Statistics for Texas Waste Water Treatment #11 Sludge Digestion Dewatering & Disposal

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General Stats

This quiz has been taken 24 times
The average score is 15 of 20

Answer Stats

Question	Answer	% Correct
Sludge types may include the following: ________.	activated	100%
Anaerobic digester mixing methods include which of the following?	Gas AND mechanical mixing	100%
The purpose of sludge digestion is to _________.	stabilize the organic matter	100%
Digester gas should contain which of the following?	65%–75% methane	91%
The proper pH for anaerobically digested sludge will ________.	be from 6.8–7.4	91%
A cause of poor quality supernatant liquor could be ________.	digester overload	91%
The digester temperature should not change more than ________.	l°C per day	91%
Primary volatile acids are converted by methane bacteria to which of the following?	Methane AND carbon dioxide	91%
Scum in a digester is mostly ________.	undigested grease	91%
Digester gas may be used to ________.	heat digesters	82%
A minimum value of ________ of oxygen should be maintained in the aerobic digester at all times.	1.0 mg/L	73%
Which of the following is a factor that influences the operation of sludge thickeners?	All of the above	73%
Which of the following processes are used to dewater sewage sludge?	All of the above	73%
Digester trouble signs include which of the following?	Increase in pH AND Decrease in volatile solids reduction	73%
The depth of sludge drawn to a drying bed should be ________.	about 9 in.	55%
The moisture content of sludge transported to a municipal landfill should be less than ________.	80%	45%
Since the majority of ________ digesters are open tanks, digester liquid temperatures are dependent on weather conditions and can fluctuate extensively.	aerobic	45%
Sludge drying time is affected most by which of the following?	Degree of digestion	45%
Sludge conditioning is the process of removing water by thickening or by adding polymers or ________ materials to improve the loading rate.	inorganic	45%
The most expensive method for the final disposal of sludge is ________.	incineration	36%