Isopropyl alcohol (IPA) is a significant pollutant in the wastewater of semiconductor manufacturing industry. This study investigated the degradation of IPA in the microwave (MW)-assisted oxidation process using hydrogen peroxide (H2O2) as the oxidant. Complete elimination of IPA was noted in the MW/H2O2 system within 90 min of irradiation. In comparison, only 4.8, 6.1, and 68.2% of IPA, respectively, was removed in MW irradiation alone, H2O2 oxidation, and the system using the combination of thermal (TH) and H2O2. The degradation kinetics of IPA followed the pseudo-first-order in MW/H2O2 and TH/H2O2 systems, whereas the pseudo-zero-order reaction kinetics was observed in others. The degradation rates increased on increasing the hydrogen peroxide dose to a certain level. An excess H2O2 would trap the hydroxyl radicals (•OH) to form weaker radicals that inhibit IPA oxidation. A series of degradation intermediates were identified and quantified corresponding to acetone and short-chain organic acids. Finally, the degradation pathways of IPA were proposed and validated by the total organic carbon mass balance.

Amidst the pandemic, the work of many security personnel increased due to the additional requirements of checking vaccination records, temperature-taking, and contact-tracing procedures. There is ample research linking work hygiene and motivator factors (from Herzberg’s two-factor theory) to both job satisfaction and intentions to quit in various types of work settings. However, little is known about what keeps security officers on the job despite the exacerbated challenges posed by the pandemic. We examine how distinct hygiene and motivator factors predict intentions to quit among security officers. One thousand security officers in Singapore participated in a cross-sectional survey that assessed their current job experiences. The findings of this study revealed that job satisfaction plays a mediating effect in the positive relationship between four out of five poor hygiene factors and intentions to quit. Furthermore, the negative mediating effect of job satisfaction between all three motivator factors and intentions to quit was significant. Specifically, the intrinsic motivation for the work itself was the most significant predictor of intentions to stay. Interventions targeted at enhancing work commitment among security officers should highlight the value of security work and its role in maintaining public safety.