Petroleum hydrocarbon (PHC) contamination is a widespread and severe environmental issue affecting many countries' resource sectors. PHCs are mixtures of hydrocarbon compounds with varying molar masses that naturally attenuate at different rates. Lighter fractions attenuate first, followed by medium-molar-mass constituents, while larger molecules remain for longer periods. This results in significant regulatory challenges concerning residual hydrocarbons in long-term contaminated soils. This study examined the potential risks associated with residual PHC and its implications for risk-based management of heavily contaminated soils (23,000-26,000 mg PHC/kg). Ecotoxicological properties, such as seedling emergence and growth of two native plant species-small Flinders grass (Iseilema membranaceum) and ruby saltbush (Enchylaena tomentosa)-and earthworm survival tests in PHC-contaminated soils, were assessed. Additionally, the effects of aging on the attenuation of PHC in contaminated soils were evaluated. Toxicity responses of plant growth parameters were determined as no-observed-effect concentrations: 75%-100% for seedling emergence, < 25%-75% for plant shoot height, and 75%-100% for earthworm survival. After 42 weeks of aging, the total PHC levels in weathered soils decreased by 14% to 30% and by 67% in diesel-spiked soil due to natural attenuation. Dehydrogenase enzyme activity in soils increased during the initial aging period. Furthermore, a clear shift of bacterial communities was observed in the soils following aging, including enrichment of PHC-resistant and -utilizing bacteria-for example, Nocardia sp. This study underscores the potential of natural attenuation for eco-friendly and cost-effective soil management, underlining that its success depends on site-specific factors like water content and nutrient availability. Therefore, we recommend detailed soil assessments to evaluate these conditions prior to adopting a risk-based management approach.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC10997687 | PMC |
http://dx.doi.org/10.1007/s11356-024-32593-7 | DOI Listing |
Front Microbiol
January 2025
School of Life Sciences, Hebei University, Baoding, China.
Introduction: Exploring the interactions between dark septate endophytes (DSE) in plant roots across diverse heavy metal habitats-considering host plants, site characteristics, and microbial communities-provides insights into the distribution patterns of DSE in metal-rich environments and their mechanisms for developing heavy metal resistance.
Methods: This study collected samples of three common plant species (, PA, , SV, and , AA) and their corresponding soil samples from three heavy metal-contaminated sites: Baiyang Lake, BY, Fengfeng mining area, FF, and Huangdao, HD. Utilizing high-throughput sequencing and physicochemical analysis methods, the biological and abiotic factors affecting DSE colonization and distribution in the roots were investigated.
Ann Glob Health
January 2025
Department of Environmental and Occupational Health, Dornsife School of Public Health, Drexel University, Philadelphia, PA 19104 USA.
Abandoned asbestos mines are a potential source of environmental contamination and exposure for nearby residents. The asbestos exposure risk may persist even after the cessation of mining activity if the mine is not properly closed. One such abandoned mine is at Roro Hills in the Jharkhand state of India.
View Article and Find Full Text PDFJ Community Hosp Intern Med Perspect
January 2025
University Maryland Medical Center Midtown Campus, Department of Internal Medicine, USA.
is a rod-shaped, flagellated, non-lactose fermenting, gram negative bacterium, usually found in water and soil habitats. generally causes nosocomial infections in immunocompromised patients. Increased infection rates are seen in those patients with medical devices inserted, due to this organism's innate ability to attach to moist and inanimate objects.
View Article and Find Full Text PDFACS Omega
January 2025
Laboratory of Biological Control of Plant Disease and Laboratory of Plant Biotechnology, Institute of Biotechnology, University of Caxias do Sul, Rua Francisco Getúlio Vargas, 1130, Petrópolis, Caxias do Sul, Rio Grande do Sul 95070-560, Brazil.
This work aimed to evaluate the potential of spp. in the bioremediation of herbicides and biostimulation of plants in herbicide-contaminated soils. In the first phase, the experiment followed a completely randomized design in a 4 × 3 × 4 factorial scheme with five replications, four strains of spp.
View Article and Find Full Text PDFInt J Phytoremediation
January 2025
College of Engineering, Agriculture Aviation Innovation Lab, South China Agriculture University, Guangzhou, China.
Biochar is a novel approach to remediating heavy metal-contaminated soil. Using various organic amendments like phyllosilicate-minerals (PSM), compost, biochar (BC) and sulfur-modified biochar (SMB), demonstrates superior adsorption capacity and stability compared to unmodified biochar (BC). The adsorption mechanisms of SMB are identified for its potential to increase soil-pH and reduce available cadmium (Cd).
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!