| Since the Activated sludge process has been commonly employed in wastewater treatment plants, it offen suffered the cancer of sludge bulking. Sludge bulking problem has the specialty of high frequency, strong damage, hard to solve and so on. Pro.Peng Yongzhen changed the view of controlling to utilizing, firstly proposed"The theory and technique of saving energy achieved by limited filamentous bulking under low DO". The method is working by controling the activated sludge wastewater treatment system under low DO conditions artificialy, to cause sludge bulking happen. But the phenomenon of sludge flowing out of the system should not happen. It can realize the aim of improving the outflow water quality and saving energy by utilizing the filamentous specialty of high ratio surface area and strong ability to resistence low DO and decompose low organic concentration. Significantly, after its introduction, there are three questions about the study: how to achieve and stay steady limited filamentous bulking;the removal effect of pollutes and the inhibitting of bulking. In this paper, the three aspects and their spread were investigated.Firstly, the operating parameter caused and stayed limited filamentous sludge bulking were investigated in a lab-scale SBR reactor. The effects of sludge loads under low DO condition on activated sludge settle ability was investigated. Results showed that when the system was kept in low DO level, the sludge settled properly at sludge load of 0.20g/(g?d),deterioration of SVI was faster as the sludge loads grew higher. And the kind of sludge bulking was not the same. When sludge load was 0.66g/(g?d) non-filamentous activated sludge bulking occurred,and when sludge load at 0.44 g/(g?d) filamentous activated sludge bulking occurred. And the removal effect under different kind of bulking was compared. The removal effect of de-nitrogenized and de-phosphorusized deteriorated in non-filamentous activated sludge bulking but it would not occur under filamentous activated sludge bulking, Besides, the rate of phosphorus absorption was faster, and SS in effluent was almost negligible. The SND rate was the biggest when sludge bulking didn't happen, which decreased when non-filamentous activated sludge bulking occurred, and was the smallest in the condition of filamentous activated sludge bulking.Secondly, through adjusting process parameters to inhibit filamentous sludge bulking. Inhibition effect of organic loading rate, dissolved oxygen(DO), feeding pattern and some other common operation parameters on filamentous sludge bulking were investigated by SBR systematically. The results showed that, the effect of inhibiting filamentous sludge bulking through increasing DO (4-6mg/L) alone is not obvious;and it is difficult to inhibit filamentous sludge bulking through increasing organic loading rate alone (>0.40kgCOD?kgMLSS-1?d-1) or enhance storage selective function. What's worse, if aerobic time and aeration rate are not proper, viscosity sludge bulking is prone to happen; setting up proposed anoxic(anaerobic) phase is an effective method to inhibit filamentous sludge bulking.Besides, the effect of over-anaerobic on inhibitting filamentous sludge bulking was studied in SBR system. Results showed that the Sludge traits became better in the two systems however the role of over anaerobism on inhibiting filamentous sludge bulking is not remarkable.And Over-anaerobic has no significant effect on the process of the process character of de-nitrogenized and de-phosphorusized; phosphorus release will not rise by means of excessive anaerobism. Besides evident SND phenomenon and SND rate increases with the higher average DO within the range of 0.4mg / L...
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