Vangsgaardforeman1171

Very low concentrations were found for the toxic elements lead, cadmium, and arsenic. Quizartinib concentration The present study showed differences in metal concentrations in multi-floral honey from different countries, confirming the strong influence of the area of origin on the chemical composition of honeys.Groundwater offers an important source for drinking water around the world; however, groundwater quality is under increasing pressure and is particularly vulnerable in karst areas. Total organic carbon (TOC) is significantly related to groundwater quality and when not removed by water treatment processes can give rise to the formation of disinfection by-products trihalomethanes (THMs) above the level of compliance. This study investigated the source of organic matter giving rise to the THM exceedances in a groundwater supply in a karst area. Results highlighted that source water for this groundwater supply was prone to surface water infiltration linked to rainfall events; was not accurately captured in the zone of contribution (ZoC); had inadequate treatment of natural organic matter (NOM) and suffered THM exceedances in 45% of sampling events. THMs were mostly represented by chloroform and caused by terrestrial delivered reprocessed organic matter. This work will support water managers tasked with decision-making.Adsorption process is suitable to the advanced treatment of tetracycline antibiotics (TCs; including tetracycline (TTC), oxytetracycline (OTC), and chlortetracycline (CTC)) in poultry wastewater. In this research, Mn oxide-doped Cu oxide (MODCO) was synthesized and used for the removal of TTC, OTC, and CTC. According to the XRD and SEM analysis results, MODCO has an amorphous crystal structure and is formed by the aggregation of nano-sized particles with a uniform distribution of Cu and Mn elements. In addition, MODCO has a BET surface area of 67.7 m2/g and a pHIEP value of 7.8. The results of batch experiments illustrated that the reaction rates for the removal of three TCs were in the order of OTC > CTC > TTC. In addition, the theoretical maximum amounts of TTC, OTC, and CTC adsorbed on MODCO were determined to be 2.90 mmol/g, 4.15 mmol/g, and 2.20 mmol/g via the Langmuir model, respectively. The optimal removal performances of TCs were achieved in the pH range of 6~9, and the coexistence of anions posed an unnoticeable effect on the removal efficiencies. The spectroscopic analysis results demonstrated that the removal mechanism of TCs was mainly attributed to surface complexation. Furthermore, a part of TCs may be decomposed by Mn oxides during the removal process according to the UV spectrogram results. Overall, MODCO has exhibited a great potential for the removal of TCs from aqueous solution.Over the past few decades, rivers have become severely polluted as a result of receiving vast quantities of domestic and industrial wastewater. The identification of the major factors that influence water quality is crucial to understand the interactions of anthropogenic and natural factors and develop river restoration projects. In this study, the QUAL2Kw water quality model was used to quantitatively evaluate the most critical factors for water quality at two sites with different meteorological conditions and urban scales. The genetic algorithm (GA) was used to optimize the parameters in the model. The Monte Carlo simulation (MCS) method was used to assess the model uncertainty and sensitivity in all reaches for five water quality outputs (temperature, CBOD, DO, TP, and TN) in two seasons. The K-means clustering method associated with the sensitivity results was used to identify the major factors influencing the water quality in all reaches from the input data and the model parameters. The results showed that CBOD, TN, and TP were most sensitive to headwater and tributary quality. DO tended to be affected by more natural reactions than the other water quality indicators. In the cold and dry seasons and the more urbanized areas, river pollution was more severe, and the impact of natural reactions was reduced. The simulation results revealed the reliability of QUAL2Kw in modeling the quantity and quality of all river reaches. The method applied in this study is beneficial for the improvement and management of the water environment.Watershed exposure caused by the use of pesticide in farmland has become a major environmental concern. Currently, there are two major approaches to quantify the watershed exposure monitoring and modeling. Watershed monitoring is expensive, and short-term monitoring is difficult to be used to address potential long-term exposure variability. Model simulation is widely used because not only can it save time and efforts, but it can also simulate the environmental transport process of pesticide over a long time frame to better understand temporal variability. Research on application of commonly used pesticide exposure assessment models such as PRZM, RICEWQ on watershed scale has found that those models need to be coupled together with waterbody models to assess pesticide exposure at the watershed level, and they are applied on a single crop in targeted area within a watershed, failing to consider the diversity of regional and watershed cropping conditions. To address pesticide exposure assessment in different waterbodies after application on multiple crops within a watershed, this study coupled PRZM, RICEWQ, and SWAT models simultaneously in North Tiaoxi watershed. PRZM model and RICEWQ model were used to simulate the exposure of pesticides in dryland and rice paddies separately, and the pesticide masses through runoff, overflow, spray drift, and other routes simulated by the above two models were set as the input of SWAT model which could simulate hydrology and pollutant transport at watershed scale. Pesticide use, cropping, hydrology, and watershed data were collected, and parameterized for exposure modeling of carbaryl in the North Tiaoxi River after uses on orchard, corn, and rice within the watershed. Model predictions showed high degree of agreement between the simulated results and the field monitoring data. The coupled PRZM, RICEWQ, and SWAT model could simulate reasonably well pesticide exposures in waterbodies with applications on multiple crops within a watershed.