Coupling of acoustic/hydrodynamic cavitation with ozone (O3), hydrogen peroxide (H2O2), magnesium oxide (MgO) and manganese dioxide (MnO2) for the effective treatment of CETP effluent

Ultrasound-Assisted Catalytic Ozonation-Based Treatment of Rare-Earth Processing Effluent Containing Ammonium Thiocyanate (NH4SCN)

“…27 Chakinala et al 20 studied the use of varying concentrations of effluent and reported that COD reduction reduces at higher loadings of the effluent. It is also reported in the literature that 22 kHz of frequency may be incapable to form sufficient OH radicals at high pollutant concentration or for pollutants having complex structure, 28 similar to the case of the present work where treatment of REI effluent containing NH 4 SCN showed no COD reduction at 22 kHz. Agarkoti et al 28 also reported very less COD reduction of around 5.64% in 1 h using only US for another commercial effluent under conditions of 250 W power and 22 kHz.…”

“…It is also reported in the literature that 22 kHz of frequency may be incapable to form sufficient OH radicals at high pollutant concentration or for pollutants having complex structure, 28 similar to the case of the present work where treatment of REI effluent containing NH 4 SCN showed no COD reduction at 22 kHz. Agarkoti et al 28 also reported very less COD reduction of around 5.64% in 1 h using only US for another commercial effluent under conditions of 250 W power and 22 kHz. The governing reason reported was again limited generation of hydroxyl radicals by US-generated cavitation.…”

“…17 Thus, ozone generally dissociates to release more OH radicals at basic conditions, and hence, this results in higher COD reduction. 36 Agarkoti et al 28 studied the extent of COD reduction of CETP effluent using the hybrid approach of US+O 3 at different pH of 3, 5, 7, 9, and 11 reporting COD reduction as 35.27%, 42.26%, 45.71%, 56.28%, and 57.6%, respectively. Gagol et al 31 also reported complete degradation of sulfides ions and organic sulfides in industrial effluent at basic pH of 10.5 for the combination of US and ozone.…”

Effect of ozonation on biodegradability enhancement and biomethanation potential of pretreatment process wastewaters from 2G ethanol production

“…Following the above‐mentioned analyses, seed germination assay was conducted for raw and pretreated wastewaters in order to assess the toxicity reduction post ozonation. The residual ozone concentrations in the treated effluents were determined using N , N ‐diethyl‐ p ‐diphenylenediamine (DPD) colorimetric method using a standard ozone test kit and found to be <0.1 ppm 17 …”

“…The residual ozone concentrations in the treated effluents were determined using N,N-diethyl-pdiphenylenediamine (DPD) colorimetric method using a standard ozone test kit and found to be <0.1 ppm. 17 Seed germination Seed germination tests were performed, as per the procedure reported by Chandra et al, 18 to evaluate the toxicity reduction of the ozone-pretreated wastewaters. Samples A0, A1, A2, B0, B1, and B2 were preliminarily centrifuged, and the supernatant collected was then filtered through Whatman filter paper No.…”