Bundgaardmahmoud3921

Fresh leachate is commonly featured with high concentrations of degradable organic matters, which can impede the performance of traditional biological treatment, especially the anaerobic reactor. Aiming at improving the biological treatment process of fresh leachate, this study creatively proposed a microaerobic-IC-AO2 (MAICAO2) process and compared it with traditional biological process, then optimized the operating conditions. Meanwhile, this work investigated the transformation rules and molecular compositions of dissolved organic matters (DOM) during MAICAO2 process, particularly the hazardous DOM (antibiotics). The innovative MAICAO2 process can effectively remove 99% chemical oxygen demand (COD), 91% total nitrogen (TN) and 91% ammonia (NH4+-N) during the operation time, and the removal efficiencies of COD, TN and NH4+-N in MAICAO2 process increased approximately 2%, 14% and 13% compared to ICAOAO process. Electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) confirmed that microaeration could ensure over 53% small molecular organic acids degrade before the subsequent anaerobic reaction so the system could resist the high concentration organic matters stress and improve the denitrification efficiency. Further analysis showed that different categories of antibiotics (including 6 sulfonamides, 4 tetracyclines, 2 macrolides, 4 quinolones and 2 chloramphenicols) could be effectively removed by MAICAO2 process with the total removal efficiency of 50%. This work proposed a new scenario for fresh leachate treatment by proposing the importance of the microaeration pretreatment during the biological treatment process.This paper reports for the first time the occurrence, fates, and carcinogenic risks of 20 substituted polycyclic aromatic hydrocarbons (SPAHs) and 16 priority PAH species in two coking wastewater treatment plants (WWTPs) (plant E and central WWTP). The measured total concentrations of PAHs and SPAHs in raw wastewater of coking plant E were 3700 and 1200 μg·L-1, respectively, with naphthalene (1400 μg·L-1), and fluoranthene (353 μg·L-1) as dominant PAH species and 2-methylnaphthalene (167 μg·L-1), anthraquinone (133 μg·L-1), and 1-methylnaphthalene (132 μg·L-1) as dominant SPAHs. For the 11 methyl-PAHs (MPAHs), 4 oxygenated-PAHs (OPAHs), and 5 nitrated-PAHs (NPAHs) investigated, the biological wastewater treatment process removed 98.6% MPAHs, 83.9% OPAHs, and 89.1% NPAHs. Mass balance analysis result revealed that transformation was the major mechanism to remove low-molecular-weight (LMW) MPAHs (59.9-77.3%), a large part of OPAHs, including anthraquinone, methylanthraquinone, and 9-fluorenone (46.7-49.6%), and some NPAHs, including 2-nitrofluorene and 9-nitroanthrancene (52.9-59.1%). Adsorption by activated sludge mainly accounted for removing high-molecular-weight (HMW) SPAHs (59.6-71.01%). The relatively high concentrations of SPAHs in excess sludge (15,000 μg·g-1) and treated effluent (104 μg·L-1) are of great concern for their potential adverse ecological impacts. SPAHS exhibited similar behaviors in central WWTP, though the influent concentrations were much lower. The concentration levels of SPAHs in the ambient air of coking plant E and central WWTP may also pose potential lung cancer risks (LCR) to the workers through inhalation, where all studied SPAHs except 3-nitrofluoranthene and 7-nitrobenz[a]anthracene exceeded the acceptable cancer risk standards (>10-6) recommended by U.S EPA. This study could help identify the ecological and healthy risks during coking wastewater treatment and provide useful information for policy-making.Vegetation establishment in urban areas is a potential solution to combat elevated particulate matter (PM) pollution, create cleaner environment for residents and enhance the sustainability of cities. However, vegetation effect at the points of interest in street-canyon on traffic pollutant from multiple interconnected factors (e.g., plant species, vegetation configurations, aerodynamic effect, deposition effect and complex wind regimes) is still not well studied. Therefore, taking roadside vegetation and street canyon as research objects, we evaluated vegetation effect (VE) for vegetation configurations (VCs) with several tree species on the dispersion, deposition, and distribution of traffic generated PM pollutant under different wind regimes. Results showed that (1) the transportation and distribution of traffic PM pollutant were different from wind regimes; (2) total VEs varied from -88.3% to 25.5%, depending on different VCs and wind regimes; perpendicular wind had the best VEs, while oblique wind had thor vegetation establishment from the viewpoint of improving air quality.Carbon/nitrogen ratio is an important parameter during the biological wastewater treatment. Our study emphasizes revealing the mechanisms of chemical oxygen demand/total nitrogen (COD/TN) ratio dependent improved greywater (GW) treatment in an oxygen based membrane biofilm reactor (O2-MBfR). Results showed that reducing COD/TN ratio from 40 to 20 g COD/g N by supplementing NH4Cl to GW improved the relative abundance of genera related to LAS-biodegradation (from 8.39% to 35.7%), nitrification (from 0.20% to 0.62%) and denitrification (from 3.01% to 7.59%). Reducing COD/TN ratio also led to an increase in the ammonia monooxygenase (AMO) activity (from 7.56 to 10.2 mg N/g VSS-h), as well as improved ammoxidation and linear alkylbenzene sulfonate (LAS) mineralization although the dissolved oxygen (DO) concentration and pH decreased. Much higher NH4+ - N at lower COD/TN ratio (10 units) led to lower DO (0.13 ± 0.01 mg/L) and pH (6.72 ± 0.02), but the continuously increased AMO activity (up to 12.9 mg N/g VSS-h) enabled the cometabolism of ammoxidation and LAS mineralization, leading to the efficient removal of organics and nitrogen under the low DO condition.Houston watersheds are susceptible to microbial contamination as well as chemical contaminations from bordering industrial facilities. Bacterial loads in various Houston bayous were determined, and pathogenic Gram-negative bacteria were isolated for characterization. Isolates included Klebsiella aerogenes and Klebsiella pneumoniae. To determine whether environmental exposures to lead (Pb), measured in our Houston bayou samples, resulted in bacterial adaptations, we compared growth kinetics, biofilm production, oxidative stress resistance, and eukaryotic co-culture growth of environmentally isolated K. aerogenes and K. pneumoniae to their respective commercially acquired reference strains. Interestingly, the K. aerogenes environmental isolate displayed significantly better growth than the reference strain in the presence of 50 ppb of Pb. Unexpectedly, we did not observe any differences in biofilm production of the aforementioned strains when challenged with a range of Pb (0.5-50 ppb). However, when comparing our K. pneumoniae environmental isolate to its reference strain, there were significantly higher levels of biofilm produced by the environmental isolate when challenged with Pb concentrations of 10 and 50 ppb. CB1954 research buy When grown in eukaryotic cell co-culture with either BAES 2B lung cells or CCD 841 colon epithelial cells in the presence of 20 ppb Pb, the environmental isolates of K. aerogenes and K. pneumoniae had a significantly higher fold-increase over 6 h than their respective reference strains. Taken together, the environmentally isolated Klebsiella spp. appeared to be more Pb-tolerant than their respective reference strains, a possible environmental adaptation. Such enhanced tolerance can promote environmental persistence and increase the possibility of causing human disease.Coastal wetlands comprise unique ecological systems such as tidal flats and wetlands coexisting with marine and terrestrial ecosystems. The Songdo wetlands in South Korea are adjacent to the Yellow Sea, and were once composed mainly of tidal flats, but as urbanization progressed, their social-ecological system changed. The social system created by land reclamation and development reduced the migratory bird population and the tidal flat area, damaging the ecological system. This study suggests adaptation and transformation plans by analyzing land use change and fragmentation of the Songdo wetlands using spatial-temporal simulation. System dynamics and GIS were used in the process of analyzing land use change through spatial-temporal simulation, and FRAGSTATS was used in the analysis of wetland fragmentation. Scenario 1 (current state maintenance) presents adaptation plans to increase the connectivity of wetland patches, since fragmentation has not progressed to the extent of wetland system collapse. In Scenario 2 (development acceleration), since the wetland system causes serious fragmentation in terms of area and shape, we propose transformation plans such as disaster response to the collapse of the ecological system and qualitative improvement of wildlife habitat. In Scenario 3 (wetland restoration), proposes transformation plans from the network and modularization perspective in response to quantitative restoration and morphological fragmentation of wetlands. The adaptation and transformation plans presented in this study can provide prediction results suitable for various contingencies such as the current state, acceleration of development, and wetlands restoration. This study is also meaningful in that it proposes plans from the perspective of resilience by predicting the change of the Songdo area, which is scheduled to be developed by 2030.As an emerging pollutant, microplastic has been demonstrated to widely cover water and sediments in marine and freshwater environments globally. Due to the differences in the regional functions of cities, the abundance and characteristics of microplastic pollution in rivers are different. Taking the Minjiang River as the research object, which flows through the Chengdu Plain, the abundance, composition, shape, and size of microplastics in the water and sediments of the Minjiang River were investigated. The results showed that serious microplastic pollution occurred in the Chengdu section of the Minjiang River, with an abundance ranging from 6.11-44.08 n/L in the water and from 573.84-2878.97 n/kg in the sediments. By using the "regional function index (Q)", the relationships between the characteristics of microplastic pollution and regional functions were analyzed. Areas with a high Q proved to be more polluted by microplastics. Densely populated areas with large construction areas and high human activity intensity tended to generate microplastics with larger sizes and a more fiber-like shapes. Rayon (RA) and nylon (PA) were identified as typical urban microplastics, while polypropylene (PP) and polyethylene (PE) were identified as typical agricultural microplastics. This study elucidated the microplastic pollution in the Chengdu section of the Minjiang River, a tributary in the upper reaches of the Yangtze River. It also provided a new direction for the study of microplastic pollution characteristics of freshwater environments with different regional functions and microplastic pollution source control.Polycyclic aromatic hydrocarbons (PAHs) have gained attention because of their environmental persistence and effects on ecosystems, animals, and human health. They are mutagenic, carcinogenic, and teratogenic. The review provides background knowledge about their sources, metabolism, temporal variations, and size distribution in atmospheric particulate matter. The review article briefly discusses the analytical methods suitable for the extraction, characterization, and quantification of nonpolar and polar PAHs, addressing the challenges. Herein, we discussed the molecular diagnostic ratios (DRs), stable carbon isotopic analysis (SCIA), and receptor models, with much emphasis on the positive matrix factorization (PMF) model, for apportioning PAH sources. Among which, DRs and PCA identified as the most widely employed method, but their accuracy for PAH source identification has received global criticism. Therefore, the review recommends compound-specific isotopic analysis (CSIA) and PMF as the best alternative methods to provide detailed qualitative and quantitative source analysis.