活性污泥缺氧转化1-2-7-三氨基-8-羟基-3-6-萘二磺酸

1—2-7-三氨基-8-羟基-3—6-萘二磺酸（TAHNDS）作为偶氮染料的脱色产物很难被常规的厌氧-好氧染料废水处理工艺所去除。研究了未经驯化的活性污泥对TAHNDS的缺氧转化效果。结果表明，只有在特定的缺氧条件下（ORP在-50～-150mV之间），TAHNDS才能被活性污泥所降解转化。当浓度在10—80mg／L范围内，TAHNDS可在72h内转化93％以上。加入100mg／L的硝酸盐和0．64mmol／L的氧化还原介体蒽醌-2-磺酸钠（AQS）可将40mg／L的TAHNDS的转化时间从84h缩短到36h。光谱及HPLC—MS分析表明，TAHNDS在缺氧条件下主要是通过脱氨基和脱磺酸作用生成已知可好氧生物降解的3，5-二氨基4-羟基萘-2-磺酸。因此，缺氧处理有望作为预处理工艺促进废水中TAHNDS的完全降解。     

羟肟酸类捕收剂2-羟基-3-萘甲羟肟酸的生物降解研究

生物法是处理难降解有机物的一种重要方法,通过投加活性污泥,采用振荡培养法,研究了以2-羟基-3-萘甲羟肟酸(H205)为唯一碳源的单基质条件、外加碳源和氮源的共基质条件下H205的生物降解过程.结果表明:(1)单基质条件下,不同初始质量浓度(10～50 mg/L)H205的生物降解符合一级动力学模型方程.(2)共基质条...     

缺氧-好氧生物滤池中高效菌对活性红KN-3B的降解特性

为了研究高效脱色菌在缺氧好氧生物滤池（A/O biofilter）中对偶氮染料的降解特性，以活性红KN-3B（C.I. reactive red 180）为降解对象，缺氧生物滤池以火山碎石为填料，接种高效脱色菌CK3柯氏柠檬酸杆菌启动，好氧生物滤池以牡蛎壳为填料，接种污水处理厂活性污泥启动。试验考察了不同工况下缺氧-好氧生物滤池对色度和COD的去除效果，结果表明：生物滤池中微生物对偶氮染料活性红KN-3B的脱色和对COD降解的最适pH条件为弱酸性；缺氧滤池中高效菌对色度的去除需要外加碳源，且增加外加碳源有助于脱色率的提高；该高效菌为耐盐菌，当进水NaCl浓度达30 g/L时，色度去除率仍可达93%以上；当染料负荷达500 mg/L时，脱色率仍可达95%。通过紫外-可见扫描图谱分析初步推断CK-3柯氏柠檬酸杆菌对偶氮染料活性红KN-3B的脱色主要是生物降解作用。     

日本污水脱氮除磷深度处理工艺分析

为提高进入琵琶湖水体水质和有效恢复并保持琵琶湖流域水生态环境,日本滋贺县10家下水道污水处理厂全部采用脱氮除磷深度处理工艺。湖南中部净化中心目前规模为26.85万t/d,采用缺氧-好氧循环硝化/反硝化(AO)、厌氧-缺氧-好氧(AAO)和多段进水多级缺氧-好氧硝化/反硝化(SMAO)3种深度处理工艺。AAO工艺是国内城镇污水处理厂广泛采用的二级生化工艺,AO、SMAO工艺在国内还没有应用实例。AO、AAO工艺采用内循环硝化/反硝化反应脱氮,SMAO工艺采用无内循环的多段进水多级硝化/反硝化反应脱氮。AO、SMAO工艺采用化学方式除磷,PAC添加浓度约50mg/L。AAO工艺采用化学和生物组合方式除磷,PAC添加浓度降低到约30 mg/L。AO、AAO工艺出水BOD、CODMn、SS、TN和TP均值分别约为0.9 mg/L、5.2 mg/L、1 mg/L、6.5 mg/L和0.06 mg/L,相应的去除率约为99.5%、94.2%、99.5%、78.0%和98.1%。SMAO工艺出水TN约为2.5 mg/L,TN去除率提高到91.6%,其他指标和AO、AAO工艺基本相同。     

城市污水处理厂反硝化聚磷菌的聚磷持久性

以桂林市第四污水处理厂氧化沟活性污泥为对象,研究在具有厌氧-缺氧-好氧环境的污水处理构筑物中富集存在的反硝化聚磷菌聚磷能力的持久性问题。结果表明,在此环境中富集的反硝化聚磷菌在经过3个周期的厌氧-缺氧条件下运行,最大释磷率由0.90 mg P/（g VSS.h）下降为0.07 mg P/（g VSS.h）,反硝化聚磷率由0.17 mg P/（g VSS.h）下降为0.04 mg P/（g VSS.h）。比较而言,在厌氧-缺氧-好氧环境下最大释磷率及聚磷率降幅较小,释磷率由0.59 mg P/（gVSS.h）下降为0.37 mg P/（g VSS.h）,反硝化聚磷率由0.17 mg P/（g VSS.h）下降为0.10 mg P/（g VSS.h）,厌氧-缺氧-好氧运行条件比单纯的厌氧-缺氧运行条件更有利于维持反硝化聚磷菌的聚磷性能。     

新型SBBR处理畜禽废水脱氮实验研究

以畜禽废水为处理对象,将序批式运行模式应用到好氧三相内循环生物流化床中,考察在不同模式下的处理效果及氮的转化情况。实验结果表明,在室温条件下,进水COD浓度为2 000 mg/L左右,总氮为140 mg/L左右时,保持溶解氧在2~2.5 mg/L,交替好氧/缺氧运行方式处理效果优于单一的好氧/缺氧方式;模式为3 h(曝气)-1.5 h(停曝)-1.5 h(曝气)-1 h(停曝)时系统对总氮和氨氮处理效果最好,总氮去除率达到90%,系统主要脱氮方式为同步硝化反硝化和短程硝化反硝化。     

1,1-二氯乙烯降解菌的分离鉴定及降解特性

从好氧活性污泥中分离得到一株能以1,1-二氯乙烯(1,1-DCE)作为惟一碳源和能源生长的革兰氏阴性菌株D-B,经鉴定属于产碱杆菌属(Alcaligenessp.)。当维持菌株D-B浓度一定时,1,1-DCE的去除率随着1,1-DCE浓度的增大先增加后降低,且降解过程主要发生在加入1,1-DCE后的3~5 h内。当1,1-DCE的初始浓度为300μg/L时去除率达到最大值85.32%。菌株D-B对1,1-DCE的降解符合Monod方程,饱和常数Ks=21.96 mg/L,1,1-DCE的最大比基质降解速率Vmax=50.76 mg/(L.h)。     

苯酚对活性污泥硝化与反硝化动力学的影响

通过批次试验,研究苯酚与活性污泥缺氧和好氧接触对微生物硝化和反硝化作用的影响。结果表明:(1)苯酚对缺氧2h后的活性污泥硝化有抑制作用,且苯酚浓度越高,抑制作用越强。当苯酚浓度较低时对自养菌的最大比氨氧化速率(AUR)的抑制作用能用竞争性抑制Monod方程拟合,半数抑制质量浓度(IC50)为19.2mg/L。(2)苯酚对直接曝气的活性污泥比对缺氧接触2h后再曝气的活性污泥的硝化抑制作用更强,当苯酚从0mg/L增加到10.0mg/L,AUR由2.51mg/(L·h)降至0.36mg/(L·h),且在10.0mg/L时,硝化抑制率(IR)高达85.7%。(3)苯酚的抑制效应随着缺氧时间延长而逐渐降低。当苯酚为10.0mg/L时,直接曝气的活性污泥受到的硝化抑制最强,IR为85.8%,并在缺氧4h后IR降为0。(4)当碳源充足时,活性污泥的反硝化菌对苯酚的耐受力较强,苯酚对活性污泥的反硝化过程没有影响,微生物的反硝化速率(NUR)维持在5.279～5.308mmol/(mg·h)。     

侧流除磷ERP-SBR新工艺中生物脱氮及影响因素研究

侧流除磷ERP-SBR新工艺在进水COD=338～527 mg/L、TN=40～60 mg/L、TP=8～11 mg/L的水质条件下,出水COD≤39 mg/L、NH3-N≤1.8 mg/L、TN≤5.8 mg/L、TP≤0.29 mg/L,且72%的总氮损失发生在好氧曝气阶段.在分析影响该工艺生物脱氮因素时发现:SBR反应器的DO时间分布是影响好氧生物脱氮和缺氧内碳源反硝化的重要因素;侧流除磷工艺特有的高浓度活性污泥、颗粒大且密实的污泥絮体有利于形成好氧生物脱氮过程所需要的微环境;控制较长的污泥龄有利于提高系统的好氧脱氮能力,SRT与好氧脱氮率之间具有良好的线性关系:ηODN(%)=0.89×SRT-5.74.     

SO_4~（2-）/TiO_2光催化降解苯酚

以工业硫酸氧钛为原料水解制得SO42-/TiO2光催化剂,并以苯酚为目标降解物,考察了SO24-/TiO2的光催化性能。结果表明：随着SO42-/TiO2制备过程中焙烧温度的升高,其光催化活性逐渐增加,650℃焙烧获得的SO24-/TiO2的光催化活性最好,此后再升高温度会因催化剂中硫的挥发而下降;在确定苯酚原液初始浓度为50 mg/L条件下,SO42-/TiO2的光催化降解苯酚的最佳工艺条件为反应时间2 h、苯酚pH为7、催化剂用量1 g/L。XRD、SEM和FTIR的分析结果显示实验温度下制得的SO42-/TiO2均为锐钛型TiO2;其间掺杂的SO24-在TiO2表面分散性较好,没有聚集成大的颗粒;红外分析的结果初步判定低温（〈550℃）焙烧制得的催化剂SO42-在TiO2表面是螯合双配位吸附,高温焙烧时（〉550℃）SO42-在TiO2表面是桥式配位吸附。     

Fate and transformation of naphthylaminesulfonic azo dye Reactive Black 5 during wastewater treatment process

Certain aromatic amines generated by the decolorization of some azo dyes are not removed substantially by conventional anaerobic–aerobic biotreatment. These aromatic amines are potentially toxic and often released in the wastewater of industrial plants. In this study, the fate and transformation of the naphthylaminesulfonic azo dye Reactive Black 5 (RB5) during different phases of a sequencing batch reactor were investigated. The major products of RB5 decolorization during the anaerobic phase include 2-[(4-aminophenyl)sulfonyl]ethyl hydrogen sulfate (APSEHS) and 1-2-7-triamino-8-hydroxy-3-6-naphthalinedisulfate (TAHNDS). During the aerobic phase, APSEHS was hydrolyzed and produced 4-aminobenzenesulfonic acid, which was further degraded via dearomatization. TAHNDS was transformed rapidly via auto-oxidation into TAHNDS_DP-1 and TAHNDS_DP-2, which were not further removed by the activated sludge during the entire 30-day aerobic phase. In contrast, different behaviors of TAHNDS were observed during the anoxic phase. The transformation of TAHNDS was initiated either by deamination or desulfonation reaction. TAHNDS was then converted into 3,5-diamino-4-hydroxynaphthalene-2-sulfonic acid, which was subsequently removed via ring cleavage reaction under aerobic condition. In conclusion, complete degradation of TAHNDS by activated sludge occurs only during anoxic/aerobic processes instead of the conventional anaerobic/aerobic processes.     

Biodecolorization of the azo dye Reactive Red 2 by a halotolerant enrichment culture.

The decolorization of the azo dye Reactive Red 2 (RR2) under anoxic conditions was investigated using a mesophilic (35 degrees C) halotolerant enrichment culture capable of growth at 100 g/L sodium chloride (NaCl). Batch decolorization assays were conducted with the unacclimated halotolerant culture, and dye decolorization kinetics were determined as a function of the initial dye, biomass, carbon source, and an externally added oxidation-reduction mediator (anthraquinone-2,6-disulphonic acid) concentrations. The maximum biomass-normalized RR2 decolorization rate by the halotolerant enrichment culture under batch, anoxic incubation conditions was 26.8 mg dye/mg VSSxd. Although RR2 decolorization was inhibited at RR2 concentrations equal to and higher than 300 mg/L, the halotolerant culture achieved a 156-fold higher RR2 decolorization rate compared with a previously reported, biomass-normalized RR2 decolorization rate by a mixed mesophilic (35 degrees C) methanogenic culture in the absence of NaCl. Decolorization kinetics at inhibitory RR2 levels were described based on the Haldane model (Haldane, 1965). Five repetitive dyeing/decolorization cycles performed using the halotolerant culture and the same RR2 dyebath solution demonstrated the feasibility of biological renovation and reuse of commercial-strength spent reactive azo dyebaths.     

亚铁羟基络合物还原转化水溶性偶氮染料

偶氮染料是印染工艺中应用最广泛的一类染料,目前染料废水脱色是污水处理难题。亚铁混凝处理染料废水过程中可能存在亚铁的还原作用,本实验制备了比溶解态亚铁更具还原反应活性的亚铁羟基络合物(ferrous hydroxycomplex,FHC),以5种不同类型的水溶性偶氮染料为目标污染物,研究FHC还原水溶性偶氮染料的脱色性能。实验结果表明,FHC对活性艳红X-3B、酸性大红GR和阳离子红X-GRL有较好的还原脱色效果,仅投加含铁89.6 mg/L的FHC,染料脱色率达到90%以上,继续增大FHC投加量可以完全脱色;中性枣红GRL的FHC还原脱色效果较差,需加入313.6 mg/L的FHC才能达到90%以上脱色率;134.4 mg/L的FHC能够将直接耐酸大红4BS完全脱色,但其脱色主要以混凝沉淀为主;溶液pH对FHC的还原性能产生重要影响,FHC还原染料脱色的适宜的pH值范围为4～10。该研究为亲水性染料脱色提供了一种新的技术,也为FHC运用于印染废水脱色提供了理论基础。     

Biological decolorization of reactive anthraquinone and phthalocyanine dyes under various oxidation-reduction conditions.

The decolorization of two anthraquinone dyes (Reactive Blue 4 [RB4] and Reactive Blue 19 [RB19]) and two phthalocyanine dyes (Reactive Blue 7 [RB7] and Reactive Blue 21 [RB21]) was investigated at an initial dye concentration of 300 mg/L using an unacclimated, enrichment culture. The culture was fed a mixture of organic compounds and maintained initially under aerobic conditions, and then progressively developed anoxic/ anaerobic conditions. Biotransformation-related decolorization of the dyes did not take place under aerobic conditions, but use of the feed organic mixture and biomass production by the enrichment culture were not affected. Complete ammonia removal occurred in the control and all dye-amended cultures. The development and extent of nitrification were much lower in the latter cultures, in which ammonia removal via air stripping was the dominant mechanism. Prolonged incubation of the culture under anoxic/anaerobic conditions with multiple carbon source additions resulted in a high decolorization extent of anthraquinone dyes (over 84%) and only partial decolorization of phthalocyanine dyes (49 to 66%). Development of significant methanogenic activity took place in the control and, to a lesser extent, in the two phthalocyanine dye-amended cultures, but the anthraquinone dyes severely inhibited the development of methanogenic activity. The RB4 and RB19 decolorization was attributed to nonreversible, microbially mediated dye transformation(s), demonstrated by the accumulation of decolorization products with absorbance maxima in the 420- to 460-nm region. The decolorization of RB4 and RB19 followed Michaelis-Menten kinetics. At an initial dye concentration of 300 mg/L, the observed maximum decolorization rate per unit biomass was 9.1 and 37.5 mg dye/mg volatile suspended solids x day for the RB4 and RB19, respectively. Thus, partial decolorization of reactive phthalocyanine dyes and extensive biological decolorization of reactive anthraquinone dyes is feasible only under anoxic/anaerobic conditions.     

Degradation of acid orange 7 in an aerobic biofilm.

A stable microbial biofilm community capable of completely mineralizing the azo dye acid orange 7 (AO7) was established in a laboratory scale rotating drum bioreactor (RDBR) using waste liquor from a sewage treatment plant. A broad range of environmental conditions including pH (5.8-8.2), nitrification (0.0-4.0 mM nitrite), and aeration (0.2-6.2 mg O2 l(-1)) were evaluated for their effects on the biodegradation of AO7. Furthermore the biofilm maintained its biodegradative ability for over a year while the effects of these environmental conditions were evaluated. Reduction of the azo bond followed by degradation of the resulting aromatic amine appears to be the mechanism by which this dye is biodegraded. Complete loss of color, sulfanilic acid, and chemical oxygen demand (COD) indicate that AO7 is mineralized. To our knowledge this is the first reported occurrence of a sulfonated phenylazonaphthol dye being completely mineralized under aerobic conditions. Two bacterial strains (ICX and SAD4i) originally isolated from the RDBR were able to mineralize, in co-culture, up to 90% of added AO7. During mineralization of AO7, strain ICX reduces the azo bond under aerobic conditions and consumes the resulting cleavage product 1-amino-2-naphthol. Strain SAD4i consumes the other cleavage product, sulfanilic acid. The ability of the RDBR biofilm to aerobically mineralize an azo dye without exogenous carbon and nitrogen sources suggests that this approach could be used to remediate industrial wastewater contaminated with spent dye.     

Effect of dissolved oxygen on biological nutrient removal by denitrifying phosphorus-accumulating organisms in a continuous-flow system

A laboratory-scale continuous-flow system with an anaerobic/anoxic/aerobic configuration was set up to study the effect of oxygen in the internal recycle stream; of particular interest was its performance of denitrifying phosphorus-accumulating organisms (DPAOs). It was found that, by using a degas device, the dissolved oxygen in the nitrate recycle stream was effectively decreased from 0.1 +/- 0.02 to 0.01 +/- 0.01 mg/L. This provided a favorable condition for DPAOs to grow under an anoxic condition and thus be sustained successfully in the system. When the degas device was removed from the system, the dissolved oxygen concentration in the anoxic reactor increased to 0.1 +/- 0.02 mg/L. The proliferation of the denitrifying glycogen-accumulating organisms (DGAOs) population and deterioration of DPAOs performance was observed. The increased population of DGAO/GAOs, which competed for the carbon source with DPAO/ PAOs, resulted in a poor performance of biological phosphorus removal.     

电吸附法去除水中刚果红的研究

以一种典型的联苯胺类直接偶氮染料刚果红为模型物,利用自制活性炭电极,研究各种因素(扫描电压、溶液初始浓度、电解质浓度、pH、电极活性炭用量等)对电吸附效果的影响.结果表明,在-1.0～1.0V的扫描电压下,刚果红没有氧化还原反应发生,电吸附是一稳定而又可逆的过程；扫描电压负极化使刚果红的吸附率降低,而正极化能明显提高吸附率,在0.9V扫描电压下的吸附率比开路(扫描电压为零)时提高了18.6百分点;刚果红溶液的初始浓度越高,吸附平衡时的吸附容量越高,但吸附率反而降低,刚果红溶液的初始质量浓度为40 mg/l时的吸附容量是10 mg/L时的4.87倍,而吸附率降低了21.4％；随着电解质Na2SO4的加入,加快了刚果红在溶液中的运动速率,但刚果红的最终去除率有所降低,并且在一定范围内Na2SO4加入的越多,刚果红的最终吸附效果越差；pH为7(未调节)时,活性炭电极对刚果红的吸附率最高,pH为2、11时,吸附率均有所降低;随着电极活性炭用量的增加,刚果红的吸附容量逐渐降低,吸附率则逐渐提高,达到吸附平衡所需时间相应也延长.     

Decolourization of azo dye methyl red by Saccharomyces cerevisiae MTCC 463

Saccharomyces cerevisiae MTCC 463 decolourizes toxic azo dye, methyl red by degradation process. Methyl red (100mgl(-1)) is degraded completely within 16min in plain distilled water under static anoxic condition, at the room temperature. Effect of physicochemical parameters (pH of medium, composition of medium, concentration of cells, concentration of dye, temperature and agitation) on methyl red decolourization focused the optimal condition required for decolourization. Biodegradation (fate of metabolism) of methyl red in plain distilled water was found to be pH dependent. Cells of Saccharomyces cerevisiae could degrade methyl red efficiently up to 10 cycles in plain distilled water. Analysis of samples extracted with ethyl acetate from decolourized culture flasks in plain distilled water (pH 6.5) and at pH 9 using UV-VIS, TLC, HPLC and FTIR confirm biodegradation of methyl red into several different metabolites. A study of the enzymes responsible for the biodegradation of methyl red in the control and cells obtained after decolourization in plain distilled water (pH 6.5) and at pH 9 showed different levels of the activities of laccase, lignin peroxidase, NADH-DCIP reductase, azoreductase, tyrosinase and aminopyrine N-demethylase. A significant increase in the activities of lignin peroxidase and NADH-DCIP reductase was observed in the cells obtained after decolourization in plain distilled water (pH 6.5), however cells obtained at pH 9 shows increased activities of azoreductase, tyrosinase, lignin peroxidase and NADH-DCIP reductase. High efficiency to decolourize methyl red in plain distilled water and low requirement of environmental conditions enables this yeast to be used in biological treatment of industrial effluent containing azo dye, methyl red.