Tetrabromobisphenol A bis (2-hydroxyethyl) ether (TBBPA-DHEE), a derivative of TBBPA, has been frequently detected in the environment. In this study, the median lethal concentration (LC₅₀) of TBBPA-DHEE at 96 h post-fertilization (hpf) was 1.573 mg/L. Based on the reported environmental concentrations, we investigated the effects of TBBPA-DHEE on the nervous system of zebrafish embryos following exposure to varying concentrations (0, 20, 100, and 500 μg/L) for 4 to 144 hpf. Our results indicated that exposure to 100 μg/L at 144 hpf led to behavioral abnormalities in zebrafish. Furthermore, exposure to TBBPA-DHEE inhibited the development of the central nervous system and motor neurons in zebrafish. Real-time polymerase chain reaction (PCR) analysis revealed that exposure to TBBPA-DHEE significantly downregulated the expression levels of neurodevelopmental genes (shha, syn2a, elavl3, gfap, and gap43). Additionally, TBBPA-DHEE increased oxidative stress in zebrafish. Transcriptomic analysis demonstrated that exposure to TBBPA-DHEE affected the signaling pathways involved in neurodevelopment. Overall, this study demonstrated that TBBPA-DHEE may disrupt the early development of the nervous system, leading to abnormal motor behavior in zebrafish larvae, and provided novel insights into the potential mechanisms of TBBPA-DHEE neurotoxicity.

The requirement of simple, efficient and accurate detection of tetracycline (TC) in water environments poses new challenges for sensing platform development. Here, we report a simple method for TC sensing via fluorescence detection based on metal–organic coordination polymers (MOCPs, (4-Hap)₄(Mo₈O₂₆)) coated with nitrogen-doped carbon dots (NCDs). These NCDs@(4-Hap)₄(Mo₈O₂₆) composites showed excellent luminescence features of NCDs with stable bright-blue emission under UV light. The results of the sensing experiment showed that the fluorescence of NCDs@(4-Hap)₄(Mo₈O₂₆) can be quenched by TC (166 µM) with 94.1% quenching efficiency via the inner filter effect (IFE) in a short time (10 s), with a detection limit (LOD) of 33.9 nM in a linear range of 8–107 µM. More significantly, NCDs@(4-Hap)₄(Mo₈O₂₆) showed a high selectivity for TC sensing in the presence of anions and metal cations commonly found in water environments and can be reused in at least six cycles after washing with alcohol. The potential practicality of NCDs@(4-Hap)₄(Mo₈O₂₆) was verified by sensing TC in real water samples with the standard addition method, and satisfactory recoveries from 91.95% to 104.72% were obtained.

Reducing the generation of excess sludge and achieving resource recovery are crucial for enhancing the economic efficiency and environmental sustainability of wastewater treatment plants (WWTPs). This study utilizes ultrasonic cavitation technology to transform organic matter into excess sludge to achieve sludge reduction and carbon source recovery. To this end, we systematically investigated the effects of various ultrasonic cavitation conditions on sludge reduction, organic matter conversion, and denitrification efficiency. The results showed that the optimal sludge reduction effect occurs at an original mixed liquid suspended solids (MLSS) of 10 g/L, under neutral and non-aerated conditions, reaching 15.07%. Ultrasonic cavitation treatment significantly enhanced the conversion efficiency of organic matter in the sludge, greatly increasing the concentration of organic matter in the supernatant, with soluble chemical oxygen demand (SCOD) maintained around 900 mg/L, thereby significantly improving the denitrification process. Furthermore, through magnetic-nanoparticle mediated isolation (MMI) and metagenomic sequencing analysis, the dominant denitrifying bacteria and their functional genes that utilize organic matter in the supernatant of ultrasonically treated sludge as a carbon source were identified. Finally, long-term pilot-scale operations further validated the practical application potential of ultrasonic cavitation technology for excess sludge reduction and resource utilization.