Pathfinder-Based Simulation and Optimization of Evacuation of Large Commercial Complexes

Large commercial complexes are large in scale, complex in function, and located in densely populated areas that are prone to casualties due to unfavorable evacuation. To comprehend the safety evacuation of large commercial complex buildings in China, investigate the safety evacuation problems encountered during the evacuation process and the evacuation optimization design strategy, the paper uses Pathfinder to build a simulation model based on literature research and study to simulate the evacuation of personnel in a large commercial complex in Dalian and explore its problems during the evacuation process. The results show that the type of personnel has an effect on the large commercial complex’s evacuation simulation results;the total number of evacuees is non-linearly correlated with the time change curve;some staircases take a long time to evacuate and have a low utilization rate. To improve evacuation efficiency, optimization suggestions for safety exits, evacuation stairs, and evacuation channels are made based on the results.

Insights into simultaneous anammox and denitrification system with short-term pyridine exposure: Process capability, inhibition kinetics and metabolic pathways

In-depth knowledge on the role of pyridine as a bottleneck restricting the successful application of anammox-based process treating refractory coking wastewater remains unknown.In this study,the effect of short-term pyridine addition on a simultaneous anammox and denitrification(SAD)system fed with 25–150 mg/L pyridine was explored.The short-term operation showed that the highest total nitrogen(TN)removal efficiency was achieved at 25–50 mg/L of pyridine.As the pyridine addition increased,the contribution of the anammox pathway in nitrogen removal decreased from 99.3%to 79.1%,while the denitrification capability gradually improved.The specific anammox activity(SAA)at 150 mg/L pyridine decreased by 56.7%of the maximum SAA.The modified non-competitive inhibition model indicated that the 50%inhibitory concentration(IC_(50))of pyridine on anammox was 84.18 mg/L and the substrate inhibition constant(Ki)of pyridine for self-degradation was 135.19 mg/L according to the Haldane model.Moreover,high-throughput sequencing confirmed the abundance of Candidatus Kuenenia as the amount of anammox species decreased,while the amounts of denitrifiers and pyridine degraders significantly increased as the pyridine stress increased.Finally,the possible pathways of nitrogen bioconversion and pyridine biodegradation in the SAD system were elucidated through metagenomic analysis and gas chromatography/mass spectrometry results.The findings of this study enlarge the understanding of the removal mechanisms of complex nitrogenous pyridinecontaining wastewater treated by the SAD process.