A with facile esterification synthesis at low temperature, modification process and excellent adsorption performance, therefore, could be used as a high efficient adsorbent for lead ions removal, which also has simultaneously achieved the reuse object of waste para aramid.