Faculty Publications
Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736
Publications by NITK Faculty
Browse
5 results
Search Results
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 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.Item Developing a biocatalyst showcasing the synergistic effect of rice husk biochar and bacterial cells for the removal of heavy metals(Royal Society of Chemistry, 2023) Manikandan, S.K.; Nair, V.Heavy metals like cadmium (Cd) and nickel (Ni) are toxic pollutants that affect the environment and pose health risks. Removal of Cd and Ni through bioremediation in the presence of biochar is a sustainable strategy. This study investigated the removal of Cd and Ni by Pseudomonas stutzeri immobilized on rice husk biochar (PRHB). The removal efficiency was calculated by varying the culture incubation time, pH, temperature, biocatalyst dosage, and initial metal ion concentration. PRHB showed a maximum metal removal capacity of 95% Cd and 92% Ni. The removal efficiency of PRHB was higher than that of free cells, which could be attributed to simultaneous adsorption, ion exchange, complexation, precipitation, and bioaccumulation caused by the biochar carrier and bacteria. The rice husk biochar material served as both an adsorbent and a carrier supplying nutrients for the growth of the bacteria. Considering the excellent metal ion removal capability and reusability, the use of PRHB could be a promising, cost-effective, and environment-friendly strategy for treating wastewater containing heavy metals. © 2023 The Royal Society of Chemistry.Item 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 Dual-role of coconut shell biochar as a soil enhancer and catalyst support in bioremediation(Springer Science and Business Media Deutschland GmbH, 2025) Manikandan, S.K.; Nair, V.The application of soil amendments has been proposed to influence soil properties, thereby improving agricultural productivity. They are known to increase the organic matter content, water holding capacity, and soil porosity, which play a significant role in the growth and development of plants. In work, experiments were carried out to evaluate the impact of coconut shell biochar as a soil amendment and microbial cell support to remediate cadmium-contaminated soil. To investigate the roles of biochar size and concentration on soil water holding capacity, the laterite loam soil is mixed with the biochar having different particle sizes of less than 1 mm, 1–2 mm, and 2–5 mm and concentrations of 1%, 5%, and 10% (w/w). The effects of combining biochar with different concentrations of 1%, 5%, and 10% (w/w) of farmyard manure on plant growth of Solanum lycopersicum L, soil nutrient changes, and enzyme activity are also investigated. The biochar particle size of <1 mm and concentration of 10% showed the highest (41.5%) water holding capacity and 90.47% germination, and 464.25 seed vigour index for Solanum lycopersicum L. Further 21 days soil incubation experiments were conducted to explain the effect of the biochar, and P. stutzeri immobilized on biochar on cadmium adsorption and bioavailability in soil. Cadmium removal of about 73.84% was obtained from contaminated soil compared to the control. It is suggested that coconut shell biochar generation from coconut shells could be a sustainable crop residue management option to enhance the soil physico chemical properties and also to remediate soil. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2023.