Faculty Publications

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    Performance Evaluation of Copper and German Silver Electrodes During Electrochemical Oxidation of Ametryn in Water
    (Springer Science and Business Media Deutschland GmbH, 2023) Manu, B.; Sangami, S.; Gritlahre, V.; Malviya, Y.
    The comparative electrocoagulation treatment was studied for the degradation and mineralization of ametryn in water using copper (CE) and German silver (GE) electrodes both in batch and continuous modes of operation. The operating variables such as the number of electrodes (2, 4), voltage (6, 12 V), current density (4–15 A/m2), initial concentration of ametryn (15, 20, 25 ppm), reaction time (0–120 min) and flow rate (0.5, 1, 1.5 Lph) were varied without changing the actual pH of the aqueous solution. The maximum removal of 80–85% of ametryn was achieved with a combination of 2 electrodes, 6 V, 1 Lph of flow rate and 80 min of reaction time. The copper electrode shows better performance than German silver electrodes, with less power consumption. The removal efficiency was decreased with increasing the initial concentration of ametryn and pH was gradually increased from 7–9.5. As the reaction proceeds, the pH was slowly increased in GE electrodes (7–9.6), which is more than in CE electrodes (7.8.6). The overall results revealed that CE and GE electrodes proved to be an alternative for other electrodes such as aluminum, iron and platinum. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.
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    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.
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    Synthesis of Green Iron Nanoparticles using Laterite and their application as a Fenton-like catalyst for the degradation of herbicide Ametryn in water
    (Elsevier B.V., 2017) Sangami, S.; Manu, B.
    The Fe nanoparticles were synthesized using eucalyptus leaf extracts. The low cost and locally available laterite was used as a source of iron rather than using iron salts (Ferrous sulfate, Ferric chloride etc.). The raw laterite particles (RLPs) and synthesized green iron nanoparticles (LGFeNPs) were characterized using FESEM-EDX, XRD, FTIR and BET techniques. The obtained results confirm that 20–70 nm of spherical iron particles were formed with surface area of 36.62m2?g. Later, the LGFeNPs were applied as a Fenton-like catalyst for the degradation ametryn in aqueous medium. The effect of variables (H2O2?COD (1–3.25), H2O2?Fe (2–10), pH (2–5) and reaction time (30–240)) involved in the treatment process was studied on two responses (COD and ametryn removal efficiency) using the response surface methodology. The optimum values were found to be 2.125, 6, 3.5 and 135 min for H2O2?COD, H2O2?Fe, pH and reaction time respectively with H2O2 dosage of 17 mg/L and 2.83 mg/L of LGFeNPs. The analysis of variance (ANOVA) results proved that, the obtained results were satisfactory with predicted values. Compared with chemical (NaBH4 reduction) and green synthesis using iron salts as a precursor, the laterite based green synthesis proved to be more effective in degradation of ametryn with faster reaction kinetics. © 2017 Elsevier B.V.
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    Optimization of Fenton’s oxidation of herbicide dicamba in water using response surface methodology
    (Springer Verlag, 2017) Sangami, S.; Manu, B.
    In this study Fenton’s oxidation of dicamba in aqueous medium was investigated by using the response surface methodology. The influence of H2O2/COD (A), H2O2/Fe2+ (B), pH (C) and reaction time (D) as independent variables were studied on two responses (COD and dicamba removal efficiency). The dosage of H2O2 (5.35–17.4 mM) and Fe2+ (0.09–2.13 mM) were varied and optimum percentage removal of dicamba of 84.01% with H2O2 and Fe2+ dosage of 11.38 and 0.33 mM respectively. The whole oxidation process was monitored by high performance liquid chromatography (HPLC) along with liquid chromatography/mass spectrometry (LC/MS). It was found that 82% of dicamba was mineralized to oxalic acid, chloride ion, CO2 and H2O, which was confirmed with COD removal of 81.53%. The regression analysis was performed, in which standard deviation (<4%), coefficient of variation (<8), F value (Fisher’s Test) (>2.74), coefficient of correlation (R2 = Radj2) and adequate precision (>12) were in good agreement with model values. Finally, the treatment process was validated by performing the additional experiments. © 2017, The Author(s).
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    Catalytic efficiency of laterite-based FeNPs for the mineralization of mixture of herbicides in water
    (Taylor and Francis Ltd. michael.wagreich@univie.ac.at, 2019) Sangami, S.; Manu, B.
    In this work, low cost, locally available laterite-based iron nanoparticles were synthesized using Tectona Grandis extract (Teak extract) with an average size of 75 nm. The synthesized FeNPs were applied as a heterogeneous Fenton catalyst for the oxidation of mixture herbicides, namely ametryn, dicamba and 2,4-D in water. The FeNPs were characterized for various analytical methods (field emission scanning electron microscopy-X-ray energy-dispersive spectrophotometer, XRD, FTIR and BET) and the effect of different variables (FeNPs dosage, H2O2, pH) was studied using the responses surface methodology. The initial herbicide concentration was considered as 25, 3.5 and 94 mg L?1 for 2,4-D, ametryn and dicamba, respectively, with the COD value of 172 mg L?1. The 100% degradation and mineralization was achieved in 135 min and >85% in 45 min (optimum dosage: FeNPs = 25.29 mg L?1, H2O2= 430 mg L?1 and pH = 5). The degradation kinetics were performed for both pseudo-first order and second order, it was observed that first-order kinetics (R2> 0.85) was well fitted in the treatment process. Recycling of FeNPs in five cycles was performed at optimum conditions and 10–40% of reduction in degradation efficiency was achieved. Finally, the whole treatment process was validated with a contour overlay plot and analysis of variance. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group.