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Arsenic contamination in environmental waters poses global health and environmental risks. This study addresses the urgent need for rapid, selective, and sensitive detection of inorganic arsenic (iAsIII) in environmental samples. Leveraging the unique properties of gold nanoparticles (AuNPs) and the selective binding affinity of homocysteine (Hcy), we developed a novel colorimetric sensor for iAsIII detection. Our investigation elucidates the mechanism by which Hcy modifies AuNPs, enabling the selective detection of iAsIII ions through chelation between amine and carboxyl groups, primarily with the predominant species H2AsO3− at pH 12.0. Our sensor achieves high selectivity (>10‐fold) for iAsIII amid various interfering ions commonly found in environmental samples. Furthermore, we demonstrate exceptional sensitivity in detecting iAsIII, with a low limit of detection (LOD) of 67 nM, aligning with regulatory standards for arsenic concentration in drinking water. The selectivity and sensitivity of our sensor were validated through experiments with various metal ions and real water samples. In conclusion, our study presents a comprehensive understanding of the mechanism, selectivity, and sensitivity of Hcy‐modified AuNPs in detecting iAsIII, offering a versatile nanosensor platform with significant implications for environmental monitoring and public health. [ABSTRACT FROM AUTHOR]

Polychlorinated diphenyl ethers (PCDEs), persistent environmental pollutants, are found in flue gas from incinerators. While air pollution control systems (APCSs) capture pollutants, the resulting sludge/fly ash (SFA) requires further treatment due to residual PCDEs and other harmful substances. This study investigated a hazardous waste thermal treatment system (HAWTTS) utilizing flameless combustion technology alongside a multistage APCS (scrubbers, cyclone demisters, bag houses). SFA from the APCS was recirculated for secondary combustion. PCDE levels were measured before and after each unit within the HAWTTS. The HAWTTS achieved a remarkable overall PCDE removal efficiency of 99%. However, the incinerator alone was less effective for low-chlorine PCDEs. Scrubbers and bag houses exhibited lower removal efficiencies (17.8% and 30.9%, respectively) due to the memory effect. Conversely, the cyclone demister achieved a high removal rate (98.2%). Following complete APCS treatment, PCDE emissions were significantly reduced to 1.02 ng/Nm3. While SFA still contained some PCDEs, the flameless combustion's uniform temperature distribution enhanced combustion efficiency, minimizing overall PCDE emissions. This system demonstrates significant potential for mitigating PCDE pollution from incinerators. Further research could focus on optimizing treatment processes to address residual PCDEs in SFA. [ABSTRACT FROM AUTHOR]

POP data are limited in the marine environment; thus, this study aimed to investigate background persistent organic pollutant (POP) levels in oceanic deep-water-deposited particulates in the South China Sea (SCS). Six POPs, including polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (DL-PCBs), polybrominated diphenyl ethers (PBDEs), polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs), polychlorinated diphenyl ethers (PCDEs), and polybrominated biphenyls (PBBs), were investigated in eight pooled samples from the SCS from 20 September 2013 to 23 March 2014 and 15 April 2014 to 24 October 2014 at depths of 2000 m and 3500 m. PBDEs were the most predominant compounds, with the highest mean Σ14PBDE of 125 ± 114 ng/g dry weight (d.w.), followed by Σ17PCDD/F, Σ12PBDD/F, and Σ12DL-PCB (275 ± 1930, 253 ± 216, and 116 ± 166 pg/g d.w., respectively). Most PBDD/F, PBB, and PCDE congeners were below the detection limits. PCDDs had the highest toxic equivalency (TEQ), followed by PBDDs and DL-PCBs. Among the six POPs, PBDEs were the major components of the marine-deposited particles, regarding both concentrations and mass fluxes. Compared to 3500 m, PBDE levels were higher at a depth of 2000 m. PBDE mass fluxes were 20.9 and 14.2 ng/m2/day or 68.2 and 75.9 ng/m2/year at deep-water 2000 and 3500 m, respectively. This study first investigated POP levels in oceanic deep-water-deposited particles from existing global data. [ABSTRACT FROM AUTHOR]