Raja Selvaraj

• B.E. M.Tech.PhD
• Professor at Manipal Academy of Higher Education

The extensive use of herbicides in agriculture contributes to water pollution, posing a significant environmental risk. This study focused on the H3PO4 activation of Tabebuia aurea leaves to prepare activated carbon. The resulting adsorbent was then tested for its capability to eliminate 2,4-dichlorophenoxyacetic acid (2,4-D), the heinous herbicide...

The present work reports the secretion of biosurfactant by probiotic Lactobacillus plantarum SVP2 (SVP2-BS) in a previously formulated fermented EPS rich milk whey beverage. The cell-free BS-SVP2 was extracted from the fermented milk whey beverage by acid precipitation giving yield of 9.62 g/L. The surface of SVP2-BS was fibrous network-like with p...

Silver nanoparticles (SNPs) were successfully synthesised using Ficus elastica (rubber fig) leaf extract and applied as catalysts for the degradation of Congo Red (CR) dye. UV-Vis spectroscopy confirmed nanoparticle formation with a surface plasmon resonance peak at 423 nm. XRD analysis indicated a face-centred cubic crystalline structure with a me...

This study evaluates mesoporous-hydrochar derived from Acacia falcata leaves via a single-step hydrothermal treatment for Cr(VI) adsorption. Material characterization indicated that the adsorbent has a rough and porous structure. FTIR analysis confirmed Cr(VI) adsorption through functional group interactions, evidenced by peak intensity changes and...

Rising fuel security challenges can be addressed by utilizing potential and renewable energy feedstocks such as microalgae. This study focuses on biodiesel production from Desmodesmus armatus NCIM 5583 by optimizing biomass productivity and lipid content. Independent optimization experiments were performed to study key growth parameters, viz., ligh...

In our world of ever-growing energy demand, it is important to look for other suitable and sustainable fuel sources. Biofuels are a renewable and sustainable source of fuel produced from biological sources. In this direction, using microalgal biomass as a sustainable feedstock to produce biofuels has many advantages including their easy and economi...

We report a sustainable approach to synthesize silver nanoparticles (SNPs) using a bio-inspired method employing Lagerstroemia speciosa fruit extract. Characterized SNPs exhibited a spherical morphology with a hydrodynamic diameter of 61.12 nm and a face-centred cubic crystalline structure confirmed by XRD with a prominent peak at 38.79°. The synth...

Microalgal feedstock is a potential source for biodiesel production that addresses the challenges of fuel security and sustainable agriculture. This study aims to maximize biomass yield and lipid accumulation for freshwater microalga Monoraphidium sp. NCIM 5585 and utilize it for biodiesel production, contributing to the development of biocatalysis...

This report investigates the preparation, characterization, and application of activated carbon derived from Spathodea campanulata flowers (SCAC) to remove Congo Red (CR) dye from aqueous streams. SCAC was synthesized using orthophosphoric acid activation which yielded a mesoporous material with a specific surface area of (986.41 m²/g), significant...

The rapid growth of the textile industry has led to a sharp increase in dye-filled wastewater, posing a significant environmental concern. Adsorption is a promising method for dye removal, but traditional adsorbents often fall short due to limited capacity, lack of sustainability, and low selectivity. Nanocellulose-based materials have shown great...

As the aviation sector is experiencing phenomenal growth, the substantial demand for aviation fuel is also increasing. Synthesis of sustainable aviation fuel would help curb this enhanced demand while reducing greenhouse gas (GHGs) emissions. In this regard, bio-jet fuels have shown promising potential as they are renewable, release less CO2 on com...

Polyaromatic hydrocarbons (PAH) are severely toxic and degradation-resistant pollutants of environmental distress. They regularly pollute water systems, presenting significant risks to ecosystems and public health. PAH exposure leads to cancer, affects embryonic development and immune systems of various life forms. Biomasses possess remarkable surf...

Background Dandruff caused by Malassezia furfur is a prevailing fungal infection. Although ketoconazole (KTZ) is widely intended for anti‐dandruff treatment, poor solubility, and epidermal permeability limits its use and the marketed KTZ shampoo adversely effects scalp and hair. Objective To prepare a novel shampoo loaded with KTZ‐coated zinc oxid...

The increased global population has concurrently increased waste disposal, whose majority is conventional plastic. In this study, polyhydroxyalkanoates (PHA), an alternative biopolymer to conventional plastics, were extracted from bacteria Bacillus sp., using response surface methodology (RSM), a statistical approach. To design, optimize and study...

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 her...

Cocoa pod shells are the byproducts of the cocoa industry. These pod shells were explored for the biogenic synthesis of silver nanoparticles. The synthesized nanoparticles were characterized, and studies were carried out to assess the catalytic and antifungal activities. UV–Vis spectral analysis recorded the surface plasmon resonance at 438 nm. Sph...

Tetracycline (TC) contamination is prevalent in aquatic systems due to its uncontrolled and excessive use for medical, livestock, and veterinary purposes. Herein, we produced low-temperature carbonized mesoporous activated carbon (AC) from rubber fig leaves for TC removal. AC surface was coarse, patchy, and covered with flakes possessing uneven por...

Developing cost-effective, eco-friendly, efficient, stable, and unique catalytic systems remains a crucial issue in catalysis. Due to their superior physicochemical and electrochemical properties, exceptional structural characteristics, environmental friendliness, economic productivity, minimal energy demand, and abundant supply, a significant amou...

Benzo(a)pyrene, a five-ring polyaromatic hydrocarbon, originating from coal tar, crude oil, tobacco, grilled foods, car exhaust etc, is highly persistent in the environment. It has been classified as a Group I carcinogen, as on its ingestion in human body, diol epoxide metabolites are generated, which bind to DNA causing mutations and eventual canc...

α-Fe2O3 nanoparticles were synthesized using Tabebuia aurea leaf extract by a facile approach. The signature peaks for Fe and O in the EDX spectrum verified the formation of Fe2O3 nanoparticles. Cuboidal-shaped nanoparticles were observed in the FE-SEM image. In the XRD pattern, it was observed that the peaks belong to α-Fe2O3 nanoparticles. These...

Microplastics have been identified in all living forms including human beings, the present need is to restrain its spread and devise measures to remediate microplastics from polluted ecosystems. In this regard, the present review emphasizes on the occurrence, sources detection and toxic effects of microplastics in various ecosystems. The removal of...

Calcium hydroxide nanoadsorbent was prepared from waste bivalve clamshells and used for the adsorptive removal of Acid blue 113 (AB 113) dye. The morphology, elemental nature, functional groups, and thermal stability of the nanoadsorbent were characterized by various methods. The nanoadsorbent had a high monolayer adsorption capacity (153.53 mg/g)...

The current study emphasizes the activated carbon fabrication from rubber fig leaves, the establishment of its composite with iron oxide nanoparticles ([email protected]2O3), and its relevance in the adsorptive elimination of tetracycline. The physical and functional properties of [email protected]2O3 nanocomposite were uncovered by multiple approa...

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 t...

Tetracycline (TC) is one of the antibiotics, which is detected at high titre in aquatic systems, inducing microbial resistance. This study highlights the adsorptive removal of TC by activated carbon (AC) using low temperature carbonization obtained from Ulva prolifera macroalgal biomass – an abundantly available algae in southern Indian beaches. Th...

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 enh...

Hydroxyapatite nanoparticles (HAp NPs) were synthesized with Muntingia calabura leaf extract as solvent and eggshell waste as a calcium source. The synthesized nanoparticles were irregular rod-like, as visualized by FESEM, while EDX and XPS studies confirmed the formation of hydroxyapatite. The synthesized HAp NPs were polycrystalline and highly th...

In the present study, ferric oxide nanoparticles impregnated with activated carbon from Ulva prolifera biomass (UPAC-Fe2O3) were prepared and employed to remove 2,4-Dichlorophenoxyacetic acid (2,4-D) by adsorption. The UPAC-Fe2O3 nanocomposite was characterized for its structural and functional properties by a variety of techniques. The nanocomposi...

Global industrialisation and overexploitation of fossil fuels significantly impact greenhouse gas emissions, resulting in global warming and other environmental problems. Hence, investigations on capturing, storing, and utilising atmospheric CO2 create novel technologies. Few microorganisms, microalgae, and macroalgae utilise atmospheric CO2 for th...

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@Fe2O3). The formed nanocomposite...

Overexploitation of natural resources to meet human needs has considerably impacted CO2 emissions, contributing to global warming and severe climatic change. This review furnishes an understanding of the sources, brutality, and effects of CO2 emissions and compelling requirements for metamorphosis from a linear to a circular bioeconomy. A detailed...

In this study, gold nanospheres were synthesized due to catalytic reduction of gold ions by phytochemicals of Cyclea peltata leaf extract (CPAuNPs) in 5 h and subsequently used for removal of methyl green (MG) dye. CPAuNPs were characterized by UV–Visible spectrophotometry, scanning electron microscopy (SEM), energy-dispersive X ray spectroscopy (E...

Bacillus sp. WD22, previously isolated from refinery effluent, degraded 71% of C8 hydrocarbons present in 1.0% v/v PCO in seawater (control medium), which reduced to 16.3%, on addition of yeast extract. The bacteria produced a biosurfactant in both media, whose surface was observed to be amorphous in nature under FESEM-EDAX analysis. The biosurfact...

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...

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 rec...

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. Individual elements present in the HAPn...

The final sinkers of polyaromatic hydrocarbons are water sources, where they undergo bioaccumulation and biomagnification, leading to adverse mutagenic, carcinogenic, and teratogenic effects on exposure in flora, fauna, and humans. Two indigenous strains, Pseudomonas sp. WDE11 and Pseudomonas sp. WD23, isolated from refinery effluent, degraded over...

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 env...

Magnetite nanoparticles are prominently used in wastewater treatment for the removal of a range of contaminants. However, the usage of toxic and costly chemicals for their synthesis greatly limits their applications. Herein, we developed a cheap and sustainable process to synthesize magnetite nanoparticles (SS–Fe3O4NPs) by employing the extract of...

Heavy metals are dumped into the environment as a result of human activities, posing a serious threat to ecology and human health. Surface water, potable drinking water, potable groundwater, and majority of wastewater include their traces, due to which, their detection by nanoparticles has received a lot of attention in recent years. Although micro...

Zirconium oxide nanoparticles (ZrO2NPs) were prepared using the leaf extract of Muntingia calabura as a reductant. The absorption peak at 232 nm confirmed the signature peak for ZrO2NPs with band energy at 5.07 eV. The ZrO2NPs were tetragonal and highly crystalline, possessing a mean diameter of 14.83 nm as confirmed by XRD studies. The lattice con...

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. The...

Effect of oil spills on living forms demands for safe, ecofriendly and cost-effective methods to repair the damage. Pseudomonads have exceptional tolerance to xenobiotics and can grow at varied environmental conditions. This study aims at biosurfactant mediated degradation of petroleum crude oil by an indigenous Pseudomonas sp. WD23 in sea water. P...

Petroleum crude oil is cleared from marine environment at the site of oil spill by various physical, chemical and biological methods. Oil spills and released petroleum hydrocarbons have been treated by bioremediation in various countries and have proven to be successful. Even though there have been over 30 major and minor oil spills in India, with...

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 na...

This is the first report describing the photocatalysis-based degradation of 2,4-dichlorophenoxy acetic acid (2,4-D) under sunlight irradiation with zinc oxide nanoparticles (ZnO NPs) obtained by utilizing the phytocomoponents present in the leaf extract of Muntingia calabura. The synthesized ZnO NPs were seen as agglomerated nanoflower structures o...

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 ascer...

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 opt...

In the present study, magnetite nanoparticles (Fe3O4NPs) synthesized using Thunbergia grandiflora leaf extract as a reducing agent were doped with hydroxyapatite sourced from waste bivalve clamshells to produce hydroxyapatite/magnetite nanocomposite (HA/Fe3O4NPs). The magnetic nanocomposite was examined using several characterization techniques. Th...

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...

Green macroalgae comprise significant amount of structural carbohydrates for their conversion to liquid biofuels. However, it generally relies on species characteristics and the variability in seasonal profile to determine its route for bioprocessing. Hence, this study was conducted to analyze the indigenous marine macroalgal strain (Ulva prolifera...

I am happy to inform you that I have been listed in Top 2 Percentile researcher in the world, by science-wide author databases of standardized citation indicators released by Stanford University USA on 19 October, 2021. Stanford University has recently released a list that represents the top 2 percentile of the most-cited scientists in various dis...

Zn–Ni–TiO2 composite coating was developed through response surface methodology. The current density and concentration of TiO2 were optimized to obtain a minimum corrosion rate. The optimized condition obtained from the central composite design achieved a minimum experimental corrosion rate of 0.122 mm/year as a response for the Zn–Ni–TiO2 composit...

Magnetic activated charcoal/Fe2O3 nanocomposite (AC/Fe2O3NC) 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...

Metal nanoparticles have lately been considered as a very promising material in a host of applications such as medicine, catalysis, energy, electronics and environmental remediation. Their green synthesis is currently driving the trend owing to operational convenience and product stability. The approach is simple, rapid, ecofriendly and compatible...

Zinc oxide nanoflowers (ZnONFs) were prepared by employing the pod extract of Peltophorum pterocarpum as a green resource and characterized by various methods. UV–vis spectrum displayed a peak at 361 nm which confirmed the formation of ZnO nanoparticles. The optical band gap was calculated as 3.43 eV. FE-SEM images exposed the flower-like morpholog...

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 o...

The reach of nanotechnology has permeated into a range of disciplines and systematically revolutionized many manufacturing techniques. Today, nanoparticles are fabricated using varied approaches, each with its pros and cons. Of them, the green synthesis approach has been very effective in terms of overall economics and the stability of nanoparticle...

In the current work, the leaf extract of Bridelia retusa was used for the first time to synthesize zinc oxide nanoparticles (ZnONPs). A zinc nanoparticle-specific 364-nm peak was discerned via UV–Vis studies with a typical bandgap energy of 3.41 eV. FE-SEM micrographs revealed flower-shaped structure of the ZnONPs. EDS analysis corroborated the pre...

Dye removal from wastewater is of prominence due to its hostile effects on human health and the environment. The complex structure of the dye molecule is responsible for its difficulty in removal. Adsorption is found to be a promising technique to eliminate dye wastes due to its high removal capacity at low concentration. Among different adsorbents...

Aqueous two-phase system (ATPS) is long seen as a technique that promotes higher purity and yield in a single step. It is witnessing increased acceptance as a preferred choice for combined goals of concentration, separation and purification of a target product, be it industrially valuable or environmentally contaminating. Purification of biomolecul...

The present work has attempted to use broken rice as an economical substrate for the solid-state fermentation (SSF) mediated by Monascus sanguineus NFCCI 2453 for red pigment production. UV-Vis spectral and FTIR analyses were employed for the confirmation of the red pigment production. Response surface methodology (RSM) was used to optimize four si...

The need for biomaterials is in ever-increasing demand for a plethora of applications nowadays. Hydroxyapatite (HAP) is a primary constituent of bones and teeth in vertebrates. HAP and organic/inorganic-coated-HAP composites are fabricated to mimic the natural properties and also endow it with special characteristics like high porosity, surface are...

Mesoporous magnetite nanoparticles (Fe3O4NPs) were synthesized by using the leaf extract of Mussaenda erythrophylla (ME) by a cheap and simple method – green synthesis. The synthesized Fe3O4[email protected] were characterized by various techniques. A strong absorption spectrum without any specific peak in the UV-vis image designated the formation...

In the current study, Thunbergia grandiflora (Bengal clock vine) leaf extract has been used as green-resource to prepare Fe3O4 nanoparticles. SEM image showed agglomerated spherical (25 nm) particles, and EDS ascertained the existence of elemental iron (between 6 – 7 k eV) and oxygen (at 0.5 keV). XRD and XPS designated signature peaks for Fe3O4. B...

In the current study, the synthesis of hydroxyapatite (HAP) and its composite by various techniques, are abridged highlighting the eco-friendly technique – a green synthesis that involves the use of eco-friendly solvents like water and precursor substitution by waste resources. Magnetic HAP plays a major role in the HAP composites because of the ea...

A new producer of fungal inulinase Penicillium amphipolaria KAS 2555, has been isolated from the soil area of dead mangroves litter in Herikudru island, followed by the production and optimization of inulinase enzyme by solid-state fermentation (SSF) utilizing a cheap substrate – hardy sugarcane (Saccharum arundinaceum) stems. During the screening...

Regenerative medicine is becoming a fast-growing technique in today’s scenario for biomedical advancement. Researchers around the globe has suggested the involvement of naturally synthesized biomaterials for repairing and healing damaged cells. Already chemically synthesized hydroxyapatite (HAp) has been used for bone tissue engineering. But the lo...

Microporous α-Fe2O3 nanoparticles were synthesized by employing the extract of Spondias dulcis leaves by green-synthesis technique for the first time. The nanoparticles were characterized by many techniques. A continual absorption band without any peak in UV-vis spectrum and a strong signal for iron and oxygen atoms in EDS confirmed the formation o...

In the present investigation, a new fungal inulinase producer Penicillium amphipolaria KAS 2555 has been isolated from the soil of dead mangroves litter area, followed by the inulinase production and optimization by solid-state fermentation using a low-cost substrate – hardy sugarcane ( Saccharum arundinaceum ). While screening, only Penicillium am...

A bacterial strain PB1 with antagonistic activity against pathogenic fungi was isolated from marine soil and was identified as Paenibacillus elgii based on phenotypic and genotypic characterization. The isolate showed good antifungal activity against “Aspergillus niger (MTCC 282), Trichophyton rubrum (MTCC 791), Microsporum gypseum (MTCC 2819), Can...