废水生物除磷电子受体及工艺研究进展

论述分析了废水生物除磷电子受体从氧到硝酸盐和亚硝酸盐的衍变过程及其相应的典型工艺形式,提出并建立了连续流亚硝化/反硝化聚磷生物除磷新工艺。该工艺具有两个关键点,一个是亚硝化段内亚硝酸盐的稳定积累,另一个是缺氧段中以亚硝酸盐为电子受体超量摄取磷。与常规的反硝化除磷技术相比,亚硝化/反硝化聚磷生物除磷工艺中引入了短程硝化技术,更加节约能耗、减少污泥排放量,具有重大的理论意义和应用价值。     

Effects of the sludge reduction system in MBR on the membrane permeability

For the sludge volume reduction, gravity thickening and mechanical thickening processes have been mainly applied. However, these processes usually cause several problems such as large footprint, low thickening efficiency, etc. To solve these problems, a sludge reduction system using submerged membrane in a reactor with excess sludge from a biological nutrient removal (BNR) system was investigated. Both lab and pilot scale experiments for sludge reduction were carried out. The hydraulic retention time (HRT) was in a range of 4.5-6.7 days during the experimental period. A flat-sheet membrane with a mean pore size of 0.08 µm was used and operated at a flux range of 7-20 L/m²·h.During the experimental period, concentrations of BOD and SS were maintained less than 8 mg/L, 3 mg/L, respectively, which indicated the high quality of treated wastewater. While extracellular polymeric substances (EPS) were lowest at a coagulant concentration of 15 ppm, soluble microbial product (SMP) concentrations did not have any correlation with coagulant concentrations. The critical flux was observed in a range of 18-24 L/m²·h.These results suggested that the sludge reduction system using membrane bioreactor (MBR) could be applied as one of suitable processes to overcome problems of conventional processes such as gravity and mechanical thickening.     

硅藻土负载羟基氧化铁的制备及除磷性能研究

采用铁盐法在硅藻原土上负载羟基氧化铁(FCD)颗粒,制备出一种新型的除磷吸附剂,利用SEM、EDAX、XRD以及物理吸附等手段对FCD样品进行表征检测.结果表明:经过改性后的硅藻土表面负载了颗粒状的羟基氧化铁,其微孔和表面粗糙度发生明显变化,比表面积比硅藻原土增大了10倍.还利用摇床实验模拟自然环境,探讨FCD的投加量、吸附扰动时间、pH以及温度等因素对FCD除磷效果的影响.研究结果表明:在常温和酸性条件下,扰动3 h时,该吸附剂能达到较好的吸附效果,在25℃、pH=3时除磷率达到92%,吸附容量为3.68 mg/g,比较适合应用于呈酸性的珠江水水样;Langmuir和Freundlich等温吸附方程都能较好地描述硅藻土对磷的等温吸附特征,为有效控制水体富营养化提供了理论依据.     

城市污水厂二级出水脱氮除磷回用于景观水体的试验研究

采用纤维生物膜滤池-强化微絮凝纤维过滤的方法,对城市污水厂二级出水进行深度处理．回用于人工景观水体。试验结果表明：出水中总磷一般可达到0．2mg/L以下,氨氮一般可以达到1．5mg／L以下;本试验系统在对氮磷去除的同时,对CODcr、BOD5、SS、浊度等也有进一步的去除作用。试验出水水质可以达到GB 3838—2002《表水环境质量标准》中Ⅲ类水体标准,可满足人工景观用水等高级回用的要求。     

海水对污泥沉降性能及脱氮除磷影响的试验

采用SBR工艺就添加海水改善生物处理系统污泥沉降性能及对生物脱氮除磷的影响进行了研究．结果表明,添加海水进入生物处理系统可以显著改善活性污泥的沉降性能,当海水与生活污水的体积比为1：4时,污泥沉降比由86％降为34％,污泥絮凝成团状结构,丝状菌含量下降,且对生物处理系统的氮、磷脱除效果没有显著影响。     

酚酞型聚醚砜对聚偏氟乙烯中空纤维膜结构及性能的影响

以二苯甲酮和N,N-二甲基乙酰胺为稀释剂,酚酞型聚醚砜(PES-C)为添加剂,通过热致相分离法制备了聚偏氟乙烯(PVDF)中空纤维膜。采用扫描电镜观察了膜的结构,测试了膜的纯水通量。在膜生物反应器(MBR)中测试了膜的污水通量和出水的化学需氧量及氨氮指标。该法制得的膜具有较为致密的皮层结构和疏松的支撑层结构,添加质量分数为2%的PES-C制备的PVDF膜与PVDF膜相比纯水通量增加60%,污水通量增加37.8%,出水COD去除率增加了3.32%,NH4+—N去除率增加了2.2%,且MBR出水达到排放标准。     

聚合硫酸铁铝的制备及除磷性能研究

介绍了利用硫酸法生产钛白粉的副产硫酸和赤泥提铁渣资源化制备聚合硫酸铁铝（PAFS）的工艺,实验得到优化后的最佳工艺条件参数：液固质量比为6∶1、溶出温度为105 ℃、溶出时间为80 min,在此工艺条件下赤泥提铁渣的溶出率达到65.2%,且优化合成的聚合硫酸铝铁中全铁的质量分数为8.23%、氧化铝的质量分数为1.12%、盐基度为12.88%。利用以上工艺条件制备得到的聚合硫酸铁铝与市售净水剂（聚合硫酸铁、聚合氯化铝）做除磷对比实验,实验结果表明,在同一加药量的情况下本研究制备的聚合硫酸铁铝除磷效果较好,去除率最高可达95.45%（加药量为300 mg/L）。     

膜生物反应器臭氧化同步污泥减量新工艺的研究

提出将臭氧直接充入到MBR中的同步臭氧化污泥减量新工艺,考察了同步臭氧化对MBR污泥产率及出水水质的影响.结果表明臭氧投加量为0.025 gO3/gVSS时,同步臭氧化对MBR具有显著的污泥减量效果,污泥产率系数Yobs为0.0096 g(MLSS)/g(COD),而对比工艺污泥产率系数Yobs为0.1147 g(MLSS)/g(COD),同时对COD和NH4+-N的去除率分别维持在91%和95.7%以上.     

混凝剂PAFC对改善MBR膜污染的研究

在MBR处理生活污水的试验中,对投加PAFC的混凝MBR和普通MBR进行了对比,考察膜污染的变化情况.在一个运行周期内,普通MBR胞外聚合物中各组分的增长速率明显大于混凝MBR,在系统运行的60d中,普通MBR膜组件共清洗了2次,分别是在30 d和50 d,混凝MBR膜组件在48 d时清洗了1次.试验结果表明微生物中胞...     

Optimization of biological nutrient removal in a pilot plant UCT-MBR treating municipal wastewater during start-up

This study shows that an MBR pilot plant with UCT configuration is able to obtain high nutrient removal efficiency already during start-up. The biological nutrient removal (BNR) efficiencies significantly increased towards the end of the experimental run, achieving a COD removal efficiency exceeding 94% and N removal efficiency in the range of 89 to 93%. P removal efficiencies in the range of 80 to 92% have been obtained. During the experimental period (4 months) the evolution of the activity of polyphosphate-accumulating organisms, obtained from P_release and P_uptake rates, showed a small increase in the activity of polyphosphate-accumulating organisms (PAOs) and denitrifying polyphosphate-accumulating organisms (DPAOs). The specific phosphate accumulation at the end of the experimental run amounted to 8.0 mg P g^− 1VSS h^− 1 and 3.29 mg P g^− 1VSS h^− 1, for the PAOs and DPAOs respectively. Moreover, the DPAOs activity increased faster than PAOs activity, i.e. from 0.36 to 0.41 of phosphate uptake rate (PUR) ratio.     

MBR工艺在石化污水处理中的应用

随着国家对石化企业节水减排、污水回用的要求不断提高,MBR工艺在石化污水处理中的研究和工程应用越来越广泛。介绍了MBR工艺在已建石化污水处理装置提标改造和新建污水处理装置中的应用现状,对在应用中存在的问题进行了归纳梳理,提出了改进措施与建议,并结合MBR技术改进和材质升级,进一步展望了MBR技术在石化污水回用方面的发展趋势。     

软硬性填料对MBR处理效率和膜污染的影响

膜生物反应器（MBR）在污水处理领域的应用日益广泛,填料的投加对MBR污水处理效率和膜污染进程有一定的影响。本文分别向MBR中投加不同量的软性和硬性悬浮填料,研究了悬浮填料对MBR运行效率及膜污染的影响。结果表明,投加填料后MBR对COD、氨氮和总磷等污染物的处理效率有所提高,明显减缓了膜污染的进程。软性填料对MBR的改善效果优于硬性填料,投加20%的软性填料时,系统对COD、氨氮和总磷的去除率分别可达96.53%、98.21%和52.75%,系统运行30天时的膜污染情况比未投加填料的系统减缓了41.43%。通过对比发现软性填料能够为微生物提供更大的生存空间,提高反应器内的微生物量,从而提高MBR对污水的处理效率同时改善膜污染,是一种加强MBR系统的适宜填料,最佳投加量为反应器有效体积的20%。     

Characteristics of simultaneous nitrogen and phosphorus removal in a pilot-scale sequencing anoxic/anaerobic membrane bioreactor at various conditions

This study was conducted to evaluate the performance of pilot-scale sequencing anoxic/anaerobic membrane bioreactor (SAM) process under various real situations. During the pilot experiment, the effect of three important operational parameters, such as hydraulic retention time (HRT), solids retention time (SRT) and internal recycling time mode were estimated and the long-term membrane fouling behaviour was also investigated. During the operation period, the COD removal efficiency was higher than 95% regardless of change of operational conditions because the membrane significantly contributed to remove COD by the complete retention of all particulate COD and macromolecular COD components. The change of Ax/An ratio representing internal recycling time mode significantly affected on nitrogen and phosphorus removal. As increasing Ax/An ratio, nitrogen removal efficiency increased but phosphorus removal efficiency decreased. As HRT decreased, phosphorus removal efficiency increased and nitrogen removal efficiency also increased until a certain limit of HRT (6.5 h in this study). However, when HRT decreased over the limit, nitrogen removal efficiency decreased because of insufficient nitrification. Relation between phosphorus removal efficiency and SRT was a little bit complex because SRT determined both the phosphorus content in the sludge and the sludge wasting rate. However, in this study, the shorter SRT resulted in the higher phosphorus removal efficiency. The effect of changes in all operational conditions was sensitive on phosphorus rather than on nitrogen removal efficiency. The increasing in influent flowrate resulted in the increase of flux and caused a rapid membrane fouling. Thus, the flux of 7.7 L/m²/h was more desirable compared to the 10.7 or 15.4 L/m²/h in this study.     

Importance of the density gradient effects in modelling electro deposition process at a rotating cylinder electrode

The rotating cylinder electrode configuration is one of the most used electrochemical configurations for electrochemical processes study. It is often used with turbulent flow regime for industrial application such as intensive corrosion or electro deposition processes. It can also be used for laminar regimes but in this case it can appear superposition between forced convection and natural free convection. This natural free convection is generally due to density gradient from electrode to bulk, due to electro deposition or to evolving bubbles. The hydrodynamic regime is then said mixed.There is few knowledge concerning the mixed hydrodynamic and the main goal of the present work is to show the qualitative and quantitative effects and differences between purely forced convective flow and purely free natural flow.     

CaO对磷渣硅酸盐水泥水化硬化影响的试验研究

通过对磷渣水泥凝结时间、力学性能、化学结合水和磷渣反应率的测定,以及XRD和SEM分析,研究了不同掺量的CaO对磷渣水泥的水化性能和微观结构的影响。结果表明,随着CaO掺量的增加,磷渣水泥的强度增加,当CaO的掺量超过2%时,磷渣水泥3d和28d抗压强度下降。CaO对磷渣活性的激发主要发生在磷渣水泥水化早期,掺2%CaO的磷渣水泥28d的磷渣反应率只比1d时增加了4.1%。     

复合式膜生物反应器强化脱氮除磷的实验研究

在传统好氧膜生物反应器(MBR)的基础上,结合厌氧/缺氧/好氧(A2/O)工艺开发了复合式A2/O膜生物反应器,并对其处理小区生活污水中的氮、磷等污染物的特性进行了研究。实验表明:在各自合适的条件下复合式A2/O膜生物反应器可保证化学需氧量(COD)的平均去除率达到90.17%,NH4+-N的去除率可达到92.32%,总氮(TN)平均去除率可达到72%,而总磷(TP)的平均去除率达到71.23%。     

MBR膜的污染及其清洗技术研究进展

针对环境污染控制中广泛应用的膜生物反应器(MBR),阐述了其污染的主要来源和影响因素,重点介绍了膜清洗的几种方法及发展状况,并提出了膜清洗技术的发展方向。     

A/O+MBR工艺在分散式污水处理工程中的应用

针对北京市通州区分散式污水处理厂站节约占地、出水水质指标要求高特点,以某分散式污水工程A/O+MBR工艺为例,对2018年1-12月工艺运行情况分析.运行结果表明:AO+MBR工艺全年对COD、NH4+-N、TN和TP的平均去除率分别为91.97％、98.83％、66.24％、92.68％,沿程水质数据分析说明COD、...     

The beneficial role of intermediate clarification in a novel MBR based process for biological nitrogen and phosphorus removal

BACKGROUND: A novel membrane bioreactor (MBR) is described, employing an intermediate clarifier. Unlike the established function of a final clarifier in a conventional biological nutrient removal system, the role of an intermediate clarifier has rarely been studied. Thus, this work focused on explaining the fate of nutrients in the intermediate clarifier, as influenced by the hydraulic retention time (HRT) of the preceding anaerobic bioreactor. RESULTS: The system was tested with two different anaerobic/anoxic/aerobic biomass fractions of 0.25/0.25/0.5 (run 1) and 0.15/0.35/0.45 (run 2) using synthetic wastewater. The major findings of the study were that phosphorus (P) removal was affected by the role of the intermediate clarifier. In run 1, P was removed at a rate 0.16 g d⁻¹ in the intermediate clarifier while in run 2, additional P was released at 0.49 g d⁻¹. The nitrogen (N) removal efficiencies were 74 and 75% for runs 1 and 2 respectively, while P removal was 91 and 96%. P uptake by denitrifying phosphate accumulating organisms (DPAOs) accounted for 41–52% of the total uptake in the MBR. CONCLUSIONS: This study found that the intermediate clarifier assisted chemical oxygen demand (COD), N, and P removal. With respect to the fate of P, the intermediate clarifier functioned as an extended anaerobic zone when the HRT of the preceding anaerobic zone was insufficient for P release, and as a pre‐anoxic zone when the anaerobic HRT was adequate for P release. Copyright © 2008 Society of Chemical Industry