Insights into brewery wastewater treatment by the electro-Fenton hybrid process: How to get a significant decrease in organic matter and toxicity.

This work aimed to perform selective experimental arrays based on the electro-Fenton hybrid (EFH) process for pollutants abatement and toxicity reduction in brewery wastewater (BW). Fenton and electrocoagulation (EC) methods were assessed preliminarily, including the Fe2+ catalyst yield and H2O2 loss. Each method performance on reducing total organic carbon (TOC) was assessed using a 33 full factorial design (FFD). Firstly, Fe2+ species were produced in short time ranges with the electric current density at 50 A m-2 and electrical conductivity at 1200 µS cm-1, followed by EFH experiments with an initial addition of 9.0 g L-1 H2O2. In three levels, initial pH (2.5-3.5) values, Fe2+ production-dedicated time (5-15 min), and H2O2 renovating percentage (70-90%) were also evaluated, assessing TOC removal. Secondly, nine EFH kinetics, upon the addition of an initial 9.0 g L-1 H2O2 along with H2O2 addition at 82.5%, every 5 min, and three levels for pH (3.0-3.4) were carried out, beginning after three Fe2+ production-dedicated times (4-6 min). Thirdly, another 60 min kinetic experiment was proposed, with an initial 6 min EC process, followed by a 39 min EFH process, and finally, a 15 min EC process, assessing TOC removal and remaining toxicity. A significant improvement in TOC removal performance, about 90%, along with high toxicity reduction was attained after a refined EFH-based treatment. Therefore, keeping permanent EFH conditions with more suitable parameters provided a unique perspective for removing highly significant pollutants.

Insights on limits of detection, precision and accuracy in TXRF analysis of trace and major elements in environmental solid suspensions.

In this work, the analytical capability of the total reflection X-ray fluorescence technique with the S2 PICOFOX spectrometer was investigated. A set of certified reference materials was prepared as solid particulate for TXRF analysis. Experimental data of sensitivity, limits of detection and recovery for many elements were obtained. Good sensitivity and limits of detection with a good recovery range of around 90-110% were achieved. Thus, the TXRF technique exhibits a good analytical potential for its applicability on different materials.