Vermicomposting emerges as an eco-friendly solution to manage a blend of agricultural residues and digested biogas slurry (DBS). This research probes the influence of two specific earthworm species, Eisenia fetida and Eugilius euganiae, on the composting dynamics of agro-residues and DBS. Moreover, it gauges their consequential impact on the growth of chili and brinjal plants. The research was conducted at the Sharda Vihar Campus in Bhopal. Several process variables, such as pH, salinity, moisture levels, temperature, carbon-to-nitrogen (C/N) ratio, nitrogen (N), phosphorus (P), potassium (K), presence of pathogens, and monoculture trends, were assessed for their influence on vermicompost yield and its effect on chili and brinjal growth. Intriguingly, reactors employing E. fetida exhibited a vermicast recovery rate of 89.7%, whereas those utilizing E. eugeniae achieved 68.2% recovery, especially with an earthworm density of 125 individuals per liter. Notably, the derived NPK values from various composted and vermicomposted materials ranged from 1.5 to 1.7% for N, 0.98 to 1.19% for P, and 1.1 to 1.49% for K. This suggests its viability as both a fertilizer and soil enhancer. The E. fetida vermicompost-enriched soil notably boosted the yield of chili and brinjal. Overall, these insights highlight vermicomposting’s dual utility in waste management and augmenting bioresources.

The use of inorganic nitrogen fertilizers in agricultural applications and oxidation of human and animal by-products, including septic discharge, has led to a considerable increase in nitrate contamination in water bodies. This excess nitrate is responsible for considerable damage to humans and biota. As a result, the removal of nitrate anions from groundwater, rivers, and lakes is critical. In most countries, the content of nitrates as an environmental quality guideline has recently been established to be less than 10 mg/L. Hence, the removal of nitrate ions from groundwater, rivers, and lakes is critical because contamination is expected to become increasingly severe in the future. Against this background, the development of an effective and sustainable treatment approach in the form of adsorption is becoming increasingly desirable. This review work specifically focuses on the effectiveness of carbonaceous materials for nitrate adsorption, with their production, modification, characterization, and morphology investigated in detail. In addition, challenges and future opportunities for applying carbonaceous materials as adsorbents for nitrate removal are also addressed. From the literature results, it has been found that there is an enhancement in the surface area through chemical activation for better nitrate adsorption. It has also been found in the literature that the maximum nitrate adsorption was on a biographene nanosheet-based wheat straw biochar at an initial nitrate concentration of 150 mg/L and a of pH of 7.17. Researchers have reported that the adsorption process with applications of carbonaceous materials is promising for the removal of the nitrate ion, but finding cost-effective, environmentally sound, and efficient adsorbents concurrently for nitrate removal from aqueous solutions remains a challenge at the industrial scale, which should be addressed in future research.

Groundwater is a critical resource for the development of any region. In Bhopal, groundwater is also used for various purposes, including domestic use and irrigation. Overexploitation due to increasing demand coupled with pollution raises concern about the sustainability of groundwater supplies in the future. This study aimed to analyze trends in groundwater parameters in Bhopal over 22 years using the Mann-Kendall (MK) and Modified Mann-Kendall (MMK) trend tests in MATLAB. The parameters SO₄²⁻, Ca²⁺, HCO₃⁻, NO₃⁻, and F⁻ showed a decreasing trend, while the trends for pH were mixed. In contrast, the Na⁺ and Cl⁻ levels significantly increased in both trend tests, suggesting the effects of various existing aquifer conditions and human activities whose long-term exposure may lead to harmful effects. The results showed that nitrate and electrical conductivity levels exceeded the permissible limits. The MMK method provided more accurate results than the traditional Mann-Kendall method. The findings of this study are valuable for policymakers and water resource managers.