Biological fluidized bed is a reactor of the integration of biological membrane technology and activated sludge process。 The biological fluidized bed technology has advantages of good mass transfer effect and less excess sludge。 It is a kind of efficient and economical sewage treatment method, which has become the hot topics in the study of water treatment technology and process both at home and abroad。 In this study, the effect of the biological fluidized bed on the denitrification and the degradation of DMAC were studied, which provided the theoretical reference for further academic research and practical engineering application。

This experiment used reactor of anaerobic - aerobic biological fluidized bed, used the carrier particle size of 0。6 ～ 1。18 mm。 With high carbon nitrogen ratio (C/N = 8) start the experiment, the COD concentration is about 1000 mg/L, and NH4+-N is 45 mg/L。 After twenty-five days’ creature hanging membrane, effluent NH4+-N concentration decreased to 1。8 mg/L, and the removal rate is about 91%。 With a microscope to observe the coke, we found a layer of biofilm attached to the surface of the coke, and on the surface of the biofilm are many protozoa。 Observing the concentration of suspended solid (MLSS) and volatile suspended solid concentration (MLVSS) during the hang membrane progress of the biological fluidized bed system, it is found that most of the microorganisms in biological fluidized bed reactor attached to the surface of the carrier, with suspended phase existing a small number of microbes, and the effluent is more clear, so attached microorganism plays a main role of the purification of wastewater。

When hydraulic retention time (HRT) is 14。9 hours, carbon nitrogen ratio (C/N) is 1, ammonia nitrogen (NH4+-N) removal efficiency is best。 And with the decrease of C/N, chemical oxygen demand (COD) and total nitrogen (TN) removal efficiency is decreasing, the concentration of nitrate nitrogen (NO3--N) increased with the decrease of COD。 The removal efficiency of DMAC was higher in the influent with 100 mg/L DMAC, and the COD value was lower。 Under the conditions of water containing DMAC, the ammonia removal efficiency of the reactor was good。 By contrast the early and late stages of the change, it was speculated that DMAC was toxic to nitrifying bacteria, but the toxicity was less inhibited。 The hypoxia-aerobic fluidized bed apparatus can achieve better purifying effect for low concentration DMAC (100 mg/L) wastewater without adding additional carbon and nitrogen sources。

The characteristics and innovations of this topic are mainly reflected in the following two aspects: (1) Compared with the traditional chemical treatment method, this paper attempts to treat DMAC wastewater by biological method, namely hypoxia-aerobic biological fluidized bed method。 On this basis, the removal efficiency of COD, NH4+-N and TN in wastewater under different C/N and DMAC concentrations was discussed in depth, and the optimal treatment parameters were obtained, which could provide some theoretical support for the development of acrylic fiber wastewater treatment process。 (2) With the acrylic wastewater containing, so it is need for an additional process to remove the organic nitrogen in the wastewater when using chemcial methods, which would increase the cost in virtually。 Therefore, this experiment using anaerobic-aerobic biological fluidized bed method purifies acrylic wastewater。 The process not only on the N, N-dimethyl acetamide have a better removal effect, but also better removal of Organic nitrogen, which can achieve the purpose of simultaneous removal of DMAC and organic nitrogen in acrylic wastewater and save the processing cost。

Keywords：Anoxic-aerobic biological fluidized bed, denitrification, DMAC, coke particles

目  录

1 绪论 9

1。1 引言 9

1。2 生物流化床技术现状