结合实时监控和数学模型提升城市污水 A/O工艺处理效率
文献类型：学位论文
| 作者 | 王启镔 |
| 学位类别 | 博士 |
| 答辩日期 | 2016-05 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 陈求稳 |
| 关键词 | A/O工艺，实时监控，活性污泥模型，生物脱氮除磷，节能降耗 |
| 其他题名 | Combining real-time monitoring with mathematical model to enhance municipal wastewater treatment efficiency of the anoxic/oxic (A/O) process |
| 学位专业 | 环境工程 |
| 中文摘要 | 水是生命之源、生产之要、生态之基，是重要的自然资源和和经济资源。人类的活动正直接威胁着水资源安全和相关公共卫生。随着工业化和城镇化的快速发展，用水量急剧增加，污水的排放量也相应增加，加剧了水资源的短缺和受纳水体的富营养化。污水处理是水环境治理的重要方式，但是污水处理是高能耗行业，节能降耗已成为当前最为关注的课题之一。为了满足日益严格的排放标准和最小化污水处理厂的操作成本，加深对污水处理过程的认识，借助先进的监控技术和数学模型优化调控污水处理系统的运行，就具有理论和实际的双重意义。 缺氧/好氧(A/O)工艺是目前实际工程中应用最广泛的污水处理工艺之一。对工艺本身认知不足和前馈控制策略缺乏导致营养物去除效率较低、操作成本较高。为了解决上述问题，本研究通过“现场调研-中试试验-数学模型”，并结合实时监控系统研究了 A/O工艺处理效率提升技术，以我国南京江心洲污水处理厂为研究对象，分析了运行条件和环境条件对营养物削减的影响，建立了适合该污水处理厂的数学模型，基于情景分析提出了优化方案；建立中试规模的反应器(1.4 m3)，研究了集成实时监控与数学模型的工艺优化调控技术。研究取得的主要结论如下： （1）物质守恒分析表明，在 A/O处理工艺中，化学需氧量(Chemical oxygen demand, COD)和总氮(Total nitrogen, TN)削减量主要发生在缺氧池（厌氧池）；好氧池内的同步硝化反硝化(Simultaneous nitrification and denitrification, SND)十分明显；总磷（Total phosphorus，TP）主要在好氧阶段去除，在缺氧区也有一定量的磷得到去除；在二沉池内发生明显的氮磷削减量，证实反硝化聚磷菌（Denitrifying phosphorus accumulating organisms, DPAOs）的存在。 （2）污水处理厂出水的 COD在不同季节没有明显差异。在春季及秋季，污水处理厂的脱氮能力良好，在夏季，氮的去除容量最低；在冬季，TN的去除与其它季节具有可比性，表明微生物能适应逐渐改变温度的环境，抵抗低温造成的不利影响。在四个季节中，该污水处理厂在冬季表现出最高的磷去除能力。水温突然变化对微生物的活性有一定的冲击，是造成氮磷去除率短期下降的重要原因。 （3）基于 ASM3+Bio-P (EAWAG)模型及当地环境条件，选取三个基准温度（10℃、20℃及 30℃），建立了适合该污水处理厂的数学模型。模拟值与实测值的均方相对误差（MSRE）在 20%以内，表明建立的数学模型能够较好的模拟该污水处理厂水质转化过程，可以作为污水处理工艺运行优化的工具。敏感性分析结果显示，易生物降解基质的缺氧贮存产物产率（YSTO, N）对模型中 COD、氨氮(NH4+-N)、硝氮(NO-3-N)及磷酸盐(PO43--P)输出结果有重要的影响。 （4）对污水处理厂的操作参数优化后，曝气速率在春季、夏季、秋季、冬季分别减少15%、41%、33%和11%。采用出水水质指数（Effluent quality index, EQI)和运行成本指数(Operational cost index,OCI)两个指标对污水处理厂在四个季节的表现进行评价。结果表明，OCI提升的空间在夏季最高，秋季次之，EQI提升幅度在春季和夏季最高；夏季是调控的重点季节。 （5）中试试验显示，集成在线监控与数学模型进行优化调控，反应器对TN和TP的去除能力显著增加，去除率分别超过 50%和 70%以上。缺氧区在总生化池容积中的比例从 25%扩大到 37.5%，进一步强化了营养物去除并节省曝气能耗。 通过研究，丰富了污水处理过程中脱氮除磷机理理论，发现反硝化除磷以及 SND等营养物去除途径在削减污染物方面发挥了重要的作用。集成实时监控与数学模型优化调控技术可以提升污水处理效率，为污水处理工艺优化调控提供理论依据和决策支持。 研究的主要创新点如下： （1）深化认识了 A/O工艺效率提升的机制，合理投加外碳源，不仅强化了除磷效果，而且也改善了好氧区的 SND脱氮能力。 （2）识别了对 ASM3+bio-P模型中 COD、NH4+ -N、NO-3-N及 PO43--P模拟结果有重要影响的因子，建立了进水负荷和季节性温度变化与提高污染物去除能力和节约能耗之间的响应关系。 （3）结合实时监测数据、运行工况、环境条件与数学模型，建立了城市污水处理优化调控系统，提升了污水处理系统效率。 |
| 英文摘要 | Water security and related public health are important issues nowadays. With the rapid development of industrialization and urbanization, water pollution has dramatically aggravated the eutrophication of receiving waters and the scacity of water resources. Wastewater treatment is a primary way in water environment management; however, wastewater treatment is an energy-intensive industry.Improvement of wastewater treatment efficiency becomes an essential issue in wastewater treatment discipline. Therefore, insightful understanding to wastewater treatment process and optimization of operation conditions with the aid of advanced information technology and mathematical model are in great need. Anoxic/oxic (A/O) process is currently one of the most widely used wastewater treatment techniques in practical engineering. Inadequate recognition of the process itself and the lack of feedback control strategy may lead to low nutrient removal efficiency and higher operational cost. In order to solve the above problems, an improved technology of treatment efficiency for the A/O process was conducted at Jiangxinzhou wastewater treatment plant (WWTP) in Nanjing, China with the combination of in-situ test-pilot-mathematical model and real-time monitoring system. The effect of operational and environmental conditions on the reduction of the nutrients was analyzed. A suitable mathematical model for the plant was developed, and the optimized schemes based on scenario analysis were proposed as well. A pilot-scale reactor (1.4 m3) was established, and integrated real-time monitoring and mathematical model for optimal control technology was studied. The main research outcomes are as follows: (1) Mass balance calculations indicated that chemical oxygen demand (COD)utilization and total nitrogen (TN) reduction mainly occurred in the anoxic (anarobic) phase at the full-scale WWTP. The simultaneous nitrification and denitrification (SND) is very obvious in the oxic zones. Total phosphorus (TP) removal mainly took place in the aerobic phase with a certain degree of phosphorus removal in the anoxic zone. Occurrence of notable nitrogen and phosphorus reductions in the secondary clarifiers suggests that denitrifying phosphorus accumulating organisms (DPAOs) exist in the system. (2) There is no clear seasonal variation for COD concentrations in the effluent of the full-scale WWTP. The plant exhibited good performance on nitrogen removal in spring and autumn, while the nitrogen removal capacity was the lowest in summer.The considerable TN removal in winter indicats that microorganism could adapt to conditions of gradual temperature change to counteract adverse influence caused by low temperature. The plant achieved the highest level of phosphorus removal in winter. Sudden temperature variations account for transient impaired biological activity, leading to lower removal efficiency of nitrogen and phosphorus. (3) Based on the ASM3+Bio-P (EAWAG) model and local environmental conditions, three base temperatures (10℃, 20℃ and 30℃) were selected and the mathematical model for the full-scale WWTP was developed. Mean square relative error (MSRE) of simulated and measured values within 20% indicats that the mathematical model could simulate water quality transformation of the plant fairly well, therefor, could be a tool for the operational approach optimization. Results from the sensitivity analysis show that anoxic yield of stored product per readily biodegradable organic substrates (YSTO, N) has an important influence on the output results of COD, ammonia (NH4+ -N), nitrate (NO-3 -N) and phosphate (PO43- -P)concentrations. (4) After optimizing operational parameters of the plant, the aeration rate for the full-scale WWTP in spring, summer, autumn and winter was reduced by 15, 41, 33 and 11%, respectively. Effluent quality index (EQI) and operational cost index (OCI) were used to evaluate the performance of the WWTP in four seasons. The results show that the maximum potential for OCI improvement appeared in summer,followed by autumn, while the potential for EQI enhancement was highest in spring and summer. Therefor, summer is one of the most important seasons in terms of regulation time. (5) The results from pilot test show that the TN and TP removal efficiency for the pilot reactor increased significantly by more than 50% and more than 70%,respectively, using optimization control technology with integration of real-time data and mathematical model. The percentage of anoxic zone increased from 25% to 37.5%, which contributed to the further nutrients removal as well as aeration energy consumption savings. Through this study, theory of nitrogen and phosphorus removal mechanism in wastewater treatment process was enriched. It is found that pathway via denitrifying phosphorus removal and SND play an important role in the reduction of pollutants.Combined real-time monitoring and the mathematical model to optimize control technology could enhance wastewater treatment efficiency, which could provide a theoretical basis and decision-making support for the optimization control of wastewater treatment processes. The main innovations of the study are as follows: (1) Improved the understanding to A/O process efficiency, and proved that adding external carbon source could not only strengthen the phosphorus removal, but also improve the nitrogen removal via SND in the aerobic zones. (2) Identified the key factors affecting the concentration of COD, NH4+ -N, -N and PO4 -P in effluent, and revealed the effects of seasonal temperature NO-3 3-variations on pollutant removal rate and energy efficiency. (3) Combined real-time monitoring, mathematical simulation and operational control to have improved the efficiency of treatment system. |
| 源URL | [http://ir.rcees.ac.cn/handle/311016/37018]  |
| 专题 | 生态环境研究中心_环境纳米材料实验室 |
| 推荐引用方式 GB/T 7714 | 王启镔. 结合实时监控和数学模型提升城市污水 A/O工艺处理效率[D]. 北京. 中国科学院研究生院. 2016. |
入库方式： OAI收割
来源：生态环境研究中心
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。