活性污泥胞外聚合物提取方法研究

考察4种方法（蒸气法、EDTA法、NaOH法和搅拌法）对3种活性污泥（可乐厌氧活性污泥、可乐好氧活性污泥和市政污水污泥）胞外聚合物的提取效率,对比分析了各提取方法对不同样品提取所得胞外聚合物的组成影响,结果表明,EDTA法提取多糖的效率最高,提取市政污水污泥、可乐好氧活性污泥和可乐厌氧活性污泥胞外聚合物糖分别在8.3、16.7和9.7 mg/g VSS左右;NaOH提取蛋白质的效率最高,提取市政污水污泥、可乐好氧活性污泥和可乐厌氧活性污泥胞外聚合物蛋白质分别为：3.15、0.55和5.57 mg/g VSS.对于3种不同种类污泥,EDTA法提取EPS总量效率最高,分别为市政污水污泥10.7 mg/g VSS、可乐好氧活性污泥16.8 mg/g VSS和可乐厌氧活性污泥9.97 mg/g VSS,分别比效率最低的搅拌法高出5倍、5倍和3倍.     

好氧颗粒污泥胞外多聚物的提取及成分分析

EPS是微生物聚集体的重要组成部分,提取和分析好氧颗粒污泥的EPS利于深入研究这一新兴微生物聚集体.采用加热、超声、高速离心和加碱等5种方法提取好氧颗粒污泥的EPS,并分析其主要成分.结果表明,匀浆预处理是提取颗粒污泥EPS首要步骤,超声和加热分别适合EPS定性与定量分析,在35 w、超声4 min的条件下,活性污泥与好氧颗粒污泥EPS提取液中TOC产量分别为105.3 mg/g VSS和96.5 mg/g VSS;加热法(80℃,60 min)提取的EPS产量略高于超声法,对于活性污泥和好氧颗粒污泥,TOC含量分别为142.6 mg/g VSS和153.2 mg/g VSS;蛋白质是活性污泥和好氧颗粒污泥EPS中比例最大的成分,且蛋白与多糖在好氧颗粒污泥与其在絮状活性污泥中的比值范围分别为3.22～5.80和1.68～2.63.     

微好氧预处理对市政污泥厌氧消化产甲烷的影响

针对目前市政污泥处理资源化与减量化效率低的问题,利用微好氧预处理技术进行预处理,提高其甲烷产量。利用有机物溶出效率、VSS减量、甲烷产量3项指标对预处理效果进行了评价;研究了不同参数条件下微好氧预处理对市政污泥厌氧消化产甲烷的影响;探讨了微好氧预处理对污泥胞外聚合物的影响。结果表明,微好氧预处理可以促进污泥溶解性有机物释放、提高VSS去除率;在最佳反应条件下(曝气强度0.30m3·(min·m3)-1、预处理时间12 h),相对于未经过预处理的工况,甲烷产量可提高26.77%;微好氧预处理对剩余污泥活性细胞的影响主要发生在胞外聚合物部分,同时也存在对活性微生物的破解作用。市政污泥经过微好氧预处理后,可有效提升后续中温厌氧消化或高温厌氧消化的甲烷产量。     

好氧颗粒污泥降解苯酚

以人工配水启动SBR,逐步提高进水苯酚浓度,探究好氧颗粒污泥对苯酚的降解能力,同时分析苯酚对好氧颗粒污泥特性的影响。经过55 d的运行,进水苯酚浓度逐渐增到3 000 mg/L,苯酚、COD及NH+4-N去除率分别达到了98.33%、97.27%和57.58%,好氧颗粒污泥表现出对苯酚的良好的去除能力。扫描电镜照片显示投加苯酚后的颗粒污泥表面更加光滑,结构更为紧凑。胞外聚合物红外光谱分析表明投加苯酚前后好氧颗粒污泥EPS的主要组分没有明显改变。苯酚毒性刺激了颗粒污泥分泌更多胞外聚合物,胞外聚合物中多糖含量由初始的12.70 mg/g VSS增加到35.17 mg/g VSS,蛋白含量由4.93 mg/g VSS增加到8.01 mg/g VSS。投加苯酚后的污泥粒径明显增大,主要污泥粒径由0.5~2.0 mm增大到2.0 mm以上。     

厌氧、好氧、厌氧/好氧交替状态对活性污泥性质的影响

实验采用活性污泥处理模拟印染废水,研究厌氧、好氧、厌氧/好氧交替3种条件对活性污泥性质的影响。3种实验条件下,污泥沉降比(SV%)均基本保持在18%~25%之间,污泥容积指数(SVI)保持在62~66 m L/g之间。活性污泥混合液中胞外聚合物(EPS)除EPSB-蛋白质浓度持续升高外,其余形式均呈现积累、达到最大值后下降的趋势,其中厌氧/好氧交替条件下EPS浓度最高而好氧条件下最小。在整个实验期间,活性污泥的脱氢酶活性基本呈上升状态,在厌氧/好氧间歇曝气条件下脱氢酶活性最高、好氧条件次之、厌氧条件最低,最终3种条件下的脱氢酶活性分别为31.27、26.63和24.37 mg/(g·h)。活性污泥中ATP浓度基本呈现先增加后减小、再趋于稳定的变化趋势。实验结果表明,活性污泥表观产率系数顺序是好氧厌氧厌氧/好氧交替运行,厌氧/好氧交替实现了系统内污泥减量,微生物的产率系数和能量状态密切相关。脱氢酶活性对污染物的降解影响明显,而实验条件下微生物能量状态和污泥减量并不对污染物降解产生影响。     

不同状态下的同一污泥胞外聚合物提取方法研究

以由厌氧污泥向好氧污泥转变前后2种不同状态下的污泥为研究对象,采用5种不同方法对污泥胞外聚合物(EPS)进行了提取实验。实验结果表明,NaOH法提取的EPS含量最高,但会导致胞内物质泄漏。CER和离心提取法较温和,但EPS产量不高。甲醛-NaOH和H2SO4法提取的EPS含量较高,且无大量细胞自溶发生,是有效的EPS提取方法。厌氧污泥转变为好氧污泥后蛋白质/多糖(PN/PS)比例有所增加,表明EPS各组分含量发生改变。红外分析表明厌氧污泥转变为好氧污泥前后EPS中主要组成成分没有发生改变,但各成分含量有所增加,特征明显的峰表明EPS中存在蛋白质、多聚糖。     

利用好氧颗粒污泥处理水产循环养殖废水的研究

在序批式活性污泥反应器(SBR)中接种生物絮体,利用水产循环养殖废水培养好氧颗粒污泥。在溶解氧为6.4~7.1mg/L的条件下,培养出的好氧颗粒污泥平均粒径为150μm,SBR内挥发性悬浮固体(VSS)稳定在16.33~17.47g/L,总悬浮固体(TSS)稳定在17.25~18.57g/L,好氧颗粒污泥对水产循环养殖废水具有较好的处理效果,硝态氮、溶解性有机碳、溶解性磷酸盐去除率均在90%以上。好氧颗粒污泥中粗蛋白和粗脂肪含量均高于接种生物絮体。生物絮体内松散结合胞外聚合物(LB-EPS)含量比好氧颗粒污泥高,而紧密结合胞外聚合物(TB-EPS)含量比好氧颗粒污泥低,生物絮体与好氧颗粒污泥中胞外聚合物(EPS)的主要区别成分是多糖。     

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。     

城市污水污泥高温好氧/中温厌氧两级消化研究

采用高温好氧/中温厌氧两级污泥消化(AerTAnM)工艺处理城市污水污泥,通过考察挥发性悬浮固体(VSS)去除率和沼气产量,研究了进泥浓度、中温相污泥投配率、搅拌速度、高温相污泥停留时间(SRT)对AerTAnM工艺消化效率的影响。结果表明,AerTAnM工艺的最佳运行条件:进泥总悬浮固体(TSS)为4.2%(质量分数),VSS为26.59g/L,高温相SRT为2.0d,中温相污泥投配率为8%,搅拌速度为100r/min。在该最佳运行条件下,系统稳定运行阶段出泥VSS去除率达45%以上,沼气产量达到1.06L/g(以VSS计),粪大肠杆菌和蛔虫卵的杀灭率达到95%以上,出泥可达《城镇污水处理厂污染物排放标准》(GB18918—2002)控制要求。     

连续流传统活性污泥系统中好氧颗粒污泥的培养

采用西安市第四污水处理厂A2/O系统中的絮体污泥为接种污泥,在连续流传统活性污泥系统中进行了好氧颗粒污泥的培养研究。当系统温度为25～27℃、沉淀时间为2 h、溶解氧为4.2 mg/L、搅拌速度为240 r/min时,系统可培养出粒径为0.5～1.5 mm的颗粒污泥,扫描电镜结果显示,颗粒污泥主要由球状菌和杆状菌组成,此外还存在少量的丝状菌。实验结果表明,相对于反应器的形式和沉淀时间,水力剪切力和接种污泥中的丝状菌对好氧颗粒污泥形成的影响更大,胞外多糖的产生对好氧颗粒污泥的形成也起着至关重要的作用。     

Ecotoxicity, phytotoxicity and extractability of heavy metals from different stabilised sewage sludges

The presence of heavy metals in the sludges produced in wastewater treatment plants restricts their use for agricultural purposes. This study compares different types of sludges (aerobic, anaerobic, unstabilised and sludge from a waste stabilisation pond) in order to assess the extractability of heavy metals using simple extraction, water and DTPA. The stabilisation treatment undergone by the sludges influenced the heavy metals extractability. The least mineralised sludges (unstabilised and aerobic) showed higher metal extractability. The sewage sludges were subjected to chemical characterisation and toxicity testing (ecotoxicity and phytotoxicity assays) in absence of substrate, to provide a preliminary assessment of their suitability for land application. The ecotoxicity assays confirmed that no sludge constituted a hazardous waste. The sludge extracts had significant adverse effect on the germination index (GI) of barley (Hordeum vulgare L.) and cress (Lepidium sativum L.), a fact which indicates that some characteristics affected root growth.     

A/O-MBR中MLSS浓度对污泥性能及膜通量的影响

采用国产聚丙烯中空纤维帘式膜组件,进行了A/O-MBR系统处理生活污水的实验研究,主要探讨了系统中污泥浓度(MLSS)与膜通量变化过程的关系。实验结果表明,MLSS由3 805 mg/L升高到6 912 mg/L时,污泥混合液胞外聚合物(EPS)由43 mg/g VSS增加到81 mg/g VSS,EPS中多糖与蛋白质的比例从0.87增加到1.08。同时,污泥相对疏水性(RH)的降低与Zeta电位的升高也在一定程度上共同促进了膜污染速率的上升。实验条件下,当运行时间为60 d左右,MLSS升高至6 200 mg/L时,跨膜压差上升迅速,膜组件清洗周期由初始的22 d缩短为11 d。A/O-MBR中由于MLSS浓度变化而导致的活性污泥混合液特性的变化,是影响膜通量变化的重要原因。     

阳离子树脂法提取活性污泥胞外聚合物的研究

考察了树脂法提取活性污泥中胞外聚合物（extracellular polymeric substance,EPS）的影响因素,确定了最佳的提取条件.试验结果表明,树脂量60g/g VSS,振摇频率200r/min下处理4 h,EPS的提取量达到111.20 mg/L,DNA占提取量的12.13%.该方法的重现性试验结果还表明,EPS及其各成分的相对标准偏差在2.21%～6.07%之间,能较好地满足试验要求,是一种可靠的EPS提取方法.     

垃圾压缩站污水的生物强化处理

垃圾压缩站污水是一种具有高COD、高NH3-N特点的有机污水.以厌氧/好氧组合工艺为基础,通过投加高效菌株对活性污泥系统进行生物强化.实验结果表明,与空白相比,厌氧出水COD去除率提高约30%,好氧出水NH3-N去除率提高约20%.最终出水COD《120 mg/L, NH3-N《25 mg/L,均达到《污水综合排放标准》(GB 8978-1996)二级排放标准.     

活性污泥胞外聚合物提取方法优化

试验对比了不同离子交换树脂(CER)含量和pH条件下胞外聚合物(EPS)的提取效果差异。结果表明,EPS各组分提取浓度均随离子交换树脂用量增加而增加,但各组分趋势不同。TOC的最佳树脂剂量为100 g CER/g VSS,而蛋白质、多糖和DNA的最佳树脂剂量约为70 g CER/g VSS。pH值对TOC、DNA和多糖的提取浓度影响较小,但对蛋白质影响比较大。各提取条件下,EPS各组分提取浓度随时间的变化过程可以分为平稳增长期、快速增长期及稳定期。     

Treatment of carbofuran-bearing synthetic wastewater using UASB process

In the present study, fate of carbofuran in anaerobic environments and the adverse effects of carbofuran on conventional anaerobic systems were evaluated. Carbofuran degradation studies were carried out in batch reactors with varying carbofuran concentrations of 0 to 270.73 mg/L corresponding to a sludge-loading rate (SLR) of 2.12 x 10(-6) to 3.83 x 10(-3) g of carbofuran/g of volatile suspended solids (VSS)/d. Carbofuran concentration was reduced to undetectable levels at the end of 8 and 13 days in the batch reactors operated with a SLR of 2.12 x 10(-6) and 3.33 x 10(-5) g of carbofuran/g of VSS/d, respectively. Performances of two anaerobic reactors i.e. upflow anaerobic sludge blanket (UASB) and modified UASB (with tube settlers) were evaluated in the presence and absence of carbofuran using synthetic wastewater. In the absence of carbofuran, the soluble chemical oxygen demand (COD) removal efficiency in the conventional UASB reactor at 8 h and 6 h hydraulic retention time (HRT) was nearly 88% and 76%, respectively, whereas in modified UASB reactor it was increased to 90% at 8 h HRT and 78% at 6 h HRT. When 28 mg/L (SLR of 1.19 x 10(-2) g of carbofuran/g of VSS/d) of carbofuran was introduced in the reactors, the COD removal efficiency was reduced to 41% and 44% in conventional and modified UASB reactors respectively. However, the reactor could maintain around 80% COD removal efficiency at a carbofuran concentration of 7.84 mg/L (SLR of 3.64 x 10(-3) g of carbofuran/g of VSS/d). The reactor efficiency was also measured in terms of specific acetoclastic methanogenic activity (SMA). The toxic effect of carbofuran was reversible to a certain extent. Carbofuran removal efficiency in the conventional UASB reactor at carbofuran concentrations of 7, 13 and 28 mg/L were 40 +/- 3%, 27 +/- 3%, and 11 +/- 3%, respectively. In modified UASB reactor, carbofuran removal efficiency was almost uniform at 7 and 13 mg/L but it was reduced nearly by 56% at 28 mg/L. The major metabolite of carbofuran i.e. 3-keto carbofuran was found in all the reactors.     

Combined anaerobic/aerobic digestion: effect of aerobic retention time on nitrogen and solids removal

A combined anaerobic/aerobic sludge digestion system was studied to determine the effect of aerobic solids retention time (SRT) on its solids and nitrogen removal efficiencies. After the anaerobic digester reached steady state, effluent from the anaerobic digester was fed to aerobic digesters that were operated at 2- to 5-day SRTs. The anaerobic system was fed with a mixture of primary and secondary sludge from a local municipal wastewater treatment plant. Both systems were fed once per a day. The aerobic reactor was continuously aerated with ambient air, maintaining dissolved oxygen level at 1.1 +/- 0.3 mg/L. At a 4-day or longer SRT, more than 11% additional volatile solids and 90% or greater ammonia were removed in the aerobic digester, while 32.8 mg-N/L or more nitrite/nitrate also was measured. Most total Kjeldahl nitrogen removal was via ammonia removal, while little organic nitrogen was removed in the aerobic digester.     

碳氮磷比例失调城市污水的同步脱氮除磷

为解决现行同步脱氮除磷工艺处理南方地区碳、氮、磷比例失调城市污水中,因C/N、C/P偏低,碳源不足而降低脱氮除磷效率的难题,试验以碳源偏低的广州市城市污水为研究对象,采用厌氧/好氧交替运行的SBR系统,通过对厌氧、好氧时段的合理调控,在无需额外添加碳源的条件下,有机物、氨氮、总氮和总磷的平均去除率分别可达90%、72%、41%和99%,不仅能使有机物和氮的出水指标达到国家排放标准,而且总磷出水浓度能达0.5 mg/L以下。通过进一步分析同步高效脱氮除磷的影响因素和控制条件,得出合理污泥龄的控制是实现同步脱氮除磷的关键,厌氧/好氧交替运行的方式不仅强化了磷的释放和吸收,而且降低了碳源偏低和硝酸盐对同步脱氮除磷影响的结论。