华东师范大学期末试卷（B） 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 list the main purposes of BOD5 test for wastewater treatment and waterbody remediation. Please discuss the effects of temperature of wastewater on its treatment unit unit/process selection(in English, 15%). 2. Please discuss the differences between absorption and adsorption and list their applications industrial wastewater treatment(in English, 15%). 3. What are the principal benefits of flow equalization in the wastewater treatment processes? (in English, 15%) 4. Please draw a schematic diagram of nitrogen cycle in the aquatic environment, discuss the main sources of nitrogen pollutants found in municipal wastewaters and list their harmful effects on ecological and environmental systems(in Chinese, 20%). 5. The average flowrate at a small wastewater treatment plant is 10000 m3/d. Design a rectangular primary settler with a channel width of 6m and depth of 4m. Use an overflow rate of 40m3/m2.d. Determine its length, volume, detention time and surface area required(in Chinese, 20%). 6. Constrast disssovled-air flotation with sedimentation and discuss their following parameters: (1)detention time; (2)surface-loading rate; (3)power input; (4)SS removal efficiency; (4)favorable applications for each type(in Chinese, 15%). 标准答案： 1. The most widely used parameter of organic pollution applied to both wastewater and surface water is the 5 day BOD (BOD). This determination involves the measurement of the dissolved oxygen used by microorganisms in the biochemical oxidation of organic matter. The purposes of BOD test are (1) to determine the approximate quantity of oxygen that will be required to biologically stabilize the organic matter present, (2) to determine the size of waste treatment facilities, (3) to measure the efficiency of some treatment processes, and (4) to determine compliance with wastewater discharge permits. High efficient wastewater treatment is got when T is suitable for microbial growth and metabolism. The Suitable range for T is 20~20℃. When T is lower than 10℃, organic pollutants, ammonia nitrification etc will be weak. T also affects the efficincy of oxygen dissolving into wastewater. 2. Adsorption means the attachment of molecules to the surface of a solid. In contrast, absorption means the dissolution of molecules within a collecting medium, which may be liquid or solid. Generally, absorbed materials are dissolved into the absorbent, like sugar dissolved in water, whereas adsorbed materials are attached onto the surface of a material, like dust on a wall. Absorption mostly occurs into liquids, adsorption mostly onto solids. This section deals only with adsorption onto the surface of a solid adsorbent. 3. Flow equalization is a method used to overcome the operational problems caused by flowrate variations, to improve the performance of the downstream processes, and to reduce the size and cost of down- stream treatment facilities. Flow equalization simply is the damping of flowrate variations to achieve a constant or nearly constant flowrate and can be applied in a number of different situations, depending on the characteristics of the collection system. The principal applications are for the equalization of (1) dry-weather flows to reduce peak flows and loads, (2) wet-weather flows in sanitary collection systems experiencing inflow and infiltration, or (3) combined stormwater and sanitary system flows. 4. 有机氮、氨氮、亚硝酸盐氮、硝酸盐氮；水体富营养化；水体黑臭；增加制水成本；氨氮和硝态氮的生物毒性。 5. 沉淀池的表面积F＝2000÷40＝50（m2）；沉淀池有效容积V＝50×4＝200（m3）；沉淀池有效水深H＝200÷（6×4）＝8.33（m）；HRT＝200×24÷10000＝0.48（h）。 6. 停留时间：沉淀池－长；气浮池－短； 表面负荷率：沉淀池－低；气浮池－高； 能耗：沉淀池－低；气浮池－高； SS去除率：二者相近； 适用场合：沉淀池－沉沙池、初沉池、二沉池，金属废水处理；给水处理。气浮池：除油；生化污泥；造纸废水处理等。