Hybrid treatment strategies for 2,4,6-trichlorophenol degradation based on combination of hydrodynamic cavitation and AOPs

Abstract

Utilization of hybrid treatment schemes involving advanced oxidation processes and hydrodynamic cavitation in the wastewater treatment forms the prime focus of the present work. The initial phase of the work includes analysis of recent literature relating to the performance of combined approach based on hydrodynamic cavitation (HC) for degradation of different pollutants followed by a detailed investigation into degradation of 2,4,6-trichlorophenol (2,4,6-TCP). The degradation of the priority pollutant, 2,4,6-TCP, using combination of HC based on slit-venturi used as the cavitating device, ozone and HO has been investigated. The effect of operating pressure (2-5bar) and initial pH (3-11) have been investigated for the degradation using only HC. The degradation using only ozone (100-400mg/h) and only HO has also been studied. The efficacy of the combined operation of HC+O at different ozone flow rates (100-400mg/h) and the combined operation of HC+HO at different loadings of HO (2,4,6-TCP:HO as 1:1-1:7) have been subsequently investigated. The degradation efficacy has also been established for the combined treatment strategies of O+HO and HC+O+HO at the optimum conditions of temperature as 30°C, inlet pressure of 4bar and initial pH of 7. Extent of 2,4,6-TCP degradation, TOC and COD removal obtained for HC+O process were 97.1%, 94.4% and 78.5% respectively whereas for O+HO process, the values were 95.5%, 94.8% and 76.2% and for HC+O+HO process the extent of reduction were 100%, 95.6% and 80.9% in the same order. The combined treatment approach as HC+O+HO was established as the most efficient approach for complete removal of 2,4,6-TCP with near complete TOC removal.

Activated Hydrotalcites Obtained by Coprecipitation as Photocatalysts for the Degradation of 2,4,6‐Trichlorophenol

“…US Environmental Protection Agency (USEPA) places them within the list of priority pollutants and has determined that 2,4,6-trichlorophenol is a probable carcinogen [15][16][17]. e technologies that have been implemented for the elimination of phenolic contaminants present in water are classified mainly into two large groups: those that separate the contaminant, such as adsorption, extraction, distillation, and ultrafiltration with membranes, and those that degrade the contaminant, for example, supercritical oxidation, moist air treatment, thermal treatment, biodegradation, and catalytic degradation [18][19][20][21][22][23][24][25]. In recent years, the processes of advanced oxidation using photocatalysts have generated great expectations as effective and effective methods for the elimination of emerging contaminants.…”

Novel Affordable, Reliable and Efficient Technologies to Help Addressing the Water-Energy-Food Nexus

“…At the respective optimized geometries, as a rule, slit Venturi reactors outperform circular Venturi in terms of process yields. This holds, for example, for the removal of total organic content from recalcitrant pollutants in wastewater, and for the creation of stable oil-in-water nanoemulsions; as well, wide margins exist for further improving the performances, including the effect of the slit length as a function of its height (Barik & Gogate, 2017;Carpenter, Badve, et al, 2017;Ramisetty, Pandit, & Gogate, 2014).…”

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

“…Ibuprofen HC Barik and Gogate [16] studied the degradation of 2,4,6-trichlorophenol (2,4,6 TCP) using hybrid methods based on HC. The cavitational effects are generated using slit venturi as a cavitating device.…”

“…The use of oxidizing agents, such as H 2 O 2 or ozone, and catalysts coupled with HC also results in the significant enhancement in the degradation efficiency making HC as a more effective technology for the removal of pollutants [10,11]. Many literature reports can be found confirming the effective use of combined treatment methods coupled with HC for the degradation of model pollutants, such as pesticides [12,13], pharmaceuticals [10,14], dyes [11,15], phenolic compounds [16,17], as well as real industrial effluents [18][19][20]. Sometimes the intermediates obtained during treatments based on HC may be more effectively treated using biological oxidation which helps in reducing the energy requirement along with the total treatment costs.…”