Electrodialysis applied for phenylacetic acid separation from organic impurities: Increasing the recovery

Electrodialysis as a potential technology for 4-nitrophenol abatement from wastewater

4-Nitrophenol is a widely used emerging pollutant in various industries, including the production of agrochemicals, drugs, and synthetic dyes. Due to its potential environmental harmful effects, there is a need to study its reuse and removal from wastewater. This study used electrodialysis technology to separate 4-nitrophenol ions using a four-compartment stack. The effects of supporting electrolyte concentration, pH, voltages, and current density on the performance of electrodialysis for separating 4-nitrophenol were investigated. A high extraction percentage of 77% was achieved with low energy consumption (107 kWh kg-1) when high 4-nitrophenol flows and transport numbers were reached.

The Combination of Carbon Source and the Addition of Phenylacetic Acid (PAA) to Growth Medium Penicillium chrysogenum to Enhance of Penicillin (Pen G) Production

The nutrition factor governs the growth and production of Penicillin G (Pen G) by Penicillium chrysogenum in a broth medium. Proper nutrition can improve Pen G antibiotic production. In this research, the optimal condition for Pen G production from P. chrysogenum in a standard culture medium and various carbon sources medium (glucose, lactose, maltose, and sucrose) were done for ten days. Phenylacetic Acid (PAA) precursor at 0.0 – 0.6 gL-1 (increment 0.1) was used to improve Pen G production. The Pen G was detected by HPLC, compared with the standard (Penicillin G Sodium Salt). The results showed that the PDB standard medium and lactose medium (150 rpm, at 30°C) produced 0.425 gL-1 and 0.107 gL-1 Pen G. Addition of 0.6 gL-1 PAA improved the Pen G production up to 0.045 gL-1 in the PDB medium, become the final concentration of 0.470 gL-1 and 2.460 gL-1 in the lactose medium, become the final concentration of 2.565 gL-1. The antibiotic’s activity against the pathogenic bacteria, i.e., B. subtilis, S. aureus, and S. typhi employing the disk diffusion method, has been done. The TLC method’s detection of the potential Pen G spots was conducted with ethyl acetate: distilled water: acetic acid (60:20:20) as the mobile phase. The Pen G extracts could inhibit the growth of all tested bacteria in Rf 0.65. This study informs the proper combination of carbon source and precursor effects and increases the bioproduction of Pen G from P. chrysogenum.

Influence of Surface Modification of MK-40 Membrane with Polyaniline on Scale Formation under Electrodialysis

A comprehensive study of the polyaniline influence on mineral scaling on the surface of the heterogeneous MK-40 sulfocationite membrane under electrodialysis has been conducted. Current-voltage curves and chronopotentiograms have been obtained and analyzed for the pristine MK-40 membrane and the MK-40 membrane which is surface-modified by polyaniline. The study of the electrochemical behavior of membranes has been accompanied by the simultaneous control of the pH of the solution outcoming from the desalination compartment. The mixture of Na₂CO₃, KCl, CaCl₂, and MgCl₂ is used as a model salt solution. Two limiting states are observed on the current-voltage curve of the surface-modified membrane. There is the first pseudo-limiting state in the range of small values of the potential drop. The second limiting current is comparable with that of the limiting current for the pristine membrane. It is shown that chronopotentiometry cannot be used as a self-sufficient method for membrane scaling identification on the surface-modified membrane at high currents. A mineral scale on the surfaces of the studied membranes has been found by scanning electron microscopy. The amount of precipitate is higher in the case of the surface-modified membrane compared with the pristine one.