Hegelund Andersen (errorpvc2)
Roxarsone (3-nitro-4-hydroxyphenylarsonic acid) is an extensively used organoarsenic feed additive. The effective removal of arsenic from roxarsone degradation before discharging is of great importance for controlling artificial arsenic pollution in aquatic environment. In this study, a bifunctional TiO2/ferrihydrite (TiO2/FeOOH) hybrid was synthesized by a hydrothermal method for the simultaneously photocatalytic degradation of roxarsone and adsorption removal of released arsenic. The analysis of the prepared TiO2/FeOOH by field-emission scanning electron microscope (FE-SEM), transmission electron microscopy (TEM), Raman spectra, X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), and X-ray photoelectron spectroscopy (XPS) confirmed the successful formation of the hybrid of crystalline TiO2 and no crystalline FeOOH. TiO2/FeOOH hybrid had better adsorption capacity for As(V) than roxarsone. Compared to TiO2, the TiO2/FeOOH hybrid exhibited much superior UV-driven photocatalytic activities for roxarsone degradation. After 12 h irradiation, more than 96% of roxarsone was degraded by 11 TiO2/FeOOH hybrid, and the released As(V) was simultaneously removed from the solution. The residual As(V) concentration was lower than 0.02 mg L-1. The reusability test indicated that TiO2/FeOOH hybrid had excellent stability and reliability. The possible mechanism of roxarsone degradation and released inorganic arsenics removal by this hybrid was also proposed. These results clearly indicated that the TiO2/FeOOH hybrid could be used for the removal of roxarsone and its degradation product.Excess sludge contains a high amount of protein, which can be recovered to prepare protein foaming agents and other products with high added value. Enzymatic hydrolysis (EH) is a promising technology for the recovery of protein from excess sludge, and ultrasound has been identified as a potential method to assist in sludge disintegration. Ultrasonic pretreatment was combined with alkaline protease hydrolysis to extract protein from excess sludge produced by A2/O treatment (S1) and an oxidation ditch treatment (S2), and the extraction effects and changes in sludge dewatering performance were studied. Dihexa order The effects of the six factors ultrasonic power density, ultrasonication time, enzyme dose, pH, hydrolysis temperature and hydrolysis time were analyzed. The results showed that the ultrasound-enhanced enzymatic method could effectively extract sludge protein. Although the extraction efficiencies for the different municipal sludges were different, their extraction conditions were relatively similar. Considering the protein extraction rate and sludge dewatering performance, the selected extraction conditions were as follows ultrasonic power density, 1 W/mL; ultrasonication time, 20 min; enzyme dose, 3500 U/g; pH 11; hydrolysis temperature, 60 °C; and hydrolysis time, 3 h. Under these conditions, the protein extraction rate (Rp) of S1 and S2 reached 55.9% and 52.3%, respectively. Moreover, the improvement in sludge dewatering performance (Dw) of S1 and S2 was 49.5% and 52.4%, respectively. Comparison of the protein, polypeptide, and amino acid contents obtained from ultrasound-assisted enzymatic hydrolysis (UEH), EH, and ultrasonic hydrolysis (UH) further demonstrated the beneficial effect of ultrasound application on enzymatic hydrolysis.Owing to their physical and chemical properties, particles generated by the abrasion of tyre tread against road surfaces, or tyre wear particles, are recognised as microplastics. Recent desk-based studies suggest tyre wear to be a major contributor of microplastic emissions to the environment. This study aimed to quantify tyre wear in roadside drains and the natural environment near to a major road intersection. Tyre particles were identified by visual identification and a subsample confirmed as tyre wear by GC-MS using N-cyclohexyl-2-benzothiazolamine (NCBA)