《氧化沟外文翻译》word版.docx

外文资料翻译Oxidation ditches 1. Introduction Oxidation ditch and continuous circular aeration tank, deformation is one of the activated sludge process. Oxidation ditch sewage treatment technology is successfully developed by the Dutch in the 1950 s and health engineering. Put into use in the Netherlands for the first time since 1954. Due to its good effluent water quality, steady operation, convenient management and other technical characteristics, has been widely used both at home and abroad in domestic sewage and industrial wastewater treatment. The types of the oxidation ditch has been widely applied at present include: pass, oxidation ditch, the Carrousel oxidation ditch, Mr. Bell oxidation ditch, T oxidation ditch, three groove type oxidation ditch, and the integration of DE type oxidation ditch and oxidation ditch. The oxidation ditch because of the differences on the structure and operation, so each has its characteristics. This paper will mainly introduce Carrousels structure, the mechanism of the oxidation ditch, the existence question and its latest development. 2. The structure of Carrousel oxidation ditch Carrousel oxidation ditch is DHV Company developed in 1967 by the Dutch. On the basis of the original Carrousel oxidation ditch DHV EIMCO its patented in the United States Company and created the Carrousel 2000 System, realizes the higher requirements of biological denitrification and phosphorus removal function. By far the world has more than 850Carrousel oxidation ditch and Carrousel 2000 System is running. Carrousel oxidation ditch with directional control of aeration and agitation device, the mixture transfer horizontal velocity, which was stirring the mixture of circulating in the oxidation ditch channels closed. Oxidation ditch has special hydraulic flow state, therefore, has the characteristics of both the completely mixed reactor and has the characteristic of push flow reactor, groove exists obvious dissolved oxygen concentration gradient. Oxidation ditch cross section is rectangular or trapezoidal, plane shape is oval, more groove depth is generally 2.5 4.5 m, width depth ratio is 2:1, also have a depth of up to 7 m, ditch water an average speed of 0.3 m/s. Oxidation ditch aeration mixing equipment have surface aerator, aeration brush or turntable, jet aerator, catheter type aerator and riser type aerator etc., also used underwater driver in recent years. 3. The mechanism of Carrousel oxidation ditch 3.1 Carrousel oxidation ditch sewage treatment principle The original Carrousel oxidation ditch process with reflux sludge sewage directly into the oxidation ditch System. Dissolved oxygen in surface aerator make mixture the DO concentration increased to about 2 3 mg/L. Under the condition of the fully mixed oxygen, get enough dissolved oxygen to remove BOD microbial; at the same time, nitrate and nitrite, ammonia was oxidized to at this point, the mixture in aerobic condition. By aeration zone in the downstream of the aerator, water turbulence state into a state of advection, maintained at a minimum velocity of flow, ensure that activated sludge in a suspended state ( 0.3 m/s) average velocity. Microbial oxidation process consumes dissolved oxygen in water, until the value to zero in the DO, mixture in hypoxia state. 3. The CD method and application widely in the large-span tunnel, the CRD construction method in this System, BOD degradation is a continuous process, nitrification and denitrification occurred in the same pool. Because of the limitation of structure of the oxidation ditch can be effective for BOD, but phosphorus removal denitrification ability is limited. 3.2 Carrousel Moseley oxidation ditch the influence factors of biological nitrogen removal Influence factors of phosphorus removal from Carrousel Moseley oxidation ditch is primarily a sludge age, nitrate concentration and substrate concentration. Research shows that when the total sludge age of 8 10 d, the lions share of the activated sludge phosphorus content is 4% of the dried sludge quantity, 11% of the quality of heterotrophic bacteria, but when sludge in sludge age more than 15 d maximum phosphorus content significantly decreased, but cannot meet the maximum phosphorus removal effect. So blindly extend sludge age (for example, 20, 25 d, 30 d d) is not necessary, appropriate within 8 15 d choose. At the same time, high nitrate concentration and low substrate concentration of phosphorus removal process. 4. Carrousel Moseley oxidation ditch existing problems and solutions Though Carrousel Moseley oxidation ditch have effluent water quality is good, strong ability to resist impact load, high efficiency of nitrogen removal and sludge is stable, power consumption province, easy to automatic control, etc. However, in the actual operation process, a series of problems still exist. 4.1 Sludge bulking problem When carbohydrates in the waste water is more, N, P content in imbalance, low pH, high oxidation ditch in sludge load, dissolved oxygen concentration, dredge not free and easy to sludge bulking caused by filamentous bacteria sex; Non filamentous bacteria mainly in wastewater sludge bulking sludge load at high temperature is low. Microbial load is high, the bacteria absorb a large amount of nutrients, because of the low temperature, metabolic speed is slow, product storage on a large amount of high viscosity polysaccharide substances, the adhered on the surface of the activated sludge in the water increase greatly, SVI value is very high, the formation of sludge bulking. Aiming at the cause of sludge bulking, can adopt different countermeasures: caused by a lack of oxygen, high water temperature, can increase air or cut into the water to lighten the load, or decrease the MLSS (control sludge return flow), reduce oxygen demand; Such as sludge loading is too high, can improve the MLSS, in order to adjust the load, when necessary to stop water, boring exposure for a period of time; Can be adjusted by adding the nitrogen fertilizer, phosphate fertilizer, mixture of nutrient balance (BOD5: N: P = 100:5); PH value is too low, but adding the lime to adjust; Chlorine bleaching powder and liquid (0.3% 0.6% in dry sludge dosing), inhibit filamentous fungi reproduction, combined with water sludge bulking control. 4.2 Bubble problem Due to water with a large number of oil, processing System cant effectively remove it completely, part of the oil concentration in the sludge, turn the brush oxygen filling mixing, produce a large number of bubbles; The sludge age slightly long, sludge aging, also easy to produce foam. With surface spray water or remove foam deforming agent, deforming agent commonly used engine oil, kerosene, silicone oil, turnover of 0.5 1.5 mg/L. By increasing the sludge concentration in aeration or reduced air, also can effectively control the bubble. When the wastewater contains surface active material is large, easily removed by foam separation process or other method in advance. Also can consider adding a set of oil removal device. But the most important is the better water management, reduce the high oil-bearing wastewater and other toxic wastewater into. 4.3 Sludge up-floating problem When the oil content in waste water is too large, qualitative light, the whole System in the process of operation cant well control the residence time in the second pond, easy cause lack of oxygen, produce sludge up-floating decay; When the aeration time is too long, high nitrification occurred in the pool, the nitrate concentration is high, in the second pond, prone to denitrification, produce nitrogen gas, sludge floating; In addition, the oil content in the waste water is too large, the sludge may carry oil to rise. After sludge floating water shall be suspended, break or removal of the sludge, ascertain the reason, adjust the operation. Sludge settle ability is poor, can dosing coagulant or inert material, improve the precipitation; Such as water load should be reduced into water or step back flow; Such as the sludge particles small can decrease the aerator speed; Denitrification is found, should reduce air, increasing the backflow or mud; Sludge decay is found, should increase air, and clean up mud, hydraulic conditions and try to improve in the pool. 4.4 And uneven velocity of sludge deposition problem In Carrousel Moseley oxidation ditch, for its unique mixing and processing results, the mixture must be circulating in the groove at a certain velocity. It is generally believed that the minimum flow rate should be 0.15 m/s, the average velocity of sedimentary does not occur should be 0.3 0.5 m/s. Oxidation ditch aeration equipment generally brush turn for aeration and aeration rotary brush turns the submerged depth of 250 300 mm, submerged depth of the wheel is 480 530 mm. With oxidation ditch depth (3.0 3.6 m), compared to brush only 1/10 1/12 of the water depth, turntable also accounts for only 1/6 1/7, so the oxidation ditch caused by upper flow velocity is larger (about 0.8 1.2 m, or even more), and at the bottom of the flow rate is small (especially in depth below two-thirds or 3/4, mixture had little velocity), the cause of a large number of mud (sometimes mud thickness up to 1.0 m), greatly reduces the effective volume of oxidation ditch, reduces the treatment effect, influence the effluent water quality. Upstream or downstream equipped with guide plate is to improve the velocity distribution, the effective method to improve aerobic capacity, and the most convenient measures. Guide plate installed upstream from the rotary axis of turn (brush) 4.0 (upstream), the guide plate height of water depth of 1/5 1/6, and perpendicular to the surface installation; Downstream of the guide plate is installed in is apart from the wheel turn (brush) axis of 3.0 m. Guide plate material can be made of metal or glass reinforced plastics, but is better to glass fiber reinforced plastic. Guide plate compared with other measures for improvement, not only does not increase the power consumption and operating costs, but also can greatly improve the efficiency of oxygen transfer ability and the theory of motivation. In addition, through setting underwater in the aerator upstream driver can also turn on aeration brush at the bottom of the low speed region mixture flow circulation play a positive role, so as to solve oxidation ditch of velocity is low, the sludge sedimentation problem. Set the underwater vehicle is dedicated to promoting mixture operation mode of oxidation ditch can be more flexible; to save energy and improve efficiency is of great significance. 5. The development of Carrousel oxidation ditch Due to biological nitrogen removal in sewage treatment standard requirements more and stricter, Carrousel Moseley oxidation ditch also got further development. At present, the research and application more consists of the following two types: type micro porous aeration Carrousel 2000 System, Carrousel 3000 System. 5.1 Microporous aeration Carrousel 2000 System Microporous aeration Carrousel 2000 System using Microporous aeration (oxygen supply equipment for blower), the Microporous aeration device can produce a large number of tiny air bubble diameter of 1 mm or so, which greatly improved the bubble surface area, and makes the pool volume increase certain cases total oxygen transfer (such as pool depth increases the mass transfer efficiency will be higher). According to the current technical ability of blower manufacturer, pool the effective depth of up to 8 m, so can according to different technological requirements to select suitable water depth. Push of traditional oxidation ditch flow is to use brush, disc or inverted umbrella table exposure machine, its low equipment utilization rate, low power consumption. Microporous aeration Carrousel 2000 System is used underwater flow way, namely fixed the propeller driving force generated in the impeller directly ACTS on the water, while pushing flow effect and can effectively prevent the sedimentation of sludge. Thus, adopting the submarine propeller both reduces the power consumption, and mud got fully combined. 5.2 Carrousel 3000 System Carrousel 3000 System is in front of the Carrousel 2000 System combined with a biological selection area. The biological selection area is the screening of strains with high organic load, suppress the growth of filamentous bacteria, and improve the removal rate of each pollutant, the subsequent process principle with Carrousel 2000 System. Carrousel s considerable improvement in performance in 3000 Systems: one is to increase the pool is deep, can reach 7.5 8 m, concentric circles type, wall sharing, reduce cover an area of an area, reduce cost and at the same time could improve the ability of resistance to low temperature (up to 7 ); Second, the clever design of the aeration equipment, table under exposure machine installation guide tube, suction oxygen mixture, using underwater propeller flow problem; Three is the use of the advanced QUTE aeration controller (it USES a kind of multivariable control mode). Four is to use integration design, starting from the center; continuous process unit consists of the following rings: into the Wells and to return water segregator of activated sludge; consists of four parts selection pool and bio-p tank respectively. It is outside has three aerator and a pre denitrifying pool, resell 2000 System (see figure 2). Five is round integration design makes the oxidation ditch without additional pipeline, backflow sludge can be realized in the allocation between different process units. 6. Conclusion Carrousel oxidation ditch due to the phosphorus denitrogenation ability, with good resistance to impact load capacity and convenient operation and management, has been widely used. But due to the development of science and technology and the progress of the society, the technology will further improve. The author thinks: Carrousel Moseley oxidation ditch of future research will be mainly reflects in the following respects. 1) Combined with biological membrane method, research and development model organism Carrousel Moseley oxidation ditch. Amount of microorganisms which can not only improve unit reactor, thereby increasing organic load, and the biofilm itself With A built-in A/O System to strengthen the denitrification effect. 2) Improve Carrousel Moseley oxidation ditch in the activity of microorganisms. Such as add EM specificity in the oxidation ditch, put iron make microorganism domestication into biological iron and activated carbon increase zoogloea form and improve resistance to toxic shock, etc. 3) Improve the Carrousel Moseley oxidation ditch equipment performance and monitoring technology. Improve the performance of table exposure machine, underwater propeller, reduce maintenance workload; using multi-objective monitoring technology such as DO and ORP and frequency conversion technology is the future Carrousel Moseley oxidation ditch science run way. 4) Improve Carrousel Moseley oxidation ditch can cold resistant, high toxicity, reduce area and project cost. Membrane theory application, deep water power condition and the process performance of hardy in order to reduce the project cost, improving the resistance to toxicity can provide the possible direction. 中文翻译氧化沟1.前言氧化沟又名连续循环曝气池，是活性污泥法的一种变形。氧化沟污水处理工艺是20世纪50年代由荷兰卫生工程研究所研制成功的。自从1954年在荷兰的首次投入使用以来。由于其出水水质好、运行稳定、管理方便等技术特点，已经在国内外广泛的应用于生活污水和工业污水的治理。目前应用较为广泛的氧化沟类型包括：帕斯韦尔氧化沟、卡鲁塞尔氧化沟 、奥贝尔氧化沟、T型氧化沟（三沟式氧化沟）、DE型氧化沟和一体化氧化沟。这些氧化沟由于在结构和运行上存在差异，因此各具特点。本文将主要介绍卡罗塞尔氧化沟的结构、机理、存在的问题及其最新发展。2.卡罗塞尔氧化沟的结构卡罗塞尔氧化沟是1967年由荷兰的DHV公司开发研制。在原卡罗塞尔氧化沟的基础上DHV公司和其在美国的专利特许公司EIMCO又发明了卡罗塞尔2000系统，实现了更高要求的生物脱氮和除磷功能。至今世界上已有850多座卡罗塞尔氧化沟和卡罗塞尔 2000系统正在运行。卡罗塞尔氧化沟使用定向控制的曝气和搅动装置，向混合液传递水平速度，从而使被搅动的混合液在氧化沟闭合渠道内循环流动。因此氧化沟具有特殊的水力学流态，既有完全混合式反应器的特点，又有推流式反应器的特点，沟内存在明显的溶解氧浓度梯度。氧化沟断面为矩形或梯形，平面形状多为椭圆形，沟内水深一般为2.54.5，宽深比为2:1，亦有水深达7m的，沟中水流平均速度为0.3m/s。氧化沟曝气混合设备有表面曝气机、曝气转刷或转盘、射流曝气器、导管式曝气器和提升管式曝气机等，近年来配合使用的还有水下推动器。3. 卡罗塞尔氧化沟的机理3.1 卡罗塞尔氧化沟处理污水的原理最初的普通卡罗塞尔氧化沟的工艺中污水直接与回流污泥一起进入氧化沟系统。表面曝气机使混合液中溶解氧DO的浓度增加到大约23mg/L。在这种充分掺氧的条件下，微生物得到足够的溶解氧来去除BOD；同时，氨也被氧化成硝酸盐和亚硝酸盐，此时，混合液处于有氧状态。在曝气机下游，水流由曝气区的湍流状态变成之后的平流状态，水流维持在最小流速，保证活性污泥处于悬浮状态（平均流速0.3m/s）。微生物的氧化过程消耗了水中溶解氧，直到DO值降为零，混合液呈缺氧状态。经过缺氧区的反硝化作用，混合液进入有氧区，完成一次循环。该系统中，BOD降解是一个连续过程，硝化作用和反硝化作用发生在同一池中。由于结构的限制，这种氧化沟虽然可以有效的去处BOD，但除磷脱氮的能力有限。3.2 卡罗塞尔氧化沟除磷脱氮的影响因素影响卡罗塞尔氧化沟除磷的因素主要是污泥龄、硝酸盐浓度及基质浓度。研究表明，当总污泥龄为810d时活性污泥中的最大磷含量为其干污泥量的4%，为异养菌体质量的11%，但当污泥龄超过15d时污泥中最大含磷量明显下降，反而达不到最大除磷效果。因此，一味延长污泥龄（例如20d、25d、30d）是没有必要的，宜在815d范围内选用。同时，高硝酸盐浓度和低基质浓度不利于除磷过程。4. 卡罗塞尔氧化沟存在的问题及解决方法尽管卡罗塞尔氧化沟具有出水水质好、抗冲击负荷能力强、除磷脱氮效率高、污泥易稳定、能耗省、便于自动化控制等优点。但是，在实际的运行过程中，仍存在一系列的问题。4.1 污泥膨胀问题当废水中的碳水化合物较多，N、P含量不平衡，pH值偏低，氧化沟中污泥负荷过高，溶解氧浓度不足，排泥不畅等易引发丝状菌性污泥膨胀；非丝状菌性污泥膨胀主要发生在废水水温较低而污泥负荷较高时。微生物的负荷高，细菌吸取了大量营养物质，由于温度低，代谢速度较慢，积贮起大量高粘性的多糖类物质，使活性污泥的表面附着水大大增加，SVI值很高，形成污泥膨胀。针对污泥膨胀的起因，可采取不同对策：由缺氧、水温高造成的，可加大曝气量或降低进水量以减轻负荷，或适当降低MLSS（控制污泥回流量），使需氧量减少；如污泥负荷过高，可提高MLSS，以调整负荷，必要时可停止进水，闷曝一段时间；可通过投加氮肥、磷肥，调整混合液中的营养物质平衡（BOD5：N：P=100：5：1）；pH值过低，可投加石灰调节；漂白粉和液氯（按干污泥的0.3%0.6%投加），能抑制丝状菌繁殖，控制结合水性污泥膨胀。4.2 泡沫问题由于进水中带有大量油脂，处理系统不能完全有效地将其除去，部分油脂富集于污泥中，经转刷充氧搅拌，产生大量泡沫；泥龄偏长，污泥老化，也易产生泡沫。用表面喷淋水或除沫剂去除泡沫，常用除沫剂有机油、煤油、硅油，投量为0.51.5mg/L。通过增加曝气池污泥浓度或适当减小曝气量，也能有效控制泡沫产生。当废水中含表面活性物质较多时，易预先用泡沫分离法或其他方法去除。另外也可考虑增设一套除油装置。但最重要的是要强水资源管理理，减少含油过高废水及其它有毒废水的进入。 4.3 污泥上浮问题当废水中含油量过大，整个系统泥质变轻，在操作过程中不能很好控制其在二沉池的停留时间，易造成缺氧，产生腐化污泥上浮；当曝气时间过长，在池中发生高度硝化作用，使硝酸盐浓度高，在二沉池易发生反硝化作用，产生氮气，使污泥上浮；另外，废水中含油量过大，污泥可能挟油上浮。发生污泥上浮后应暂停进水，打碎或清除污泥，判明原因，调整操作。污泥沉降性差，可投加混凝剂或惰性物质，改善沉淀性；如进水负荷大应减小进水量或加大回流量；如污泥颗粒细小可降低曝气机转速；