华东师范大学期末试卷（A） 200×—200× 学年第二学期 课程名称：_环境工程概论（双语） 学生姓名：___________________ 学 号：___________________ 专 业：___________________ 年级/班级：__________________ 课程性质：公共必修、公共选修、专业必修、专业选修 一 二 三 四 五 六 七 八 总分 阅卷人签名              样题： 1. Please draw a schematic diagram of the municipal wastewater treatment process and explain in details the principles involved in each treatment step(in English, 20%). 2. A rectangular settling tank has a wastewater flowrate of 3000m3/d and dimensions of 3m deep by 5m wide by 10m long. The SS concentration of the wastewater is 200mg/L. Please determine its:(1)hydraulic retention time; (2)overflow rate(surface area); (3)SS loading rate. If the SS removal efficiency is 50%, please determine the SS quantity removed daily(in Chinese, 20%). 3. What are the purposes of aeration in wastetwater treatment. List the types of aerators and discuss their advantages and disadvantages(in English, 15%). 4. What are the differences between aerobic biological transformations(aerobic compost) and anaerobic biological transformations(anaerobic compost) of municipal solid wastes?(definition, reaction equation, biological conversion step, corresponding organisms, environmental factors) (in Chinese, 20%) 5. Please discuss the purposes of microscopic observation of activated sludge for wasterwater biological treatment systems(in English, 10%) 6. Please list the four types of gravitational sedimentations and discuss their characteristics and occurrences in wastewater treatment(in Chinese, 15%). 标准答案 1. (1)flow diagram (2)principles of each step Treatment unit Principles and functions  Screens, grit channels, primary settling tanks (Preliminary and primary treatment units) Removing pollutants(rags, sticks, floatables, grit, grease, sands, suspended solids etc) by physical processes(mechanical retention, filtration, gravitational sedimentation).  Activated sludge aeration tanks and biofilm filters(Secondary treatment units) Removal of biodegradable organics, suspended solids, N/P nutrients by microbial adsorption, assimilation, degradation and transformation.  GAC adsorption, chemical oxidation(Advanced treatment) Enhanced removal of suspended solids, color and organic matter from the wastewater. Typically accomplished by chemical addition or filtration or adsorption.  Disinfection Application of chemicals such as chlorine gas for killing harmful microbes.  2. (1)V=3m×5m×10m=150(m3), HRT=150÷3000×24(h)=1.2(h); (2)3000 m3/d÷(10m×5m)=60 m2/d=2.5 m2/h; (3) 3000 m3/d×200mg/L=600kg/d; (4)600kg/d×50%=300 kg/d 3. Purposes: (1) satisfy the bCOD of the waste, (2) satisfy the endogenous respiration by the biomass, (3) satisfy the oxygen demand for nitrification, (4) provide adequate mixing, and (5) maintain a minimum dissolved oxygen concentration throughout the aeration tank Types: (1)fine bubble type(panel/dome/membrane, very high transfer efficiency); (2)coarse bubble type(low transfer efficiency); (3)static tube mixers/aerators(medium transfer efficiency); (4)rotor brush/disk(low transfer efficiency); (5)cascade type(low transfer efficiency); (6)slotted tube(low transfer efficiency). 4. 城市有机生活垃圾的堆肥处理分厌氧和好氧两种类型。前者主要是指在缺氧或绝对厌氧条件下有机物发生的生化反应，具有速度慢、转化不彻底、臭味较重等问题。后者是城市有机生活垃圾堆肥的主要方法，其反应过程主要包括有机碳的降解和转化、有机氮的分解，形成的堆肥产品中腐殖酸及无机氮磷含量较高，经好氧堆肥后病原体得到有效杀灭，堆肥产品可以作为优质肥料和土壤改良剂用于农林业生产，好氧堆肥的控制条件主要有温度、垃圾含水率、通风和供氧、搅拌、微生物菌剂等。 5. Routine microscopic observations provide valuable monitoring information about the condition of the microbial population in the activated-sludge process. Specific information gathered includes changes in floc size and density the status of filamentous organism growth in the floc, the presence of Nocardia bacteria, and the type and abundance of higher life-forms such as protozoans and rotifers. Changes in these characteristics can provide an indication of the changes in the wastewater characteristics or of an operational problem. A decrease in the protozoan population may be indicative of DO limitations, operation at a lower SRT inhibitory substances in the wastewater. Early detection of filamentous or Nocardia growth will allow time for corrective action to be taken to minimize potential problems associated with excessive growth of these organisms. Procedures may be followed to identify the specific type of filamentous organism, which may help identify an opeating or design condition that encourages their growth. 6.（1）自由（离散）沉淀：沉沙池、初沉池初期；固体颗粒絮凝性差、粒径较大、浓度较低，沉淀过程中互不干扰，独立完成沉淀过程。 （2）絮凝沉淀：初沉池后期、二沉池初期；固体颗粒有明显的絮凝性，沉淀过程中通过絮凝作用使得粒径越来越大、沉淀越来越快。 （3）成层沉淀：二沉池后期；固体颗粒浓度较高，相互干扰严重，小颗粒和大颗粒拥阻在一起形成沉淀层，颗粒的沉淀从外观上看是该层的沉降。 （4）压缩沉淀：污泥浓缩池。固体浓度很高，因固体颗粒下沉，污泥中游离态水和颗粒间隙水被逐渐压出，污泥得以浓缩。