Mercury contamination represents a critical environmental and public health challenge, demanding efficient and sustainable remediation approaches. A comparative investigation of removal of mercury ions (Hg2+) using MnO2 modified zeolite and unmodified zeolite has been carried out. The zeolite was chemically functionalized via controlled MnCl2 precipitation to deposit MnO2, generating a composite adsorbent with enriched active sites and improved binding affinity. Comprehensive characterization using FTIR, SEM-EDX, XRD, and BET analyses confirmed significant structural and surface modifications upon MnO2 loading. Batch adsorption experiments were carried out to optimize pH, adsorbent dosage, contact time, and initial Hg2+ concentration. The MnO2-modified zeolite exhibited a maximum adsorption capacity of 4.28 mg/g under optimized conditions. Kinetic analysis revealed that the adsorption followed the pseudo-second-order and Elovich models, indicating a chemisorption-controlled process; while equilibrium data best fitted the Langmuir isotherm with a monolayer capacity of 4.10 mg/g. Thermodynamic parameters suggested the adsorption to be spontaneous and endothermic. The enhanced mercury uptake is attributed to increased surface area, additional MnO2 binding sites, and stronger adsorbate-adsorbent interactions. Overall, MnO2-modified zeolite demonstrates excellent potential as a cost-effective and efficient adsorbent for mercury remediation in aqueous environments.
Nuclear energy is a highly energy-dense, low-greenhouse gas power source whose long-term sustainability depends on advanced fuel cycle strategies which enable efficient and proliferation-resistant separation of actinides from lanthanides. In this work, a new class of amide-functionalized bis-1,2,4-triazinyl-2,6-pyridine (BTP) complexants, inspired by N,N,N ',N '-tetraoctyldiglycolamide (TODGA), for the selective partitioning of 241Am3+ from 154-152Eu3+ in a 1-octanol/kerosene (1:1 v/v) biphasic diluent system is presented. The optimized system achieves rapid extraction in a mere ten minutes of contact time, high Am distribution values and separation factors, while surpassing previously reported performance metrics of BTP analogues of this class, and others. Importantly, decomplexation studies revealed efficient actinide recovery and excellent complexant recyclability, underscoring the potential of these hybrid amide-triazine architectures for sustainable spent nuclear fuel reprocessing. Equilibration, acid and complexant concentration dependency, back-extraction, and recyclability are reported herein.
