Degradation of magenta dye using cavitation‐based transducers to glass marble: Lab to semi‐pilot scale operations

Abstract

In the present work, the degradation of magenta dye has been investigated using ultrasonic (US) and ultraviolet (UV) irradiation at a laboratory scale.Additionally, the investigation was conducted at a semi-pilot scale by employing hydrodynamic cavitation and a novel air-marble cavitation reactor. Initially, optimization studies such as the effect of initial dye concentration and catalyst loading of TiO 2 and MnO 2 followed by the effect of combined catalyst loading (TiO 2 /MnO 2 ) on the extent of degradation have been studied at a capacity of 3 L. It was observed that the US irradiation results in 87.1% and 68.2% of degradation, whereas the UV irradiation results in 79.8% and 56.4% extent of degradation at 1 g/l of TiO 2 and 0.8 g/l of MnO 2 , respectively.The maximum degradation was 92.1% at the combined loading of 0.6 g/l (1:0.8; TiO 2 :MnO 2 ) using US irradiation with a capacity of 3 L and 81.3% using a hydrodynamic cavitation reactor with a semi-pilot scale capacity of 7 L. The chemical oxygen demand (COD) analysis also showed the highest COD removal of 92% at a small scale using the US irradiation and 76% at a semi-pilot scale using hydrodynamic cavitation. On a small scale, the cost of a US/TiO 2 + MnO 2 treatment scheme is US$ 0.01/L, whereas on a semipilot scale using HC/TiO 2 + MnO 2 , the cost is US$ 0.04/L. Both of these treatment schemes offer viable pathways for degradation based on energy and economic assessments. Overall, the current work has clearly demonstrated the effectiveness of the cavitational reactor for the efficient degradation of magenta dye from lab to semi-pilot scale operation. Practitioner Points:• Small-scale dye containing wastewater treatment using ultrasound and ultraviolet irradiation • Combined use of catalysts at large-scale operations with novel cavitation techniques • Novel cavitation techniques studied for dye degradation.• Energy efficiency and cost analysis evaluated for AOPs studies.

Degradation of pesticides using hybrid processes based on cavitation and photocatalysis: A review

“…(Bagal et al., 2022; Bokhale et al., 2014; Mohod et al., 2023). Biological treatments are mainly microbial processes that can oxidize the pollutants based on the consumption as food (Bagal et al., 2023; Thurman & Meyer, 1996). However, both physical and biological treatments offer disadvantages as high cost of treatment, lack of total mineralization, higher treatment time, higher carbon footprint (Ayare & Gogate, 2020).…”