Degradation of 4-chloro 2-aminophenol using combined strategies based on ultrasound, photolysis and ozone

Abstract

The present work investigates the degradation of 4-chloro 2-aminophenol (4C2AP), a highly toxic organic compound, using ultrasonic reactors and combination of ultrasound with photolysis and ozonation for the first time. Two types of ultrasonic reactors viz. ultrasonic horn and ultrasonic bath operating at frequency of 20 kHz and 36 kHz respectively have been used in the work. The effect of initial pH, temperature and power dissipation of the ultrasonic horn on the degradation rate has been investigated. The established optimum parameters of initial pH as 6 (natural pH of the aqueous solution) and temperature as 30 ± 2°C were then used in the degradation studies using the combined approaches. Kinetic study revealed that degradation of 4C2AP followed first order kinetics for all the treatment approaches investigated in the present work. It has been established that US+UV+O3 combined process was the most promising method giving maximum degradation of 4C2AP in both ultrasonic horn (complete removal) and bath (89.9%) with synergistic index as 1.98 and 1.29 respectively. The cavitational yield of ultrasonic bath was found to be eighteen times higher as compared to ultrasonic horn implying that configurations with higher overall areas of transducers would be better selection for large scale treatment. Overall, the work has clearly demonstrated that combined approaches could synergistically remove the toxic pollutant (4C2AP).

Developing the Ternary ZnO Doped MoS2 Nanostructures Grafted on CNT and Reduced Graphene Oxide (RGO) for Photocatalytic Degradation of Aniline

“…It is noteworthy that only 4% of solar light is placed in the UV region, while nearly 46% of its spectrum is placed in the visible region which is far abundant. Hence, developing a robust solar-responsive photocatalyst is urgently required for the next-generation of photocatalysts [16][17][18][19][20][21][22][23] .…”

Degradation of 4-chloro 2-aminophenol using combined approaches based on microwave and photocatalysis

“…Under moderately acidic conditions, the structural orientation of molecule support the photon attack favorably [30]. It is also important to note that as 4C2AP is highly photo-sensitive [23], higher degradation is obtained under conditions of natural pH, which also correspond to moderately acidic condition. To maintain strongly acidic pH conditions (pH < 5), strong acid (H 2 SO 4 ) was used which possibly creates interference in the photon interaction with the compound (4C2AP) giving lower degradation at pH of 2 and 4 as compared to natural pH.…”

“…Barik and Gogate [23] investigated the degradation of 4C2AP using combined processes as ultrasound (US) + UV, UV + O 3 , US + O 3 and US + UV + O 3 and reported that maximum degradation (99.27%) was obtained in the combined approach of US + UV + O 3 after 2 h of treatment. Arora et al [24] investigated biodegradation of 4C2AP and reported complete degradation after 36 h of treatment.…”

Application of Hydrodynamic Cavitation Reactors for Treatment of Wastewater Containing Organic Pollutants: Intensification Using Hybrid Approaches

“…Barik and Gogate [17,53] studied the degradation of 4-chloro 2-aminophenol using the combined process of Ultrasound (US) and HC with UV of wavelength 254 nm. In the case of the combined approach of the US with UV, the maximum degradation of 88.42% was reported whereas, the individual approach of US and UV resulted in degradation of 24.17% and 80.8% as the degradation respectively.…”