A Viable and sustainable flat- membrane plate-and-frame module for spent acid regeneration and metal ion recovery.

This study provides techno-economical insights for acid regeneration and metal recovery from spent acidic wastewater by a diffusion dialysis plate-and-frame module using Quaternized Polyepichlorohydrin - Polyacrylonitrile (QPECH-PAN) membranes. Quaternized Polyepichlorohydrin (QPECH) membranes were synthesized using 1,4-diazobicyclo[2.2.2]octane (DABCO) and blended with polyacrylonitrile (PAN). Said membranes were analyzed in terms of their mechanical, physicochemical, and electrochemical characteristics, providing significant results comparable to the commercial membranes (IEC: 1.76 mmol/g, SD: 60.91%, Permselectivity: 79.5 ± 0.31%, and transport no. t(-): 0.5). Mechanical characterization reveals that the QPECH-PAN membranes possess comparable mechanical strengths (tensile strength: 329.56 MPa). Further, sheet resistivity (6.11 Ω cm2) and conductivity (0.16 S/cm2) reveal the relative conductive nature of these membranes. Percent acid recovery and metal ion recovery ratios were found to be 72% and 48% respectively, and separation factors were 126.8 and 84.57 respectively. The QPECH-PAN membrane's techno-economic feasibility was also analyzed within the context of a textile industry processing up to 5500 kg/d of acidic wastewater. It indicates a potential cost saving of US $0.53 million on H2SO4 and NaOH, as well as an OPEX saving of 40.91% against a semi-continuous acid neutralizer.

Design of a facile, green and efficient graphene oxide-based electrochemical sensor for analysis of acetaminophen drug.

In this study an efficient and environment friendly electrochemical sensor has been designed for the analysis of acetaminophen (APAP) drug. Electrochemical impedance spectroscopy, differential pulse voltammetry and cyclic voltammetric techniques were used to demonstrate the fabricated erGO/GCE sensor performance. Voltammetric assessment of acetaminophen drug was done using bare GC electrode, drop-casted GO/GC electrode and erGO/GCE electrochemical sensor. Proposed sensor was precisely validated for APAP detection by differential pulse voltammetric technique. Subsequently LOD, LOQ, sensitivity and linearity were determined and found to be 7.23 nM, 21.909 nM, 20.14 µA nM-1 cm-2 and 0.0219-2.30 µM, respectively. The diffusion coefficient of APAP was determined by chronoamperometry, and it was found to be 2.24 × 10-5 cm2.s-1. The synthetic and analytical steps were assessed as per the Green Chemistry's 12 Principles giving a 66 score (acceptable) and 93 score (excellent) for the said steps, respectively. Supplementary Information: The online version contains supplementary material available at 10.1007/s11696-022-02628-9.