Environmental Engineering (Part-2) (General Engineering) (SSC JE)

Pollution of air by ground level ozone damages vegetation ozone enters plant leaves and reduces photosynthesis slowing a plants growth and increasing its vulnerability to pests and disease at the ecosystem level, high levels of ground level ozone can drive the less of species diversity and lead to changes in ecosystem structure and habitat quality.

Biochemical energy is the energy stored in organic and living mater. Biochemical conversion process include anaerobic digestion or decomposition and anaerobic fermentation, the organism uses gaseous mixture containing oxygen, nitrogen and carbon dioxide to liberate biochemical energy.

Alkalinity is a measure of the acid-neutralizing capacity of water and usually determined by titration against sulphuric acid to the endpoint of the acid base reaction.
• Alkalinity is expressed in mg/l, equivalent CaCO₃.

Fluoride concentrations desirable amount in potable water for optimal dental health is taken as 1.0 mg/ℓ.
• If fluoride content less than 1.5 mg/ℓ, it causes, dental cavities.
• If fluoride content greater than 1.5 mg/ℓ, it causes dental fluorisis or mottling of teeth.

Primary pollutant–These pollutant which emitted directly from identifiable sources known as primary pollutants.

Ex. (i) Sulphur compound
(ii) Nitrogen oxide
(iii) Carbon monoxide
(iv) Halogen compounds
(v) Organic compound
(vi) Radioactive compound

Secondary pollutants–These pollutants emitted interaction among two or more primary pollutants.

Ex. (i) Ozone
(ii) Formaldehyde (CHO)
(iii) Peroxyacetyl-nitrate (PAN)
(iv) Photochemical smoke

Statistical noise levels L₉₀ are commonly used environmental noise monitoring of back ground noise level.
• L₉₀ is the level exceeded for 90% of the time.

Detritus food chain– It start with dead organic matter which the detrivaorons and decomposers consume. Partially decomposed dead organic matter and even the decomposer are consumed by detrivorous and their predators. Following is an example of the detritus flood chain seen in mangrove (Estuary).

Gastrointestinal disorder associated with untreated water primarily are caused by bacteria and viruses. A wide range of gastrointestinal disease are caused by bacterial contamination illness caused by variety of different microbes and germs which causes symptoms such as diarrhea nausea, vomiting etc.

Turbidity is estimated against standard suspension of a siliceous material such as fuller earth. The silica scale being base on standardization by photometric means the started unit of turbidity is the turbidity produced by one part of fuller's earth in a million parts of distilled water. i.e. 1 mg/l SiO₂.

Air pollutants that produce photochemical oxidants are found in photochemical smog which is a complex mixture of primary and secondary air pollutants.

• Photochemical smog formed by a complex series of chemical reactions involving sunlight, oxide of nitrogen and volatile organic compounds that are present in the atmosphere as a result of air pollution.

• Most important photochemical oxidants in the atmosphere include NO₂, O₃ and PAN.