Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202604002
A robust analytical method was developed for the simultaneous determination of 22 per- and polyfluoroalkyl substances (PFAS) in surface water using ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). To address the loss of particle-bound PFAS, the method incorporates a methanol extraction step for particulate matter retained on filters, followed by combining the extract with the filtrate. Samples were then concentrated and purified using weak anion exchange (WAX) solid-phase extraction (SPE) cartridges. After nitrogen evaporation, the residue was reconstituted in methanol/water (8:2, v/v) and filtered prior to analysis. Quantification was performed using isotope dilution. The method exhibited excellent linearity (R² > 0.995) over a concentration range of 1–250 µg/L. Method detection limits ranged from 0.2 to 0.6 ng/L, and method quantification limits from 0.8 to 2.4 ng/L. Recoveries in blank water and surface water matrices were 85.3%–139% and 76.4%–127%, respectively, with relative standard deviations (RSD, n=6) below 15%. Compared to conventional methods without particulate extraction, this approach significantly improved recovery rates in surface water, effectively eliminating negative bias caused by particle adsorption. The method is sensitive, accurate, and reliable, making it suitable for routine monitoring of PFAS in surface water.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025010306
Sulfur autotrophic denitrification (SAD) has attracted increasing attention due to its low cost, no need for external carbon sources, and low sludge production. This review systematically examines the reaction principles and key material elements of various electron donors for SAD, including elemental sulfur, sulfide, thiosulfate, and iron sulfide. It discusses recent research progress on different SAD processes and the influence of environmental factors. A comparative analysis between heterotrophic denitrification and SAD highlights SAD's advantages in reaction rate, secondary pollution, and cost-effectiveness, underscoring its promising application prospects. Notably, iron sulfide-based autotrophic denitrification maintains stable pH and produces fewer by-products (e.g., sulfate, nitrous oxide). When developed into an aggregate sulfur concrete system, it can purify nitrogen and phosphorus from secondary effluent standards to Class IV surface water standards within a hydraulic retention time of only 0.5–2 hours, addressing the contradiction between SAD reaction rate and engineering demands. This enables efficient simultaneous nitrogen and phosphorus removal, making it viable for groundwater remediation, advanced wastewater treatment, eutrophication control, and deep nitrogen removal. The national 'Dual Carbon Strategy' (carbon neutrality and peak) positions SAD as a promising method for wastewater treatment plants to meet increasingly stringent nitrogen and phosphorus discharge standards.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202607014
Reducing ammonia emissions and recovering lost nitrogen are critical for enhancing nitrogen content in compost. Biological trickling filters, as end-of-pipe odor control, retain ammonia nitrogen in effluent, offering a reuse pathway. However, the impact of nitrogen-rich wastewater reuse within the optimal C/N range (20.0:1–30.0:1) remains unclear. This study composted biogas residue, sawdust, food waste, and mushroom residue, setting initial C/N as the control variable. Four groups were established: low C/N with nitrogen-rich wastewater (LRN), low C/N with deionized water (LRW), high C/N with nitrogen-rich wastewater (HRN), and high C/N with deionized water (HRW). Simulated wastewater (2000 mg/L NH4+-N and 2000 mg/L NO2−-N) was recycled. Results showed no inhibition of final maturity; pH (8.17–8.48) and seed germination index (GI) (90.85%–122.96%) met organic fertilizer standards. HRN reduced cumulative total greenhouse gases, N2O, and NH3 by 20.32%–30.35%, 0.67%–53.38%, and 52.14%–62.15% compared to LRN and LRW. Although HRN emissions were slightly higher than HRW (total GHGs +4.56%, NH3 +4.99%), HRN final nitrogen content (4691.27 mg/kg) exceeded HRW (4514.96 mg/kg), attributed to sufficient carbon enhancing microbial assimilation. Conversely, low C/N with nitrogen-rich wastewater increased NH3 and N2O emissions (LRN vs LRW: +26.43% and +112.99%) due to carbon limitation. Thus, high initial C/N with nitrogen-rich wastewater reuse effectively reduces gaseous nitrogen loss and greenhouse gas emissions while maintaining compost maturity.