| With the development of economy, the pollution of chemical and industrial wastewater to environment was gradual severity. During the production of chemical and industrial product, large numbers of organic contaminated matter of configuration complexity, toxicity and difficult metabolism was discharged. This kind of wastewater was difficult treatment. The nitrilon wastewater belonged to these.The nitrilon wastewater mostly contained oligomer(PAN and AN), SCN-and CN-. In this kind of wastewater, oligomer was difficult treatment, and CN- had biological toxicity. Because of the characteristic of the nitrilon wastewater, the effluent of actual treating processes is difficult to obtain wastewater discharge standard of two grade of china. The nitrilon wastewater made severe environment pollution and great environment press to discharge area. For resolving this question, the new integrated processes of treating nitrilon wastewater were studyied and operational parameter was comfirmed, which was EGSB-aerobic.At the first, the characteristic of EGSB and influencing factors of operation were studied, and some operational parameters were confirmed under the different conditions. Under the medium temperature (31~35℃), the COD concentration of 400~5000mg/L degradable wastewater could be treated with EGSB, and the removal efficiency was over 95%. When the low concentration of wastewater was treated (400mg/L), the low HRT may be applied for enhancing sludge loading rate and increasing the concentration of nutritional material. When the high concentration of wastewater was treated (>3000mg/L), the fit HRT was 10 hours. This made the COD removal efficiency and the efficiency of EGSB high. Under the low temperature (under 20℃), the EGSB could operate stably and effectively. The adaptive time of microbe in EGSB was about 20 days and the COD removal efficiency was up to 93%, but the VFA concentration of effluent was slight high (4.0m mol/L).The granule sludge in the EGSB need domesticated when treating the toxicity wastewater. The domestication time of granule sludge was over 3 months for treating the nitrilon wastewater, because of the effect of CN- concentration. The mithridatism of the acid-producing bacteria and mathanogen could be increased when the domestication time was prolonged. The removal efficiency of the nitrilon wastewater of EGSB was 35% to 50%. The main function of EGSB was to improve the biochemical performance of nitrilon wastewater. The B/C of nitrilon wastewater was enhanced from 0.2 to over 0.4. This is beneficial for the normal and effective operation of sequential aerobic treating reactor.Then, the characteristic of suspended carrier expanded bed (SCEB) was researched, treating the nitrilon wastewater. When the toxicity wastewater was treated with SCEB, continue influent of influent was easy to form bio-membrane on carrier, the dominant microbe of treating special wastewater was easy to reproduce, and the time of forming bio-membrane was short. The sludge concentration of SCEB should be kept under 4g/L. Under this condition, the contamination was degraded by bio-membrane and active sludge together. If the sludge concentration was over 4g/L, the bio-membrane on the carrier was easy to desquamate because of competing to nutrition material. Controlling the aeration intensity and hydraulic residence time (HRT) could form the aerobic granule sludge in SCEB. The size of aerobic granule sludge was 289~464μm and the settled velocity was 4~14m/h.These were good for enhancing the sludge concentration and settled rate of sludge in SCEB. And it could avoid the sludge bulking. The removal efficiency of SCEB was over 40%.Adsorption function of active carbon and degradation of microbe were two main modes, when the nitrilon wastewater was treated with biological active carbon reactor (BACR). The best volume loading rate of active carbon was 1.2kgCOD/m3·d and the best HRT were 12 hours. The removal efficiency of COD of BACR was over 50%.Afterward, the microbe of different reactors of EGSB-SCEB-BACR processes was analyzed and judged. In EGSB, the concentration of granule sludge was low and property was not good. The reason was that water quality of nitrilon wastewater. The degradation function to nitrilon wastewater was mainly from the acid-producing bacteria, and the function of mathanogen was restrained. In SCEB, the aerobic small granule sludge of high settled velocity was formed, and the color of aerobic granule sludge is brown-red. In the SCEB and BACR, the species of microbe was more, and the biological chain was long. These results were good for the degradation of the contaminant. Applying the technology of DGGE, the relativity and group in three reactors were analyzed, and ten germs were made certain. These germs were gist of cultivated engineering application microbe for treating nitrilon wastewater.Finally, the academic formula was applied and the experimental data was operated by using FORTRAN software. The kinetics formers of material degradation of acid-producing bacteria and mathanogen were obtained, under the different temperature, when the operation of EGSB was steady. The conclusions offer theoretic direction for the operation of EGSB.The results of paper research are very significant on application of EGSB to guide practice and theory. The EGSB-SCEB-BACR processes are valuable to rebuild wastewater treating system of Daqing nitrilon factory.
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