The fate of pharmaceuticals after discharged from hospital into wastewater was clarified experimentally by using a new lab-scale conventional activated sludge (CAS) treatment reactor. The 43 target compounds belong to nine therapeutic classes (antivirals, antibacterials, anticancer drugs, psychotropics, antihypertensives, analgesic–antipyretics, contrast media, herbal medicines, and phytoestrogens) were selected with inclusion of 16 newly estimated compounds. The efficiency of the present reactor was estimated by comparing the reaction rate constant of the solid-water partition coefficients (log Kd) between liquid and solid samples and half-life during 48-h experiment obtained by using hospital effluents with those obtained by using STP wastewater. The results that no significant difference in removal efficiency was observed between both water samples (P?>?0.05) indicate high reliability of the present lab-scale reactor. The actual rates of removal when hospital effluent was applied varied widely (mean, 59?±?40%) independent of type of the pharmaceuticals. More than 90% of 17 compounds were removed after 8 h of treatment. However, the values for psychotropics (mean, 19?±?26%) and contrast media (mean, 24?±?17%) were generally low, indicating high stability. The log Kd values ranged from 1.3 to 4.8. Notably, clarithromycin, acridine, and glycitein could be removed in both liquid and solid phases. The dominant removal mechanisms were found to be different for individual pharmaceutical. These results suggest the effectiveness of introduction of the lab-scale biological treatment system for development of a new solution for discharge of pharmaceuticals from hospital.
The residual levels of antibiotics in Vietnamese eggs were monitored from 2014 to 2015. A total of 111 egg packages, distributed by 11 different companies, were collected from supermarkets in Ho Chi Minh City and the levels of 28 antibiotics were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) screening method. Sixteen samples tested positive for antibiotics; a total of eight compounds (enrofloxacin, ciprofloxacin, norfloxacin, sulfadimethoxine, sulfamethazine, sulfamonomethoxine, tilmicosin and trimethoprim) were detected. Enrofloxacin was detected in eight samples, with two samples exhibiting concentrations exceeding 1,000 µg kg?1. Tilmicosin was detected in three samples at a range of 49–568 µg kg?1. We observed that two of the 11 companies frequently sold antibiotic-contaminated eggs (detection rates of 56 and 60%), suggesting that a number of companies do not regulate the use of antibiotics in egg-laying hens. Our findings indicate that livestock farmers require instruction regarding antibiotic use and that continual antibiotic monitoring is essential in Vietnam. 相似文献
In the Republic of Estonia, local low-grade carbonaceous fossil fuel--Estonian oil-shale--is used as a primary energy source. Combustion of oil-shale is characterized by a high specific carbon emission factor (CEF). In Estonia, the power sector is the largest CO(2) emitter and is also a source of huge amounts of waste ash. Oil-shale has been burned by pulverized firing (PF) since 1959 and in circulating fluidized-bed combustors (CFBCs) since 2004-2005. Depending on the combustion technology, the ash contains a total of up to 30% free Ca-Mg oxides. In consequence, some amount of emitted CO(2) is bound by alkaline transportation water and by the ash during hydraulic transportation and open-air deposition. The goal of this study was to investigate the possibility of improving the extent of CO(2) capture using additional chemical and technological means, in particular the treatment of aqueous ash suspensions with model flue gases containing 10-15% CO(2). The results indicated that both types of ash (PF and CFBC) could be used as sorbents for CO(2) mineral sequestration. The amount of CO(2) captured averaged 60-65% of the carbonaceous CO(2) and 10-11% of the total CO(2) emissions. 相似文献
Abstract: Water resources planning and management efficacy is subject to capturing inherent uncertainties stemming from climatic and hydrological inputs and models. Streamflow forecasts, critical in reservoir operation and water allocation decision making, fundamentally contain uncertainties arising from assumed initial conditions, model structure, and modeled processes. Accounting for these propagating uncertainties remains a formidable challenge. Recent enhancements in climate forecasting skill and hydrological modeling serve as an impetus for further pursuing models and model combinations capable of delivering improved streamflow forecasts. However, little consideration has been given to methodologies that include coupling both multiple climate and multiple hydrological models, increasing the pool of streamflow forecast ensemble members and accounting for cumulative sources of uncertainty. The framework presented here proposes integration and offline coupling of global climate models (GCMs), multiple regional climate models, and numerous water balance models to improve streamflow forecasting through generation of ensemble forecasts. For demonstration purposes, the framework is imposed on the Jaguaribe basin in northeastern Brazil for a hindcast of 1974‐1996 monthly streamflow. The ECHAM 4.5 and the NCEP/MRF9 GCMs and regional models, including dynamical and statistical models, are integrated with the ABCD and Soil Moisture Accounting Procedure water balance models. Precipitation hindcasts from the GCMs are downscaled via the regional models and fed into the water balance models, producing streamflow hindcasts. Multi‐model ensemble combination techniques include pooling, linear regression weighting, and a kernel density estimator to evaluate streamflow hindcasts; the latter technique exhibits superior skill compared with any single coupled model ensemble hindcast. 相似文献
Activated carbon (AC) has been widely used in the removal of SO2 from flue gas owing to its well-developed pore structure and abundant functional groups. Herein, the effect of alkali/alkaline earth metals on sulfur migration was investigated based on the dynamic adsorption and temperature programmed desorption experiment. The adsorption and desorption properties of six types of AC (three commercial and three laboratory-made) were carried out on a fixed-bed experimental device, and the physical and chemical properties of samples were determined by X-ray fluorescence, X-ray diffraction, scanning electron microscopy/energy dispersive X-ray, and X-ray photoelectron spectroscopy analysis. The experimental results showed that the adsorbed SO2 cannot be completely desorbed by increasing the regeneration temperature (350 – 850°C), while the SO2 fixed in the AC combines with the Ca-based minerals in the ash to form a stable sulfate. For different samples, higher ash content, higher CaO content in the ash and a more developed pore structure lead to a higher SO2 fixation rate. Moreover, the multiple adsorption-desorption cycles experiment showed that the effect of SO2 fixation is mainly reflected in the first cycle, after which the adsorption and desorption amount are approximately the same. This study elucidates the effect of alkali/alkaline earth metals on the adsorption-desorption cycle of AC, which provides a deeper understanding of sulfur migration in the AC flue gas desulfurization process. 相似文献