知到答案Environmental Biotechnology智慧树答案_2022年

第七章

Advantages of anaerobic treatment include ( ) .
答案:High organic loading is possible.;Produce useful end products. ;Low production of waste biological solids.
The successful start-up and operation of an anaerobic system requires: ( ).
答案:Begin with as much good anaerobic seed as possible.;Add buffering material in the form of chemical to protect against pH drop.;Bring the system to temperature.;Fill the digester with seed and water.
Possible methods to control toxicity in anaerobic treatments: ( ).
答案:Maintaining a lower pH can reduce ammonia toxicity.;The toxicity of sulfide can be reduced by gas stripping from the reactor.;The toxicity of long-chain fatty acids can be reduced by calcium.;The toxicity of some heavy metals can be removed by addition of sulfide.
Which of the following statements is false about the characteristics of baffled reactor: ( ).
答案:Design loading typically is in the range of 4 to 15 kg COD/m3-d.
Estimating the methane production of anaerobic treatment process for wastewater containing 1.0 M glucose: ( ).
答案:2.4 mol.
The process of anaerobic treatment can be broken into which of the following steps: ( ).
答案:Hydrolysis and fermentation of complex organic matter into simple organic acid and hydrogen.;The conversion of the organic acids and hydrogen into methane.
An absolute minimum value of θx to allow stable methanogenesis for a CSTR is: ( ).
答案:10 day.
The contents of the digester can be heated through: ( ).
答案:Pumping back warmed sludge through external heat exchangers;Heat exchangers located inside the digester.;Injected steam through lances or diffusers.
The primary design criterion of CSTR contains: ( ).
答案:The volatile-solids loading rate.;Detention time.
The routine measurement of volatile acid concentration is of great-importance in the operation and control of anaerobic system.（ ）
答案:对
About 15 to 20 percent of the organic matter is converted into biological solids in anaerobic treatment.（ ）
答案:错