Sunita Raut-Jadhav

Bio: Sunita Raut-Jadhav is an academic researcher from Vishwakarma Institute of Technology. The author has contributed to research in topics: Adsorption & Freundlich equation. The author has an hindex of 3, co-authored 3 publications receiving 181 citations.

Synergetic effect of combination of AOP's (hydrodynamic cavitation and H2O2) on the degradation of neonicotinoid class of insecticide

Abstract: In the present work, degradation of imidacloprid (neonicotinoid class of insecticide) in aqueous solution has been systematically investigated using hydrodynamic cavitation and combination of hydrodynamic cavitation (HC) and H2O2. Initially, effect of different operating parameters such as inlet pressure to the cavitating device (5–20 bar) and operating pH (2–7.5) has been investigated. Optimization of process parameters was followed by the study of effect of combination of HC and H2O2 process on the rate of degradation of imidacloprid. Significant enhancement in the rate of degradation of imidacloprid has been observed using HC + H2O2 process which lead to a complete degradation of imidacloprid in 45 min of operation using optimal molar ratio of imidacloprid:H2O2 as 1:40. Substantial synergetic effect has been observed using HC + H2O2 process which confer the synergetic coefficient of 22.79. An attempt has been made to investigate and compare the energy efficiency and extent of mineralization of individual and combined processes applied in the present work. Identification of the byproducts formed during degradation of imidacloprid has also been done using LC–MS analysis. The present work has established a fact that hydrodynamic cavitation in combination with H2O2 can be effectively used for degradation of imidacloprid.

Effect of process intensifying parameters on the hydrodynamic cavitation based degradation of commercial pesticide (methomyl) in the aqueous solution.

Abstract: Methomyl, a carbamate pesticide, is classified as a pesticide of category-1 toxicity and hence shows harmful effects on both human and aquatic life In the present work, the degradation of methomyl has been studied by using hydrodynamic cavitation reactor (HC) and its combination with intensifying agents such as H2O2, fenton reagent and ozone (hybrid processes) Initially, the optimization of operating parameters such pH and inlet pressure to the cavitating device (circular venturi) has been carried out for maximizing the efficacy of hydrodynamic cavitation Further degradation study of methomyl by the application of hybrid processes was carried out at an optimal pH of 25 and the optimal inlet pressure of 5 bar Significant synergetic effect has been observed in case of all the hybrid processes studied Synergetic coefficient of 58, 1341 and 476 has been obtained by combining hydrodynamic cavitation with H2O2, fenton process and ozone respectively Efficacy of individual and hybrid processes has also been obtained in terms of energy efficiency and extent of mineralization HC+Ozone process has proved to be the most effective process having highest synergetic coefficient, energy efficiency and the extent of mineralization The study has also encompassed the identification of intermediate by-products generated during the degradation and has proposed the probable degradation pathway It has been conclusively established that hydrodynamic cavitation in the presence of intensifying agents can effectively be used for complete degradation of methomyl

Intensification of degradation of imidacloprid in aqueous solutions by combination of hydrodynamic cavitation with various advanced oxidation processes (AOPs)

Abstract: The degradation of imidacloprid (a systemic chloronicotinoid insecticide) has been carried out in the aqueous solutions using the combination of hydrodynamic cavitation (HC) with various other advanced oxidation processes such as fenton, photo-fenton, photolytic and photocatalytic processes. HC + fenton process significantly enhanced the rate of degradation of imidacloprid, which lead to a complete degradation of imidacloprid within 15 min of operation using the molar ratio of imidacloprid:H2O2 as 1:40 and the molar ratio of FeSO4·7H2O:H2O2 as 1:40. Similar results of an increase in the rate of degradation of imidacloprid have also been obtained in case of HC + photo-fenton process. Synergetic index of 3.636 and 2.912 have been obtained using HC + fenton and HC + photo-fenton processes respectively. The combination of hydrodynamic cavitation with photolytic and photocatalytic processes have also resulted in the enhancement in the rate of degradation of imidacloprid, however synergetic effect has not been observed. Comparison of efficiency of all the processes applied has also been done by computing extent of mineralization achieved and energy requirement of the process.

Nano-metal oxides-activated carbons for dyes removal: A review

Abstract: It is common for dyes to be utilized in a wide range of industries such as leather and textiles as well as the printing, paper, and packaging industry. Most dyes fall into a dangerous category of water toxins that have had a significant impact on the ecosystem. Dye removal from wastewater can be done in a variety of methods. It is now necessary to develop advanced and cost-effective methods. Organic dyes may be removed from textiles using adsorption, which is a more effective and environmentally beneficial process. Nanomaterials are a more attractive option for dye removal because of their unique characteristics. An approach to the synthesis, characterization, and dye removal capabilities of nano-metal oxides-activated carbons is presented. This review also includes a discussion of several operating parameters associated with the adsorption process, adsorption isotherms, kinetics, thermodynamic behavior, and reusability of the adsorbent.

An overview of antimicrobial nanoparticles for food preservation

Abstract: Nanotechnology opens up new possibilities for food innovation at an incredible rate, yet new technology needs evaluations of both potential negative impacts and numerous good effects. We aimed to cover some of the latest breakthroughs in nanotechnology and their application to food processing in this overview. Applications of nanoparticles in the food sector are growing rapidly. Nanoparticles (NPs) play a significant role in enhancing food quality by protection and preservation and are preferred over traditional preservatives. In this work on organic and inorganic nanoparticles in various forms such as single and multiple metal oxides, polymeric nanocomposite, nanocapsules, etc., as well as various methods of their preparations are discussed. Nanoparticles in food are currently most explored for their antimicrobial applications; factors affecting their antimicrobial potential, their antimicrobial mechanisms, and laboratory methods applied to evaluate antimicrobial potentials are also discussed. Various properties of NPs in relevance to antimicrobial activities and methods used for their characterization are also discussed. Antimicrobial NPs used for the purpose in various ways such as active packaging, mixed in food, incorporated in edible film and coating, etc. discussed. In the current state NPs used in the food industry, have various concerns such as safety, and regulatory policies relevant to preparing, processing, packaging, and consumption are discussed. NPs do possess some functional properties and harmful effects as well in this relevant future perspective of antimicrobial NPs in food and their other applications explored in current work. Various aspects of the most intensively studied NPs as an antimicrobial in food technology such as silver oxide, and zinc oxide, are discussed.

Wastewater treatment by means of advanced oxidation processes based on cavitation – A review

Abstract: Hydrodynamic and acoustic cavitation combined with advanced oxidation processes (AOPs), including, among others, the Fenton process, is a promising alternative to the technologies of wastewater treatment technologies in use today. The present review discusses processes based on cavitation combined with AOPs and evaluates their effectiveness in oxidation of organic contaminants. Complete degradation of, among others, p-nitrotoluene, p-aminophenol, 1,4-dioxane, alachlor, chloroform, trichloroethylene, sodium pentachlorophenate and carbon tetrachloride was achieved by using hydrodynamic cavitation or acoustic cavitation alone. Cavitation is also an effective method of disinfection of water. Complete oxidation of hardly degradable organic contaminants, including pharmaceuticals, organic dyes, insecticides, phenol and its derivatives was observed when using hybrid processes: hydrodynamic or acoustic cavitation combined with the Fenton process, ozonation, hydrogen peroxide, UV irradiation, catalysts and persulfates. The review also discusses the cavitational reactors used in the wastewater treatment and the effect of process parameters (including pH, temperature, concentration and kind of contaminants) on the effectiveness of oxidation. The oxidation effectiveness for individual treatment methods is compared and their advantages and limitations discussed. The analysis of economics of the treatment processes performed to evaluate the possibility of scaling up reveals that the only economical processes should be based on hydrodynamic cavitation (mainly due to low cost of reactors and low consumption of electrical energy compared with ultrasonic reactors).

Combination of photocatalysis with hydrodynamic cavitation for degradation of tetracycline

Abstract: Hydrodynamic cavitation is a promising technology for wastewater treatment. In this study, TiO2 (P25) photocatalytic degradation of tetracycline, an antibiotic compound extensively used and environmentally hazardous, was conducted with hydrodynamic cavitation employed simultaneously. Many factors, such as initial tetracycline concentration, solution pH and presence of inorganic anions, were explored. Kinetics were investigated at varied contaminant concentrations, and the pseudo-first-order rate constant for tetracycline photocatalysis coupled with hydrodynamic cavitation was 1.5–3.7 times of the sum of those for the individual processes. These results indicated that a synergistic effect occurred in the combined method. Tetracycline degradation was pH-dependent and favored at alkaline pH. The presence of HCO3− in the medium induces promotive effect on the photocatalytic degradation of tetracycline in the presence of hydrodynamic cavitation, while sulfate and chloride exhibit only minor effect. UV/Vis spectra, Fourier transform infrared (FTIR) adsorption spectra and liquid chromatography–mass spectra (LC–MS) were used to evaluate the degradation mechanism. Scanning electron microscopic (SEM) images of TiO2 confirmed that hydrodynamic cavitation can prevent photocatalytic particles from agglomeration.

Degradation of a cationic dye (Rhodamine 6G) using hydrodynamic cavitation coupled with other oxidative agents: Reaction mechanism and pathway.

Abstract: In the present study, decolorization and mineralization of a cationic dye, Rhodamine 6G (Rh6G), has been carried out using hydrodynamic cavitation (HC). Two cavitating devices such as slit and circular venturi were used to generate cavitation in HC reactor. The process parameters such as initial dye concentration, solution pH, operating inlet pressure, and cavitation number were investigated in detail to evaluate their effects on the decolorization efficiency of Rh6G. Decolorization of Rh6G was marginally higher in the case of slit venturi as compared to circular venturi. The kinetic study showed that decolorization and mineralization of the dye fitted first-order kinetics. The loadings of H2O2 and ozone have been optimized to intensify the decolorization and mineralization efficiency of Rh6G using HC. Nearly 54% decolorization of Rh6G was obtained using a combination of HC and H2O2 at a dye to H2O2 molar ratio of 1:30. The combination of HC with ozone resulted in 100% decolorization in almost 5-10min of processing time depending upon the initial dye concentration. To quantify the extent of mineralization, total organic carbon (TOC) analysis was also performed using various processes and almost 84% TOC removal was obtained using HC coupled with 3g/h of ozone. The degradation by-products formed during the complete degradation process were qualitatively identified by liquid chromatography-mass spectrometry (LC-MS) and a detailed degradation pathway has been proposed.

Degradation of imidacloprid using combined advanced oxidation processes based on hydrodynamic cavitation

Abstract: The harmful effects of wastewaters containing pesticides or insecticides on human and aquatic life impart the need of effectively treating the wastewater streams containing these contaminants. In the present work, hydrodynamic cavitation reactors have been applied for the degradation of imidacloprid with process intensification studies based on different additives and combination with other similar processes. Effect of different operating parameters viz. concentration (20–60 ppm), pressure (1–8 bar), temperature (34 °C, 39 °C and 42 °C) and initial pH (2.5–8.3) has been investigated initially using orifice plate as cavitating device. It has been observed that 23.85% degradation of imidacloprid is obtained at optimized set of operating parameters. The efficacy of different process intensifying approaches based on the use of hydrogen peroxide (20–80 ppm), Fenton’s reagent (H 2 O 2 :FeSO 4 ratio as 1:1, 1:2, 2:1, 2:2, 4:1 and 4:2), advanced Fenton process (H 2 O 2 :Iron Powder ratio as 1:1, 2:1 and 4:1) and combination of Na 2 S 2 O 8 and FeSO 4 (FeSO 4 :Na 2 S 2 O 8 ratio as 1:1, 1:2, 1:3 and 1:4) on the extent of degradation has been investigated. It was observed that near complete degradation of imidacloprid was achieved in all the cases at optimized values of process intensifying parameters. The time required for complete degradation of imidacloprid for approach based on hydrogen peroxide was 120 min where as for the Fenton and advance Fenton process, the required time was only 60 min. To check the effectiveness of hydrodynamic cavitation with different cavitating devices, few experiments were also performed with the help of slit venturi as a cavitating device at already optimized values of parameters. The present work has conclusively established that combined processes based on hydrodynamic cavitation can be effectively used for complete degradation of imidacloprid.

The issue of cavitation number value in studies of water treatment by hydrodynamic cavitation.

Abstract: Within the last years there has been a substantial increase in reports of utilization of hydrodynamic cavitation in various applications. It has came to our attention that many times the results are poorly repeatable with the main reason being that the researchers put significant emphasis on the value of the cavitation number when describing the conditions at which their device operates. In the present paper we firstly point to the fact that the cavitation number cannot be used as a single parameter that gives the cavitation condition and that large inconsistencies in the reports exist. Then we show experiments where the influences of the geometry, the flow velocity, the medium temperature and quality on the size, dynamics and aggressiveness of cavitation were assessed. Finally we show that there are significant inconsistencies in the definition of the cavitation number itself. In conclusions we propose a number of parameters, which should accompany any report on the utilization of hydrodynamic cavitation, to make it repeatable and to enable faster progress of science and technology development.