Statement (I): Anaerobic sludge digester, by itself, is considered to be the better method than other methods of sludge treatment: Statement (II): During anaerobic sludge digestion, CH4 is produced; also rodents and other pests are attracted when digester sludge is dried. 

Statement (I): Anaerobic sludge digester, by itself, is considered to be the better method than other methods of sludge treatment: Statement (II): During anaerobic sludge digestion, CH4 is produced; also rodents and other pests are attracted when digester sludge is dried.  Correct Answer Statement (I) is true<strong>;</strong> but Statement (II) is false

The anaerobic sludge digester is a better method for handling the sludge because it produces a large amount of energy in the form of Methane.  It also reduces the nuisance of digested sludge and reduces the vectors such as rodents, flies etc. attraction towards sludge.

∴ Statement I is true and Statement II is false

Other points about gas production in anaerobic sludge digester:

1. Out of total volatile solids, 65 % are induced to gasses and 35 % formed in digested sludge.

2. The total volume of gasses formed during digestion is either 0.6 m3/kg of Volatile solids or 0.9 m­3 /kg of volatile solids reduce to gasses.

3. Out of the total gasses formed 70 % is methane (CH4) and 30 % is Carbon Dioxide (CO2). 

Related Questions

In which secondary treatment of sewage treatment sludge is broken down in an anaerobic digester?
Statement (I): When waste water is treated at an oxidation ditch, anaerobic sludge digester is not required. Statement (II): Oxidation ditch admits an extended aeration process whereby sludge gets mineralized.