Environmental Engineering (Part-4) (General Engineering) (SSC JE)

Alkalinity–It is capacity to neutralise acid.

Sedimentation–
• It is the process of removal of suspended particle from water.
• Sedimentation is based on Stoke's law.
• It is assume that discrete setting take place during settlement.

Slow sand filter–
• Filter median used fine sand, anthracite, garnel, activated carbon, geo-textile.
• Gravel layer is provided to support sand median
• Depth of sand 90-110 cm.

The primary treatment for domestic sewage consists of the removal of suspended particles.
• These are removed initially by sequential filtration which removes the floating debris and grit is removed by sedimentation.
• The objective of secondary treatment is the further treatment of the effluent from primary treatment to remove the residual organics and suspended solid.

The genetic variability in the population also includes–
1. recombination
2. gene flow
3. mutation and genetic drift.

Water pipeline in cold countries is laid at a certain depth from the surface in order to prevent water from freezing because in winter, when the temperature starts falling down and reaches 0ºC, the density of water drops suddenly and water in pipelines expands carring bursting in pipelines.

As per IS 10500:2012 (drinking water specifications)–

According to IS : 10500-2012

According to IS : 10500-2012–

According to IS : 10500 - 2012, the maximum acceptable limit of fluoride in drinking water is 1.0 mg/ l.
• The permissible limit of fluoride in the absence of alternate source – 1.5 mg/l.