Question

The masses of bacteria held together by slime and fungal filaments to form mesh-like structures are called as
A. Primary sludge
B. Flocs
C. Activated sludge
D. Anaerobic sludge

Answer 1

Hint: Slimy masses of microorganisms are formed in the process of sludge generation during wastewater treatment.
It occurs due to aeration and rapid growth of microbes in the primary effluent.

Complete answer: Let us discuss all the above mentioned options.
1. Primary sludge is formed due to the accumulation of suspended solids such as grit, grease, etc. from wastewater.
2. Some organic molecules may also be captured by the primary process of sedimentation.
3. Activated sludge means the suspended aerobic sludge that contains a high concentration of microorganisms such as bacteria.
4. It is basically activated waste biomass and referred to as secondary sludge.
5. When the primary sludge effluent is passed onto the aeration tanks, the random growth of aerobic microbes takes place that results in the formation of flocs.
6. Flocs are slimy masses of bacteria along with fungal filaments.

So, the correct option is B. flocs

Note: Sludge is a semi-solid substance formed due to the physical removal of industrial waste particles by filtration and sedimentation processes.
It is an important part of sewage management in urban areas.