Browsing by Author "Saurabh Kumar Pathak"

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Agronomic practices and road proximity drive plastic pollution in agricultural soils: Insights from Bihar, India on weathering, elemental association, and ecological risk
(Elsevier Ltd, 2025) Jayant Karwadiya; Alok Ranjan Kerketta; Saurabh Kumar Pathak; S. Srivastava; Gopala Krishna Krishna Darbha
The widespread use of plastics in agriculture, particularly through mulching and polyhouse practices, has intensified concerns over soil contamination. However, limited research has addressed how spatial factors and agronomic practices, such as proximity to roads and mulching, influence macroplastics (MaP) and microplastics (MP) distribution in agricultural soils, particularly in India. This study assessed plastic contamination across 22 sites in six districts of Bihar, revealing mean MaP concentrations of 7.5 ± 3.6 particles kg−1 soil (d.w.) and MP levels ranging from 150 to 1460 particles kg−1 soil. MP concentrations were highest in mulched fields near roads (803 ± 371 particles kg−1), followed by distant mulched sites (657 ± 143 particles kg−1). Elevated levels were observed even in unmulched near-road fields (494 ± 327 particles kg−1), while the unmulched, distant fields (335 ± 76 particles kg−1) had the least contamination, indicating a combined influence of agricultural practices and road proximity. Polymer characterization revealed four types of MPs (PP > PE > PET > PS), with PE and PP accounting for over 95 % of the total. Weathering assessment via carbonyl index (CI) showed significantly higher values in MPs than MaPs, and field-extracted mulch films exhibited reduced contact angles relative to pristine films, indicating increased surface oxidation and hydrophilicity. Furthermore, MPs were found to adsorb multiple heavy metals, including Pb, Cu, Cr, Cd, Co, As, and Zn, highlighting risks of co-contaminant transport. Based on the MultiMP framework, all field types were classified as high-risk for MPs related impacts. These findings emphasize the need for sustainable plastic use in agriculture and call for targeted policy measures, including improved disposal practices and adoption of biodegradable alternatives, to mitigate long-term soil degradation and ecological harm. © 2025 Elsevier Ltd
An assessment of various potentially toxic elements and associated health risks in agricultural soil along the middle Gangetic basin, India
(Elsevier Ltd, 2022) Nidhi Tyagi; Munish Kumar Upadhyay; Arnab Majumdar; Saurabh Kumar Pathak; Biswajit Giri; Manoj Kumar Jaiswal; Sudhakar Srivastava
The present study analysed the levels of potentially toxic elements along with physico-chemical properties of agricultural soil samples (n = 59) collected from fields situated along the path of river Ganga in the middle Gangetic floodplain in two districts, Ballia and Ghazipur. Arsenic (As), chromium (Cr), copper (Cu), nickel (Ni), zinc (Zn), lead (Pb), iron (Fe) and manganese (Mn) levels were analysed by Wavelength Dispersive-X-Ray Fluorescence Spectroscopy (WD-XRF) and the associated health risks along with diverse indices were calculated. The mean concentrations of As, Cu, Cr, Pb, Zn and Ni were found to be 15, 42, 85, 18, 87 and 47 mg kg−1, respectively in Ballia and 13, 31, 73, 22, 77 and 34 mg kg−1, respectively in Ghazipur. Physico-chemical properties like pH, ORP and organic matter were found to be 7.91, 209 and 1.20, respectively in Ballia and 8.51, 155 and 1.25, respectively in Ghazipur. The calculated health quotient (HQ) for all the elements was observed to be within the threshold value of one, however with few exemptions. Therefore, the present study showcases the contamination of potentially toxic elements in agricultural fields and possible health hazards for people. © 2022 Elsevier Ltd
Application of Thiourea Ameliorates Stress and Reduces Accumulation of Arsenic in Wheat (Triticum aestivum L.) Plants Grown in Contaminated Field
(Springer, 2023) Anurakti Shukla; Saurabh Kumar Pathak; Shraddha Singh; Sudhakar Srivastava
The contamination of arsenic (As) in agricultural soil and groundwater poses a serious threat to both plants and human health worldwide. Wheat, being a predominant staple food crop, is considered a major source of carcinogenic threats due to As. The present study aimed to investigate the effect of a foliar spray of thiourea (TU; 500 mg L−1) on As accumulation in various parts of the plant, growth, and yield of wheat plants grown in contaminated field (soil As: 18.90 mg kg−1). Exogenous application of TU resulted in a significant decrease in As accumulation in grains (54% lower in comparison to control). The decrease in grain As reduced hazard quotient (HQ) and incremental lifetime cancer risk (ILCR) to safe levels. TU supplementation also improved the average grain yield by 30%. The shoot and root MDA concentrations were decreased by 26 and 60%, respectively at 75 d on TU supplementation. The activity of various antioxidant enzymes (superoxide dismutase, ascorbate peroxidase, guaiacol peroxidase, catalase, and glutathione reductase) in general depicted significant decline or no significant change denoting amelioration of As stress upon supply of TU. In conclusion, TU supplementation decreased As load in the wheat grains and enhanced the productivity of the crop by ameliorating As stress. The strategy of TU supplementation may find field application after evaluation of the strategy in several wheat varieties and in different environmental conditions. © 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
Charring the Waste Biomass To Precious Biochar: A Resource for Sustainable Agriculture
(Springer Science and Business Media Deutschland GmbH, 2025) Saurabh Kumar Pathak; Aman Kumar; S. Srivastava
Biochar has emerged as a sustainable tool in advancing the agricultural productivity. Biochar production and its application have drawn attention because of its unique properties, including carbon content, high specific surface area, stable structure, and cation exchange capacity. The papers selected for this review present the latest and appropriate information. Special attention was given to various modification techniques, biochar’s role in soil health, effects on crop productivity and pollutant remediation. Many sources such as Scopus, Elsevier, Springer and other online databases were used for searching the publications. Several previous studies have shown that biochar addition in the soils increased the mean crop productivity up to 10%. Despite the overall gain being slight, it was statistically significant. However, as part of the whole study, outcomes from every analysis ranged from − 28% to 39%. Additionally, biochar application enhances crop yield by 10–14% by altering soil texture and pH. Thus, improved water-holding capacity, crop nutrient availability, and the liming effect of biochar were the key factors for crop productivity. It also reduces the mobility and toxicity of various pollutants from soil and minimizing ecological risk. Moreover, biochar production can aid in the reduction of greenhouse gas emissions (6–90%). Although extend of mitigation largely depends on application rate and other environmental factors. Biochar surface qualities can be modified using physical or chemical techniques to make it better for the intended use. Oxidising agents, metal ions, acid, alkali, steam, and gas purging can be used to alter biochar and accordingly, biochar can be used to address various environmental issues. The preparation, modification, and environmental use of biochar are thoroughly examined and reported in this review. This review will contribute to our understanding of the viability, security, and efficiency of biochar use for sustaining soil fertility and enhancing plants’ resilience to various stresses. © The Author(s) under exclusive licence to Sociedad Chilena de la Ciencia del Suelo 2025.
Sulfur-modified tea-waste biochar improves rice growth in arsenic contaminated soil and reduces arsenic accumulation
(Elsevier Inc., 2024) Saurabh Kumar Pathak; Shraddha Singh; Vishnu D. Rajput; Shengdao Shan; Sudhakar Srivastava
Arsenic (As) is a non-essential carcinogenic metalloid and an issue of concern for rice crops. This study investigated the effects of sulfur-loaded tea waste biochar (TWB) due to modification with sodium sulfide (SSTWB) or thiourea (TUTWB) on As stress and accumulation in rice plants. The results showed that sulfur-modified TWB improved plant morphology compared to plants grown in As-contaminated soil alone. Biochar amendments elevated the activity of antioxidant enzymes in rice plants harvested at 15 and 30 days after transplant (DAT). Additionally, SSTWB and TUTWB significantly reduced As content in shoots by 26% and 19% at 15 DAT, respectively, as compared to TWB. This trend continued at 30 DAT with SSTWB achieving the maximum decrease of 30%. Similar reductions were observed in plant roots. The study suggests that sulfur-modified biochar amendments offer a promising strategy to mitigate the negative effects of As on, and reduce its accumulation in, rice. © 2024 The Authors
Syzygium aromaticum-mediated green synthesis of iron oxide nanoparticles for efficient heavy metal removal from aqueous solutions
(Elsevier B.V., 2024) Jyoti Yadav; Pratima Chauhan; Ravindra Kumar Rawat; Saurabh Kumar Pathak; Sudhakar Srivastava
The current study focused on the environmentally friendly synthesis of iron oxide nanoparticles (IONPs) using ferric nitrate Fe(NO3)3 9H2O as a precursor and aqueous Syzygium aromaticum (clove) extract as a reducing agent. Several analytical methods, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and ultraviolet–visible (UV–Vis.) spectroscopy, were used to confirm the synthesized iron oxide nanoparticles. These procedures were carried out to learn more about the surface shape and chemical composition of the produced iron oxide nanoparticles. The mean size of iron nanoparticles was determined by TEM examination to be 4.7 nm. The characterization revealed that the primary component of iron nanoparticles was magnetite when the Syzygium aromaticum extract was utilized as a reducing agent for Fe3+. For application, synthesized material was used to remove the harmful Cr (VI) ions from an aqueous solution. The batch adsorption approach was utilized to maximize the effects of significant elements such as pH, adsorbent dose, treatment duration, and initial Cr (VI) ions concentration to achieve the highest removal of Cr (VI) ions. The experimental adsorption data were fitted using various isotherm and kinetic adsorption models. © 2024 Indian Chemical Society