Ambient concentrations of PANs and other related air pollutants were monitored at an urban site in Beijing each August from 2006 to 2014. The NO_x concentration decreased at a rate of 1.7 nL/(L/yr) (about 4%/yr), and the PAN concentration decreased at a rate of 0.03 nL/(L/yr) (about 3%/yr), while the O₃ concentration increased at a rate of 1.5 nL/(L/yr) (about 4%/yr), indicating that the measures taken to cut NO_x were effective for controlling PAN concentration. Beijing needs to strengthen the control of VOCs with reducing NO_x emissions for reducing O₃ concentration.

The concentrations of atmospheric PAN and PPN were measured by online instrument in Beijing from Aug.15 to Sep.12, 2006, and the correlation and concentration variation of PANs were analyzed. The results show that there was a high concentration of PAN and PPN in urban and rural atmosphere in Beijing. The highest concentrations of PAN and PPN were 11219×10^-12 and 1953×10^-12 L/L respectively at Zhongguancun site and 2505×10^-12 and 413×10^-12 L/L at Yufa site. PAN had a good correlation with PPN, also correlated with O_3. Thermal decomposition of PAN (TDPAN) accounted for 10%-70% of the total PAN (the measured PAN+TDPAN).

Based on the optimum condition for removal of pentachlorophenol in water by using HRP immobilized by Ｆe_３Ｏ_４sorption-gelatin embedding-cross linkage method as catalyzer, the reacting fitting and the removal efficiency were studied. The flow rate of PCP solution through the fitting was selected for better removal efficiency of Pentachlorophenol. The repetitive use of immobilized HRP for PCP removal, and the effect of secondary treatment of wastewater were also examined. The results indicate that the optimal flow rate of PCP solution for the removal efficiency of the reacting fitting is around 3mL/min and the PCP removal rate is quite stable. Repetitive use of immobilized HRP for PCP removal is stable. Once the PCP removal efficiency of primary treatment couldn't meet the drainage standard for PCP concentration, secondary treatment is also feasible. The PCP removal rate of secondary treatment can reach 92.7%, and the residual concentration of PCP can reach 0.98mg/L, which is under national first drainage standard (5mg/L) evidently.