Q1: The recommended detention period for grit chambers is

ANS:A - 1 minute

A detention period of 1 minute for a grit chamber would be exceptionally short and is generally not considered sufficient for effective grit removal in wastewater treatment processes. Grit chambers are designed to allow heavier particles, such as sand, gravel, and other abrasive materials, to settle out of the wastewater before it continues through the treatment process. A detention time of only 1 minute would not provide adequate time for these heavier particles to settle and be removed from the wastewater stream effectively. In wastewater treatment design, detention times for grit chambers are typically longer, often around 2 to 5 minutes or more, to ensure thorough removal of grit and other suspended solids. Longer detention times allow for more effective settling of particles, resulting in cleaner effluent and reduced wear and tear on downstream equipment. Therefore, while a 1-minute detention time may be mentioned in some contexts, it is not generally recommended or practical for grit chamber design in wastewater treatment systems.