关键词: 种子雨, 天然更新, 杉阔混交林, 杉木纯林

Abstract: Photocatalytic degradation of nitrobenzene in wastewater by Fe-doped nanostructured ZnO suspended system was studied under a high voltage fluorescence mercury lamp. Effects of initial concentration of nitrobenzene, mass concentration of Zn_1-xFe_x-O, ratio of amount of substance between Zn and Fe, reaction temperature, initial pH and photodegradation time were investigated. The results showed that the removal of nitrobenzene was effective, the rate of photodegradation in aqueous solution followed firstorder kinetics, and activation energy (E_a) was 9.3 kJ·mol^-1. When mass concentration of Zn_1-xFe_x-O was 0.8 g·L^-1 (the molar ratio of Zn and Fe was 1∶99), the first order photodegradation rate constant of nitrobenzene (initial concentration was 400 mg·L^-1, reaction temperature was 30 ℃, reaction pH was 3.27) was 0.0136 min-1, irradiated by a 125 W  high voltage fluorescence mercury lamp in wastewater. The photodegradation rate constant of nitrobenzene was related to the influential factors mentioned above. More-over, the catalyst Zn_0.99Fe_0.01-O prepared by us significantly lowered activation energy and improved the effect of the photodegradation of nitrobenzene in contaminated wastewater.

Key words: natural regeneration, Chinese fir pure plantation, mixed broadleaf-conifer forest, seed rain