Publications by authors named "Thivaharan Varadavenkatesan"

The widespread use of 2,4-Dichlorophenoxyacetic acid (2,4-D) as a weedkiller has resulted in its persistence in the environment, leading to surface and groundwater pollution. In this study, the fixed bed column experiments were performed to remove 2,4-D from aqueous solutions using magnetic activated carbon derived from Peltophorum pterocarpum tree pods. The evaluation was done on effects of operating parameters such as bed depth (2-4 cm), influent flow rate (4.

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Article Synopsis
  • This study evaluated a magnetic activated carbon material (CPAC@FeO) made from copper pod tree pods for its ability to adsorb the harmful herbicide 2,4-D from water.
  • Characterization of CPAC@FeO revealed a high surface area, mesoporous structure, and strong magnetic properties, indicating its effectiveness in adsorption processes.
  • The adsorbent demonstrated high reusability and a maximum adsorption capacity of 246.43 to 261.03 mg/g, surpassing previous materials, making it a promising solution for removing 2,4-D from contaminated water.
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The current investigation reports the usage of adaptive neuro-fuzzy inference system (ANFIS) and artificial neural network (ANN), the two recognized machine learning techniques in modelling tetracycline (TC) adsorption onto Cynometra ramiflora fruit biomass derived activated carbon (AC). Many characterization methods utilized, confirmed the porous structure of synthesized AC. ANN and ANFIS models utilized pH, dose, initial TC concentration, mixing speed, time duration, and temperature as input parameters, whereas TC removal percentage was designated as the output parameter.

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The present study reports the synthesis, characterization, and application of sustainable magnetic biochar composite. The inedible fruits of Vateria indica, a powerful ayurvedic plant were hydrothermally transformed into magnetic biochar (BC-FeO) in a single step and characterized by several sophisticated techniques. FESEM analysis portrayed fibrous irregular mesh-like biochar with surface clustered FeO nanoparticles, while the incidence of carbon, oxygen, and iron in the elemental analysis by EDS established magnetic biochar formation.

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Article Synopsis
  • The research focused on the adsorption of 2,4-Dichlorophenoxyacetic acid (2,4-D) onto biochar made from Vateria indica fruits, using both traditional adsorption studies and advanced statistical physics models.
  • The study found that the biochar, characterized by a high specific surface area and diverse functional groups, exhibited a remarkable 91.67% adsorption efficiency for 10 mg/L of 2,4-D, indicating its efficacy as an adsorbent material.
  • Overall, the findings suggest that the adsorption process operates mainly through physisorption mechanisms, with favorable thermodynamic properties, highlighting the biochar's potential as a sustainable material for environmental cleanup.
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The usage of various herbicides in the agricultural field leads to water pollution which is a big threat to the environment. Herein, the pods of the Peltophorum pterocarpum tree were used as a cheap resource to synthesize activated carbon (AC) by low-temperature carbonization to remove 2,4-dichlorophenoxyacetic acid (2,4-D) - an abundantly used herbicide. The exceptional surface area (1078.

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The discovery of zero-dimensional carbonaceous nanostructures called carbon dots (CDs) and their unique properties associated with fluorescence, quantum confinement and size effects have intrigued researchers. There has been a substantial increase in the amount of research conducted on the lines of synthesis, characterization, modification, and enhancement of properties by doping or design of composite materials, and a diversification of their applications in sensing, catalysis, optoelectronics, photovoltaics, and imaging, among many others. CDs fulfill the need for inexpensive, simple, and continuous environmental monitoring, detection, and remediation of various contaminants such as metals, dyes, pesticides, antibiotics, and other chemicals.

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The present study aimed at the synthesis of cobalt oxide nanoparticles (CONPs) mediated by leaf extract of Muntingia calabura using a rapid and simple method and evaluation of its photocatalytic activity against methylene blue (MB) dye. UV-vis absorption spectrum showed multiple peaks with an optical band gap of 2.05 eV, which was concordant with the literature.

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The current study emphasizes the activated carbon fabrication from rubber fig leaves, the establishment of its composite with iron oxide nanoparticles (RFAC@FeO), and its relevance in the adsorptive elimination of tetracycline. The physical and functional properties of RFAC@FeO nanocomposite were uncovered by multiple approaches. Elemental analysis portrayed the existence of carbon, oxygen, and iron, while FESEM analysis revealed that FeO nanoparticle agglomerates were entrenched in the activated carbon matrix rendering it a rough abrasive texture.

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Herein, the sustainable fabrication of magnetic iron oxide nanoadsorbent prepared with activated carbon of inedible Cynometra ramiflora fruit has been investigated. Activated carbon was obtained from phosphoric acid-treated C. ramiflora fruit, which was then utilized for the synthesis of magnetic nanocomposite (CRAC@FeO).

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In the present study, ferric oxide nanoparticles impregnated with activated carbon from Ulva prolifera biomass (UPAC-FeO) were prepared and employed to remove 2,4-Dichlorophenoxyacetic acid (2,4-D) by adsorption. The UPAC-FeO nanocomposite was characterized for its structural and functional properties by a variety of techniques. The nanocomposite had a jagged, irregular surface with pores due to uneven scattering of FeO nanoparticles, whereas elemental analysis portrayed the incidence of carbon, oxygen, and iron.

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Nanotechnology is considered the budding discipline in various fields of science and technology. In this review, the various synthesis methods of iron and iron oxide nanoparticles were summarised with more emphasis on green synthesis - a sustainable and eco-friendly method. The mechanism of green synthesis of these nanomaterials was reviewed in recent literature.

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In this study, magnetite nanoparticles (MNPs) were synthesized using the seaweed - Ulva prolifera, an amply found marine source in the Western coastal regions of India. The surface and other properties of MNPs were characterized by many sophisticated methods. Spherical nanoclusters were observed in the FESEM image and iron and oxygen elements were seen in EDS results.

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This study deals with the synthesis of hydroxyapatite nanoparticles (HAPnps) mediated by Acacia falcata leaf extract. Aggregates of needle-shaped crystalline nanostructures were confirmed by FE-SEM and TEM analysis. Well-defined rings in the SAED patterns corroborated the polycrystalline nature of the HAPnps.

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The conventional synthesis of hematite nanoparticles (HNPs) is expensive and creates secondary contaminants. Therefore, to combat these issues, there is a requirement for a cheap, effective, and eco-friendly technique. Herein, HNPs were prepared using the fruit extract of Spondias pinnata - an abundant source available in Western-coastal India.

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The homeostasis of extremophiles is one that is a diamond hidden in the rough. The way extremophiles adapt to their extreme environments gives a clue into the true extent of what is possible when it comes to life. The discovery of new extremophiles is ever-expanding and an explosion of knowledge surrounding their successful existence in extreme environments is obviously perceived in scientific literature.

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Zirconium oxide nanoparticles (ZrONPs) were prepared using the leaf extract of Muntingia calabura as a reductant. The absorption peak at 232 nm confirmed the signature peak for ZrONPs with band energy at 5.07 eV.

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The present work reports the study on the green synthesis of hydroxyapatite (HAP) nanoadsorbents using Peltophorum pterocarpum pod extract. HAP nanoadsorbents were characterized by using FESEM, EDS, TEM, XRD, FTIR, XPS, and BET analyses. The results highlighted the high purity, needle-like aggregations, and crystalline nature of the prepared HAP nanoadsorbents.

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The present work reports the synthesis of hydroxyapatite (HAp) via the green chemistry approach by using the leaf extract of copper pod tree and its adsorptive potential to remove Acid blue 113 (AB113) dye. FESEM-EDS characterization of the synthesized HAp confirmed rod-shaped HAp with prominent Ca and P elements. The crystallinity of HAp was ascertained by XRD and thermal stability was analyzed by TGA.

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This study focused on the sustainable removal of chromium in its hexavalent form by adsorption using sugar-extracted spent marine macroalgal biomass - Ulva prolifera. The adsorption of Cr (VI) from aqueous solutions utilizing macroalgal biomass was studied under varying conditions of pH, adsorbent amount, agitation speed, and time to assess and optimize the process variables by using a statistical method - response surface methodology (RSM) to enhance the adsorption efficiency. The maximum adsorption efficiency of 99.

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The leaf extract of Muntingia calabura is being first reported to be used for the synthesis superparamagnetic hematite nanoparticles by following the green-chemistry approach. Field Emission - Scanning Electron Microscopic image revealed the formation of irregular nano spheroids averaging at 48.57 nm in size and characteristic of Fe and O atoms, as revealed by Energy Dispersive X-Ray spectrum.

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Article Synopsis
  • - The textile industry's effluent discharge poses significant environmental challenges, prompting research into absorption technologies for harmful dyes like Malachite Green using biochar from Chinese Fan Palm seeds.
  • - In a lab experiment, 1.346 kg of cleaned Chinese Fan Palm fruit was pyrolyzed at 500 °C, yielding 0.487 kg of biochar and 0.803 L of bio-oil, while the rest converted to gas.
  • - The study found that the adsorption of Malachite Green on the produced biochar fits well with the Langmuir isotherm model, with a maximum adsorption capacity of 21.4 mg/g and a high correlation coefficient over 0.97, indicating the model's
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Magnetic activated charcoal/FeO nanocomposite (AC/FeONC) was fabricated using Spondias dulcis leaf extract by a facile method and used for the adsorptive removal of 2,4-Dichlorophenoxyacetic acid (2,4-D) from aqueous solutions for the first time. The nanocomposite was characterized by methods such as FE-SEM, EDS, XRD, FTIR, TGA, VSM, and BET to identify and confirm the surface morphology, elemental composition, crystalline nature, functional groups, thermal stability, magnetic behavior, and surface area respectively. Box-Behnken Design (BBD) - an optimization method, which belongs to the Response surface methodology (RSM) and a modeling tool - Artificial Neural Network (ANN) were employed to design, optimize and predict the relationship between the input parameters (pH, initial concentration of 2,4-D, time and agitation speed) versus the output parameter (adsorption efficiency of 2,4-D).

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Third generation biomass (marine macroalgae) has been projected as a promising alternative energy resource for bioethanol production due to its high carbon and no lignin composition. However, the major challenge in the technologies of production lies in the fermentative bioconversion process. Therefore, in the present study the predictive ability of an integrated artificial neural network with genetic algorithm (ANN-GA) in the modelling of bioethanol production was investigated for an indigenous marine macroalgal biomass (Ulva prolifera) by a novel yeast strain, Saccharomyces cerevisiae NFCCI1248 using six fermentative parameters, viz.

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Article Synopsis
  • The study focuses on developing a new fluorescent probe (NIB) to target bioreductive enzymes called nitroreductases (NTR), which are overexpressed in hypoxic tumor cells, for imaging tumor hypoxia.
  • NIB was designed based on a nitronaphthalimide structure and showed favorable interactions with NTR, demonstrating its potential for effective reduction under hypoxic conditions.
  • Experimental results indicated that NIB could successfully visualize hypoxia in human breast cancer cells (MCF-7) by changing fluorescence properties, making it a promising tool for diagnostic applications in cancer.
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