一维分层弥散模型在二沉池模拟中的应用

通过在二沉池一维分层模型中加入弥散作用建立了二沉池一维分层弥散模型,并采用数值求解的方法开发了二沉池模拟程序.利用竖流式沉淀池中试试验实测数据验证了模型的可靠性,以COST(欧洲科技领域研究合作组织)624/682文件中基准污水处理厂二沉池晴天时的稳态和动态进水数据为模型输入值,分析比较了一维分层弥散模型模拟程序与国外成熟软件的模拟结果.结果表明,纳入了弥散作用的一维分层模型能较好地描述实际二沉池中的悬浮固体浓度分布,模拟结果具有较好的精度,有待于在二沉池模拟和控制领域进一步深入研究.     

某城市污水处理厂废水化学除磷沉淀特性及影响因素

通过对西安市某污水处理厂进水、厌氧池上清液、二沉池出水、污泥浓缩水、污泥脱水进行Fe CI_3·6H_2O、PAC除磷实验,并以Fe CI_3·6H_2O为沉淀剂对厌氧池上清液从p H、Fe/P摩尔比、腐殖酸、挥发性脂肪酸(VFA)等因素进行批次实验分析磷去除状况。实验显示,三氯化铁、PAC对进水除磷效果不佳,厌氧池上清液用Fe CI_3·6H_2O为沉淀剂时磷去除率较低,二沉池出水、污泥浓缩水以及污泥脱水用Fe CI_3·6H_2O、PAC时其正磷去除率均可达到80%左右。通过对比不同p H值、Fe/P摩尔比、腐殖酸和VFA浓度对厌氧池上清液除磷效果的影响,结果表明,在p H=4~5,Fe/P=1.3时磷的去除效果达到78%以上,腐殖酸浓度对磷去除率影响不大,VFA在低于10 mg/L和高于60 mg/L时对磷去除率影响较大。     

二沉池动态仿真模型研究

建立了二沉池的一维动态模型,同时定义偏差函数作为模型参数校核的目标函数,并对某污水厂二沉池进行动态仿真的模拟.通过对模拟数据和实际运行数据的对比,验证了二沉池模拟的合理性以及参数校核方法的有效性.     

不同进水条件下ASM1模型参数的灵敏度分析

编制了BSM1的仿真程序,并分析了不同进水条件下ASM1模型的16个参数对BSM1出水COD、TN、NH4+-N、NO3--N灵敏度的影响.结果表明,9个参数的灵敏度在规定的划分范围内没有区别,7个参数在不同进水条件下差别较明显；各参数灵敏度的变化规律,与出水的NH4+-N及NO3--N浓度变化有一定相关性；灵敏度变化与ASM1模型速率方程中的开关函数有关.研究不同进水条件下模型参数的灵敏度,有助于提高污水处理仿真计算的准确性.     

两点进水在倒置AAO流程除磷中的作用

利用计算机仿真研究两点进水对倒置AAO流程除磷的作用,发现将污水按选择池进水流量与厌氧池进水流量的分配比(简称进水流量分配比)为1.0/0、0.9/0.1、0.8/0.2、0.7/0.3、0.6/0.4、0.5/0.5分流到选择池和厌氧池,会影响中等COD负荷(200~220 mg/L)下该流程的除磷效果。原因在于,污水分流到厌氧池虽然能提高厌氧池内乙酸浓度,但同时会因稀释作用而降低厌氧池及好氧池中聚磷菌的浓度,影响聚磷菌厌氧释磷及好氧吸磷的作用。两点进水对低COD负荷(140~180 mg/L)及高COD负荷(260~340 mg/L)下该流程的除磷效果无明显影响,前者因各反应池(除二沉池外)内聚磷菌浓度本身很低,后者则因各反应池内聚磷菌浓度本身很高,改变进水流量分配比不会改变这2种情况下各反应池内聚磷菌释磷或吸磷的强度。     

微孔曝气氧化沟工艺问题诊断及分析

污水厂升级改造仍是目前水处理研究的热点问题,通过桂林七里店污水厂的微孔曝气氧化沟处理过程进行诊断分析,结果表明,将七里店污水厂微孔曝气氧化沟的一个A/O运行模式改造为2个分段A/O供氧模式,改变进水点,提高氧化沟内梯度脱氮环境,缺氧区和好氧区容积比调整为1∶1.2,氧化沟出水口DO浓度到0.5 mg/L以上,二沉池中NO-3-N平均浓度达到7.2 mg/L,氧化沟到二沉池出水口阶段NH+4-N和PO3-4-P的平均释放量由改造前的3.85和1.69mg/L降低到-0.1和-0.2 mg/L的无释放状态。同时也表明,二沉池中NO-3-N浓度适当可抑制沉淀池中氨氮和磷酸盐的释放,改善出水水质。     

二段生物接触氧化工艺在中水回用中的特性研究

以规模小区生活污水为水源，对采用聚丙烯网状填料和强化炉渣组合填料的二段生物接触氧化工艺（以下简称二段法）进行了试验研究，试验针对本工艺的各项技术指标、影响因素以及各相关参数进行了较系统的试验测试。结果表明，反应器在第一接触氧池HRT为20 min、气水比为6∶1和第二接触氧池HRT为25 min、气水比为5∶1条件下，接触氧化池达到最佳降碳条件；反应器在第一接触沉池上升流速5.5 m/h和第二接触沉池上升流速4.5 m/h条件下，接触沉淀池达到最佳处理条件。     

两种A~2/O工艺的活性污泥2D模型动力学参数灵敏度分析

使用GPS-X软件对传统A~2/O工艺和氧化沟型A~2/O工艺的污染物(COD、硝酸盐氮、氨氮和溶解性正磷酸盐)去除效果进行模拟,选用活性污泥2D模型(ASM2D)对厌氧池、缺氧池和好氧池中20个重要动力学参数进行了灵敏度分析。结果发现,在两种A~2/O工艺中,动力学参数对出水COD和硝酸盐氮浓度的灵敏度影响较小,对出水氨氮和溶解性正磷酸盐浓度的灵敏度影响很大。与聚磷菌相关的动力学参数灵敏度最高,与异养菌相关的动力学参数灵敏度最低。参数向上浮动与向下浮动对同一水质指标的影响程度不同,饱和/抑制系数类参数的灵敏度一般低于其他参数。     

分段进水A/O工艺的一些关系式

设计分段进水A/O工艺的主要目的是为了充分利用原水中的有机碳进行反硝化,因而便产生了由缺氧池反硝化所需有机碳与硝态氮数量相匹配的原则分配各段污水流量的设计思想。在该设计思想下,分段进水A/O工艺的脱氮效率及按照一定的设计条件确定的反应池容积或水力停留时间与污泥回流比、原水碳氮比等因素间存在着具有一定规律性的关系式,这些关系式直观反映了这些影响因素对脱氮效率的影响及其在反应池设计中所起的作用。对这些关系式进行了推导,分析了各因素对脱氮效率的影响和提高脱氮效率的途径,并推导说明了按照容积负荷相等进行工艺设计时,各缺氧池或各好氧池的容积之间的相对比例关系,以及按照污泥负荷相等进行设计时,各缺氧池或各好氧池的水力停留时间之间的相对比例关系。     

宜兴市徐舍污水处理厂的工程设计

宜兴市徐舍污水处理厂的一期工程设计规模为1．0×10^4m^3／d，厂区总规模为3．0×10^4m^3／d。一期工程处理工艺采用改良型C-AAO工艺，该工艺以改良型AAO工艺Sure进周出辐流式二沉池为基础，将缺氧池、厌氧池、好氧池、二沉池、硝化液回流、污泥回流系统组合为一体，具有占地面积小、投资省、能耗低、原水适应能力强、运行管理方便的突出优点。处理出水水质优于《城镇污水处理厂污染物排放标准》（GB18918-2002）一级A标准。文中详述了该工程的设计参数、处理工艺流程及其设计特点。     

Determination of the required surface area of a final clarifier for an activated-sludge system.

A generic methodology for determining the required surface area of a final clarifier is presented. Clarification and thickening requirements are integrated to form a unified procedure for final clarifier design. The new method is based on results obtained by Yuen (2002) on the solids flux theory for a secondary clarifier; it does not require the specification of recycle rate, which is computed as an output of the method. The author shows that there is a minimum required surface area (A(m)) for a final clarifier under the thickening requirement when the designed recycle rate is set at the maximum allowable value (FR)m (at the critical state). The designed surface area and the return activated sludge pumping capacity can be determined by applying a safety factor to A(m) and (FR)m, respectively. The method is shown to conform to conventional design criteria under typical design conditions.     

Evaluation on estrogenicity and oxidative hepatotoxicity of fossil fuel industrial wastewater before and after the powdered activated carbon treatment

There are 10 manufacturers who produce fossil fuel products in the Da-Hse Industrial District, Kaohsiung County, southwestern Taiwan. Before discharging the wastewater into the nearby aquatic environment, the pretreated wastewater from these manufacturers must be processed in a treatment plant which includes four major processing units: equalization, a primary clarifier, an aeration basin, and a final clarifier. In order to estimate the potential environmental risks of industrial wastewater from each manufacturer and the treatment efficiency of the powdered activated carbon treatment (PACT) system used in this wastewater treatment plant, in vitro bioassays for estrogenicity and oxidative hepatotoxicity were carried out using a stably transfected human breast cancer cell line, MVLN, and a human hepatocellular carcinoma cell line, HepG2, respectively. Estrogenic substances occurred in nine of 10 pretreated wastewaters from these manufacturers in which the relative luciferase activity ranged from 18.9% to 98.0% for 1-fold-condensed wastewaters corresponding to the concentration of the original wastewater. The estrogenicity was highest at the influent of the treatment plant and decreased through the treatment process. About 81% estrogenicity clearance was found through all processing units. On the other hand, oxidative hepatotoxic substances existed in seven of 10 pretreated wastewaters from these manufacturers in which relative TBARs activity ranged from 18.5% to 43.0% for 1-fold-condensed wastewater. The TBARs of influent samples apparently decreased through the processing units until the aeration basin, but abruptly rose in the final clarifier, which was a result of the addition of an active charcoal-retrieving agent with the molecular formula of (C(2)H(3))(n)CONHCH(2)N(CH(3))(3)Cl and which had high TBARs activity. No TBARs activity being found in effluent samples could be a consequence of allowing sufficient time for coagulation between the active charcoal and its retrieval agent which decreased the residual active charcoal-retrieving agent. We concluded that the industrial wastewater treatment plant using the PACT system in the Da-Hse Industrial District is suitable for removing estrogenic substances and oxidative hepatotoxic substances discharged from these industrial manufacturers.     

Fate of sex hormones in two pilot-scale municipal wastewater treatment plants: conventional treatment

The fate of seven sex hormones (estrone (E1), estradiol (E2), estriol (E3), ethinylestradiol (EE2), testosterone, androstenedione, and progesterone) was determined in two pilot-scale wastewater treatment plants operated under conventional loading conditions. The levels of hormones in both the liquid and the solid matrixes of the plants were determined. Each of the two 20-l/h pilot-scale plants consisted of a primary clarifier followed by a three-stage aeration tank and a final clarifier. The primary sludge and the waste activated sludge (WAS) were digested anaerobically in one pilot plant and aerobically in the other. The pilot plants were fed a complex synthetic wastewater spiked with the hormones. Levels of testosterone, androstenedione and progesterone were close to method detection limit (MDL) concentrations in the final and digester effluents (both liquid and solid phases) and were considered as completely removed. Average mass flux removals from the liquid streams (plant influent minus secondary clarifier effluent) for the natural estrogens were 82% for E1, 99% for E2, and 89% for (E1+E2). An average overall removal of only 42% was achieved for EE2. These values reflect removals averaged for the two pilot plants.     

膜生物反应器工艺污水处理厂设计进水水质的确定

城市污水处理厂进水水质是工程设计的基本参数,进水水质的测定分析对污水处理厂的设计具有重要意义。对无锡市城北污水处理厂的现状进水水质进行了调查和分析,提出按照水质指标浓度出现的频率确定污水处理厂设计进水水质的方法,并针对采用的膜生物反应器(MBR)工艺的特点,提出:(1)根据实测数据按照一定的保证概率可以用来确定城市污水处理厂设计进水水质;(2)为了使水质的确定更加符合设计工程的实际情况,根据实测数据分析确定设计进水水质指标时,一般还需要进行趋势性调整和季节性调整;(3)确定合理的指标浓度与流量,以此为依据进行反应池的工艺设计,同时要校核夏季温度高、浓度低、流量大和冬季温度低、浓度高、流量小的工况是否满足处理要求,然后取冬、夏季校核值以及未作季节性调整设计值中最不利情况作为设计值,才能充分保证出水达到处理要求。     

容积负荷对ANAMMOX生物滤池脱氮效能的影响及其基质动力学

采用2套启动成功的上向流厌氧氨氧化（ANAMMOX）生物滤柱，通过调节进水NaNO₂和（NH₄）₂SO₄ 的浓度负荷及水力负荷，改变进水容积负荷，探讨容积负荷对ANAMMOX生物滤柱脱氮效能的影响及其动力学模型。结果表明，滤速恒定条件下，通过提高进水基质浓度来提高进水TN容积负荷，其容积负荷去除动力学过程符合Monod-Haldane基质抑制模型。进水NH₄⁺-N与NO₂^--N浓度分别低于100 mg/L和133 mg/L时，反应器脱氮效果不受明显影响，TN容积去除负荷可达4.21 kg/（m³·d），TN去除率可达80%以上。进水基质浓度恒定条件下，通过提高滤速来提高进水TN容积负荷，其容积负荷去除动力学过程符合零级动力学方程。不受基质浓度抑制的条件下，滤速为3.0 m/h、进水容积负荷为8.82 kg/（m³·d）时，反应器总氮容积负荷去除量可达7.15 kg/（m³·d），总氮去除率可达81.1%。     

Optimal design of predenitrification systems.

A coupled model of biological and settling phases aimed at optimal design of predenitrification systems is presented. Each unknown is obtained in explicit form, and is expressed as a function of the system's required performance. A model, taking into account both suspended and dissolved substrates, is adopted for the biological phase, while the limiting solid flux theory is assumed for the design of the settling phase. Finally, a relationship correlating the two phases is obtained expressing opportunely the sludge recycle flow and the sludge waste flow, without recourse to empirical parameters. The effect of different influent and effluent wastewater characteristics on the model's results is also analyzed.     

合流制排水系统溢流污染就地调蓄处理控制技术研究

在对高效混合絮凝斜板沉淀工艺进行现场中试的基础上,将化学强化处理工艺与调蓄池相结合,针对上海市某合流制排水系统,进行调蓄/沉淀池的概念设计,提出主要设计参数,利用计算流体力学(CFD)模型对调蓄/沉淀池进行优化设计.试验和模拟结果表明,调蓄/沉淀池与单纯的调蓄池相比具有更好的溢流污染控制效果和效益/造价比.     

Influence of source characteristics, chemicals, and flocculation on chemically enhanced primary treatment.

The overall objective of this research was to investigate various methods and parameters to increase the efficiency of chemically enhanced primary treatment (CEPT). The performance of CEPT was evaluated based on its efficiency of removal of nonsettleable solids (NSS). Some of the source characteristics that influenced NSS concentration included influent total suspended solids, influent turbidity, and influent total chemical oxygen demand. A higher concentration of the influent constituents led to a higher NSS concentration, suggesting that NSS represented a somewhat fixed fraction or percent of these influent constituents. The specific particle surface area (SPSA) was found to correlate with percent NSS in the effluent. A higher SPSA is a result of smaller-sized nonsettleable colloidal particles, thus leading to an increase in percent NSS. In summary, there are several parameters that affect NSS, which could be used to control NSS to improve CEPT, as demonstrated by this study.     

城市污水处理中的工艺运行优化

由于实际进水水质与设计值有偏差，造成采用改良氧化沟工艺的邯郸市西污水处理厂的运行管理困难且费用较高。针对该厂的实际运行情况，探讨了曝气系统的DO、MLSS、泥龄等运行参数的控制问题，并对各参数进行分析、优化调整，最终使该工艺具有较好的脱氮除磷效果。     

HRT对固定床厌氧反应器运行效果的影响

为了考察水力停留时间(HRT)对炭纤维载体固定床厌氧反应器运行效果的影响,在进水COD分别为20 000~25 000 mg/L和40 000~45 000 mg/L2个浓度范围下,研究了不同HRT对反应器运行效果的影响。结果表明,通过HRT的调整,在达到相同有机负荷(OLR)下,进水COD为20 000~25 000 mg/L的COD去除率和产气量,明显比进水COD为40 000~45 000 mg/L的运行效果好;进水COD为20 000~25 000 mg/L,HRT为14 h,相应的OLR为41.09 kgCOD/(m3.d)时,COD去除率仍然维持在68%以上,沼气容积产气率达到14.55 m3/(m3.d)。炭纤维载体固定床厌氧反应器具有较高的COD去除率、产气效率以及抵抗低pH、高负荷冲击的能力,运行过程中没有发生反应器堵塞的现象。