Abstract: Granular sludge formation and zooplankton succession in the process of domesticating activated sludge and treating papermaking wastewater were investigated with sequencing batch reactor (SBR). The results showed that in the initial stage of sludge domestication, the sludge granularity and the removal capability of COD were low, Mastigophora appeared firstly, and Sarcodina appeared later. In the metaphase, sludge granularity and wastewater treatment capability advanced, and Ciliate dominated. In the stationary phase, wastewater treatment capability reached the maximum, and granular sludge matured. The appearance and increase of Vorticella, a kind of sessile ciliate, symbolized activated sludge maturation. During the running process of the reactor, if the work condition changed, e.g., the appearance of overload, pH abnormity, or nutrition deficiency, the community composition and activities of zooplankton would be changed accordingly.

Key words: Pteroceltis tatarinowii, Ca²⁺ concentration, Height growth, Biomass, Bark quality