This study emphasized on the removal performance of polychlorinated-ρ-dibenzodioxins and dibenzofurans (PCDD/Fs) and mercury by different activated carbon injection (ACI) rates from a full-scale (700 t/d) MSW incinerator. The result exhibited that the emission standard of PCDD/Fs and mercury could be met when the ACI rate reached 50 mg/Nm3 and 30 mg/Nm3, respectively. Lower chlorinated PCDD/Fs and PCDFs showed higher removal efficiencies compared with highly chlorinated PCDD/Fs and PCDDs, which could be attributed to the larger competitiveness of highly volatile congeners in AC adsorption than the lower volatile ones. AC turned out to have different adsorption selectivity for CP-routes PCDD/Fs congeners, among which 1379-TCDD was preferred to be absorbed while others exhibited little or poor selectivity for AC adsorption. The removal efficiency of PCDD/Fs was positively correlated with ACI rate at 99% confidence interval with a linear relationship (R2?=?0.98). Also, the outlet concentration of mercury decreased with the increase of ACI rate in a nearly linear function (R2?=?0.96). These results will be meaningful for the rational use of AC for pollutants control.
Typical thermal fingerprints are rather evenly composed of all available polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) congeners, a feature also linked with CuCl2-catalysis. Conversely, chlorophenol condensation patterns are supported strongly by CrCl3-, ZnCl2- and CdCl2-catalysis; they feature selective formation of, e.g., 1,3,6,8- and 1,3,7,9-TCDD arising from mainly 2,4,6-trichlorophenol, a chlorophenol well-represented in incinerator flue gas. Just few, well-defined PCDD-congeners steadily emerge from chlorophenols. Surprisingly, it is experimentally established that these are not generally formed by parallel processes. Additionally, the formation of four important 2,3,7,8-substituted TCDD/F- and PeCDD/F-congeners is statistically quasi-unrelated. Apparently, external (α) or lateral (β)-chlorination occurs as a chance event, contrary to observations and hypotheses in earlier studies. These statements are corroborated by selected congener-to-congener representations. For performing this statistical analysis, simple techniques are followed. Cross-correlation matrices show a relationship for each pair of PCDD/F-congeners in a particular data set: PCDD/F-congener pairs statistically correlate, anti-correlate, or appear rather neutral. In this paper, these novel concepts were applied on data, established during tests on Model Fly Ash (MFA); principal component analysis was used to demonstrate the relevance of MFA-data in relation to municipal solid waste incineration signatures. 相似文献
Devils Lake is an endorheic lake in the Red River of the North basin in northeastern North Dakota. During the last two decades, the lake water level has risen by nearly 10 m, causing floods that have cost more than 1 billion USD in mitigation measures. Another increase of approximately 1.5 m in the lake water level would cause spillage into the Sheyenne River. To alleviate this potentially catastrophic spillage, two artificial outlets were constructed. However, the artificial drainage of water into the Sheyenne River raises water quality concerns because the Devils Lake water contains significantly higher concentrations of dissolved solids, particularly sulfate. In this study, the Soil and Water Assessment Tool (SWAT) was coupled with the CE‐QUAL‐W2 model to simulate both water balance and sulfate concentrations in the lake. The SWAT model performed well in simulating daily flow in tributaries with ENS > 0.5 and |PBIAS| < 25%, and reproduced the lake water level with a root mean square error of 0.35 m for the study period from 1995 to 2014. The water temperature and sulfate concentrations simulated by CE‐QUAL‐W2 for the lake are in general agreement with the field observations. The model results show that the operation of the two outlets since August 2005 has lowered the lake level by 0.70 m. Furthermore, the models show pumping water from the two outlets raises sulfate concentrations in the Sheyenne River from ~100 to >500 mg/L. Editor's note : This paper is part of the featured series on SWAT Applications for Emerging Hydrologic and Water Quality Challenges. See the February 2017 issue for the introduction and background to the series. 相似文献
Climate change is causing severe negative consequences to small low-lying islands. To mitigate and adapt to climate change, it is important to improve public knowledge on its causes and consequences. As a social issue that needs collective action to address, the knowledge gap among different segments of population would be a barrier to people’s behaviors toward mitigation and adaption to climate change. This study aims to investigate public knowledge acquisition of climate change by revisiting the knowledge gap hypothesis. A nationally representative random computer-assisted telephone interview survey (N?=?1093) was conducted in Singapore. Quantitative analyses revealed that both newspaper reading and television viewing could reduce the knowledge gap between high and low socioeconomic status individuals. We recommend that governments and relevant authorities should utilize mass media to disseminate information and cultivate public understanding of climate change. 相似文献