Faculty Publications
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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 Adsorption mechanism of emerging and conventional phenolic compounds on graphene oxide nanoflakes in water(Elsevier B.V., 2018) Catherine, H.N.; Ou, M.-H.; Manu, B.; Shih, Y.-H.Emerging contaminants (ECs) such as bisphenol A (BPA), 4-nonylphenol (4-NP) and tetrabromobisphenol A (TBBPA) have gained immense attention worldwide due to their potential threat to humans and environment. Graphene oxide (GO) nanomaterial is considered as an important sorbent due to its exceptional range of environmental application owing to its unique properties. GO was also considered as one of ECs because of its potential hazard. The adsorption of organic contaminants such as phenolic ECs on GO affects the stability of GO nanoflakes in water and the fate of organic contaminants, which would cause further environmental risk. Therefore, the adsorption behaviors of emerging and common phenolic compounds (PCs) including phenol, 4-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, 4-NP, BPA and TBBPA on GO nanoflakes and their stability in water were studied. The adsorption equilibrium for all the compounds was reached <10 h and was fitted with Langmuir and Freundlich isotherms. In addition to hydrophobic effect, adsorption mechanisms included ?-? bonding and hydrogen bonding interactions between the adsorbate and GO, especially the electrostatic interactions were observed. Phenol has the highest adsorption affinity due to the formation of hydrogen bond. GO has a good stability in water even after the adsorption of PCs in the presence of a common electrolyte, which could affect its transport with organic contaminants in the environment. These better understandings illustrate the mechanism of emerging and common PC interaction with GO nanoflakes and facilitate the prediction of the contaminant fate in the aquatic environment. © 2018 Elsevier B.V.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 Evaluation of pyrolyzed areca husk as a potential adsorbent for the removal of Fe2+ ions from aqueous solutions(Academic Press, 2019) Sheeka Subramani, B.; Shrihari, S.; Manu, B.; BabuNarayan, K.S.[No abstract available]Item Removal of ametryn and organic matter from wastewater using sequential anaerobic-aerobic batch reactor: A performance evaluation study(Academic Press, 2019) Mahesh, G.B.; Manu, B.The present study was aimed to investigate biodegradation of 2-(ethylamino)-4-(isopropylamino)-6-(methylthio)-s-triazine (ametryn) in a laboratory-scale anaerobic sequential batch reactor (ASBR) and followed by aerobic post-treatment. Co-treatment of ametryn with starch is carried out at ambient environmental conditions. The treatment process lasted up to 150 days of operation at a constant hydraulic retention time (HRT) of 24 h and an organic loading rate (OLR) of 0.21–0.215 kg-COD/m3/d. Ametryn concentration of 4 and 6 mg/L was removed completely within 48–50 days of operation with chemical oxygen demand (COD) removal efficiencies >85% at optimum reactor conditions. Ametryn acted as a nutrient/carbon source rather causing toxicity and contributed to methane gas production and sludge granulation in the anaerobic reactor. Biotransformation products of ametryn to cyanuric acid, biuret, and their further conversion to ammonia nitrogen and CO2 are monitored during the study. Adsorption of ametryn on to reactor sludge was negligible, sludge granulation, presence of ANAMMOX bacteria, and low MLVSS/MLSS ratio between 0.68 and 0.72. The study revealed that ametryn removal occurred mainly due to biodegradation and co-metabolism processes. Aerobic post-treatment of anaerobic effluent was able to remove COD up to 95%. The results of this study exhibit that anaerobic-aerobic treatment is feasible due to easy operation, economic, and highly efficient. © 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 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.Item Sustainable replacement of EDTA–Biojarosite for commercial iron in the Fenton’s and UV–Fenton’s degradation of Rhowedamine B – a process optimization using Box–Behnken method(IWA Publishing, 2022) Bhaskar, S.; Rashmishree, K.N.; Manu, B.; Sreenivasa, M.Y.Biojarosite as a replacement for commercial iron catalyst in the oxidative degradation of the dye Rhodamine B was confirmed and established. Investigations on the oxidative degradation by Fenton’s oxidation and UV–Fenton’s oxidation with EDTA at neutral pH were conducted and degradation of target compound was evaluated. UV–Fenton’s oxidation was shown to be efficient over Fenton’s oxidation in the degradation of Rhodamine B with removal efficiency of 90.0%. Design of Experiments was performed with Box–Behnken design. Investigation was conducted for the predicted values separately for both Fenton’s oxidation and UV–Fenton’s oxidation and the Rhodamine B removal was taken as response. Variable parameters biojarosite, H2O2 dosage and EDTA were optimized in the range of 0.1–1 g/L, 2.94–29.4 mM and 10–100 mM, respectively. A quadratic regression model is fitted for both Fenton’s and UV–Fenton’s oxidation. Analysis of variance (ANOVA) is performed and model fit is discussed. © 2022 The Authors.