Environmental Biotechnology章节测试课后答案2024春

第七章测试

1.Advantages of anaerobic treatment include ( ) .
A:Low production of waste biological solids. B:Produce useful end products. C:High organic loading is possible. D:High removal efficiency with dilute wastes.
答案:ABC
2.The successful start-up and operation of an anaerobic system requires: ( ).
A:Bring the system to temperature. B:Add buffering material in the form of chemical to protect against pH drop. C:Fill the digester with seed and water. D:Begin with as much good anaerobic seed as possible. 3.Possible methods to control toxicity in anaerobic treatments: ( ).
A:The toxicity of long-chain fatty acids can be reduced by calcium. B:The toxicity of sulfide can be reduced by gas stripping from the reactor. C:The toxicity of some heavy metals can be removed by addition of sulfide. D:Maintaining a lower pH can reduce ammonia toxicity. 4.Which of the following statements is false about the characteristics of baffled reactor: ( ).
A:A recycle line can be added to remove biosolids from the last chamber and return them to the first. B:Design loading typically is in the range of 4 to 15 kg COD/m3-d. C:Overcome the biosolids loss from the UASB system. D:Wastewater moves upward and downward. 5.Estimating the methane production of anaerobic treatment process for wastewater containing 1.0 M glucose: ( ).
A:0.24 mol. B:2.64 mol. C:2.4 mol. D:3.36 mol. 6.The process of anaerobic treatment can be broken into which of the following steps: ( ).
A:The conversion of the organic acids and hydrogen into methane. B:Hydrolysis and fermentation of complex organic matter into simple organic acid and hydrogen. C:The simple carbohydrates and acids are utilized to obtain energy for growth by fermenting bacteria. D:The organic acids are then partially used by archael methanogens to convert them into methane. 7.An absolute minimum value of θx to allow stable methanogenesis for a CSTR is: ( ).
A:20 day. B:5 day. C:10 day. D:15 day. 8.The contents of the digester can be heated through: ( ).
A:Injected steam through lances or diffusers. B:Heat exchangers located inside the digester. C:Pumping back warmed sludge through external heat exchangers D:Direct heating the reactor. 9.The primary design criterion of CSTR contains: ( ).
A:Detention time. B:The net sludge production. C:The methane-gas yield. D:The volatile-solids loading rate. 10.The routine measurement of volatile acid concentration is of great-importance in the operation and control of anaerobic system.（ ）
A:错 B:对 11.About 15 to 20 percent of the organic matter is converted into biological solids in anaerobic treatment.（ ）
A:对 B:错