中国科学院生态环境研究中心机构知识库
Advanced  
RCEES OpenIR  > 水污染控制实验室  > 学位论文
题名: Orbal氧化沟工艺特征与节能降耗研究
作者: 周鑫
学位类别: 博士
答辩日期: 2012
授予单位: 中国科学院研究生院
授予地点: 北京
导师: 刘俊新
关键词: Orbal氧化沟 ; Orbal oxidation ditch ; 污水处理 ; wastewater treatment ; 节能降耗 ; energy-saving ; 脱氮除磷 ; nitrogen and phosphorus removal ; 工艺特征 ; process charateristics ; 优化运行 ; operational optimization
其他题名: Study on process characteristics and energy consumption reduction for Orbal oxidation ditches
中文摘要:       城市污水处理是一种能量密集型行业,污水处理过程中的节能降耗技术日益受到人们的关注。因结构简单、运行管理简便等特点氧化沟工艺已经在国内外广泛采用。然而氧化沟延时曝气的运行方式及较低的设备效率导致其能耗高于传统活性污泥法。本文以国内氧化沟污水处理厂最常采用的Orbal氧化沟做为研究对象,通过对Orbal氧化沟能耗特征识别和工艺优化,以期为氧化沟污水处理厂的节能降耗探索有效途径。 国内14家典型实际规模氧化沟法城市污水处理厂能耗调查结果表明:污水厂能耗受处理规模、实际污水处理率、进水水质、工艺运行条件及处理水质要求等因素影响;用于氧化沟充氧和混合的能量是最高能耗环节,占整个污水处理厂总能耗的56~77%。实现氧化沟节能降耗的技术途径包括调整工艺结构、提高设备的动力效率、工艺优化,以此改善混合液流体力学性能并优化微生物微环境特性并提高微生物活性。 由于不合理的设计和运行,Orbal氧化沟存在着能耗较高、脱氮除磷效率较低的问题,为此提出并研究了一种强化脱氮除磷与节能的改良型Orbal氧化沟系统。273天的中试运行结果表明:通过溶解氧(DO)在线控制,TN的去除在Orbal氧化沟外沟成功实现;当DO约为0.2mg/L,系统总氮去除率最高可达80%以上。通过增加混合液内回流设备,将内回流比控制在900~1000%,可以进一步提高脱氮效率并降低能耗。通过排放来自厌氧浓缩池富磷浓缩上清液的方式可以在不影响脱氮效率的同时,增强Orbal氧化沟生物除磷效率,与传统Orbal氧化沟相比,生物除磷效率可提高50%。 在能耗特征调查及中试模拟研究的基础上,对一座实际Orbal氧化沟污水厂开展了工艺优化与节能降耗的生产试验以此提升出水水质并降低电耗。574天的生产试验结果表明:系统总充氧量和单一沟道用于输氧和推流的能量分配决定着Orbal氧化沟DO分布,进而导致氮和磷沿程转化及去除效率。Orbal系统外沟对于同时硝化、反硝化以及生物释磷具有重要作用。通过运行模式的优化调控及能量的合理分配,可以同时提高工艺效率并降低能耗。PCR-DGGE及基因测序结果表明:Orbal氧化沟外沟同时存在着厌氧菌和好氧菌及兼具硝化和反硝化的功能菌,尽管曝气模式会导致微生物数量和活性不同。 为深入了解Orbal氧化沟宏观和微观微环境工艺特性以优化和降低运行能耗,Orbal氧化沟外沟内的流态及传氧特征通过现场监测与计算流体力学(CFD)数值模拟方式进行识别,发现在圆形弯道存在着明显的二次螺旋流从而使得Orbal氧化沟着流场分布不均匀,螺旋流影响了混合和传氧效率,甚至整体处理性能。利用这种特殊的流态特征并适当控制充氧量,由于沟内传氧速率和耗氧速率可以创造出交替的缺氧/好氧区域,通过硝化和反硝化作用实现高效的脱氮效果并大大降低运行能耗。
英文摘要:      
      Energy-saving technologies during wastewater treatment have increasingly been paid attention as wastewater treatment is an energy-intensive industry. Oxidation ditch (OD) processes have widely researched and applied in the worldwide due to their simple structure and easy operation. However, energy consumption in OD was higher than that in conventional activated sludge processes due to its extended aeration and low equipment efficiency. As one of the most widely used ditch-type in OD process wastewater treatment plants (WWTPs) in China, Orbal oxidation ditch was chosen as a study object to explore effective measures for energy-saving in OD through the identification of energy consumption characteristics and process optimization. Investigations on energy consumption of fourteen typical full-scale OD WWTPs showed that energy consumptions were influenced by plant size, actual treatment efficiency, influent wastewater characteristics, operating conditions and treatment requirements and so on. Energy use for aeration and mixing of oxidation ditches was the highest component accounting for 56~77% of the total electricity power in WWTP. Technological approaches for energy saving in OD processes mainly included structure modification, devices improvement of and process optimization to improve hydromechanics performance of the mixed liquor and optimize microbial micro-environmental features and enhance microbial activities. Due to higher energy consumption and poor N and P removal efficiencies in Orbal oxidation ditches as a result of improper design and operation, an improved pilot-scale Orbal process system was developed and researched to enhance nitrogen and phosphorus simultaneously removals. The long-term operational results lasting for 273 days showed that TN removal in an Orbal oxidation ditch was successfully occurred in outer channel through dissolved oxygen (DO) online control. Maximum TN removal as high as above 80% was obtained at DO of about 0.2mg/L. Through the addition of internal mixed liquor recycling devices into the ditch, improved nitrogen removal capacity and reduced energy consumption were concurrently achieved when internal recycling ratio was kept at 900~1000%. Discharge of rich-P sludge concentrated supernatant from an anaerobic thickener was able to improve biological P removal by about 50% in comparison with conventional Orbal systems without adverse effects on nitrogen removal. On the basis of the analysis of energy consumption characteristics and the pilot-scale experiment, process optimization and energy-saving for the Orbal oxidation ditch were conducted in an actual full-scale domestic WWTP to enhance effluent qualities and reduce electricity consumptions. The 574-day full-scale experimental results showed the total oxygen input and oxygen input for each channel strongly influenced DO profiles in an Orbal ditch, which led to transformations of N and P and removal efficiencies along the each channel. The outer channel played an important role in nitrification, denitrification and P release in the Orbal system. Removal efficiencies of N and P were greatly influenced by total oxygen input and energy distribution for aeration and mixing within the single each channel of the Orbal oxidation ditch. Optimal treatment efficiency and economic energy use were simultaneously achieved through the optimization of aeration modes and proper distribution of energy input. PCR-DGGE and gene sequencing analysis demonstrated that anaerobic and aerobic bacteria as well as other nitrification and denitrification bacteria coexisted in the outer channel in despite of different microbial quantity and activity under two different aeration modes in an Orbal oxidation ditch. To deeply understand macro- and micro-environment process characteristics of an Orbal oxidation ditch to optimize and reduce operational energy consumptions. Flow pattern and oxygen transfer inside the outer channel of the Orbal ditch were identified and revealed using field measurements and CFD simulations. Non-uniform flow characteristics were found due to secondary flow (spiral flow) occurred in the circular channel which affected efficiencies of mixing and oxygen transfer, and even overall performance. With its particular flow pattern, alternation of anoxic and oxic conditions developed in non-aerated and aerated zones caused by the rates of oxygen transfer and consumption through suitable aeration control might be favorable for efficient nitrogen removal via nitrification and denitrification and largely reduce energy consumption.
内容类型: 学位论文
URI标识: http://ir.rcees.ac.cn/handle/311016/35094
Appears in Collections:水污染控制技术研究室_学位论文

Files in This Item:
File Name/ File Size Content Type Version Access License
Orbal氧化沟工艺特征与节能降耗研究.pdf(5609KB)学位论文--限制开放 联系获取全文

Recommended Citation:
周鑫. Orbal氧化沟工艺特征与节能降耗研究[D]. 北京. 中国科学院研究生院. 2012.
Service
Recommend this item
Sava as my favorate item
Show this item's statistics
Export Endnote File
Google Scholar
Similar articles in Google Scholar
[周鑫]'s Articles
CSDL cross search
Similar articles in CSDL Cross Search
[周鑫]‘s Articles
Related Copyright Policies
Null
Social Bookmarking
Add to CiteULike Add to Connotea Add to Del.icio.us Add to Digg Add to Reddit
所有评论 (0)
暂无评论
 
评注功能仅针对注册用户开放,请您登录
您对该条目有什么异议,请填写以下表单,管理员会尽快联系您。
内 容:
Email:  *
单位:
验证码:   刷新
您在IR的使用过程中有什么好的想法或者建议可以反馈给我们。
标 题:
 *
内 容:
Email:  *
验证码:   刷新

Items in IR are protected by copyright, with all rights reserved, unless otherwise indicated.

 

 

Valid XHTML 1.0!
Copyright © 2007-2018  中国科学院生态环境研究中心 - Feedback
Powered by CSpace