Oxidation of small aromatic compounds in rainwater by UV/H2O2: Optimization by response surface methodology

Review of trace organic chemicals in urban stormwater: Concentrations, distributions, risks, and drivers

Urban stormwater, increasingly seen as a potential water resource for cities and towns, contains various trace organic chemicals (TrOCs). This study, conducted through a comprehensive literature review of 116 publications, provides a detailed report on the occurrence, concentration distribution, health, and ecological risks of TrOCs, as well as the impact of land use and rainfall characteristics on their concentrations. The review uncovers a total of 629 TrOCs detected at least once in urban stormwater, including 228 pesticides, 132 pharmaceutical and personal care products (PPCPs), 29 polycyclic aromatic hydrocarbons (PAHs), 30 per- and polyfluorinated substances (PFAS), 28 flame retardants, 24 plasticizers, 22 polychlorinated biphenyls (PCBs), nine corrosion inhibitors, and 127 other industrial chemicals/intermediates/solvents. Concentration distributions were explored, with the best fit being log-normal distribution. Risk assessment highlighted 82 TrOCs with high ecological risk quotients (ERQ > 1.0) and three with potential health risk quotients (HQ > 1.0). Notably, 14 TrOCs (including six PAHs, five pesticides, three flame-retardants, and one plasticizer) out of 68 analyzed were significantly influenced by land-use type. Relatively weak relationships were observed between rainfall characteristics and pollutant concentrations, warranting further investigation. This study provides essential information about the occurrence and risks of TrOCs in urban stormwater, offering valuable insights for managing these emerging chemicals of concern.

Hierarchical N-doped porous carbon scaffold Cu/Co-oxide with enhanced electrochemical sensing properties for the detection of glucose in beverages and ascorbic acid in vitamin C tablets

This research focuses on the development of a highly efficient electrocatalyst, CuxO/NPC@Co3O4/NPC-10-7, for detecting glucose and ascorbic acid. In a 0.1 M NaOH solution, the modified electrode exhibits a sensitivity of 3314.29 μA mM-1 cm-2 for glucose detection. The linear range for ascorbic acid sensing is 0.5 μM - 23.332 mM, with a detection limit as low as 0.24 μM. In a 0.1 M PBS solution, the linear range for ascorbic acid detection extends to 43.328 mM, which represents the best performance reported to date by chronoamperometry. Moreover, the electrode demonstrates high accuracy, with a recovery rate of 96.80 % - 103.60 % for glucose detection and a recovery rate of 95.25 % - 104.83 % for ascorbic acid detection. These results suggest that the CuxO/NPC@Co3O4/NPC-10-7 modified electrode shows significant potential for practical applications in food detection.

Exploration for cobalt/nitrogen-doped catalyst to creatinine degradation via peroxymonosulfate activation: toxicity evaluation, statistical modeling, and mechanisms study

Developing multifunctional catalysts applied in diversiform modes via advanced oxidation processes (AOPs) is a promising and attractive approach for organic pollution degradation. Herein, a novel hollow bamboo-like structural cobalt/nitrogen-doped carbonized material (CoC/N) was employed as a catalyst for AOPs, in which CoC/N was prepared in situ through calcining a Co-based coordination polymer. When CoC/N was utilized as a peroxymonosulfate (PMS) activator, the catalyst stood out prominent activities for effective CA oxidation. Furthermore, a five-level central composite rotatable design (CCRD) model describing CA decay as a function of PMS concentration, CoC/N dosage, and solution pH value was successfully constructed and engaged to explore the optimal operating conditions. Finally, the possible degradation mechanism of CA in CoC/N-PMS system was proposed by quantum chemistry calculation and LC/MS analysis. This work shed light on the structural morphology of the catalyst and its PMS synergy degradation pathway, which promotes its applications in miscellaneous pollutant degradation. A new Co/N-doped material was used to degrade unconventionality organic pollutant creatinine (CA) for the first time, in which the scientific approaches of five-level central composite rotatable design (CCRD) model, response surface methodology (RSM) and density function theory (DFT) were employed to evaluate the material performance and CA degradation pathway. The toxicity evaluation, statistical modeling and mechanisms study have been investigated meticulously.

Influence of vehicle and pavement characteristics on dust resuspension from soil pavement of open-pit mine

It is essential to explore the distribution characteristics of dust concentration distribution near the surface of soil pavement in open-pit mines to develop effective dust control measures. Therefore, in this study, the dust resuspension process of soil pavement was analyzed by building the dust resuspension experimental system of open-pit mine, and the change rules of dust concentration under different factors were investigated. The results showed that under the action of wheel rolling, the dust moved around the wheel along the vertical direction, and the diffusion trajectory in the horizontal direction was approximately parabolic. After re-suspension of the open-pit mine soil pavement, the area of high dust concentration behind the wheel is roughly triangular. The relationship between the average dust concentration (Total dust, Respirable dust and PM2.5) and the vehicle speed and weight were fit to a power function, while the relationship with silt content and water content were quadratic. Vehicle speed and water content had significant effect on the total dust, respirable dust (RESP) and PM2.5 average concentration, while vehicle weight and silt content had little effect on the respirable dust and PM2.5 average concentration. When the water content of mine soil pavement reached 3 %, the average dust concentration could be reduced to <10 mg/m³, and the vehicle speed should be reduced as much as possible under the mine production permitting conditions.