腈纶是六大化纤产品之一，在国民经济中占据十分重要的地位。DMAc二步湿法腈纶生产典型企业混合废水水质分析表明，腈纶废水中含有DMAc等有毒有机物；阴离子SO42-浓度较高，可能会影响生化反应的进行；混合废水的B/C值0.2-0.4，可生化性较差；废水中除含无机氮外，还含部分有机氮；水质波动明显，271.4-3304.6mg/L；腈纶废水中含有26种有机污染物，8种含氮化合物，其中，含C-N键化合物1种，含C=N键化合物2种，含C≡N键化合物1种，含双C≡N键化合物2种，含氮芳环化合物2种；还含有PAN聚合物。利用分级膜对污染物的分子量分布发现，腈纶废水中污染物都是水溶性的，从不同分子量污染物对水质指标的贡献来看，对COD和TOC贡献最大的是小于1kDa（超过60%）和1kDa-3kDa范围的污染物。设计了一套好氧-多级厌氧-好氧生物膜新工艺（Aerobic-Multistage Anaerobic-Aerobic Biofilm Novel Process，O1MAO2）处理腈纶生产混合废水，利用腈纶废水处理厂曝气池的污泥接种，反应器运行23d后启动成功。利用OMAO生物膜工艺处理腈纶废水时，延长HRT时将缓慢提高COD的去除率，逐渐减少COD容积去除负荷率，污染物去除负荷与HRT呈指数关系，HRT以33h为宜。对第一曝气池而言，溶解氧浓度(5-6mg/L)比低溶解氧浓度(4-5mg/L)对COD去除更有利；对第二曝气池而言，低溶解氧浓度(2-3mg/L)比高溶解氧浓度(5-6mg/L)对COD去除更有利。研究认为第一、二好氧池的DO分别为5-6mg/L和2-3mg/L，碳酸氢钠为0.75g/L，回流比为200%。应用OMAO生物膜工艺处理腈纶废水时，丙烯腈首先生物降解生成丙烯酰胺，然后再生成丙烯酸和氨根；DMAc首先分解为醋酸和二甲胺，二甲胺再分解为甲醇和氨根；有机污染物含量和种类大大减少。GC/MS检测表明，特征污染物已经完全降解，与进水相比，尽管有机污染物种类只减少了5种，但大部分有机污染物含量都大大减少，而以＜1kDa为主。腈纶废水原水和生物处理出水荧光强吸收峰主要有三个（A+B+C），不同MW下TOC与A、B、C峰荧光强度之和有很好的正相关性。利用PCR-DGGE检测技术发现，OMAO反应器每格均有多种微生物，各反应格间既有相同种属微生物，也有不同种属微生物，多种微生物共同作用使腈纶废水得净化。腈纶废水质和反应条件影响微生物种群结构，反应器的处理功能与微生物的种群差异有一定的映射关系，OMAO生物膜工艺处理腈纶废水过程中主要微生物有：Thiothrix sp. AS、Magnetobacterium sp.、Pelodictyon luteolum、Delta proteobacterium、Desulfococcus biacutus、Caldimonas manganoxidans、Thiothrix caldifontis等。利用“过滤→OMAO生物膜→MBR”组合工艺处理腈纶废水，OMAO部分HRT=33h时，组合工艺运行四天即可启动完成，出水CODCr达到小于150mg/L的国家排放标准；静态石英砂过滤器可以连续运行52天，更换滤料后，出水水质即可恢复；MBR反应器中污染物的去除以膜截留为主，占整个MBR反应器去除率的72.7%；腈纶废水原水中聚合物对微生物的生长环境影响较大，影响了载体与微生物的接触作用，也影响了载体内外污染物和营养物质的迁移。

Acrylic fiber, one of six categories of chemical fiber products, is very important in national economy. Acrylic fiber wastewater contains 26 kinds of toxic organic matters, 8 kinds of nitrides (a C-N, two C=N, one C≡N, two double C≡N and Nitrogen aromatic), as well as PAN polymers. The concentration of SO42- is high, which can influence the process of biochemical reactions. Due to B/C 0.2-0.4, the biochemical level is low in the wastewater. Application of film classification technique to anlyse molecular weights, the results indicates that pollutants are Water-soluble, and COD and TOC are attributed to the pollutants within less than 1kDa and 1kDa-3kDa. Based on the pass studies and the properties of acrylic fiber wastewater, a set of aerobic-multistage anaerobic-aerobic biofilm novel process (OMAO) is proposed to treat the wastewater. Inoculated microbes by sludge in aeration tank of wastewater treatment plant, the treatment is successful, after 23 days of the reactor operation.The regressive equation between COD and HRT is , indicating COD removal rate exponentially increases with the decreasing HRT. When HRT is 33 hours, the removal rate is the most reasonable. In the first aeration tank, the removal rate is higher under 5-6 mg L-1 of dissolved oxygen (DO) than that under 4-5 mg L-1. In the second aeration tank, the removal rate is higher under 2-3mgL-1 than that under 5-6 mgL-1. Therefore 5-6 mg L-1 or 2-3 mg L-1 is suggested in the first tank or the second, added NaHCO3 is 0.75 g L-1, and refluence rate is 200%.The water quality is mainly attributed to less 1kDa polymers, a part of which is water-solute, degraded by microbial, and adheres microbial surface to impact their growth. Therefore pretreatment of the polymers is deeply concerned to prevent them from impact on microbial activities, before treatment of acrylic fiber wastewater using microbial technique. Ferric chloride, nickel chloride and zinc chloride can slightly increase anaerobic degradation rate, and cobalt chloride (0.1 mg L-1) obviously increases the rate. Diffusion of pollutants can be one of the limiting factors to treatment of acrylic fiber wastewater by aerobic reaction, but anaerobic treatment can increase biodegradability of the wastewater. Delayed hydraulic retention time can increase COD removal rate.In the process of acrylic fiber wastewater treatment using OMAO technics, added NaHCO3 (0.75 g L-1) can keep the highest removal rate of NH4+-N and TN. Meanwhile NH4+-N consumes 5.96 g g-1（CaCO3/ NH4+-N）and TN consumes 4.34 g g-1（CaCO3/ TN. The factual consumption of CaCO3 for NH4+-N is higher 70% than theoretical consumption, indicating that added NaHCO3 can maintain pH in the reactor system, and a little part of inorganic carbon can benefit synthesis of microbial. Refluence of discharge water can benefit removal N in the microbial treatment of acrylic fiber wastewater. The mean removal N rate is about 1.23% without refluence, the mean 11.34% with 50% refluence, the mean 19.22% with 100% refluence and the mean 22.66% with 200% refluence. A large quantities of NO3- occurs using strong oxidizer fenton to treat the wastewater, but NO3- little increases with delayed the anaerobic process. The results indicate that organic N can be ammonified with only delayed the anaerobic reaction, and ammonification can repress removal N in the wastewater, whose reason may be the difficult diffusion of PAN.Acrylonitrile (AN), a small molecule of organic pollutants, is firstly degraded acrylamide by microbial, then acrylic acid and NH4+-N. DMAc is decomposed of acetic acid and dimethylamine, and the latter is decomposed of methanol and NH4+-N again. Twice hydrogen transfer occurs in the inner PAN: firstly lateral chain C≡N forms CH＝NH, which forms hydroxyl in hydrolysis; secondly it forms amide, which forms carboxyl in ammonification, and release NH4+-N; at last its lateral chain breaks and forms straight-chain alkanes and formic acid. The PAN is decomposed of NH4+-N, straight-chain alkanes and formic acid by microbial in the end. For straight-chain alkanes is not degraded by microbial, discharge from wastewater treatment plants contains COD 300mg L-1.In the first aerobic tank, suspended microbial community is composed of Flavobacterium, whose shape is white-wet and yellow-wet microbe communities. The white-wet is Bwrkholderia glumae. In the third anaerobic tank, the shape of microbial film communities in the surface of additions are similar to the aerobic, whose shape is yellow-wet and orange-wet microbe communities, and the former is Flavobacteriom, the latter is menTOCina. In the fourth and fifth anaerobic tanks, the shapes of microbial communities are orange. In the seventh aerobic tanks, the shapes of microbial communities in suspended sludge and addition are white and orange, and the former is Aeromonas, the latter is Burkholderia.