The biosorption of Direct Black 38 by dried anaerobic granular sludge in a batch system under specific temperatures and initial
pH was investigated. The adsorption reaction is pH dependent with higher removal at low pH. The adsorption equilibrium data
fit very well with both Langmuir and Freundlich models in the concentration range of Direct Black 38 at all chosen temperatures.
The adsorption parameters show that the adsorption of Direct Black 38 is an endothermic and more effective process at high
temperatures. The kinetics of adsorption was found to be second order and adsorption rate constants increased with increasing
temperature. Activation energy was determined as 26.8 kJ/mol for the process. This suggests that the adsorption of Direct
Black 38 by dried anaerobic granular sludge is chemically controlled. 相似文献
Effects of thiobencarb on growth, photosynthesis and photoinhibition of Nostoc sphaeroides colonies were examined. Thiobencarb concentrations higher than 2 mg/l led to a significant decrease in phycoerythrin, phycocyanin and allophycocyanin content, but no significant effect on chlorophyll a (chl a) content. Biomass yield, protein content and photosynthetic rate were reduced only in the highest thiobencarb concentration (10 mg/l). Colonies exposed to high thiobencarb dose (10 mg/l) were more sensitive to high light than those exposed to the control and 4 mg/l thiobencarb. Dim light induced recovery from photoinhibition to more great extent in colonies grown in the control and 4 mg/l thiobencarb than 10 mg/l thiobencarb. Darkness resulted in a insignificant recovery regardless of thiobencarb treatments. 相似文献
Objectives: This article aims to model fault in e-bike fatal crashes in a county-level city in China.
Method: Three-year crash data are retrieved from the crash reports (2012–2014) from the Taixing Police Department. A mixed logit model is introduced to explore significant factors associated with fault assignment, as well as accounting for similarity among fault assignment and heterogeneity within unobserved variables.
Results: The modeling results indicate some interesting new findings. First, precrash behaviors of both drivers and e-bike riders are found to be significant to fault assignment. Second, bike lane and median type are significantly associated with e-bike rider fault commitment. Third, specific groups of e-bike riders (low-educated and older) and drivers (heavy good vehicles) are more likely to be at fault in e-bike crashes. Last, crash location and the built environment have significant correlations with faulty behaviors of e-bike riders.
Conclusions: Safety countermeasures are proposed including (1) the deployment of traffic design and control elements including physically separated bike lanes, medians, video surveillance systems for e-bike riders, and left-turning treatments for nonmotorists (e.g., a 2-step e-bike left turning); (2) the amendment of the current traffic regulations on drunk e-bike riders and child e-bike passengers; (3) the development of a license system for specific e-bike rider groups (older and low-educated) and a safety campaign for drivers (to increase safety awareness when parking on-street or driving heavy good vehicles). Some interesting future research topics are also suggested: e-bike riders' behaviors at unsignalized intersections and mid-block openings, e-bike safety in suburban areas, and an in-depth study of the effect of the built environment on e-bike safety. 相似文献