Worldwide, there is a continuous need to develop alternative treatment methods to replace conventional processes for textile wastewater. In this regard, Fenton oxidation, with the potential of hydroxyl radical production, is an efficient method. Nevertheless, pH dependence, high chemical consumption and sludge production are a few aspects that limit its wide application. Therefore, to overcome these limits, integration of Fenton oxidation with other advanced oxidation processes is considered a viable option. Therefore, in this study, Ultrasonic-assisted Fenton oxidation was investigated to observe the increase in degradation efficiency of Fenton oxidation. For this purpose, low frequency ultrasonic water bath was used and malachite green dye was used as a model pollutant. Central composite design was used for experimental design, and [OP] ini , OP:Fe +2 (wt/wt), H 2 O 2 :Fe +2 (wt/wt) and pH were used as control factors. Based on experimental results, maximum of 97.5% Chemical Oxidation Demand (COD) reduction was obtained at the process conditions of [OP] ini : 100 mg/L, OP:Fe +2 : 50, H 2 O 2 :Fe +2 : 1.5 and pH:3. Furthermore, 10 times reduction in the consumption of hydrogen peroxide was obtained. According to Pareto analysis, organic pollutant (OP) in interaction with OP is the most significant while pH was identified as the least. The process followed pseudo-first order kinetics (k = 0.0196 min −1) with electrical energy order of 26.21 kWh/m 3 and the maximum energy consumption per COD removal of 0.8 kJ/COD, lower than those available in the literature. The results suggested that US-assisted Fenton oxidation could be considered as an efficient method for treating the recalcitrant wastewater.

The ability to determine combustion and thermal decomposition (pyrolysis) products at trace concentrations can lead to important information on catalytic pathways, the degradation process itself, and structural (fingerprint) information on the parent molecule(s), among others. Gas chromatography coupled with mass spectrometry (GC/MS) is well suited to separate and identify the volatile molecules and molecular fragments generated by combustion and pyrolysis processes. Whereas, pyrolysis (conducted in an inert atmosphere) is often used as a sample introduction device directly coupled to GC/MS, combustion is generally carried out offline and its products are collected and analyzed with GC/MS, or even pyrolysis‐GC/MS. In the past few years, this powerful technique has been used to examine a variety of sample types for quite diverse applications. This chapter describes the state of the art and the progress of GC/MS for the measurement of combustion and pyrolysis products. An introduction to the technique, including the principles of GC/MS, is first provided, followed by a demonstration of the instrument's capabilities for combustion and pyrolysis research. All reports discussed herein were selected in part to demonstrate the diversity of current combustion and pyrolysis research using GC/MS. The present authors' studies with temperature‐programmed desorption in conjunction with GC/MS to characterize oxygen shuttling on the chars derived from different gaseous environment, are highlighted. Finally, the use of GC/MS in combination with isotope‐labeling techniques to reveal complex reaction pathways and mechanisms is discussed.