A novel fine-tuning mesoporous adsorbent for simultaneous lead(II) detection and removal from wastewater

The functionalized mesoporous silica based fine-tuning mesoporous adsorbent was developed for ultratrace lead (Pb(II)) detection and removal from wastewater. The mesoporous adsorbent was fabricated by direct immobilization of 1E,1 'E,1"E,1"'E(tetrakis(3-carboxysalicylidene)) naphthalene-1,2,5,5-tetramine (TSNT) onto mesoporous silica monoliths. The design of the ligand into ordered pore-based mesoporous adsorbent transformed the Pb(II) detection and removal systems into smart and stable assemblies. The ability of the mesoporous adsorbent to detect and remove Pb(II) from aqueous solutions has been studied and discussed with different optimized conditions of concentrations, the amount of mesoporous adsorbent, concentration of coexisting electrolyte and pH. The design of such a tunable mesoporous adsorbent offered a simple procedure in such toxic Pb(II) ions removal without using high-tech, sophisticated instruments. The mesoporous adsorbent was able to detect the ultra-trace Pb(II) ions with high sensitivity and selectivity based on charge transfer ((intense pi-pi transition) transduction. Therefore, the mesoporous adsorbent proved to have an efficient ability for continuous monitoring of toxic Pb(II) ions even on-site and in situ chemical analyses. The removal data revealed that mesoporous adsorbent has high sorption capacity (184.32 mg/g) based on sorption isotherms measurements. The major advantage of the tunable design mesoporous adsorbent was that the mesoporous adsorbent retained highly efficient sensitive selectivity without a significant kinetic hindrance, despite the slight decrease of sorption after several regeneration/reuse cycles. Uptake of Pb(II) onto mesoporous adsorbent to equilibrium occurred quickly and the mesoporous adsorbent could be regenerated for reuse with diluted HCl. Therefore, the mesoporous adsorbent has been shown to have the potential to be used as an effective adsorbent for ultra-trace Pb(II) ions detection and removal from wastewater. (C) 2014 Elsevier B.V. All rights reserved.