Effects and mechanisms of aged polystyrene microplastics on the photodegradation of sulfamethoxazole in water under simulated sunlight

FeCl3-activated biochar catalyst for heterogeneous Fenton oxidation of antibiotic sulfamethoxazole in water

Promoted elimination of antibiotic sulfamethoxazole in water using sodium percarbonate activated by ozone: Mechanism, degradation pathway and toxicity assessment

LaCoO3@Fe3O4 as peroxymonosulfate activator derived from spent lithium battery cathode materials for degradation of sulfamethoxazole in water

Heterogeneous photocatalytic degradation of sulfamethoxazole in water using a biochar-supported TiO2 photocatalyst

Improved adsorption and charge transfer capacity by coupling g-C3N4 and NH2-MIL-125 for efficient degradation of sulfamethoxazole in water: Characterization, degradation efficiency, influence factors, and mechanism

Heat-activated persulfate oxidation of sulfamethoxazole in water

This study aimed to preconcentration of sulfamethoxazole (SMX) in water and biological samples. Ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) and ultrasound-assisted dispersive solid-phase microextraction (UA-DSPME) methods paired with spectrophotometry were applied to extraction and preconcentration of SMX. ZnFe2O4 nanoparticles were prepared as adsorbent in UA-DSPME method by hydrothermal method. The scanning electron microscopy (SEM) technique showed that the adsorbent had symmetrical, bullet-shaped particles with uniform size. The results of the X-ray diffraction (XRD) showed the successful synthesis of the ZnFe2O4 nanoparticles. Effective parameters in extraction, including ultrasonication time, disperser solvent volume, adsorbent amount, extraction solvent volume, eluent volume, and pH were investigated and optimized. The practical and optimal conditions of the process were determined by the central composite design (CCD). The optimal conditions were 0.024 g of adsorbent, 535 µL of disperser solvent volume, 7.5 min of ultrasonication time, 235 µL of eluent volume, pH of 5, and 185 µL of extraction solvent volume. Linear ranges and detection limits were 20–1,200 μg L−1 and 6 μg L−1 for UA-DSPME and 10–800 μg L−1 and 3 μg L−1 for UA-DLLME. Relative standard deviation (RSD) of less than 4% were obtained for UA-DSPME and UA-DLLME methods. The reusability showed that the ZnFe2O4 adsorbent could extract SMX up to five cycles of adsorption/desorption without significant reduction in its efficiency. Also, interference studies showed that the presence of different cations and anions did not significantly interfere in the extraction of SMX. The outcomes of real-time samples analysis showed that the extraction of SMX for both methods was in the range of 92.44%–99.12%. The results showed the developed methods are simple, sensitive, and suitable for SMX preconcentration in environmental water and biological samples.

Surface imprinted polymer on a metal-organic framework for rapid and highly selective adsorption of sulfamethoxazole in environmental samples

Effects of pyrolysis temperature on the physicochemical properties of alfalfa-derived biochar for the adsorption of bisphenol A and sulfamethoxazole in water

At present, the most commonly used advanced oxidation technology for drinking water treatment has the disadvantage of low utilization rate of oxidant. After research and comparison, the UV/H2O2/Fe(III) combined process selected in this study can effectively degrade sulfamethoxazole (SMX) in water and improve the utilization rate of hydrogen peroxide. The results showed that the removal rate of SMX by UV/H2O2/Fe(III) process was 96.7%, and the utilization rate of H2O2 was increased by 25%; the UV/H2O2/Fe(III) combined process also had a good effect on the degradation of fluorescent components and other organic matter in water; the presence of nitrite ion and humic acid significantly reduced the degradation efficiency of SMX, under the condition of nitrite ion concentration of 5mg/L or humic acid concentration of 10mg/L, the removal rate of SMX by UV/H2O2/Fe(III) combined process decreased by 10.68% or 11.92%, respectively. In terms of mechanism research, the reactivity of SMX molecules was theoretically calculated by density functional theory (DFT), and the atoms with higher contribution rate were calculated, and the degradation products and four degradation pathways of SMX were identified and analyzed by mass spectrometry. Finally, the potential ecological toxicity of SMX and its degradation products was predicted by ECOSAR software and luminescent bacteria experiments; it was found that the toxicity of SMX and its degradation products was relatively high at 15min.

In this study, we examine the role of the hydroxyl (OH*) radical as a mechanism for the photodecomposition of chromophoric dissolved organic matter (CDOM) in sunlit surface waters. Using gamma-radiolysis of water, OH* was generated in solutions of standard humic substances in quantities comparable to those produced on time scales of days in sunlit surface waters. The second-order rate coefficients of OH* reaction with Suwannee River fulvic (SRFA; 2.7 x 10(4) s(-1) (mg of C/L)(-1)) and humic acids (SRHA; 1.9 x 10(4) s(-1) (mg of C/L)(-1)) are comparable to those observed for DOM in natural water samples and DOM isolates from other sources but decrease slightly with increasing OH* doses. OH* reactions with humic substances produced dissolved inorganic carbon (DIC) with a high efficiency of approximately 0.3 mol of CO2/mol of OH*. This efficiency stayed approximately constant from early phases of oxidation until complete mineralization of the DOM. Production rates of low molecular weight (LMW) acids including acetic, formic, malonic, and oxalic acids by reaction of SRFA and SRHA with OH* were measured using HPLC. Ratios of production rates of these acids to rates of DIC production for SRHA and for SRFA were similar to those observed upon photolysis of natural water samples. Bioassays indicated that OH* reactions with humic substances do not result in measurable formation of bioavailable carbon substrates other than the LMW acids. Bleaching of humic chromophores by OH* was relatively slow. Our results indicate that OH* reactions with humic substances are not likely to contribute significantly to observed rates of DOM photomineralization and LMW acid production in sunlit waters. They are also not likely to be a significant mechanism of photobleaching except in waters with very high OH* photoformation rates.

Effects and Mechanisms of Aging Polystyrene Microplastics on the Photodegradation of Sulfamethoxazole In Water Under Simulated Sunlight

Microplastics pollution and seawater temperature rise have been the major environmental issues, threatening the survival and biodiversity of marine organisms. This study evaluated the combined effect of temperature and polystyrene microplastics (MP) on Artemia, a filter-feeding crustacean that is widely used for environmental toxicology studies. Brine shrimp Artemia franciscana were exposed to three MP concentrations (0, 0.2, and 2.0 mg/L) and three temperatures (22, 26, and 30 °C) for 14 d. In general, higher MP concentration and temperature led to a decreased survival rate and growth. Two-way ANOVA analysis indicated that the survival rate of Artemia was significantly impacted by both MP concentration and temperature (P 0.05). Growth of Artemia was significantly impacted by temperature (P<0.05), and with a significant interaction between two factors (P<0.05). Furthermore, the enzymatic activity, intestinal histological analyses, and immune gene expression were determined for Artemia reared at 30 °C with three MP concentrations (0, 0.2, and 2.0 mg/L). The results showed that 2.0 mg/L MP resulted in reduced Artemia intestinal microvilli and exfoliated epithelia cells, significantly increased acid phosphatase (ACP) activity (P<0.05) and immune-related gene ADRA1B and CREB3 expression, revealing that higher MP concentration could induce oxidative and immunological stress on Artemia at 30 °C. Overall, our study suggests that MP and temperature have combined adverse effect on Artemia, especially at relatively high temperature and polystyrene MP concentration. These findings are important to understand the potential ecological risks posed by these two factors on the organisms in marine environment.

Polystyrene microplastics reduce Cr(VI) and decrease its aquatic toxicity under simulated sunlight.

P040 New active models of a sitting human body