Synergistic effects and mechanisms of hydroxyl radical-mediated oxidative degradation of sulfamethoxazole by Fe(II)-EDTA catalyzed calcium peroxide: Implications for remediation of antibiotic-contaminated water

The performance of nCaO2 for BTEX removal: Hydroxyl radical generation pattern and the influences of co‐existing environmental pollutants

“…Though CHCs or surfactants would affect the BTEX oxidation efficiency because that the presence of CHCs or surfactants could compete for with BTEX, the degradation of BTEX could be improved by the following technical methods: (a) increasing the amounts of nCaO 2 and Fe(II) to make the system produce enough , (b) adding Fe(II) in two or three stages rather than one stage to ensure the activity of catalyst, (c) optimizing the catalyst availability by chelating reagents (e.g., Fe(II) was used with EDTA) (Amina, Wu, Si, & Yousaf, ; Bai et al, ; Wang, Peng, Xie, Deng, & Deng, ; Xue et al, ; Xue, Lu, et al, ; Xue, Sui, et al, ). Further improving the efficiency of nCaO 2 /Fe(II) system by the above‐mentioned methods will be investigated in our future work.…”

Synergetic Effect of Combined CaO2 and Microwave Treatment on Waste Active Sludge Dewaterability and Organic Contaminants’ Removal

“…FeSO 4 (NH 4 ) 2 SO 4 (1.0 mmol/L, 5 μl), phosphate-buffered saline (50 mmol/L, pH 7.4, 5 μl), DMPO (0.9 mol/L, 5 μl), and 5 μl sludge samples were mixed together, and then measured immediately. IPA and CF were used as scavenger for •OH and •O 2 − , respectively (Amina et al, 2018).…”

“…oxidation-reduction reaction, radical chain reaction, and hydrogen atom transfer). Through these reaction ways, organic pollutants can be degraded or produce less toxic intermediates (Qian et al, 2015;Amina et al, 2018;Zhang et al, 2018). Furthermore, MW irradiation can facilitate CaO 2 to generate more •OH and •O 2 − radicals, so the oxidation capacity of CaO 2 is improved.…”

“…However, the enhancement of sludge dewatering properties is limited with single CaO 2 treatment (Chen et al, 2016). Research has shown that both ferrous iron and montmorillonite can catalyze the formation of •OH from CaO 2 , thus exhibiting synergistic effects on enhancing sludge dewaterability (Amina et al, 2018;Wu et al, 2018). Chen et al (2016) opined that the combination of CaO 2 and chemical flocculation exhibits superior performance in sludge dewatering performance.…”

Degradation of BTEX in groundwater by nano-CaO2 particles activated with L-cysteine chelated Fe(III): enhancing or inhibiting hydroxyl radical generation

“…amount of 0.47 g H 2 O 2 /g of CaO 2 ) can participate in the Fenton reaction and generate HO• which are the dominant radicals for the pollutant degradation under aqueous conditions (Xue et al 2018a(Xue et al , 2018bAmina et al 2019;Sun et al 2019;Tang et al 2020). At the same time, hydroperoxyl radical (HO 2 •), superoxide radical (O 2 À •), singlet oxygen ( 1 O 2 ) and hydroperoxide anions (HO 2 À ) can be generated as well in CaO 2 -based Fenton system (Ma et al 2007;Zhang et al 2015aZhang et al , 2015bPan et al 2018;Zheng et al 2019).…”