Karan Sathish

This study examines the prevalence, characteristics, and distribution of microplastics in the Gaula River, Uttarakhand, India. Microplastics collected from surface water samples at four upstream and four downstream locations along the Gaula River in Uttarakhand were analyzed using SEM–EDS and FTIR spectroscopy to assess their concentration and composition. A total of 212 microplastic particles were identified, with higher downstream accumulation (122 particles) than upstream (90 particles). Fibers and fragments were the dominant shapes, primarily composed of polyethylene (PE) and polypropylene (PP). FTIR confirmed polymer-specific functional groups, while SEM–EDS revealed smooth surfaces with minimal heavy metal adsorption, indicating recent contamination. Findings suggest improper waste disposal and urban runoff as primary pollution sources. This study enhances understanding of microplastic pollution in freshwater ecosystems, particularly in urbanized regions, and underscores the urgent need for effective monitoring and mitigation strategies to reduce environmental impacts.

Understanding the impact of urbanization on soil quality is crucial for sustainable land management practices. This study was conducted in Bengaluru, India, to estimate the soil quality index (SQI) under different rural‒urban gradient (RUG) zones. Twenty-four sampling sites were identified along the RUG, and soil samples were collected monthly over five months during the October to February of 2020-2021. The soil quality assessment involved selecting the minimum data set (MDS) via principal component analysis (PCA) and correlation, scoring soil indicators, and combining these scores to create the soil quality index (SQI). PCA was used to identify key soil properties, which included microbial biomass carbon (MBC), SOC, N, manganese (Mn), and urease for different RUG zones derived from the MDS. The rural zones had the highest SQI (0.57), followed by the peri-urban (0.47 and 0.48) and urban (0.45 and 0.47) zones. These findings emphasize the importance of sustainable land management practices to preserve and boost soil quality across diverse regions, particularly in the face of rapid urbanization and industrialization.

Aims: This study explores the efficacy of sand filtration in treating greywater (GW) collected from a hostel. Methodology: An experimental setup was designed using five connected polyvinyl chloride (PVC) pipes filled with sand sourced from the Cauvery River. The GW was filtered through sand columns of varying lengths (40 ft, 60 ft, 80 ft, and 100 ft), with the filtered water analyzed for various physio-chemical parameters. Results: The results indicate that sand filtration significantly reduces the levels of total suspended solids (TSS), electrical conductivity (EC), and other anions and cations, including chloride (Cl⁻), sulphate (SO₄²⁻), and sodium (Na⁺). The pH of the untreated GW was initially alkaline but was reduced to near-neutral levels after treatment with the 100 ft sand column. Key water quality indices such as Sodium Adsorption Ratio (SAR), Sodium Ratio (SR), and Soluble Sodium Percentage (SSP) were within safe limits post-treatment, making the filtered GW suitable for irrigation. Conclusion: The study concludes that sand filtration is an effective method for treating GW, particularly when longer sand columns are used, though further research is needed to optimize the filtration process for specific contaminants.

Understanding the impact of diverse land-use systems (LUS) on soil quality is crucial for sustainable land management practices. This study was conducted in Bengaluru, India, to estimate the soil quality index (SQI) under different LUSs. Twenty-four sampling sites were identified in four different LUSs across the Bangaluru, and soil samples were collected monthly over five months during the Rabi cropping season of 2020-2021. The soil quality assessment involved selecting the minimum data set (MDS) via principal component analysis (PCA) and correlation, scoring soil indicators, and combining these scores to create the soil quality index (SQI). PCA was used to identify key soil properties, which included soil organic carbon (SOC), pH, dehydrogenase, nitrogen (N), and urease, for different LUSs derived from the MDS. The SQI was highest in the horticulture cropping system (0.58), followed by the agro + horticulture cropping system (0.53) and the vegetable cropping system (0.49), and lowest in the pulse cropping system (0.44). These findings emphasize the importance of sustainable land management practices to preserve and boost soil quality across cropping systems.

The study focused on the composition of soil mesofauna within changing cropping systems influenced by urbanization in Bengaluru, Karnataka, India during the rabi season of 2020 (October)–2021 (February). Four major cropping systems, namely pulses (red gram), vegetables (tomato and ridge gourd), horticulture (grapes and chickoo), and agriculture + horticulture crops, (coconut + fodder plantation), were examined across urban, peri-urban, and rural zones in Bengaluru. The research uncovered a total of 714 individuals belonging to 16 different soil mesofauna taxa among the crops studied. Collembolans were found to be the most abundant members of the mesofauna community, with mites following closely. In terms of population dynamics, the highest mesofauna population was observed in December 2020, totaling 248 individuals, while the lowest count was recorded in February 2021, with 104 individuals. Among the crops studied, the highest number of individuals was found in Horticulture systems, with 277 individuals, closely followed by the Agri + horticulture cropping system, which had 158 individuals. When considering the geographical zones, the highest number of individuals was recorded in the urban zones, with 270 individuals, followed by peri-urban areas with 229 individuals, and the rural zone had the lowest count, totaling 225 individuals. From the results, less disturbed soil environment in horticulture cropping system, post-monsoon conditions in December (2020), and the urban heat in urban zone appeared to favor the proliferation of soil mesofauna.

The study focused on the composition of soil mesofauna within changing cropping systems influenced by urbanization in Bengaluru, Karnataka, India during the rabi season of 2020–2021. Four major cropping systems, namely pulses, vegetables, horticulture, and agriculture + horticulture crops, were examined across urban, peri-urban, and rural zones in Bengaluru. The research uncovered a total of 714 individuals belonging to 16 different soil mesofauna taxa among the crops studied. Collembolans were found to be the most abundant members of the mesofauna community, with mites following closely. In terms of population dynamics, the highest mesofauna population was observed in December 2020, totaling 248 individuals, while the lowest count was recorded in February 2021, with 104 individuals. Among the crops studied, the highest number of individuals was found in Horticulture systems, with 277 individuals, closely followed by the Agri + horticulture cropping system, which had 158 individuals. When considering the geographical zones, the highest number of individuals was recorded in the urban zones, with 270 individuals, followed by peri-urban areas with 229 individuals, and the rural zone had the lowest count, totaling 225 individuals. It was observed that a less disturbed soil environment, post-monsoon conditions, and the urban heat appeared to favor the proliferation of soil mesofauna.