• The inhibition of the main organic pollutions in CMW was demonstrated.• Variations of AK and BK showed a high correlation with the SAA of Ac and n-Bu.• The inhibitory degree was in the order of Ac>n-Bu for individual toxicants.• Biodegradation products of the main toxicants were analyzed. This work aims to investigate the inhibitory effect of crotonaldehyde manufacture wastewater (CMW) on biological acidification. To reveal the inhibitory effect of wastewater to the anaerobic granular sludge (AnGS), variations of the specific acidogenic activity (SAA) and activities of key enzymes were investigated. The results indicated that the dosage of CMW causing a 50% effect concentration (EC50) on the activity of total volatile fatty acids (TVFA) production was 380 mg COD/g VSS. The inhibitory effect of individual toxicants in CMW on the activity of TVFA production were in the order of crotonaldehyde>ethyl sorbate>(E,E)-2,4-hexadienal, and their inhibitory degrees on individual VFA products were acetic acid (Ac)>n-butyric acid (n-Bu), which could correspond to the variations in the activities of acetate kinase (AK) and butyrate kinase (BK). Furthermore, the combined effect of three toxicants on the activity of TVFA production was significantly higher than that of any individual toxicant, and the contribution of the relative toxicity to CMW was 77.27%. Additionally, the biodegradation products of the main toxicants indicated that the removal of crotonaldehyde and (E,E)-2,4-hexadienal was primarily due to the hydrogenation of alkene and aldehyde and the oxidation of aldehyde. Nevertheless, the removal of ethyl sorbate was primarily based on adsorption. In conclusion, biological acidification has a limited ability to treatment CMW, therefore, a further pretreatment technology should be used to remove the main toxicant of wastewater. 相似文献
• 5R (Recover, Reduce, Recycle, Resource and Reuse) approaches to manage urban water.• 5R harvests storm water, gray water and black water in several forms.• 5R offers promise for moving solutions for urban water scarcity in practice. Demand for water is expanding with increases in population, particularly in urban areas in developing countries. Additionally, urban water system needs a novel perspective for upgradation with urbanization. This perspective presents a novel 5R approach for managing urban water resources: Recover (storm water), Reduce (toilet flushing water), Recycle (gray water), Resource (black water), and Reuse (advanced-treated wastewater). The 5R generation incorporates the latest ideas for harvesting storm water, gray water, and black water in its several forms. This paper has briefly demonstrated each R of 5R generation for water treatment and reuse. China has the chance to upgrade its urban water systems according to 5R principles. Already, a demonstration project of 5R generation has been installed in Qingdao International Horticultural Exposition, and Dalian International Convention Center (China) has applied 5R, achieving over 70% water saving. The 5R offers promise for moving solutions for urban water scarcity from “hoped for in the future” to “realistic today”. 相似文献
Environmental Chemistry Letters - The demand for lithium is growing rapidly with the increase in electric vehicles, batteries and electronic equipments. Lithium can be extracted from brines, yet... 相似文献
Environment, Development and Sustainability - Due to rapid socioeconomic development, seeking the coordination of resources exploitation and the ecological environment has become an objective... 相似文献
Environmental Geochemistry and Health - Recently, particulate matter pollution has been worsening, which has been affecting the asthma visits in children. In this study, we assessed the short-term... 相似文献
• Aerosol transmission is an indispensable route of COVID-19 spread.• Different outbreak sites have different epidemiologic feature.• SRAS-CoV-2 can exist for a long time in aerosol.• SRAS-CoV-2 RNA can be detected in aerosol in diverse places.• Some environmental factors can impact SARS-CoV-2 transportation in aerosol. Patients with COVID-19 have revealed a massive outbreak around the world, leading to widespread concerns in global scope. Figuring out the transmission route of COVID-19 is necessary to control further spread. We analyzed the data of 43 patients in Baodi Department Store (China) to supplement the transmission route and epidemiological characteristics of COVID-19 in a cluster outbreak. Incubation median was estimated to endure 5.95 days (2–13 days). Almost 76.3% of patients sought medical attention immediately upon illness onset. The median period of illness onset to hospitalization and confirmation were 3.96 days (0–14) and 5.58 days (1–21), respectively. Patients with different cluster case could demonstrate unique epidemiological characteristics due to the particularity of outbreak sites. SRAS-CoV-2 can be released into the surrounding air through patient’s respiratory tract activities, and can exist for a long time for long-distance transportation. SRAS-CoV-2 RNA can be detected in aerosol in different sites, including isolation ward, general ward, outdoor, toilet, hallway, and crowded public area. Environmental factors influencing were analyzed and indicated that the SARS-CoV-2 transportation in aerosol was dependent on temperature, air humidity, ventilation rate and inactivating chemicals (ozone) content. As for the infection route of case numbers 2 to 6, 10, 13, 16, 17, 18, 20 and 23, we believe that aerosol transmission played a significant role in analyzing their exposure history and environmental conditions in Baodi Department Store. Aerosol transmission could occur in some cluster cases when the environmental factors are suitable, and it is an indispensable route of COVID-19 spread. 相似文献
Sb release characteristics of blast furnace slag, mining waste rock and tailing sand were investigated in static immersion and dynamic leaching test. These three kinds of waste samples were collected from the antimony mine in Lengshuijiang, China, produced in mining smelting process. Effects of solid/liquid ratio, sample size and pH of leaching solution on Sb release characteristics were inspected based on the analysis of scanning electron microscope, pH and EC of leachate. The optimal parameters for Sb leaching of each sample were analyzed. For blast furnace slag and mining waste rock, Sb release contents increased along with the decline of solid/liquid ratio. The maximum accumulative release contents were 42.13, 34.26 mg/kg at the solid/liquid ratio of 1:20. While Sb release content for tailing sand decreased first and then increased with the reduction of solid/liquid ratio. When the solid/liquid ratio was 1:5, the accumulative Sb release content reached the most (24.30 mg/kg). Sb release content of mining waste rock increased with the drop of leaching solution pH, with the highest accumulative release content of 26.01 mg/kg at pH 2.0. Sb release contents of blast furnace slag and tailing sand showed positive correlation with the variation of leaching solution pH. The maximum accumulative release contents of these two samples were 215.91 and 147.83 mg/kg, respectively, when leaching solution pH was 7.0. In summary, Sb release capacity of the three samples in descending order was tailing sand, blast furnace slag and mining waste rock. pH and EC of the leachate in dynamic test varied independently with the initial pH of leaching solution while showing close relationship with mineral hydrolysis in the waste. 相似文献
Stroke was demonstrated to correlate with seasonal variation. However, the relevant studies were incongruous. To better understand the rules of seasonal impact on ischemic stroke (IS) patients, we performed this meta-analysis. We systematically searched relevant observational studies in Pubmed, Web of science and Embase from January 1, 1980, to November 1, 2017, in English. Patients included in this study were adults who suffered from IS. Stata version 12.0 software was used to pool useful data and calculate incidence rate ratios (IRRs) and their 95% confidence intervals (CIs). We also performed heterogeneity and sensitivity analyses and evaluated publication bias. Thirty-three observational studies involving 234,196 participants were incorporated into the meta-analysis. Summer and December were regarded as reference, respectively. The IRRs were calculated showing: IRRWinter 1.05 (95% CI 1.04–1.07), IRRAutumn 1.03 (95% CI 1.02–1.04), IRRSpring 1.02 (95% CI 1.01–1.03). No obvious difference existed among 12 months. Stratified analyses on Köppen classification were also conducted. Between-study heterogeneity was discovered; however, predefined stratified analyses and meta-regression could not reduce this heterogeneity. Our meta-analysis has revealed very little seasonal variation in the overall study. Both cold and hot months may be high risky for IS after stratified by Köppen Climate Classification. Thus, a rationale to environmental setting of risky patient management could be provided. More studies with specific assessments are warranted for further comprehensive investigation.