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Результаты 4631-4640 из 7,292
An online participatory system for SWMM-based flood modeling and simulation Полный текст
2022
Zhang, Beichen | Chen, Min | Ma, Zaiyang | Zhang, Zhuo | Yue, Songshan | Xiao, Dawei | Zhu, Zhiyi | Wen, Yongning | Lü, Guonian
In the context of the continuous development of urbanization and global climate change, urban flooding risk has become a well-publicized research issue. The Storm Water Management Model (SWMM) performs very well in urban rain-runoff simulations and is widely used to build flood models in specific areas. Because of the complicated and tedious processing work for urban flood modeling and simulation, multifield participants’ cooperation is becoming a trend. To promote the research and application of flood modeling and simulation, some resource sharing-oriented systems and platforms have been proposed with the advantages of network technology. However, they still require a participatory environment that can help modeling participants overcome the difficulties of distributed cooperation in the process of SWMM-based flood modeling and simulation. Therefore, we designed and implemented an online participatory system to coordinate the effective collaboration of modeling participants in this process. By referring to the scenarios and specific participatory demands in the modeling process, the system provides a guiding framework that consists of multiple participatory activities and prepares a series of online auxiliary tools designed for these activities. Using the main urban area of Lishui City as the study area, it was confirmed that the process of SWMM-based flood modeling and simulation can be demonstrated collaboratively on the online participatory system developed in this study.
Показать больше [+] Меньше [-]Synergistic adsorption and advanced oxidation activated by persulfate for degradation of tetracycline hydrochloride using iron-modified spent bleaching earth carbon Полный текст
2022
Chen, Yue | Shi, Yahui | Wan, Dongjin | Zhao, Jihong | He, Qiaochong | Liu, Yongde
At present, tetracycline hydrochloride (TCH) is a widely used antibiotic, and is often detected in water, posing a serious harm to human and ecological health. In this study, spent bleaching earth (SBE) was pyrolyzed to obtain spent bleaching earth carbon (SBE@C) and the nano Fe⁰/SBE@C prepared after zero-valent iron loading was adopted to remove TCH in water for the first time. The combination of nano Fe⁰/SBE@C and PS, the strong adsorption of SBE@C coupled with the oxidation of free radicals could achieve TCH efficient removal. The effects of nano Fe⁰ load, nano Fe⁰/SBE@C dosage, solution initial pH, and PS/TCH molar ratio on TCH removal efficiency in nano Fe⁰/SBE@C + PS system were studied. The results indicate that the optimal reaction conditions are 5% nano Fe⁰ load, 0.2 g/L nano Fe⁰/SBE@C dosage, initial pH of 3, PS/TCH molar ratio of 100:1. Under these conditions, TCH removal efficiency could reach 91%. Meanwhile, response surface methodology (RSM) was applied to predict optimal value of reaction conditions. The removal efficiency corresponding to the predicted optimal conditions was consistent with the actual removal efficiency obtained from the experiment. Moreover, six reaction systems were tested, and TCH removal efficiency in the SBE@C + PS system was 22.6%. When nano Fe⁰ was loaded on SBE@C, TCH removal efficiency in Fe⁰/SBE@C + PS system increased to 78.2%, in which TCH was first adsorbed on the surface of nano Fe⁰/SBE@C, and then was degraded by the oxidation of SO₄•⁻ and •OH. Totally, the nano Fe⁰/SBE@C + PS system displayed excellent TCH removal efficiency, good stability and reusability, exhibiting a promise toward TCH removal.
Показать больше [+] Меньше [-]Development characteristics, influencing mechanism and coping strategies of resource-based cities in developing countries: a case study of urban agglomeration in Northeast China Полный текст
2022
Wang, Yufeng
The transformation of resource-based cities and coordinated regional development are of great value to global urbanization and sustainable economic development in developing countries. Based on Landsat satellite monitoring data and urban economic data, statistical analysis and geospatial model were used to analyze the characteristics of urban development in urban agglomeration in Northeast China from 2000 to 2020, and the influencing mechanism was quantitatively revealed. The results show that the expansion of urban agglomerations rate reached its peak from 2005 to 2010, and then the expansion rate continued to decline. The resources of central cities were concentrated, while the development of sub-central cities was weak. The overall urbanization rate slows down, the scale difference between high-order cities and low-order cities expands, and the regional urban system shifts from balanced development to polarized development. The overall development of urban agglomerations shows a centripetal agglomeration characteristic centered on the Harbin Changchun-Daqing and Central and southern Liaoning Economic belt. Its west expands faster than the East, and its south expands faster than the north. The driving factors of urban agglomeration development are mainly administrative power, followed by market power, external power and weak internal power. From the point of time and space, the external power is on the rise, while the internal power is affected by the industrial adjustment and lacks the staying power. In view of the coordinated development of resource-based cities, this paper proposes to establish the linkage and coordination mechanism of integrated development of urban agglomeration, speed up the construction of unified market system, carry out transformation positioning according to market demand and implement differentiation policy.
Показать больше [+] Меньше [-]Sodium nitrate as a methanogenesis suppressor in earthen separator microbial fuel cell treating rice mill wastewater Полный текст
2022
Bagchi, Somdipta | Sahoo, Rudra Narayan | Behera, Manaswini
The microbial fuel cell (MFC) is one of the sustainable technologies, which alongside treating wastewater, can generate electricity. However, its performance is limited by factors like methanogenesis where methanogens compete with the anode respiring bacteria for substrate, reducing the power output. Thus, sodium nitrate, which has been previously reported to target the hydrogenotrophic methanogens, was used as a methanogenic suppressor in this study. The performance of MFC with and without sodium nitrate was studied during the treatment of rice mill wastewater. A significantly higher power density and coulombic efficiency (CE) were noted in the MFC with sodium nitrate (MFCT) (271.26 mW/m³) as compared to the control MFC (MFCC) (107.95 mW/m³). Polarization studies showed lower internal resistance for the MFCT (330 Ω) as compared to MFCC (390 Ω). Linear sweep voltammetry and cyclic voltammetry indicated a higher electron discharge on the anode surface due to enhancement of electrogenic activity. Considerable reduction (76.8%) in specific methanogenic activity was also observed in anaerobic sewage sludge mixed with sodium nitrate compared to the activity of anaerobic sewage sludge without any treatment. Due to the inhibition of methanogens, a lower chemical oxygen demand (COD) and phenol removal efficiency were observed in MFCT as compared to MFCC. The COD balance study showed an increase in substrate conversion to electricity despite the increase in nitrate concentration. Therefore, selective inhibition of methanogenesis had been achieved with the addition of sodium nitrate, thus enhancing the power generation by MFCs.
Показать больше [+] Меньше [-]Investigation of indole biodegradation by Cupriavidus sp. strain IDO with emphases on downstream biotransformation and indigo production Полный текст
2022
Dai, Chunxiao | Ma, Fang | Ma, Qiao | Yang, Jing | Li, Yan | Yang, Bingyu | Qu, Yuanyuan
Indole, as a typical N-heterocyclic aromatic pollutant, poses risks to living things; however, indole-biotransformation mechanisms remain under-discussed, especially those related to its downstream biotransformation. Here, we systematically investigated the characteristics of indole degradation by strain Cupriavidus sp. IDO. We found that Cupriavidus sp. IDO could utilize 25 to 150 mg/L indole within 40 h and identified three intermediates (2-oxindole, indigo, and isatin). Additionally, integrated genomics and proteomics analysis of the indole biotransformation mechanism in strain IDO revealed 317 proteins showing significant changes (262 upregulated and 55 downregulated) in the presence of indole. Among these, three clusters containing indole oxidoreductase, CoA-thioester ligase, and gentisate 1,2-oxidoreductase were identified as potentially responsible for upstream and downstream indole metabolism. Moreover, HPLC-MS and -omics analysis offered insight into the indole-degradation pathway in strain IDO. Furthermore, the indole oxidoreductase IndAB, which initiates indole degradation, was heterologously expressed in Escherichia coli BL21(DE3). Optimization by the response surface methodology resulted in a maximal production of 135.0 mg/L indigo by the recombination strains in tryptophan medium. This work enriches our understanding of the indole-biodegradation process and provides new insights into multiple indole-degradation pathways in natural environments.
Показать больше [+] Меньше [-]Multivariate tools to investigate the spatial contaminant distribution in a highly anthropized area (Gulf of Naples, Italy) Полный текст
2022
Mali, Matilda | Di Leo, Antonella | Giandomenico, Santina | Spada, Lucia | Cardellicchio, Nicola | Calò, Maria | Fedele, Alessandra | Ferraro, Luciana | Milia, Alfonsa | Renzi, Monia | Massara, Francesca | Granata, Tommaso | Moruzzi, Letizia | Buonocunto, Francesco Paolo
The Gulf of Naples located in a high anthropized coastal area is subjected to an infrastructural intervention for the installation of a submarine power pipeline. In order to evaluate the distribution of contaminants in the seafloor sediments, a preliminary study has been conducted in the area using multivariate techniques. The statistic approach was performed to gain insights on the occurrence of organic and inorganic contaminants within the area, aiming to identify the relevant hot spots. Three geographical sub-areas influenced by different contaminant association were recognized: Torre Annunziata (TA), Capri (CA), and middle offshore (MO). TA and CA resulted marked by a severe contamination pattern due to anthropogenic pressures. In addition, the influence of the depositional basin in governing the contamination trend has been pointed out. The supervised technique PLS_DA resulted to be a powerful tool in addressing the complexity of the huge dataset acquired during the marine survey, highlighting the main trends in the variability of quality indicators, orienting thus the deeper investigations during follow-up monitoring activities.
Показать больше [+] Меньше [-]Influence of various additives on stability and phase change characteristics of DI water-GnP-based NFPCM for cold thermal energy storage systems Полный текст
2022
Palanichamy, Sundaram | Athiimoulam, Kalaisselvane
The present work aims to investigate the effects of various additives on the stability of graphene nanoplatelet (GnP)–based nanofluid phase change material (NFPCM) for cold thermal energy storage (CTES). The NFPCMs are prepared by dispersing six different types of surfactants (anionic, cationic, and non-ionic types) in deionized (DI) water at a mass ratio of 1:0.5 GnP to surfactant. NFPCMs can be found to be stable with a suitable surfactant even after 30 days using zeta-potential distribution, UV–vis absorption, visual inspection, and sedimentation tests at low temperature. The maximum enhancement in thermal conductivity of 8.3% and 48.3% is recorded in both liquid and solid states for the NFPCM with gum arabic (GA) respectively. The viscosity was enhanced by the dispersion of non-ionic surfactants, where the anionic surfactant (sodium dodecylbenzene sulfonate (SDBS)) NFPCM had a 29.9% lower augmentation compared to DI water. Furthermore, differential scanning calorimetry (DSC) results demonstrate that the phase change properties of the NFPCM are significantly affected depending on the surfactant type. The maximum phase change enthalpy is lowered (10.6%) in the Tween 80 NFPCM as compared to the base PCM. The long-term stability with the highest thermal transport property of the NFPCM storage unit integrated with the chiller is capable of achieving environmental pollution remediation by minimising the time it takes to charge the PCM.
Показать больше [+] Меньше [-]Antibiotics in elderly Chinese population and their relations with hypertension and pulse pressure Полный текст
2022
Li, Zhenkun | Liu, Kaiyong | Zhao, Jianing | Yang, Linsheng | Chen, Guimei | Liu, Annuo | Wang, Qunan | Wang, Sufang | Li, Xiude | Cao, Hongjuan | Tao, Fangbiao | Zhang, Dongmei
Although antibiotic exposure in the general population has been well documented by a biomonitoring approach, epidemiologic data on the relationships between urinary antibiotic burden in the elderly with blood pressure (BP) are still lacking. The current study revealed thirty-four antibiotics in urine specimens from 990 elderly patients in Lu’an City, China, with detection frequencies ranging from 0.2 to 35.5%. Among the elderly, the prevalence of hypertension was 72.0%, and 12 antibiotics were detected in more than 10% of individuals with hypertension. The elderly with hypertension had the maximum daily exposure (5450.45 μg/kg/day) to fluoroquinolones (FQs). Multiple linear regression analyses revealed significant associations of BP and pulse pressure (PP) with exposure to specific antibiotics. The estimated β values (95% confidence interval) of associations with systolic blood pressure (SBP) in the right arm were 4.42 (1.15, 7.69) for FQs, 4.26 (0.52, 8.01) for the preferred as human antibiotics (PHAs), and 3.48 (0.20, 6.77) for the mixtures (FQs + tetracyclines [TCs] (tertile 3 vs. tertile 1)), respectively. Increased concentrations of TCs were associated with decreased diastolic BP (DBP; tertile 3: −1.75 [−3.39, −0.12]) for the right arm. Higher levels of FQs (tertile 3: 4.28 [1.02, 7.54]), PHAs (tertile 3: 4.25 [0.49, 8.01]), and FQs + TCs (tertile 3: 3.99 [0.71, 7.26]) were associated with increased SBP, and an increase in DBP for FQs (tertile 3: 1.82 [0.22, 3.42]) was shown in the left arm. Also, higher urinary concentrations of FQs (tertile 3: 3.18 [0.53, 5.82]), PHAs (tertile 3: 3.42 [0.40, 6.45]), and FQs + TCs (tertile 3: 3.06 [0.40, 5.72]) were related to increased PP, whereas a decline in PP for TCs (tertile 2: −2.93 [−5.60, −0.25]) in the right arm. And increased concentrations of penicillin V (tertile 3: 5.31 [1.53, 9.10]) and FQs + TCs (tertile 3: 2.84 [0.19, 5.49]) were related to higher PP in the left arm. By utilizing restricted cubic splines, our current study revealed a potential nonlinear dose-response association between FQ exposure and hypertension risk. In conclusion, this investigation is the first to present antibiotic exposure using a biomonitoring approach, and informs understanding of impacts of antibiotic residues, as emerging hazardous pollutants, on the hypertension risk in the elderly.
Показать больше [+] Меньше [-]The impact of mucormycosis (black fungus) on SARS-CoV-2-infected patients: at a glance Полный текст
2022
Islam, Md Rezaul | Rahman, Md Mominur | Ahasan, Md Tanjimul | Sarkar, Nadia | Akash, Shopnil | Islam, Mahfuzul | Islam, Fahadul | Aktar, Most Nazmin | Saeed, Mohd | Hāruna-ara-Raśīda, Moḥ. | Hosain, Md Kawsar | Rahaman, Md Saidur | Afroz, Sadia | Bibi, Shabana | Md. Habibur Rahman, | Sweilam, Sherouk Hussein
The emergence of various diseases during the COVID-19 pandemic made health workers more attentive, and one of the new pathogens is the black fungus (mucormycosis). As a result, millions of lives have already been lost. As a result of the mutation, the virus is constantly changing its traits, including the rate of disease transmission, virulence, pathogenesis, and clinical signs. A recent analysis revealed that some COVID-19 patients were also coinfected with a fungal disease called mucormycosis (black fungus). India has already categorized the COVID-19 patient black fungus outbreak as an epidemic. Only a few reports are observed in other countries. The immune system is weakened by COVID-19 medication, rendering it more prone to illnesses like black fungus (mucormycosis). COVID-19, which is caused by a B.1.617 strain of the SARS-CoV-2 virus, has been circulating in India since April 2021. Mucormycosis is a rare fungal infection induced by exposure to a fungus called mucormycete. The most typically implicated genera are Mucor rhyzuprhizopusdia and Cunninghamella. Mucormycosis is also known as zygomycosis. The main causes of infection are soil, dumping sites, ancient building walls, and other sources of infection (reservoir words “mucormycosis” and “zygomycosis” are occasionally interchanged). Zygomycota, on the other hand, has been identified as polyphyletic and is not currently included in fungal classification systems; also, zygomycosis includes Entomophthorales, but mucormycosis does not. This current review will be focused on the etiology and virulence factors of COVID-19/mucormycosis coinfections in COVID-19-associated mucormycosis patients, as well as their prevalence, diagnosis, and treatment.
Показать больше [+] Меньше [-]Recent advances in photocatalytic remediation of emerging organic pollutants using semiconducting metal oxides: an overview Полный текст
2022
Prakruthi, Komargoud | Ujwal, Mukkati Praveena | Yashas, Shivamurthy Ravindra | Mahesh, Basavaraju | Kumara Swamy, Ningappa | Shivaraju, Harikaranahalli Puttaiah
Many untreated and partly treated wastewater from the home and commercial resources is being discharged into the aquatic environment these days, which contains numerous unknown and complex natural and inorganic compounds. These compounds tend to persist, initiating severe environmental problems, which affect human health. Conventionally, physicochemical treatment methods were adopted to remove such complex organic chemicals, but they suffer from critical limitations. Over time, photocatalysis, an advanced oxidation process, has gained its position for its efficient and fair performance against emerging organic pollutant decontamination. Typically, photocatalysis is a green technology to decompose organics under UV/visible light at ambient conditions. Semiconducting nanometal oxides have emerged as pioneering photocatalysts because of large active surface sites, flexible oxidation states, various morphologies, and easy preparation. The current review presents an overview of emerging organic pollutants and their effects, advanced oxidation processes, photocatalytic mechanism, types of photocatalysts, photocatalyst support materials, and methods for improving photodegradation efficiency on the degradation of complex emerging organic pollutants. In addition, the recent reports of metal-oxide-driven photocatalytic remediation of emerging organic pollutants are presented in brief. This review is anticipated to reach a broader scientific community to understand the first principles of photocatalysis and review the recent advancements in this field.
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