| The task of this research subject is to find out the most economical and effective operating parameters, guaranteeing a good pollutant removal, slowing down the membrane fouling velocity, and considering the economic factor through the treatment experiment for dyeing wastewater by the technic of hydrolization and acidification pretreatment-compound membrane bioreactor. If this technic can be applied into the practice of dyeing wastewater treatment and reuse, the research results will offer the theoretical foundation, thus the wastewater can be turned into resource.The contamination removal effect and the system stability under different condition of HRT of aeration part and anoxic part were studied in this paper. It indicated that this technic has strong ability of shock loading resistance and could not only guarantee the good effluent quality but also reduce the volume of the reactor. Though the contamination removal rate of the biological treatment unit decreased as HRT reducing, but because of the function of holding back of the membrane, the system produced effluent with good and stable quality, and the removal rate of the system to COD were all above 90%. The membrane could not hold back NHs-N and chroma. So HRT reducing of anoxic part would have effect on NHs-N removal to a certain extent. And the short HRT would have adverse impact to chroma removal. In addition, the effect of aeration intensity on COD and NHj-N removal were investigated. It showed that the removal rate would increase as the aeration intensity rose.The proliferation characteristics and activity variability of attached growth microorganisms were analyzed in the experiment, and the mixed liquor characteristic in MBR was also investigated. The attached growth sludge concentration and its proportion to the total sludge amount increased with organic loading. When the organic loading was at a low level, the microorganisms' endogenous respiration would happen for lack of nutrition, so the amount of the microorganisms would reduce. The SOUR activity of microorganism was related to organic concentration and loading factor. According to the results, exorbitant or least sludge loading would lead SOUR to decrease. In addition, the concentration of supernatant COD, turbidity, viscidity, protein and polysaccharide initially increased with time then declined.The variety of the transmembrane pressure during the long-term running test was analyzed. The results showed that the transmembrane pressure and resistance were related to flux and accumulated degree of soluble organic in the MBR. A brief analysis of membrane fouling resistance indicated that the membrane inherent resistance was equivalent to the fouling resistance, and the polarization layer resistance accounted forabout half of total resistance, so the main factor causing total resistance to increase was the polarization layer resistance. Then effects of pump period, aeration intensity, HRT of anoxic part on the increasing rate of the transmembrane pressure were investigated and the optimal operational parameters were defined.The membrane fouling was visualized by scanning electron microscope and the membrane cleaning ways were investigated. It was found that the membrane fouling was concentrated on the surface mainly, and the internal fouling was not obviotis. After soaking by the lye, the cake layer on the membrane surface was removed basically.The economic analysis of dyeing wastewater treatment by this technic indicated that the project gross investment and running cost were higher than those of the normal biological, physical and chemical treatment method, but this technic could not only reduce the expense of sludge treatment and disposition, but also save a large amount of water cost. Membrane expense and changing cost were the most reasons that the membrane technology can not be used widely. With the decline of the membrane price and the improvement of the membrane material, the small-scale MBR technic would have very great competitiveness.In a word, this new-type techn...
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