Surfactant-modified biochar is a viable adsorbent for eliminating Cr(VI) from synthetic wastewater. The biochar obtained from the zea mays plant (BC) was tailored with sodium dodecyl sulfate (SDS) as an anionic surfactant forming SDS-BC adsorbent. Different controlling conditions have been evaluated including pH of the solution, biomass concentration, primary Cr(VI) concentration, time of adsorption, and temperature. Under the best controlling circumstances, the percentage of removal has attained 99%. The pseudo-second-order kinetic model best described the removal process, according to the kinetic data, while the Temkin model, one of the applicable adsorption isotherm models, well expressed the adsorption process. The thermodynamic parameters were computed, which disclosed the spontaneity and exothermic character of the Cr(VI) elimination. According to the regeneration cycles, SDS-BC was cost-effective and had a good removal capability. Graphical Abstract

The present work deals with the investigation of the efficiency of the electrocoagulation (EC) technique in the removal of two different reactive dyes as a simple, durable, and cost-effective technique for wastewater treatment. The difference in structure between Reactive Red 49 (RR49) and Reactive Yellow 15 (RY15) is explored during the treatment process through the use of a novel design of electrodes. The optimum conditions obtained were 80 and 60 mg/L of initial dye concentrations, pH of 5.9 and 4 for RR49 and RY15, respectively, 0.5 g of NaCl electrolyte, and 900 and 500 rpm of stirring rate for RR49 and RY17 dyes respectively, which led to the highest percent removal (98.5%) for both dyes. The suitable temperatures were 20 and 30 °C for RR49 and RY15, respectively. The thermodynamic parameters were designated, and it was a spontaneous process for both dyes. The removal process was designated to pseudo- second-order for the RR49 dye and pseudo- first-order for the RY15 dye and fitted to the Langmuir model. Analysis of Variance (ANOVA) was presented to assess the variation of the outcomes attained from each factor.

This study examines the security features used in polymer banknotes by comparing the new polymeric 10-Egyptian banknote and its English counterpart notes. Video Spectral Comparator 8000/HS (VSC 8000/HS) and visual inspection were used to study and compare the security features of both banknotes. There are similarities between the design of the two banknotes, which is undesirable from a security point of view. Still, the English banknote is superior to its Egyptian counterpart in design and security features. Although many studies deal with the security features of banknotes, with many countries switching to polymer banknotes every year, such as Egypt recently, there is a need for more studies on securing the polymer substrate and comparing the security features used in polymer banknotes. This study offers the first structured, side-by-side forensic mapping of overt and covert security features across two same-denomination polymer banknotes—EGP-10 and £10. Standardised visible/IR/UV examinations (transmitted/oblique; VSC8000/HS) contrast design strategies with direct implications for counterfeit detection and examiner training.