Faculty Publications
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Item Photocatalytic degradation of Irgalite violet dye using nickel ferrite nanoparticles(IWA Publishing, 2020) Vijay, S.; Mohan Balakrishnan, R.M.; Rene, E.R.; Priyanka, U.Nanotechnologies have prominent applications in the field of science and technology owing to their size-tunable properties providing a promising approach for degradation of various pollutants. In this scenario, the present work aims to study the effect of nickel ferrite nanoparticles on the degradation of Irgalite violet dye by Fenton’s reaction using oxalic acid as an oxidizing agent in the presence of sunlight. The effect of pH and adsorbent dosage on the rate of dye degradation was monitored. Based on these studies it was observed that 99% dye degradation was achieved for catalyst dosage of 0.2 g, 400 ppm dye concentration and 2.0 mM oxalic acid at pH 3.0 within 60 min. The studies reveal that the degradation follows pseudo-first-order kinetics and the catalyst reusability remained constant almost for five cycles. Further, nickel ferrite nanoparticles are proven to be an efficient alternative for the removal of dyes from coloured solutions. © 2020 IWA Publishing.Item Enhanced degradation of paracetamol by UV-C supported photo-Fenton process over Fenton oxidation(2011) Manu, B.; Mahamood, S.For the treatment of paracetamol in water, the UV-C Fenton oxidation process and classic Fenton oxidation have been found to be the most effective. Paracetamol reduction and chemical oxygen demand (COD) removal are measured as the objective functions to be maximized. The experimental conditions of the degradation of paracetamol are optimized by the Fenton process. Influent pH 3, initial H 2O 2 dosage 60 mg/L, [H 2O 2]/[Fe 2+] ratio 60 : 1 are the optimum conditions observed for 20 mg/L initial paracetamol concentration. At the optimum conditions, for 20 mg/L of initial paracetamol concentration, 82% paracetamol reduction and 68% COD removal by Fenton oxidation, and 91% paracetamol reduction and 82% COD removal by UV-C Fenton process are observed in a 120 min reaction time. By HPLC analysis, 100% removal of paracetamol is observed at the above optimum conditions for the Fenton process in 240 min and for the UV-C photo-Fenton process in 120 min. The methods are effective and they may be used in the paracetamol industry. © IWA Publishing 2011.Item Low cost Fenton's oxidative degradation of 4-nitroaniline using iron from laterite(IWA Publishing 12 Caxton Street London SW1H 0QS, 2016) Amritha, A.S.; Manu, B.The present study aims to establish the use of iron (Fe) from larerite in the case of Fenton's oxidation process which is a simple and cost-effective method for degradation of nitro compounds in effluents and in surface or ground water. 4-nitroaniline (4-NA) degradation by Fenton's oxidation method is the subject of the present study so as to optimize pH, hydrogen peroxide/iron (H/F) ratio at different initial concentrations of 4-NA. The optimum pH obtained was 3. The present study has also established optimum H/F ratio for the different initial concentrations of 4-NA for both conventional and use of Fe from laterite. The maximum removal efficiency of 99.84% was obtained for an H/F ratio of 100 for 0.5 mM initial concentration of 4-NA. The study establishes the use of Fe extracted from locally available laterite soil (LS) as a replacement of Fe salts so as to reduce the cost of the process. © 2016 IWA Publishing.Item Fenton's treatment of actual agriculture runoff water containing herbicides(IWA Publishing 12 Caxton Street London SW1H 0QS, 2017) Sangami, S.; Manu, B.This research was to study the efficiency of the Fenton's treatment process for the removal of three herbicides, namely 2,4-dichlorophenoxy acetic acid (2,4-D), ametryn and dicamba from the sugarcane field runoff water. The treatment process was designed with the Taguchi approach by varying the four factors such as H 2 O 2 /COD (1-3.5), H 2 O 2 /Fe 2+ (5-50), pH (2-5) and reaction time (30-240 min) as independent variables. Influence of these parameters on chemical oxygen demand (COD), ametryn, dicamba and 2,4-D removal efficiencies (dependent variables) were investigated by performing signal to noise ratio and other statistical analysis. The optimum conditions were found to be H 2 O 2 /COD: 2.125, H 2 O 2 /Fe 2+ : 27.5, pH: 3.5 and reaction time of 135 min for removal efficiencies of 100% for ametryn, 95.42% for dicamba, 88.2% for 2,4-D and with 75% of overall COD removal efficiencies. However, the percentage contribution of H 2 O 2 /COD ratio was observed to be significant among all four independent variables and were 44.16%, 67.57%, 51.85% and 50.66% for %COD, ametryn, dicamba and 2,4-D removal efficiencies, respectively. The maximum removal of herbicides was observed with the H 2 O 2 dosage of 5.44 mM and Fe 2+ dosage of 0.12 mM at pH 3.5. © IWA Publishing 2017 W.Item rGO/MnO2 nanowires for ultrasonic-combined Fenton assisted efficient degradation of Reactive Black 5(IWA Publishing 12 Caxton Street London SW1H 0QS, 2017) Ramesh, M.; Rao, M.P.; Rossignol, F.; Nagaraja, H.S.Reduced graphene oxide (rGO) coated manganese dioxide (MnO2) nanowires (NWs) were prepared by the hydrothermal method. Raman spectra confirmed the presence of rGO and the Brunauer-Emmett-Teller surface area of rGO/MnO2 NWs was found to be 59.1 m2g-1. The physico-chemical properties of prepared catalysts for the degradation of Reactive Black 5 (RB5) dye were investigated. 84% of RB5 dye in hydrogen peroxide solution was successfully degraded using rGO/MnO2 NWs, while only 63% was successfully degraded with pristine ?-MnO2 NWs in 60 min owing to the smaller crystallite size and large surface area. Further, the ultrasonic-combined Fenton process significantly enhanced the degradation rate to 95% of RB5 by the catalyst rGO/MnO2 NWs due to synergistic effects. The decomposition products identified using gas chromatography-mass spectrometry revealed a higher production rate of fragments in the ultrasonic-combined Fenton process. Therefore, rGO/MnO2 NWs with the ultrasonic-combined Fenton process is an efficient catalyst for the degradation of RB5, and may be used for environmental protection. © IWA Publishing 2017.Item Bacteriological synthesis of iron hydroxysulfate using an isolated Acidithiobacillus ferrooxidans strain and its application in ametryn degradation by Fenton's oxidation process(Academic Press, 2019) Bhaskar, S.; Manu, B.; Sreenivasa, M.Y.The investigation reports the application of biogenic jarosite, an iron hydroxy sulfate mineral in Fenton's Oxidation process. Ametryn, a herbicide detrimental to aquatic life and also to human is treated by Fenton's oxidation process using synthesized iron mineral, jarosite. The jarosite synthesis was carried out by using an isolated Acidithiobacillus ferrooxidans bacterial strain with ferrous as an iron supplement. The isolated strain was characterized by molecular techniques and biooxidation activity to ferrous to ferric iron was checked. On Fenton's treatment ametryn degradation upto 84.9% and COD removal to the extent of 56.1% was observed within 2 h of treatment and the reaction follows the pseudo first order kinetics with the curve best fit. The slight increase in kinetic rate constant on jarosite loading rate increase from 0.1 g/L to 0.5 g/L with H2O2 dosage of 100 mg/L confirms that jarosite has a catalytic role in the removal of ametryn. Mass spectroscopy analysis of treated synthetic ametryn solution at various intervals reveal the degradation follows dealkylation and hydroxylation pathway with the formation of three major intermediate compounds discussed here. © 2018 Elsevier LtdItem Acetaminophen micropollutant: Historical and current occurrences, toxicity, removal strategies and transformation pathways in different environments(Elsevier Ltd, 2019) Vo, H.N.; Le, G.K.; Nguyen, T.M.; Bui, X.-T.; Nguyen, K.H.; Rene, E.R.; Vo, T.D.H.; Cao Ngoc, N.-D.; Mohan, R.Acetaminophen (ACT) is commonly used as a counter painkiller and nowadays, it is increasingly present in the natural water environment. Although its concentrations are usually at the ppt to ppm levels, ACT can transform into various intermediates depending on the environmental conditions. Due to the complexity of the ACT degradation products and the intermediates, it poses a major challenge for monitoring, detection and to propose adequate treatment technologies. The main objectives of this review study were to assess (i) the occurrences and toxicities, (2) the removal technologies and (3) the transformation pathways and intermediates of ACT in four environmental compartments namely wastewater, surface water, ground water, and soil/sediments. Based on the review, it was observed that the ACT concentrations in wastewater can reach up to several hundreds of ppb. Amongst the different countries, China and the USA showed the highest ACT concentration in wastewater (?300 ?g/L), with a very high detection frequency (81–100%). Concerning surface water, the ACT concentrations were found to be at the ppt level. Some regions in France, Spain, Germany, Korea, USA, and UK comply with the recommended ACT concentration for drinking water (71 ng/L). Notably, ACT can transform and degrade into various metabolites such as aromatic derivatives or organic acids. Some of them (e.g., hydroquinone and benzoquinone) are toxic to human and other life forms. Thus, in water and wastewater treatment plants, tertiary treatment systems such as advanced oxidation, membrane separation, and hybrid processes should be used to remove the toxic metabolites of ACT. © 2019 Elsevier LtdItem Bioleaching of iron from fly ash using a novel isolated Acidithiobacillus ferrooxidans strain and evaluation of catalytic role of leached iron in the Fenton’s oxidation of Cephelaxin(Scientific Publishers, 2020) Bhaskar, S.; Manu, B.; Sreenivasa, M.Y.Iron is the sole energy source for the acidophilic bacterium Acidithiobacillus ferrooxidans. Feeding indirect iron source to this bacteria results in leaching of iron from complex minerals. In this study fly ash, a waste is fed to the isolated bacteria under stress condition and is made to recover the traces of iron present in the fly ash for its application as a Fenton’s catalyst to degrade Cephalexin. The investigation evaluates the leaching potential of a novel isolated strain Acidithiobacillus ferrooxidans BMSNITK17 in leaching iron from fly ash. About 89 mg/L of iron is recovered within the initial five days of inoculation. It is observed that the rate of metabolism of bacteria is very slow with fly ash as source. Catalytic efficiency of recovered iron was investigated to degrade Cephalexin, a major waste found in pharmaceutical and hospital discharge. About 87.98% of Cephalexin is degraded in first two hours with COD reduction of 74.21%. Reaction follows pseudo-first order kinetics with rate constant 0.017/min. © 2020 Scientific Publishers. All rights reserved.Item An efficient system for electro-Fenton oxidation of pesticide by a reduced graphene oxide-aminopyrazine@3DNi foam gas diffusion electrode(Elsevier B.V., 2020) Senthilnathan, J.; Younis, S.A.; Kwon, E.E.; Surenjan, A.; Kim, K.-H.; Yoshimura, M.A stable rGO-AmPyraz@3DNiF gas diffusion electrode was prepared via modification of 3D nickel foam (3D-NiF) with aminopyrazine functionalized reduced graphene oxide (rGO-AmPyraz) for the electro Fenton (EF) process. The generation capacity of H2O2 and OH radicals by this electrode was assessed relative to 3DNiF and rGO-AmPyraz@indium tin oxide (ITO) electrodes and with/without a coated Fe3O4 plate. The rGO-AmPyraz@3DNiF electrode showed the maximum production of these radicals at 2.2 mmol h?1 and 410 ?mol h?1, respectively (pH 3) with the least leaching of Ni2+ such as < 0.5 mg L?1 even after 5 cycles (e.g., relative to 3DNiF (24 mg L?1). Such control on Ni ion leaching was effective all across the tested pH from 3 to 8.5. Its H2O2 generation capacity was far higher than that of the nanocarbon supported on commercially available ITO conductive glass. The mineralization of dichlorvos (at initial concentration: 50 mg L?1) was confirmed with its complete degradation as the concentrations of the end products (e.g., free Cl?1 (5.36 mg L?1) and phosphate (12.89 mg L?1)) were in good agreement with their stoichiometric concentration in dichlorvos. As such, the proposed system can be recommended as an effective electrode to replace nanocarbon-based product commonly employed for EF processes. © 2020 Elsevier B.V.Item Bioleaching of iron from laterite soil using an isolated Acidithiobacillus ferrooxidans strain and application of leached laterite iron as Fenton’s catalyst in selective herbicide degradation(Public Library of Science, 2021) Bhaskar, S.; Manu, B.; Sreenivasa, M.Y.A novel isolated strain Acidithiobacillus ferrooxidans BMSNITK17 has been investigated for its bioleaching potential from lateritic soil and the results are presented. System conditions like pH, feed mineral particle size, pulp density, temperature, rotor speed influences bioleaching potential of Acidithiobcillus ferrooxidans BMSNITK17 in leaching out iron from laterite soil. Effect of sulfate addition on bioleaching efficiency is studied. The bioleached laterite iron (BLFe’s) on evaluation for its catalytic role in Fenton’s oxidation for the degradation of ametryn and dicamba exhibits 94.24% of ametryn degradation and 92.45% of dicamba degradation efficiency. Fenton’s oxidation performed well with the acidic pH 3. The study confirms the role of Acidithiobacillus ferrooxidans in leaching iron from lateritic ore and the usage of bioleached lateritic iron as catalyst in the Fenton’s Oxidation. © 2021 S et al.