【作者】 冯斐；

【导师】 许振良；

【作者基本信息】 华东理工大学 ， 环境工程， 2010， 博士

【摘要】 蒽醌染料废水是染料行业较难处理降解的废水之一。本文采用芬顿氧化+MBR耦合技术对蒽醌活性染料X-BR进行了降解研究。研究发现,通过芬顿试剂的预处理后,X-BR废水的可生化性得到了很大的提高,综合毒性减弱,为生化处理创造了良好的条件。在考察MBR工艺处理的过程中发现铁离子的投加能改善污泥特性、提高微生物的活性和减缓膜的污染。具体结果如下：首先实验固定X-BR浓度为100mg／L,最佳的芬顿氧化工艺条件为双氧水=5.2mmol/L、亚铁离子浓度=0.52mmol/L、初始pH=3。在此条件下X-BR能获得近乎99.9%的脱色效果和44.23%的TOC去除率(铁离子絮凝沉淀后)。通过傅里叶红外和紫外光谱跟踪X-BR的降解发现,染料的发色基团蒽醌环容易被芬顿试剂产生的羟基自由基攻击而脱色。在芬顿氧化过程中,TOC的降解远远滞后于染料的脱色速度。在选的工艺条件下,40分钟内,脱色率可以达到99.7%。芬顿试剂在高效使用的过程中,将产生大量的含铁离子固体废物(芬顿污泥)。实验设计芬顿污泥通过过滤、低温脱水后返回到芬顿氧化体系中,作为催化剂使用形成类芬顿体系。实验证明,芬顿污泥／H2O2体系对TOC的降解效率略低于经典的Fe2+／H2O2和Fe3+／H2O2。芬顿污泥／H202体系对X-BR的TOC去除率低于Fe2+／H2O2体系大约8%。其次采用水质指标法(B／C)、好氧呼吸指数法、赞恩-惠伦斯试验法对X-BR溶液、芬顿降解产物进行了综合性的可生化性评估。B／C的评估表明,X-BR溶液属于基本不可生物降解类底物,而通过芬顿氧化后,其产物的B／C比提高到了0.25左右。好氧呼吸曲线法的OUR检测表明,对于不同的X-BR浓度50mg/L、100mg/L和200mg／L,其OUR分别为0.564 mgO2/(L·h)、0.462 mgO2/(L·h)、0.222 mgO2/(L·h);都低于该测试条件下微生物的内源呼吸速率0.708 mgO2／(L·h)；而对于芬顿氧化产物,其对应的OUR分别为3.37mgO2/(L·h),3.58 mgO2/(L·h)和3.74mgO2/(L·h)。赞恩-惠伦斯实验表明,当X-BR的浓度为50mg／L时,检测微生物的生命活动受到严重抑制,而芬顿降解产物最终能达到大约78%左右。DeltaTox(?)的综合毒性检测表明,当X-BR浓度分别为25mg／L、50mg／L和100mg／L时,发光细菌(Vibrio fischeri)的光强损失分别为17%,34%和41%。对于芬顿降解产物(X-BR=100mg/L和50mg／L),其光强损失分别为10%和6%。同时,通过驯化培养后,确定MBR降解X-BR芬顿氧化产物的最佳工艺条件为：MLSS=6000mg/L; DO=2.5mg/L; HRT=18hr,在此基础上能获得大约75%左右的TOC降解率和27%的总氮去除率。对平行实验的三组MBR,分别往反应器中投加干污泥量的0%(MBR1)、0.5%(MBR2)、1%(MBR3)的氯化铁离子。实验结果表明：(1)铁离子的投加对微生物的生命活动有影响,MBR1、MBR2、和MBR3反应器中的脱氢酶浓度分别为29、31、42μgTF／(mgMLSS·hr)。(2)铁离子的投加有利于增大污泥粒径,减缓膜污染的发生,MBR1、MBR2和MBR3的平均粒径分别为76.2μm、92.3μm和83.4μm；MBR1、MBR2和MBR3的dTMP/dt分别为：0.592kPa/d,0.51 kPa/d和0.487 kPa／d。(3)铁离子能抑制微生物EPS的分泌,MBR1、MBR2和MBR3的平均含量为36.85mg／g、31.02mg／g和28.93mg／g。分析发现,主要是EPS中多糖类物质减少。膜表面吸附的滤饼层的ESP含量是混合液的2倍左右。(4)铁离子能减少有机物在膜表面的沉积,膜的阻力主要以凝胶极化阻力Rp和内部阻力Rif为主,两项指标占总阻力的80-90%。傅利叶红外光谱(FTIR)和能谱(EDX)分析表明膜污染以有机污染为主,因此碱洗作为膜清洗的首选清洗方法。最后介绍了反渗透对MBR产水的脱盐效果和某印染污水处理厂的MBR工艺技术革新。更多还原

【Abstract】 Anthraquinone dying wastewater is one of the most refractory wastewater in dyeing industry. In this paper, the coupled process of Fenton oxidation and MBR was investaged to degrade the simulated Anthraquinone dye of X-BR water. It was found that the biodegradability of X-BR wastewater was improved and the toxicity was weakened. The pretreatment of Fenton oxidation was readily to create conditions for the subsequent bio-treatment. During the process of MBR, it was found that the dosing of ferric ions could ameliorate the sludge characteristics and the activity of microorganism. And also the membrane fouling was retarded due to the dosing of ferric ions.Firstly, when the X-BR concentration was fixed to be 100mg/L, the optimal parameters of Fenton oxidation were found to be H2O2=5.2mmol/L、Fe2+=0.52mmol/L and initial pH value=3. Under these conditions, about 99.9% color removal and 44.23% TOC (after the coagulation of ferric ions) removal ratio could obtain. By monitor the degradation of X-BR by FTIR and UV-vis spectra, it could be found that the chromophore of X-BR (anthraquinone group), was easily to be attacked by the generated hydroxyl radical (·OH) of Fenton oxidation. During the Fenton oxidation, the TOC degradation rate was far away lagging behind the decolor rate. In 40 minutes, the decolorization rate obtained was almost 99.7%It was sure that vast waste solids of Fenton sludge were produced during the application of Fenton reagent. The experiments were designed to recover the Fenton sludge to oxidation process as catalyst by the pretreatment of filtration and dehydration. Based on the recover of Fenton sludge, Fenton-like oxidation system was established. It was proved that the oxidation efficiency of Fenton sludge/H2O2 was slightly lower than that of classic Fe2+/H2O2 and Fe3+/H2O2. Compared with Fenton sludge/H2O2 and Fe2+/H2O2 system, TOC removal ratio gap was about 8%.Secondary, the synthetical evaluations of bio-degradability of X-BR solution and the products of Fenton oxidation were carried out by means of water quality of B/C index、aerobic respiration index and Zahn-Wellens-Test(ZWT). It was proved by the B/C index that X-BR solution was in the category of the most recalcitrant wastewater, while the B/C index of Fenton oxidation products was increased to a level of 0.25. According to different X-BR concentration of 50mg/L、100mg/L and 200mg/L, the corresponded aerobic respiration rate was 0.564 mgO2/(L·h)、0.462 mgO2/(L·h) and 0.222 mgO2/(L·h), respectively. All the results were lower than that of endogenous respiration rate (0.708 mgO2/(L·h)). On the contrary, the aerobic respiration rate of the products of Fenton oxidation were higher than 0.708 mgO2/(L·h), which were 3.37 mgO2/(L·h),3.58 mgO2/(L·h) and 3.74 mgO2/ (L·h), respectively. It was proved by Zahn-Wellens-Test that the bio-activity of microorganism was severely obstructed even in the X-BR concentration of 50mg/L. And the Fenton oxidation products could achieve a degradation of about 78%. When the X-BR concentration were 25mg/L、50mg/L and 100mg/L, the light loss ratio of Vibrio fischeri were 17%、34% and 41%, respectively. As a contrast to the products of Fenton oxidation of initial X-BR concentration of 100 mg/L and 50mg/L, the light loss ratio were 10% and 6%.After the acclimation stage, the optimal parameters of MBR system obtained were MLSS=6000mg/L, DO=2.5mg/L, HRT=18hr. Based on these data, about 75% TOC removal ration and 27% TN removal ratio could be obtained. As for the three MBR system, different dosage of FeCL3 (MBR1:0%, MBR2:0.5%, MBR3:1%) were added to the aerobic system. The results revealed the followings. (1)There were big influence on the bio-activity of microorganism, and the dehydrogenase concentration of MBR1、MBR2 and MBR3 were 29、31、42μgTF/(mgMLSS·hr),respectively. (2)The dosage of ferric ions could enlarge the particle size and retard the membrane fouling. It was detected that the average particle size of MBR1、MBR2 and MBR3 were 76.2μm、92.3μm and 83.4μm, respectively. Besides, the dTMP/dt of MBR1、MBR2 and MBR3 were 0.592kPa/d,0.51 kPa/dt and 0.487 kPa/d, respectively. (3) Due to the inhibition effect of ferric ions on the secretion ability of microorganism, the EPS concentration was varied at 36.85mg/g(MBR1)、31.2mg/g (MBR2) and 28.93(MBR3). It was also revealed that the Carbohydrate was reduced more significantly than protein. The adsorbed EPS concentration in cake layer of membrane was 2 fold of that in mixed liquor. (4) The ferric ions can reduce the sedimentation of organic substance on the membrane surface. The main membrane resistances were gel-polarization (Rp) and inner membrane resistance (Rif), which contributed about 80-90% of the total resistance. By the detection of FTIR and EDX methods, it was found that the main fouling substance of membrane was organic pollution. And the alkaline cleaning was the preferred cleaning method.Finally, it were introduced the desalination efficiency of the MBR effluent by reverse osmosis (RO) and a technology innovation for the dyeing wastewater plant by MBR process.更多还原