Coastal wetlands provide critical ecosystem services yet face increasing per- and polyfluoroalkyl substance (PFAS) contamination, and comparison of wetland microbiome responses to PFAS remains poorly resolved. Laboratory-enriched microbial consortia derived from freshwater marsh and salt marsh soils were exposed to perfluorooctanoic acid (PFOA) in 75-day microcosms at 0, 1, and 10 mg/L, then characterized by 16S rRNA gene sequencing, phylogenetic null modeling, neutral community modeling, and KEGG-level functional prediction. Both enriched consortia showed a modest decrease in aqueous PFOA (~11–13%) at 1 mg/L but not at 10 mg/L, consistent with a potential contribution from biosorption-mediated immobilization. Incubation time dominated beta-diversity shifts (ANOSIM R > 0.90, p = 0.001), while PFOA produced no detectable compositional separation. Exploratory additive mixed-effects models indicated that alpha diversity varied primarily with microbial community source and sampling day, whereas PFOA concentration showed a nominal overall association only with Shannon diversity. Assembly analyses showed that PFOA was associated with stronger heterogeneous selection in the salt-marsh-derived consortium, whereas the freshwater-derived consortium remained stochastically dominated. When PFOA-exposed samples were pooled across both enriched consortia, the neutral community model fit collapsed (R2 < 0), signaling a regime shift toward deterministic, PFOA-mediated selection. Functionally, the salt-marsh-derived consortium showed predicted enrichment in taurine/hypotaurine metabolism and broad-spectrum proteolytic functions (serralysin and creatinase), whereas the freshwater-marsh-derived consortium showed predicted enrichment in glutathione metabolism, xenobiotic dioxygenase functions, and DNA repair pathways. Candidate PFOA-sensitive (Pseudohongiella, Flavobacterium, Parvibaculum) and PFOA-tolerant (Sericytochromatia, Legionella) taxa were identified as source-associated candidate biomarkers. Under the tested culture conditions, PFOA responses differed between the laboratory-enriched freshwater-marsh- and salt-marsh-derived bacterial consortia. These results describe source-associated responses of the enriched consortia but may need further validation with native wetland communities.
Antidepressants are among the most widely prescribed pharmaceutical compounds worldwide and are increasingly recognised as contaminants of emerging concern owing to their occurrence in wastewater as parent compounds and metabolites. Their continuous release into aquatic systems reinforces the need for reliable analytical methods for environmental monitoring. In this study, a solid-phase extraction coupled with gas chromatography-tandem mass spectrometry method was developed and validated for the determination of five antidepressants in wastewater: fluoxetine, citalopram, sertraline, paroxetine, and venlafaxine. Different extraction conditions were assessed in order to improve analytical performance. Method validation was carried out according to Food and Drug Administration guidelines. The method showed good linearity over the concentration range of 49–25,000 ng/L, with coefficients of determination higher than 0.99. Limits of detection ranged from 12 to 195 ng/L, while limits of quantification ranged from 49 to 195 ng/L. Precision and accuracy were within acceptable limits, with coefficients of variation below 15%, and recoveries ranged from 6.91% to 81.14%. Most analytes remained stable under the tested conditions. The method was successfully applied to 50 real wastewater samples, confirming its applicability to the routine monitoring of antidepressants in this complex environmental matrix.
The co-pyrolysis of corncob (CC) and water hyacinth (WH) was investigated to characterize their thermal decomposition behavior, kinetic properties, and resulting biochars. Thermogravimetric (TGA) and derivative thermogravimetric (DTG) analyses were conducted at heating rates of 5 and 20 °C min−1 for the individual feedstocks and their blends. Biochars from CC, WH, and CC50:WH50 were produced at 350 °C and characterized for physicochemical properties. At 5 °C min−1, apparent activation energies estimated using the Coats–Redfern method were 135.4, 73.2, 83.1, 96.4, and 103.6 kJ mol−1 for CC, WH, CC30:WH70, CC50:WH50, respectively. Experimental and theoretical thermogravimetric profiles were compared to assess deviations from additive behavior. Biochar yields ranged from 39.22% to 46.17%, while mean pH values ranged from 9.34 to 9.56. One-way analysis of variance indicated significant treatment differences in yield, electrical conductivity, total nitrogen, available phosphorus, cation exchange capacity, and bulk density, whereas pH differences were not significant. WH biochar exhibited the highest electrical conductivity, total nitrogen, and available phosphorus, while CC50:WH50 had the highest cation exchange capacity and bulk density. These findings show that feedstock composition influences thermal behavior and biochar properties.
Mitigating nitrous oxide (N2O) emissions while maintaining maize productivity and soil quality is an important challenge for sustainable crop production. A three-year field experiment comprising six cropping seasons was conducted in tropical Thailand to evaluate the effects of soil-analysis-based fertilization (SF), two organically modified biochars—organic acid-soaked biochar (BI-OS) and co-composted biochar (BI-CP)—and selected combinations of these treatments with reduced tillage (RT) on N2O emissions, grain yield, and soil properties. Compared with traditional farmer practice (TP), SF reduced annual direct N2O emissions by 28.1% without a statistically significant reduction in grain yield. The addition of BI-OS to SF further reduced N2O emissions, whereas BI-CP resulted in emissions comparable to those under SF alone but provided greater improvements in soil fertility indicators. Among the tested treatments, SF+BI-OS+RT achieved the greatest N2O mitigation, reducing annual emissions by 46.6%, from 3.52 kg N2O ha−1 under TP to 1.88 kg N2O ha−1, while maintaining maize productivity and reducing yield-scaled emissions. In contrast, SF+BI-CP+RT produced the greatest increases in soil pH, cation exchange capacity, and soil organic carbon sequestration. Overall, integrating SF, organically modified biochar, and RT improved the environmental performance of tropical maize production, with BI-OS providing greater N2O mitigation and BI-CP offering greater benefits for soil fertility.
The efficiency of bioremediating oil-contaminated serozem (gray desert soil) of Southern Kazakhstan was investigated in the study. The first stage involved choosing hydrocarbon-degrading microorganisms suitable for the bioremediation of this desert soil. The second stage assessed the bioremediation potential of the selected microorganisms in laboratory microcosms. The final stage was a field trial experiment investigating oil removal under conditions of in situ natural attenuation, biostimulation (application of NPK fertilizer Nitroammophoska), reintroduction of indigenous oil-degrading microorganisms isolated from soils of the Aral Sea region and bioaugmentation using degrader strains from the laboratory collection. Additionally, the resulting native desert soil microbiomes were compared. Results showed that natural attenuation of the desert soil occurred over two months (with 68.5% of hydrocarbons removed), while biostimulation, reintroduction, and bioaugmentation were—as expected—also effective, achieving 89.4–97.0% oil removal. In the contaminated soil during the spring season, a significant increase in the proportion of Gammaproteobacteria within the soil microbiome was observed, with Alphaproteobacteria and Bacilli also representing significant fractions.
