Faculty Publications

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    Enhancing the Dewatering Ability of Sludge by Locally Available Biomass
    (Springer Nature, 2023) Chopade, G.; Devatha, C.P.
    In this study, the effect of modified coconut shell biochar is analyzed for its efficacy achievable in sludge dewatering properties. Initially the coconut shell biochar is modified at different molar concentrations of FeCl3, i.e., 1, 2, and up to 5 mol/L, and it is analyzed with different dosages at 0.1, 0.2, and up to 0.4 (g/g of dry solids (DS)) for the improvement in capillary suction time (CST) (s), moisture content reduction (%), filterability (min), and settleability (SV30%) of the sludge. It is found that there is significant decrease in each of these parameters. The optimization study is carried out to optimize the process of sludge conditioning, considering independent regression parameters as dosage (g/g of DS), molarity (M), mixing time (min), and response taken as moisture content (%), the optimum values for the dosage, molarity, mixing time is found to be 0.4 (g/g of DS), 2.5 M and 24.72 min, respectively, with optimized moisture content value of 78% was achieved. Hence, the modified coconut shell biochar can be used as a potential candidate to increase the dewatering ability of the sludge. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2023.
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    Nanomaterials modified bio asphalt as cutting-edge material for pavement construction: a review on the present status and future outlook
    (BioMed Central Ltd, 2025) Vidya, V.; Das, B.B.; Cyril Thomas, C.T.A.; Durairaj, M.; Bhuvaneshwari, B.
    Nanomaterials research field has gained prominence in scientific community. The current scenario of exhaustion of sustainable resources and excessive energy usage have impacted the research thrust on potential use of cutting-edge materials and technologies. The current scenario of nanomaterials modified bio asphalt (NMBA) for pavements is reviewed. Firstly, the blends of nanomaterial and bio asphalt studies with their performance aspects are summarized in a methodical manner highlighting the enhancements of conventional properties like penetration, ductility, softening point, viscosity, rheological characteristics namely age, fatigue, high and low temperatures. The outcomes of the review present that nano materials could considerably show improved viscosity, Low & high-temperature property of NMBA. The low temperature of NMBA is marginally reduced in comparison to bio-asphalt without nanoparticles. Additionally, sustainability of biochar modified bitumen is assessed, taking into account its economic viability, environmental impact, life cycle evaluation, and reduction of carbon footprint. Subsequently, potential paths ahead are explored unearthing its prospective applications and future prospects to support safer and sustainable roads. Large scale and real time implementation of such studies would contribute to reducing environmental burden and will pave way for achieving sustainable development goals. © The Author(s) 2025.
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    Nutmeg seed shell biochar as an effective adsorbent for removal of remazol brilliant blue reactive dye: kinetic, isotherm, and thermodynamic study
    (Taylor and Francis Ltd., 2022) Thomas, T.; Thalla, A.K.
    Biochar derived from agricultural wastes has emerged as an effective adsorbent for wastewater treatment. However, studies on nutmeg seed shell (NSS) utilization in textile wastewater treatment is limited. This study explores the possibility and efficacy of using a modified nutmeg seed shell as an adsorbent to remove remazol brilliant blue reactive dye (RBBR) from the aqueous wastewater. The adsorbent was characterized before and after adsorption using FTIR, FE-SEM, TGA, and XRD, respectively. Response surface methodology (RSM), based on Box–Behnken design (BBD), was utilized to optimize the effects of initial concentration (5–100 mg/L), pH (2–12), contact time (10–120 min), and adsorbent dosage (0.5–3 g/L) on the RBBR removal. The quadratic model generated by RSM describes the best relationship between the independent parameters and the dye removal efficiency. The optimum conditions for the RBBR dye removal were observed at an initial concentration of 100 mg/L, adsorbent dose of 2.85 g, pH of 10, and contact time of 110 min, which resulted in 93.41% removal efficiency. The adsorption model fits the pseudo-second-order and Langmuir isotherm models with correlation factors (R2) > 0.99. Langmuir adsorption isotherm gives an optimum adsorption capacity of 173.31 mg/g. The adsorption isotherm and kinetics study shows that the adsorption process is based on monolayer chemisorption. The thermodynamic studies suggest that adsorption is a spontaneous and endothermic process. The result indicates that modified NSS is an efficient adsorbent for removing reactive dye RBBR. © 2022 Taylor & Francis Group, LLC.
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    Role of coconut shell biochar and earthworm (Eudrilus euginea) in bioremediation and palak spinach (Spinacia oleracea L.) growth in cadmium-contaminated soil
    (Academic Press, 2022) Noronha, F.R.; Manikandan, S.K.; Nair, N.
    The contamination of soil with heavy metals is known to affect the yield the soil fertility, which in turn affects the growth of agricultural crops. This study investigates the role of coconut shell biochar (CSB) and earthworms (Eudrilus euginea) in the bioremediation and growth of Palak spinach (Spinacia oleracea L.) in cadmium (Cd) contaminated soil. The soils were amended with different combinations of CSB and earthworms and incubated for 35 days. Later, the soil samples were analyzed for the changes in the soil properties, soil enzyme activity, and heavy metal contents. It is observed that the treatments with both CSB and earthworms resulted in the improvement of soil properties and soil enzyme activity which was directly related to soil fertility. Meanwhile, the maximum removal of 94.38% of total Cd content in the soil was obtained for the soil sample contain both CSB and earthworms. The improved soil properties resulted in a higher germination percentage of Spinacia oleracea L. seeds in the Cd contaminated soil. © 2021 Elsevier Ltd
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    Effect of dry torrefaction pretreatment of the microwave-assisted catalytic pyrolysis of biomass using the machine learning approach
    (Elsevier Ltd, 2022) Ramesh, R.; Suriapparao, D.V.; Sankar Rao, C.S.; Sridevi, V.; Kumar, A.
    This study employs the Leave-One-Out cross-validation approach to build a machine-learning model using polynomial regression to predict pyro product yield through microwave-assisted pyrolysis of sawdust over KOH catalyst and graphite powder a susceptor. The determination of coefficient (R2) validates the developed models. All the developed models achieved a high prediction accuracy with R2 > 0.93, which signifies that the experimental values are in good agreement with the predicted one. The dependence of the catalyst loading and pretreatment temperature on dominating process parameters such as heating rate, pyrolysis temperature, susceptor thermal energy, and pyro products, namely bio-oil, biochar, and biogas, are explored. The yield of biochar is reduced; however, bio-oil and biogas are enhanced as the catalyst loading increased. On the other hand, increasing the temperature of pretreated sawdust decreased bio-oil and biogas yields while increasing biochar yields. Further, microwave conversion efficiency, and susceptor thermal energy increased with increased catalyst quantity and pretreatment temperatures of sawdust. It was observed that the average heating rate was increased by increasing the catalyst quantity while maintaining the same pyrolysis time until pretreatment temperatures of 150 °C were reached, after which the heating rate dropped due to the continuous microwave energy input to the system. © 2022 Elsevier Ltd
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    Composites of Lignin-Based Biochar with BiOCl for Photocatalytic Water Treatment: RSM Studies for Process Optimization
    (MDPI, 2023) Singh, A.K.; Giannakoudakis, D.A.; Arkas, M.; Triantafyllidis, K.S.; Nair, V.
    Textile effluents pose a massive threat to the aquatic environment, so, sustainable approaches for environmentally friendly multifunctional remediation methods degradation are still a challenge. In this study, composites consisting of bismuth oxyhalide nanoparticles, specifically bismuth oxychloride (BiOCl) nanoplatelets, and lignin-based biochar were synthesized following a one-step hydrolysis synthesis. The simultaneous photocatalytic and adsorptive remediation efficiency of the Biochar–BiOCl composites were studied for the removal of a benchmark azo anionic dye, methyl orange dye (MO). The influence of various parameters (such as catalyst dosage, initial dye concentration, and pH) on the photo-assisted removal was carried out and optimized using the Box–Behnken Design of RSM. The physicochemical properties of the nanomaterials were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, thermogravimetric analysis, nitrogen sorption, and UV–Vis diffuse reflectance spectroscopy (DRS). The maximum dye removal was observed at a catalyst dosage of 1.39 g/L, an initial dye concentration of 41.8 mg/L, and a pH of 3.15. The experiment performed under optimized conditions resulted in 100% degradation of the MO after 60 min of light exposure. The incorporation of activated biochar had a positive impact on the photocatalytic performance of the BiOCl photocatalyst for removing the MO due to favorable changes in the surface morphology, optical absorption, and specific surface area and hence the dispersion of the photo-active nanoparticles leading to more photocatalytic active sites. This study is within the frames of the design and development of green-oriented nanomaterials of low cost for advanced (waste)water treatment applications. © 2023 by the authors.
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    Phosphomolybdic acid embedded into biomass-derived biochar carbon electrode for supercapacitor applications
    (Elsevier B.V., 2023) J.e, M.; Chandewar, P.R.; Shee, D.; Mal, S.S.
    In high-performance, clean, safe, and cost-effective ways, supercapacitors are among the most promising ways to store and release nonfossil energy. In recent years, renewable biomass-derived activated carbon has been explored as a potential option for electrode material. It restricts their specific capacitance despite being environment-friendly and possessing intrinsic mechanical strength. In order to overcome this limitation and preserve all other properties, we are infusing polyoxometalate into the activated carbon; this increases specific capacitance with its fast reversible redox behaviour and preserves the carbon's characteristics. Beside suffusing phosphomolybdic acid (PMA) into biomass waste material, such as orange peel-derived activated carbon (OPAC), a new hybrid material (OPAC-PMA) was developed. The nanohybrid design was revealed by structural and morphological research, which showed high interfacial contact, allowing polyanions to redox rapidly. The novel hybrid electrode material (OPAC-PMA) has a capacitance value of 66% higher than the bare OPAC electrode. A further study showed that OPAC-PMA composite showed 88.23% cycle stability in 0.5 M H2SO4 electrolyte at 6 A g−1 for 4000 cycles. © 2023 Elsevier B.V.
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    Application of Box-Behnken Design in Optimization of the Okra (Abelmoschus esculentus L.) Plant Growth in Loamy Sand Soil
    (Springer Science and Business Media Deutschland GmbH, 2023) Shilli, A.; Manikandan, S.K.; Nair, V.
    Seedling emergence and its vigor index are the decisive steps for increasing vegetable crop yield performance using a sustainable approach. Response surface methodology (RSM) is an effective statistical method used to determine the significance of independent variables and the range of optimum conditions to maximize seedling growth in large-scale plant production. In this study, the RSM method was used to predict the maximum germination percentage and seed vigor index of an okra (Abelmoschus esculentus L.) plant in loamy sand soil. A Box-Behnken design of RSM having 15 triplicated runs was designed for okra seed germination experiments. A second-order polynomial model having three levels of biochar (10, 5.5, and 1%), cow dung (10, 5.5, and 1%), and water content (100, 70, and 40%) was used to optimize okra seed germination and seed vigor index. We evaluated the individual effect of biochar and cow dung manure on β-glucosidase and alkaline phosphatase activity in the soil. The results showed that the water content had a significant influence on the selected response variables. Based on the plant growth studies, the use of 5.5% of both biochar and cow dung concentration and 70% of water content in the soil resulted in the highest germination percentage and seed vigor index of 93% and 2479. The ANOVA studies revealed good agreement between the experimental data and the proposed model, indicating the suitability of the employed model in optimizing germination conditions. Enzyme activity analysis revealed that the amendment of 10% cow dung enhanced 55% β-glucosidase activity compared to control, while the application of 5.5% biochar along with cow dung improved 29% of alkaline phosphatase activity. The current study found that applying biochar and cow dung manure while maintaining water content can improve okra seedling emergence and growth in loamy sand soil. Future research includes long-term field experiments and studies on various biochar and their suitability for other soil types. Moreover, the RSM method can be used to study the effect of parameters like oxygen content, salt, heavy metals, and humus substance in soil on plant growth. © 2023, The Author(s) under exclusive licence to Sociedad Chilena de la Ciencia del Suelo.
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    A review on analysis of biochar produced from microwave-assisted pyrolysis of agricultural waste biomass
    (Elsevier B.V., 2023) Ramesh, R.; Surya, D.V.; Sankar Rao, C.S.; Yadav, A.; Sridevi, V.; Remya, N.
    Every year the agricultural product processing industries produce large quantities of agricultural waste biomass (AWB). Whose disposal has become a serious issue concerning solid waste management due to environmental and health issues. Microwave-assisted pyrolysis (MAP) is an intriguing technology for producing valuable products from waste feedstocks. AWB is converted into a valuable product like biochar by using MAP. The conversion of AWB into biochar by MAP is influenced by several factors such as type of feedstock, pyrolysis temperature, residence time, pressure, heating rate, susceptor, particle size, and microwave power. However, no review article is available to understand the role of MAP on biochar production from AWB. The current review focused on understanding the fundamentals of biochar production. It also reviews the challenges in producing biochar process by compatible, acceptable, and sustainable and its future directions to gain economic benefits even at small-scale applications. The generation of biochar from MAP and its uses in agriculture are discussed. The current review would address the knowledge gap and highlight the critical implications in biochar production and applications. © 2023 Elsevier B.V.
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    Two-step synthesis of biochar using torrefaction and microwave-assisted pyrolysis: Understanding the effects of torrefaction temperature and catalyst loading
    (Elsevier B.V., 2023) Ramesh, P.; Sankar Rao, C.S.; Surya, D.V.; Sridevi, V.; Kulkarni, A.
    The study focused on synthesizing the biochar from sawdust using torrefaction followed by pyrolysis. Sawdust was torrefied at different temperatures (125 °C, 150 °C, and 175 °C) using a conventional hot air oven. The obtained torrefied biochar was subjected to Microwave-assisted pyrolysis at a power of 300 W for 10 min. Graphite was used as a susceptor, and KOH was used as a catalyst. The maximum biochar product yield varied from 24 to 48 wt% and increased with torrefaction temperature. The average heating rates ranged from 54.5 to 74.6 °C/min. At 10 g of KOH, higher heating rates were obtained. The pyrolysis index analyzed varied between 97.5 and 111.5 and decreased with the increase in torrefaction temperature. The obtained biochar was analyzed using SEM, BET, XRD, FTIR, ICP-OES, and Raman spectroscopy. Porous structure formation enhanced, and the concentrations of Ca, Al, and Fe decreased with the increase in torrefaction temperature. © 2023 Elsevier B.V.