Poultry litter (PL) and plant growth-promoting rhizobacteria (PGPR) are being evaluated as cost-effective alternatives to conventional agrochemicals. Flue gas desulfurization (FGD) gypsum (FGD-gypsum) has also shown promise in recent years as a potential bedding replacement for poultry production. However, limited research has explored the effects of FGD-gypsum litter amendments alone or with PGPR on soil microbial functionality. This study aimed to (i) evaluate the impact of PGPR on soil microbial community function, dehydrogenase activity, and pH in soil amended with various FGD-gypsum PLs, and (ii) explore the relationships among microbial functional indices, dehydrogenase activity, and pH. Four PL types, SD (shaving, decaked), SWR (shaving, windrowed and rotovated), GD (FGD-gypsum, decaked), and GWR (FGD-gypsum, windrowed and rotovated), plus an unamended control (CTL) were evaluated, with and without a Bacillus-based PGPR consortium. The results showed that PGPR enhanced average well color development (AWCD) and substrate richness by 18.7
Lake Sevan (Armenia), the largest high-altitude freshwater lake in Eurasia, has an ecologically important catchment. However, data on trace elements (TEs) in the sediments and waters of rivers feeding Lake Sevan remain limited. To address this, sediment and water samples were collected across the basin to determine water-soluble TEs in sediments and dissolved TEs in river waters and to assess their spatial distribution, geochemical patterns, relative enrichment, and potential environmental and human health implications. Relative enrichment, pollution, and potential human health risks were evaluated using contamination factor (CF), pollution load index (PLI), Nemerow pollution index (NPI), and hazard index (HI). Results showed substantial spatial variability in TE concentrations, consistent with the combined influence of geological conditions and anthropogenic pressures. Cluster analysis separated upper and lower river reaches into geochemical groups. CF indicated high relative enrichment in the water-soluble sediment fraction by As, Mn, Mo, Ni, Pb, Sb, and V at specific locations, with the upper Masrik River system, downstream of the Sotk gold mine, showing the most pronounced relative enrichment. This pattern is consistent with the mineralogical characteristics of the Sotk deposit and may reflect mining-related inputs. PLI revealed pronounced spatial variability in the combined relative enrichment of water-soluble TEs, with the highest enrichment in the upper Masrik River system and elevated values at sites in the lower reaches of the Dzknaget, Karchaghbyur, and Gavaraget rivers and the Masrik River system. In waters, most TE concentrations were within local standards, but NPI indicated heavy pollution in the Masrik River system and the lower reaches of the Gavaraget and Vardenis rivers. Health risk assessment indicated potential non-carcinogenic risks under the hypothetical drinking-water exposure scenario in the upper Masrik River system and occasionally in the lower Masrik River system, primarily associated with elevated dissolved As and Sb levels. Principal component analysis further supported spatial differentiation in TE composition and identified distinct elemental associations among sampling sites. Overall, the Masrik–Sotk system emerged as the most prominent area of multi-element enrichment among the investigated sites, while localized enrichment was also observed in several other downstream reaches.
This study evaluates the current status of groundwater quality and its suitability for domestic, irrigation, and industrial applications within Tien Giang province, Vietnam, located in the Mekong Delta area. Groundwater samples were collected from 31 locations during March, June, and September in 2020 and 2022, and analyzed for key physico-chemical and microbial parameters. Water quality analysis was conducted by direct comparison with national water quality standards (QCVN 09-MT:2015/BTNMT for groundwater quality; QCVN 01–1:2018/BYT for domestic water quality) and statistical analysis using the Integrated Water Quality Index (IWQI), Principal Component Analysis (PCA), and Absolute Principal Component Score-Multiple Linear Regression (APCS-MLR). Results revealed that while most parameters met general groundwater standards according to QCVN 09-MT:2015/BTNMT, and IWQI classified samples as good and excellent, indicating suitability for irrigation. However, a pollution risk was observed for heavy metal concentrations, which suggests water treatment before consumption. Due to stricter domestic water regulations according to QCVN 01–1:2018/BYT, many groundwater samples were found unsuitable for consumption: Fe (65.6
Odorous emissions from agricultural and industrial activities are a major source of pollution. As urban areas expand, odor sources often lie closer to sensitive receptors, intensifying conflicts and attracting growing attention from researchers and regulators. In Europe, odor has recently been acknowledged as an atmospheric pollutant in the revised Industrial Emissions Directive (IED 2.0). However, the absence of harmonized Odor Impact Criteria (OICs) across jurisdictions results in highly variable approaches to odor impact assessment. This study analyzes the implications of such regulatory heterogeneity through a comparative evaluation of existing OICs and their application using the CALPUFF dispersion model. Results show that different OIC definitions—combining concentration thresholds, percentiles, and averaging times—lead to substantial variation in predicted impacts. Non-European countries generally exhibit higher exceedance percentages and broader isopleths, whereas European regulations tend to yield lower exceedance levels more localized around sources. Nevertheless, considerable variability is also found within Europe, even between regions of the same country, with Italy standing out for applying the strictest criteria in Europe. Population density emerges as a statistically significant driver of regulatory stringency, reflecting attempts to balance environmental health protection with industrial and economic development. While stricter OICs strengthen safeguards for exposed populations, they may also impose higher compliance costs, whereas more lenient criteria risk undermining citizens’ well-being and property values. The findings highlight the risks of adopting OICs without critical evaluation and underscore the need for harmonized standards—particularly within the EU—to ensure consistent environmental protection.
Biochar is a valuable soil amendment widely used in agriculture to improve soil health, enhance crop productivity, and strengthen climate resilience, thereby supporting sustainable farming systems. In this study, biochar derived from common rush (Juncus effusus) grown on the watershed was evaluated for its ability to improve soil quality, increase water retention, enhance nutrient availability, and stimulate beneficial microbial activity. The research was conducted at Prairie View A M University (PVAMU) research farms. The study investigated the effects of this biochar on soil physical and chemical properties, sorghum production, and greenhouse gas (GHG) emissions (CO₂, N₂O, and CH₄). Treatments included half, recommended, and double-recommended application rates based on standards established by the United States Department of Agriculture (USDA). Although the double-recommended rate yielded the highest biomass and grain yield, it did not align with USDA guidelines (grain yield: 8.1–8.3 kg per 240 ft² plot compared with 4.16 kg per 240 ft² in the control). The recommended fertilizer rate performed best among the compliant treatments and improved soil moisture retention, nutrient availability, and overall soil quality (soil moisture increased by approximately 10–18
