Elements and Gases And Their Role In Fresh Water Environment, Zones of Lotic Water

Some Elements and Gases and their Role in Freshwater Environment

1: Chlorine

• It occurs in the form of the chloride salts.
• The amount of chloride may vary from 1 mg/lit in unpolluted water and 200 to 300 mg/lit in polluted water.
• The chloride ion is highly active.
• Guideline value is 200-300 mg/lit.

Source of chlorine:

• Industrial effluents example paper factory, galvanizing plants, water softening plant, petroleum manufacturing etc.
• Domestic sewage, especially human excreta.
• Chloride salts disposal in the urban effluent.

Roles of chlorine:

• Important in the photosynthesis to form ATP by photolysis process.
• Corrosive to metal.
• High chloride gives unpleasant taste.

2: Iron

• Iron occurs in the form of iron oxides ( ferric and ferrous form).
• The ferric form is dominated in fresh water bodies.
• Guideline value is 0.3 mg/lit

Sources

Leaching from the landfills and also from ferric deposition.

Roles of iron:

• Required in an enzymatic reaction in different metabolism.
• Form hemoglobin component.
• Important for the activity of enzyme nitrogenase in some lower aquatic plant and bacteria.
• Important in oxidative metabolism in the aquatic organism and photosynthesis process.

3: Manganese

• Most of the natural water may contain less than 0.02 mg/lit manganese or lesser but in some water, it may found up to 10 mg/lit.
• Guideline value 0.1 mg/lit.

Sources:

• It occurs in the soil in the form of the manganese dioxide which dissolves in the natural water by the action of the anaerobic bacteria.

• Industrial effluent from the food products example meat dairy, grains, cereals, nut variables.

Roles of manganese

• More than 2mg/lit is toxic to the aquatic life.
• Essential for the photosynthesis.
• Acts as the co-factor in the several enzymatic reactions such as in the respiration and the nitrogen metabolism.

4: Zinc

• The concentration of zinc in the fresh water may vary from 0.1 to 1 mg/lit.
• It acts as the cofactor carbonic anhydrase which is related to the utilization of the carbon during the photosynthesis.
• Guideline value is 5mg/lit.

Sources:

Normal flow trace elements of zinc loaded sediments.

5: copper

• It is widely distributed chemical in nature which occurs in many forms.
• The source may be an anthropogenic origin of copper, copper mining activities, copper fungicides, industrial effluents and alloys manufacture copper electroplating.

Roles of copper:

• Essential in some of the enzymes in nitrate transfer system.
• It forms the blood pigment i.e hemocyanin in molluscans.
• Copper deficiency may cause the disturbance in the cell division and the physiological disorder in the aquatic life.
• Toxic effects i.e disturb in cell division.

6: Nitrogen

• Nitrogen in the form of the nitrate is an important nutrient.
• Sources: nitrogen fixation, biogeochemical cycle in the water bodies, land water interaction, domestic and the industrial effluents, land use patterns.
• Guideline value is50mg/lit.

Roles of nitrogen:

• High nitrate loads cause the eutrophication, especially in the lakes.
• The high amount of the nitrate released in the deep dam may kill fish.
• Nitrate less than the 1mg/lit is non-toxic and 50mg/lit is setup for the drinking water.
• High nitrate caused the methemoglobinemia i.e blue baby syndrome in the higher aquatic that reduces oxygen carrying capacity.
• Nitrate usually found high in water.

7: Ammonia

• Flooded running water bodies contain the high amount of the ammonia because there is the insufficient time for the uptake by the plant and the microbial transformation and the ammonia into nitrate.
• Guideline value is 1.5 mg/lit.
• High ammonia in the water is toxic to aquatic life.
• Ammonia mount about 0.5 mg/lit may affect photosynthesis of some algae but some algae may tolerate up to the 500 mg/lit ammonia.
• Ammonia is added in the water bodies as the excretory product of the aquatic animal.
• Toxicity of the ammonia may vary as:

0.3mg/lit for the kill of rainbow trout

3 mg/lit for the survive of minnow fish

8mg/lit for the survive of some algae.

8: Phosphorous

• It is usually converted into the phosphate which is important for the plant nutrient.
• Sources: leaching from the agricultural runoff, precipitation, and the industrial waste, urban and the domestic wastes and especially detergent utilization and the zooplankton excretion.

Roles of phosphorous

Phosphate plays an important role in the phytoplankton growth.

9: Methane

Sources of methane:

It is produced due to the decomposition of the organic loaded sediment by the anaerobic process.

Roles of methane

Methane reduces the DO in the water bodies.

10: Carbon monoxide gas

Sources of carbon monoxide gas:

It is produced by the microbial fermentation which depletes the DO.

11: Hydrogen sulfides

• 05mg/lit is the guideline value.
• Sources of hydrogen sulfides are:

Produced due to the decomposition of the organic matter by the aerobic process.

It gives the rotten odor.

It depletes the DO.

12: Hydrogen gas

• It is produced by the aerobic decomposition especially carbohydrate decomposition.
• It used to decrease the DO level.

Zones of lotic water

There are mainly two zones of the lotic waterbodies which are present in the horizontal pattern. They are as follows:

1: Rapid zone or Swift zone:

In the rapid zone, the velocity of the water is usually very high. Therefore, the eroding capacity of the water in this zone is also high. Stony structures are present in this region. Rarely occurrence of the planktons, diatoms, blue-green algae and the water moss. Less number of the organisms are found in this zone. Benthic i.e bottom-dwelling organism and the periphytic are dominant organisms of this zone.

2: Pool zone or slow flowing zone:

In this type of zone, the velocity of the water is comparatively low than that of the rapid zone. Hence due to this reason, the deposition is very high in this zone. The major substrate structure present is slit, debris, and the deposition. Nektons i.e strongly swimming organism found in the aquatic system are dominant in this type of zone.

References:

Miller, Jr. G.T. Living in the Environment. Wadsworth Publication, 2003.

S.C., Santee. Environmental Science. India, New Center: New Center Book Agency (P) Ltd, 2004.