SMBR处理含油废水出水COD数学模型

根据微生物生长动力学特征以及膜分离特征,建立恒通量下运行的一体式膜生物反应器系统出水COD数学模型,提出膜生物反应器处理效率的数学模型。以实验及模型为基础,分别对进水COD浓度控制在300、400、500 mg/L附近时经过反应器后COD的去除效率进行了比较。通过公式计算的数据和实验数据分析可得:COD去除率的公式计算值与实验结果比较吻合,相对偏差仅为0.0223,为膜系统有机物的去除效果估算提供了基础,可为该类工艺的参数选择与优化提供参考。     

载体内微孔孔径对生物膜特性及废水处理效果的影响

为解决载体內部微孔孔径在废水生物膜法中缺乏选型依据的问题,采用5种孔径(0.6~4 mm)聚氨酯海绵生物载体构建了SBBR,考察了载体内微孔孔径对生物膜特性(MLSS、EPS、DHA)及废水处理效果的影响,分析了载体内部微孔孔径与生物膜特性的相关性。结果表明：载体内微孔孔径与MLVSS、MLSS呈显著负相关,而与PN、PS、EPS和f呈显著正相关;高生物量使小孔径载体(0.6 mm,1 mm)在反应器运行前中期拥有最佳的废水处理效果,同时过多的生物膜在微孔环境中会堵塞内部的通道和空穴,进而抑制传质,使生物膜活性(DHA、f )降低;而大孔径载体(4 mm)内部传质快、水力剪切作用强,加速生物膜解吸脱落速率,促进了生物膜活性的提高与EPS(主要是TB-EPS)的释放,但同样限制了生物膜量的增长。相较而言,中等孔径载体(2 mm,3 mm)适宜的微孔不仅能维持适量的微生物量,还能保持良好的生物膜结构和活性,为生物膜反应器提供良好的长期运行条件和处理效果。     

盐度对膜生物反应器处理含盐废水影响的研究进展

总结了国内外采用膜生物反应器( MBR)处理含盐废水的研究进展,分析了盐度对有机物去除的影响、对脱氮效果的影响、对总磷去除的影响以及对微生物活性和膜污染的影响.指出当前MBR处理高盐度废水的研究热点主要是如何降低对各类功能微生物活性的抑制作用,以及降低溶解性微生物产物、胞外聚合物的释放量,从而减轻膜污染,但目前大多数的研究仍处在实验配水阶段.最后还对今后的研究方向进行了展望.     

Metal ferrite incorporated polysulfone thin-film nanocomposite membranes for wastewater treatment

Effluents from food, fermentation, and sugar industries contain a large quantity of glucose which has to be removed to limit the chemical oxygen demand (COD) of the water discharged. This work proposes novel thin-film nanocomposite (TFN) membranes incorporated with MgFe₂O₄ and ZnFe₂O₄ nanoparticles to address this concern. The nanoparticles synthesized by the sol–gel method was extensively characterized and then incorporated into the active polyamide layer of the thin-film composite polysulfone membranes. The change in membrane morphology, wettability, chemical structure, and mechanical strength with the incorporation of nanoparticles was studied in detail. Membranes with 0.005 wt.% MgFe₂O₄ nanoparticle exhibited highest glucose rejection (96.52?±?2.35%) at 10 bar, 25 °C, and sufficiently high pure water flux (50.54?±?1.92 L/m²h). This membrane also displayed 69.1?±?5.12% salt rejection when challenged with 2000 ppm synthetic NaCl solution.

     

Effect of high influent sulfate on anaerobic wastewater treatment.

A laboratory-scale study was conducted using a completely mixed reactor with a constant influent-total-organic carbon (TOC) of 3750 mg/L to evaluate the effect of increasing influent-sulfate levels on anaerobic-treatment performance. The sulfate levels were increased stepwise from 333 to 666, 1000, 1333 and 1666 mg S/L. The results showed that an elevation of influent sulfate actually increased the TOC removal efficiency as long as the produced sulfide level did not induce toxicity. At 1333 mg S/L influent sulfate, the produced dissolved sulfide was 613 mg S/L (free sulfide = 228 mg S/L), which started to impose toxicity to the methane-producing bacteria (MPB). It was also found that the percent electron flow to the sulfate-reducing pathway increased with the increasing influent sulfate, but the direction toward the methanogenesis was correspondingly reduced. Nevertheless, under the experimental conditions tested, the majority of the influent organics was still degraded through the methanogenic pathway. Through this study, an oxidation-reduction-potential (ORP)-based oxygenation process was developed for online oxidation of sulfide in recirculating biogas. With controlled oxygen injection to raise the reactor's ORP by 25 mV, the residual sulfide in the reactor was almost totally eliminated. In case of over oxygenation, any excess oxygen was quickly consumed by the facultative organisms in the reactor, thereby imposing no toxicity to the MPB.     

高膜通量厌氧微网生物反应器处理生活污水的研究

将动态膜技术与厌氧膜生物反应器相结合,形成一体式厌氧微网生物反应器(AnFBR),用于城市生活污水的处理,研究了在高膜通量条件下,AnFBR的运行情况和对生活污水的处理效果。结果表明,AnFBR在膜通量为72 L/(m2.h)条件下可连续稳定运行40 d;系统对COD平均去除率为58.4%,对TN和NH3-N有一定的去除效果;出水SS最高为15.0 mg/L,出水中污染物粒径在10μm以下;微网动态膜对小分子物质的截留量不高,但对分子量大于1 000 kU的物质有明显的截留效果,进水中的大部分大分子物质被转化为小分子物质;AnFBR在保留了泥水分离特点的情况下还具有结构简单、膜通量高、微网过滤周期长等优点。     

水解+加压MBR处理淀粉废水研究

对水解+加压MBR处理中等难降解淀粉废水进行了探索性研究。试验结果表明增加水解酸化预处理后加压MBR处理效果有明显增加,不同操作压力下,膜过滤出水COD仅为无水解酸化预处理时的1/2。在操作压力为045MPa,进水COD10430mg/L,容积负荷522kgCOD/m3·d时,膜滤出水COD仅为202mg/L,COD去除率高达9981%。     

碳氮比对人工湿地污水处理效果的影响

采用表面流人工湿地系统静态小试装置,考察了低、中、高3组不同进水COD/N(2,5,10)对系统中氮、磷及COD去除效果的影响。结果表明:进水C/N的变化对COD的去除率影响不大,平均去除率达到94.6%。TN的去除率随着COD/N的增大而逐渐升高,在C/N=5时达到63.8%,继续提高COD/N,TN的去除率变化不大。NH4+-N去除率随着COD/N的增加而降低。随着碳源的增加,释磷菌能够从进水中获得充足的碳源,从而可以比较充分地释磷,因此,磷的去除率随COD/N的增加而提高。     

微量金属对废水厌氧处理效果的影响

以葡萄酒蒸馏废水的厌氧生物处理为例,研究了Fe、Ni、Co、Mo、Cu、Zn对厌氧反应器的COD去除率、出水中挥发性有机酸含量、气体产量、气体成分、pH缓冲能力和碱度等的影响.对比了微量金属投加前后,厌氧反应器污泥中微量金属含量的变化.得出微量金属具有提高厌氧运行效果的作用,其中,Co的作用要更大一些.Ni、Co、Mo在附着态、悬浮态污泥中具有逐渐积累的特点;Fe、Cu、Zn在附着态污泥中是淋失的,而在悬浮态污泥中变化不大.     

填料传质性能对污水生物反应处理工艺的影响研究

通过水力自旋填料与常规生物填料的对比试验,研究了传质性能对污水生物反应处理工艺的影响.结果表明:生物反应器内物系间的传质条件对氧传递效率有较大影响;SCMT型自旋传质填料良好的传质性能,能够创造理想的传质条件,使生物反应器内DO基本保持一致;使用SCMT型自旋传质填料生物反应器处理城市污水,可以在较短的停留时间(1.00 h)或较小的气水比(体积比,4∶1)的情况下,出水水质达到《城镇污水处理厂污染物排放标准》(GB 18918-2002)二级标准.     

内置转盘式PVDF膜生物反应器污水处理的试验研究

对内置转盘式PVDF膜生物反应器(SRMBR)处理污水工艺及膜清洗进行了研究.SRMBR处理污水可以长期稳定运行,在实验模拟污水COD为180～368 mg/L时,出水COD在运行1d后稳定在20 mg/L以内,COD去除率>93%.增大转盘式平板膜组件转速可以增大SRMBR的平衡水通量,转速从15 r/min增大到25 r/min,平衡水通量从42.5 L/(m2·h)增大到47.5L/(m2·h).在一定自吸泵停抽时间内(0～1 min),延长停抽时间有利于减缓膜污染、提高平衡水通量.对污染的膜进行水洗、水洗 碱洗、水洗 碱洗 酸洗,3种清洗方式分别使膜平衡水通量恢复至新膜平衡水通量的48.4%、83.5%、90.2%.     

改性聚丙烯填料水处理性能试验研究

采用化学氧化-铁离子覆盖技术对普通聚丙烯填料进行改性,并对改性前后的填料进行生物亲水性、表面特性、临界表面张力以及模拟污水的生物挂膜等特性研究。结果发现,改性填料的亲水性和表面粗糙度大大提高,临界表面张力变大,表面电性为正,在生物膜法水处理中,其挂膜速度提高了46.7%,终期氨氮去除率提高了8.84%。可见改性填料与普通填料相比,其水处理性能较好。     

5种湿地沉水植物对模拟污水厂尾水的深度处理

选取四季常青苦草、普通苦草、黑藻、狐尾藻和马来眼子菜等5种沉水植物构建表面流人工湿地系统,观察不同沉水植物品种对模拟污水厂尾水中主要污染物的去除效果,筛选出具有最佳去污效果的沉水植物,为优化沉水植物表面流人工湿地系统的处理效果提供理论依据。结果表明：沉水植物表面流湿地系统和无植物表面流湿地系统对各污染物的去除效果均呈现出随着实验时间的延长先波动变化后逐渐趋于稳定的规律。四季常青苦草、黑藻和狐尾藻湿地系统出水COD、TP浓度均低于10 mg·L-1、0.1 mg·L-1,分别达到了《地表水环境质量标准》（GB 3838-2002）Ⅰ和Ⅱ类水标准。除马来眼子菜外,其余4种沉水植物对主要污染物的净化效果存在较大差异,以四季常青苦草的综合净化效果最好,出水COD、TP、NH4+-N、NO3--N和TN的平均浓度分别为36.83、0.269、1.17、0.563和3.31 mg·L-1,平均去除率分别达到41.32%、72.77%、84.29%、79.28%和76.72%。黑藻次之,接着是狐尾藻,而普通苦草的去污效果较差。综合考虑其对模拟城市污水处理厂尾水的深度处理效率,宜选择四季常青苦草作为表面流人工湿地的优选沉水植物。     

纳米生态基对水产养殖污水的处理效果

采用三因子四水平的正交设计,实验研究了纳米生态基在不同温度、溶解氧和水力停留时间下对水产养殖污水的处理效果,确定了纳米生态基处理养殖污水的最佳条件。结果表明,含氨氮和亚硝氮浓度较高的模拟养殖污水用纳米生态基挂膜,所需时间约为22 d。纳米生态基对氨氮的去除效果明显,平均去除率达到93.5%。对氨氮去除率的影响程度,水力停留时间>温度>溶解氧。当温度为30℃,DO为5.43 mg/L,HRT为0.33 h时,纳米生态基对氨氮的处理能力最佳,去除率达到94.6%。纳米生态基对亚硝氮的平均去除率为69.3%。对亚硝氮去除率的影响程度,水力停留时间>溶解氧>温度。当温度为21℃,DO为6.40 mg/L,HRT为0.33 h时,纳米生态基对亚硝氮的处理能力最佳,去除率为71.5%。纳米生态基处理养殖污水的最佳条件:温度为30℃,DO为6.40 mg/L,HRT为0.33 h。     

Effect of humification processes on polyaromatic hydrocarbons concentration during wastewater treatment.

The aim of the present work was to compare the concentration changes of polyaromatic hydrocarbons (PAH) and the course of humification processes during wastewater treatment. Studies of samples from a biological-mechanical wastewater treatment plant in Sosnowiec-Zagórze (Poland) were carried out. Determination of PAH was performed both for wastewater sludge and sludge water. Observations of the course of humification processes for humic acid fractions isolated from sludges were conducted. Analysis of PAH extracted from wastewaters and from sludge was performed by means of high-performance liquid chromatography. Investigations of humification processes were conducted by electron paramagnetic resonance and nuclear magnetic resonance methods. The elementary composition changes in the structure of the extracted humic acids were determined. It was found that polyaromatic hydrocarbons appear during the processes of humification. Their content in water decreased only after the process of sludge aeration; however, sludge water leaving the settlers was PAH-enriched.     

ABR-好氧颗粒污泥处理黄连素废水的启动研究

实验研究了ABR-好氧颗粒污泥组合工艺处理黄连素制药废水的启动运行,通过分析发现,ABR装置在HRT为4 d,黄连素浓度为50 mg/L的运行方式下成功启动,反应器运行稳定后每个格室MLSS平均值分别为25 840、21 560、27 500和11 200 mg/L。以ABR出水为营养物,成功培养出粒径在2～10 mm,沉降速率为104～137 m/h,沉降性能优良的好氧颗粒污泥。该组合工艺在启动实验的末期,进水COD浓度为3 000～4 000 mg/L左右,出水COD浓度到达168.4～271mg/L,系统总的去除率保持在90%～95%之间,表明ABR-好氧颗粒污泥组合工艺能够有效地处理黄连素制药废水。     

城镇污水处理厂的综合绩效评价

近年来我国城镇污水处理厂的修建得到很大发展,但其在运行管理方面存在一些问题,为了促进污水处理厂的稳定运行与升级改造,需要建立一套综合绩效评价体系对其进行科学的评价与管理。在对城镇污水处理厂的调查研究基础上,提出将DPSIR原理融入到城镇污水处理厂综合绩效评价指标体系的构造中,形成了一个3层19个指标的综合绩效评价指标体系,通过层次分析法(AHP)和模糊综合评价法相结合,创建了城镇污水处理厂综合绩效的AHP-模糊综合评价模型,并选取成都市两座(A和B)城镇污水处理厂展开实例应用研究。结果表明:A污水处理厂综合绩效评价结果有26.3%隶属于"较好"等级,B污水处理厂综合绩效评价结果有28.1%隶属于"一般"等级。根据最大隶属度原则,A和B污水处理厂综合绩效评价等级分别属于"较好"和"一般"。     

Effect of membrane type and material on performance of a submerged membrane bioreactor

This study evaluated the impact of membrane type and material on filtration performance in a submerged membrane bioreactor (MBR) for municipal wastewater treatment. Three types of microfiltration membranes with similar pore size of 0.1 microm but different materials and types, phase-inversed polytetrafluoroethylene (PTFE), track-etched polycarbonate (PCTE) and track-etched polyester (PETE), were used. Changes in permeability with time for the PCTE and PTFE membranes appeared similarly, whereas the PETE membrane exhibited the most rapid flux decline. Lower TOC in the permeate compared to the supernatant was probably due to a combination of biodegradation by the biofilm (cake layer) developed on the membrane surface and further filtration by cake layer and narrowed pores. The faster permeability decline and higher TOC removal rate of the PETE membrane were attributed to an initial permeate flux higher than an average design flux, which led to a faster rate of fouling and thicker cake layer. Therefore, an MBR should not be operated at a flux higher than the average design flux for a specific type of membrane. A gradual increment of biomass concentration did not significantly affect membrane permeability of each membrane investigated. Dissolved organic carbon fractionation results showed that the composition of each fraction between the supernatant and permeates did not change significantly with time, suggesting that membrane hydrophobicity was not a dominant factor affecting MBR fouling in this study. The organic foulants desorbed from the PCTE membrane contained approximately 60% of hydrophobic fraction, which was probably attributable to the extracellular polymeric substances proteins released from the biomass attached to the membrane. While the total filtration resistance of the PTFE membrane was influenced by a higher surface roughness, those of the PETE and PCTE membranes, which had a similar and lower roughness, were affected by the initial operating flux.     

Co-conditioning of the anaerobic digested sludge of a municipal wastewater treatment plant with alum sludge: benefit of phosphorus reduction in reject water.

In this study, alum sludge was introduced to co-conditioning and dewatering with an anaerobic digested sludge from a municipal wastewater treatment plant, to examine the role of the alum sludge in improving the dewaterbility of the mixed sludge and also in immobilizing phosphorus in the reject water. Experiments have demonstrated that the optimal mix ratio for the two sludges is 2:1 (anaerobic digested sludge:alum sludge: volume basis), and this can bring approximately 99% phosphorus reduction in the reject water through the adsorption of phosphorus by alum in the sludge. The phosphorus loading in wastewater treatment plants is itself derived from the recycling of reject water during the wastewater treatment process. Consequently, this co-conditioning and dewatering strategy can achieve a significant reduction in phosphorus loading in wastewater treatment plants. In addition, the use of the alum sludge has been shown to beneficially enhance the dewaterability of the resultant mixed sludge, by decreasing both the specific resistance to filtration and the capillary suction time. This is attributed to the alum sludge acting in charge neutralization and/or as adsorbent for phosphate in the aqueous phase of the sludge. Experiments have also demonstrated that the optimal polymer (Superfloc C2260, Cytec, Botlek, Netherlands) dose for the anaerobic digested sludge was 120 mg/L, while the optimal dose for the mixed sludge (mix ratio 2:1) was 15 mg/L, highlighting a huge savings in polymer addition. Therefore, from the technical perspective, the co-conditioning and dewatering strategy can be viewed as a "win-win" situation. However, for its full-scale application, integrated cost-effective analysis of process capabilities, sludge transport, increased cake disposal, additional administration, polymer saving, and so on, should be factored in.     

间歇曝气潜流人工湿地的污水脱氮效果

采用间歇曝气运行方式,提升潜流人工湿地生活污水处理系统中的溶解氧浓度,强化脱氮效果。结果表明,间歇曝气运行方式有效提高了湿地内部溶解氧水平,曝气时溶解氧浓度可达6~9 mg/L,停止曝气后,溶解氧浓度迅速下降至0.5 mg/L以下,在湿地内部营造了一种交替的好氧和缺氧环境,分别促进好氧硝化和缺氧反硝化作用。在水力停留时间为3 d的情况下,间歇曝气潜流人工湿地系统对氨氮、总氮和COD的去除率分别可达到98.0%、87.6%和96.3%,较常规潜流人工湿地系统分别提高了74.1%、56.4%和18.1%,实现了氨氮、总氮和COD的同步高效去除。