Faculty Publications
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Item Removal of acutely hazardous pharmaceuticals from water using multi-template imprinted polymer adsorbent(Ecomed Publishers susanne.kuehbandner@hjr-verlag.de, 2014) Venkatesh, A.; Chopra, N.; Krupadam, R.J.Molecularly imprinted polymer adsorbent has been prepared to remove a group of recalcitrant and acutely hazardous (p-type) chemicals from water and wastewaters. The polymer adsorbent exhibited twofold higher adsorption capacity than the commercially used polystyrene divinylbenzene resin (XAD) and powdered activated carbon adsorbents. Higher adsorption capacity of the polymer adsorbent was explained on the basis of high specific surface area formed during molecular imprinting process. Freundlich isotherms drawn showed that the adsorption of p-type chemicals onto polymer adsorbent was kinetically faster than the other reference adsorbents. Matrix effect on adsorption of p-type chemicals was minimal, and also polymer adsorbent was amenable to regeneration by washing with water/methanol (3:1, v/v) solution. The polymer adsorbent was unaltered in its adsorption capacity up to 10 cycles of adsorption and desorption, which will be more desirable in cost reduction of treatment compared with single-time-use activated carbon. © 2014 Springer-Verlag Berlin Heidelberg.Item A new strategy to refine crude Indian sardine oil(Japan Oil Chemists Society yukagaku@jocs-office.or.jp, 2017) Charanyaa, S.; Belur, B.D.; Iyyaswami, R.Current work aims to develop a refining process for removing phospholipids, free fatty acids (FFA), and metal ions without affecting n-3 polyunsaturated fatty acid (n-3 PUFA) esters present in the crude Indian sardine oil. Sardine oil was subjected to degumming with various acids (orthophosphoric acid, acetic acid, and lactic acid), conventional and membrane assisted deacidification using various solvents (methanol, ethanol, propanol and butanol) and bleaching with bleaching agents (GAC, activated earth and bentonite) and all the process parameters were further optimized. Degumming with 5%(w/w) ortho phosphoric acid, two stage solvent extraction with methanol at 1:1 (w/w) in each stage and bleaching with 3% (w/w) activated charcoal loading, at 80ºC for 10 minutes resulted in the reduction of phospholipid content to 5.66 ppm from 612.66 ppm, FFA to 0.56% from 5.64% with the complete removal of iron and mercury. Under these conditions, the obtained bleached oil showed an enhancement of n-3 PUFA from 16.39% (11.19 Eicosapentaenoic acid (EPA) + 5.20 Docosahexaenoic acid (DHA)) to 17.91% (11.81 EPA + 6.1 DHA). Replacing conventional solvent extraction with membrane deacidification using microporous, hydrophobic polytetrafluoroethylene membrane (PTFE), resulted in a lesser solvent residue (0.25% (w/w)) in the deacidified oil. In view of lack of reports on refining of n-3 PUFA rich marine oils without concomitant loss of n-3 PUFA, this report is significant. © 2017 by Japan Oil Chemists’ Society.Item 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 LtdItem Experimental investigation on sludge conditioning and dewatering using an agricultural biomass coupled with resource recovery(Academic Press, 2024) Chopade, G.; Devatha, C.P.In this study, the effect of modified areca husk fibre biochar (MAFB-AlCl3) on dairy sludge conditioning and dewatering along with raw and modified coconut shell biochar (MCSB-FeCl3) was investigated. Further, MgO impregnated biochars of areca husk fibre and coconut shells was carried out to evaluate the performance on phosphate recovery from the diary sludge. The enhancement in sludge dewatering with MAFB-AlCl3 were evaluated experimentally and significant reduction of capillary suction time (CST) (51.6 %), moisture content (18%), zeta potential (1.3 mV) and increased settleability (32.7%) were observed. The sludge conditioning parameters namely dosage (% of dry solids (DS)), rapid mixing time (RMT), slow mixing time (SMT) were optimized by response surface methodology for the modified biochars. Optimum CST (31.51 s) was obtained at dosage (50 % of DS), RMT (9.89 min) and SMT (17.23 min). Results of batch study for phosphate recovery by MgO impregnated biochars (MgB) was found to be 96.6 % and 100 % by MgB of areca husk fibre (MgAFB) and coconut shells (MgCSB) respectively. The morphological characteristics and elemental distribution using field emission scanning electron microscopy (FE-SEM) & energy dispersive X-ray spectroscopy (EDS) reveals the structural change in the sludge particles for the modified biochars as well as for sludge. Hence MAFB-AlCl3, MgAFB and MgCSB is proved to be suitable and an effective candidate for sludge conditioning and dewatering coupled with phosphate recovery in handling the diary sludge. © 2024 Elsevier LtdItem Combination of ensemble machine learning models in photocatalytic studies using nano TiO2 - Lignin based biochar(Elsevier Ltd, 2024) K C, A.; Sankar Rao, C.; Nair, V.Synergizing photocatalytic reactions with machine learning methods can effectively optimize and automate the remediation of pollutants. In this work, commercial Degussa TiO2 nanoparticles and lignin based biochar (LB) where used to prepare TiO2: lignin based biochar (TLB) composites using ultrasound-assisted co-precipitation method. The photocatalytic property of the TLB composites where studied by conducting the photocatalytic degradation of a Basic blue 41 (BB41) dye. The influence of calcination temperature, T:LB compositions, catalyst dosage, initial dye pH, initial dye concentration, and illumination time on photocatalytic dye degradation were experimentally studied. The degradation efficiency of 96.72 % was obtained under optimized conditions for the photocatalyst calcined at 500 °C containing a 1:1 wt percentage of TiO2 and LB. The experimental data was further used to predict the photocatalytic degradation efficiency using Gradient Tree Boosting (GTB) and Extra Trees (ET) models. The GTB model gave the highest prediction accuracy of 94 %. The permutation variable importance revealed catalyst dosage and dye concentration as the most influential parameters in the prediction of the photocatalytic dye degradation efficiency. © 2024 Elsevier LtdItem Mechanistic studies on bioremediation of dye using Aeromonas veronii immobilized peanut shell biochar(Academic Press Inc., 2024) Singh, A.; Manikandan, S.K.; Nair, V.Recalcitrant chemicals in the environment not only present obstacles to living organisms but also contribute to the degradation of natural resources. One contribution to environmental pollution is the discharge of synthetic dyes from the textile sector. This study investigates the combined effect of microbial cells and biochar on eliminating methyl orange (MO) dye. The immobilization of Aeromonas veronii on peanut shell biochar (APSB) was conducted to investigate its efficacy in removing MO dye from water. PSB synthesized by pyrolysis at 300 °C for 120 min showed maximum bacterial immobilization potential. The highest degradation rate of 96.19 % was achieved in APSB within 96 h using MO dye concentration of 100 mg L?1, incubation temperature of 37 °C, pH 7, and biocatalyst dosage of 1g L?1. In comparison, free cells achieved degradation rates of 72.53 % and 61.56 % for PSB. Moreover, the adsorption process was primarily controlled by PSB, with subsequent dye mineralization by A. veronii, as supported by FTIR and LC-MS studies. Moreover, this innovative approach exhibited the reusability of the biocatalyst, giving 76.23 % removal after fifth cycle, suggesting sustainable alternative in dye remediation and potential option for real-time applications. © 2024 Elsevier Inc.Item Non-reactive biochar and Bacillus pumilus RSB17-based healing powder: A sustainable solution for enhanced bacterial viability in self-healing mortar(Elsevier B.V., 2025) Anoop, P.P.; Palanisamy, T.Existing mortar uses self-healing powders that are based on mineral admixtures, whose reactive nature negatively impacts bacterial viability and diminishes their effectiveness over time. This study aims to develop non-reactive, sustainable biochar-based healing powders with extended bacterial viability to serve as self-healing admixture in bio-mortar. Biochar from coconut husk, coconut shell, and coconut leaf petiole was evaluated for compatibility with Bacillus pumilus RSB17, emphasizing bacterial growth and calcium carbonate precipitation. Coconut shell biochar demonstrated superior performance and was used to formulate a microbial biochar healing powder. Another healing powder was prepared by lyophilizing the bacterial spore solution without protectants. The shelf life was evaluated for 180 days at 4 °C and 25 °C, demonstrating that microbial biochar healing powder at 4 °C maintained bacterial viability above the 4.5 log CFU/g threshold necessary for effective calcium carbonate precipitation, while lyophilized spore powder stored at 25 °C dropped below the threshold at 90 days. Microbial biochar healing powder stored at 4 °C for 180 days was integrated into the mortar, which healed crack width up to 0.80 mm at 56 days under submerged rainwater maintained at 27 °C ± 2 °C and 85 % ± 5 % relative humidity. Electrical resistivity decreased from 28.16 ?·m to 21.35 ?·m, the permeability coefficient dropped from 153.90 mm/s to 0 mm/s, and compressive strength regained 90.53 %, which collectively indicated enhanced self-healing. Microstructural analysis confirmed the stable cuboid calcite crystals with a crystallite size of 86.62 nm. Thus, Microbial biochar healing powder produced from coconut shell biochar and Bacillus pumilus RSB17 and stored at 4 °C is an effective self-healing admixture for bio-mortar applications with a minimum storage period of 180 days. © 2025 Elsevier B.V.Item Effects of coconut shell charcoal powder combined with SBS on rheological properties of asphalt binder(Elsevier Ltd, 2025) Rahul, M.S.; Anjani, H.; T S, P.; Bhanu V, U.; Suresha, S.N.Conventional asphalt binders often suffer from inadequate stiffness, elasticity, and aging resistance under high temperatures and heavy traffic conditions. This study addresses these limitations by utilizing coconut shell charcoal powder (CSCP), a carbon-rich, porous biochar derived from agricultural waste, along with styrene-butadiene-styrene (SBS) polymer to enhance the rheological performance and sustainability of VG-30 asphalt binder. CSCP, incorporated at 2 %, 4 %, and 6 % by weight, provides high surface activity and thermal stability that improve binder stiffness and aging resistance, while 1 % SBS enhances elasticity and recovery through its elastomeric network. Rheological tests using the dynamic shear rheometer (DSR), multiple stress creep recovery (MSCR), and linear amplitude sweep (LAS) on unaged, rolling thin-film oven (RTFO)-aged, and pressure aging vessel (PAV)-aged samples, supported by field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR) analyses, revealed that the dual-modified binder (CSMB6S1) achieved an optimal balance of stiffness and elasticity, exhibiting superior rutting resistance, fatigue life, and high-temperature stability. The results highlight the synergistic reinforcement between CSCP and SBS and demonstrate the potential of coconut shell–derived carbon as a sustainable modifier for high-performance asphalt pavements. © 2025 Elsevier Ltd.