Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2024102303
Fluoride-containing wastewater treatment typically relies on calcium-based precipitation and flocculation, which suffer from low compliance rates and difficult valorization of fluoride-laden sludge. This study introduces a novel bismuth upconversion luminescent glass (BULG) synthesized from Bi2O3, SiO2, Yb2O3, and Er2O3, designed for efficient fluoride removal and subsequent photocatalytic application. By varying the Bi2O3:SiO2 molar ratio, a series of BULGs with superior upconversion luminescence were obtained. Under optimal conditions (Bi3+:F− molar ratio = 1:1, pH = 2), fluoride removal efficiencies exceeded 97% for all compositions, with the 0.7:0.3 Bi2O3:SiO2 formulation achieving 99.9% removal and rapid settling of the precipitate. The fluoride removal products retained upconversion luminescence and exhibited semiconductor heterojunctions, enabling complete photocatalytic degradation of ciprofloxacin (100% within 60 min). This approach not only efficiently removes fluoride ions but also valorizes the waste into a functional photocatalyst, offering a promising strategy for fluoride-containing wastewater treatment.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025102002
The ultraviolet/chlorine (UV/Cl2) advanced oxidation process generates multiple radical species, enabling synergistic disinfection. However, the systematic influence of UV intensity on process performance remains inadequately characterized. This study investigated UV intensities from 0.25 to 2.0 mW·cm−2, assessing chlorine photolysis kinetics, bacterial inactivation, and disinfection by-product (DBP) formation. Results demonstrate that inactivation efficiency is not solely governed by total UV energy but is co-regulated by reaction kinetics and mass transfer. Increasing UV intensity accelerated chlorine photolysis by 33.7%–277.8%, elevating steady-state concentrations of hydroxyl radicals and chlorine radicals by factors of 1.6–3.8 and 1.3–3.2, respectively, thereby enhancing initial inactivation rates. However, higher intensities reduced cumulative chlorine exposure (CT value) to 14.3%–55.7% of baseline, causing overall inactivation to first increase then decrease. At a fixed UV dose of 150 mJ·cm−2, an intensity of 1.0 mW·cm−2 achieved optimal 6.5-log inactivation of Escherichia coli and the lowest bacterial reactivation rate (0.07%). Common water constituents (HCO3−, Cl−, natural organic matter) inhibited disinfection, with natural organic matter exerting the strongest suppression (2.7-log reduction). Notably, 1.0 mW·cm−2 exhibited the greatest resistance to interference. Elevated intensity reduced total organic halogen formation from 33.7 μg·L−1 to 19.0 μg·L−1. Balancing disinfection efficacy and DBP risk, 1.0 mW·cm−2 is identified as the optimal UV intensity for the UV/Cl2 process in sand-filtered water treatment.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025111302
High-concentration chloride ions (Cl−) in industrial wastewater cause severe corrosion and environmental hazards. Conventional removal methods suffer from low efficiency, high cost, and difficulty in product recovery. This study fabricated porous metallic bismuth-based blocks (Bi-PM) via 3D printing, combining chemical precipitation with additive manufacturing. Systematic evaluation of Cl− removal under varying pH and light irradiation revealed that at pH 0.1 and 0.5, dark-condition efficiencies were 53.6% and 31.0%, respectively, increasing to 69.3% and 38.1% under light. Radical trapping identified photogenerated holes as the primary active species, oxidizing metallic Bi to release Bi3+ and enhance precipitation. At pH 0.5, Bi-PM exhibited balanced efficiency and structural stability; over five cycles, average removal efficiency was 25% in darkness versus 41.2% under light, with superior stability under illumination. XRD and SEM confirmed abundant BiOCl formation on the surface under light, mitigating Bi loss. This approach ensures high chloride removal while minimizing material degradation, offering a novel pathway for industrial wastewater treatment.