1Ekatpure Sachin Chandrakant, 2 Hegade Priti Manohar, 3 Tejashree Lachyan, 1 Kiran A. G.
1 Department of Plant Biotechnology, College of Agriculture, Vellayani
2 Savitribai Phule Pune University, Pune
3 Department of Plant Breeding and Genetics, College of Agriculture, Vellayani
*Corresponding Author: email@example.com
In recent year clean drinking water is increasingly becoming scarce. Climate change and over use has made water a scarce commodity in many parts of the world. Available water in made unsafe for drinking due to pollution. Near about one billion people lack access to safe drinking water and 1.4 million child deaths from diarrhea each year.
Sources of water pollution
Various sources can contribute in the water pollution such as
- Domestic sewage
- Industrial effluents
- Underground storage and tube leakage
- Atmospheric sources
a) Domestic sewage
- Municipal waste water and sewage which comprise both household waste and waste from commercial enterprises are dumped into rivers and streams.
- Synthetic detergents used for cleaning purpose contain many toxic chemicals.
b) Industrial effluents
- Waste water from manufacturing or chemical process in industry
- Major polluting industries include sugar mills, distilleries, leather processing industries and thermal power station
- Pollutants from industries include
Sulfur : Affects marine life
Asbestos : Causes cancer
Lead and mercury: Environmental and health problem
Nitrates and phosphates: they originate from fertilizers and cause eutrophication
Oils : Oil forms thick layer on water surface
- They affect marine ecosystem
- They obstruct light for photosynthesis
c) Underground tube leakage
- Leakage of underground pipes carrying petroleum or sewage contaminate soil and water bodies nearby
d) Atmospheric sources
- SO2 and NO pollution cause acid rain which ends up in polluting water bodies
Composition of waste water consists of-
- Pathogens such as bacteria and virus
- Non pathogenic bacteria
- Organic and inorganic particles
- Soluble organic and inorganic material
- Gases like hydrogen sulfide, CO2, methane
- Emulsions like paints, adhesives etc.
- Toxins like pesticides and herbicides
- Pharmaceuticals and hormones
Effects of water pollution
- Destroys aquatic life
- Affects animals, birds and human
- Diminishes aesthetic quality of rivers
- Heavy metals and toxins from industrial process accumulating in lakes and rivers are toxic to fishes and also affect the rest of the food chain
- Microbial pollutants from sewage cause infectious diseases that infects fishes and affects terrestrial life forms
- Organic matter and nutrients cause an increase in aerobic algae and depletes oxygen from water bodies (Eutrophication)
- Sulfate from acid rain acidifies water and affects marine life
- Suspended particle prevents penetration of sunlight and affects photosynthesis and food cycle in water bodies
- Higher temperatures of polluted water affects ecosystem that thrives there.
Effects on Human health
- Organophosphates and carbonates present in pesticides affect and damage nervous system (NS).
- Nitrates in water affects infants
- Lead poisoning affects Central NS
- Excess Fluorides can cause yellowing of teeth and damage spinal chord
- Benzene and other petrochemicals cause cancer
- Arsenic poisoning cause liver and NS damage
- Exposure to polluted water causes diarrhea, skin irritation, respiratory problems etc.
- Stagnant polluted water is breeding ground for mosquitoes which act as vectors of many pathogens.
- Excess amount of nutrients in fresh water cause eutrophication
- Discharge of waste from industries, urban communities and run off from agriculture fields lead to nutrient accumulation
- Accumulation of nutrients cause excessive growth of aquatic plants and algae
- Water bodies become choked with organic substances and organisms
- Organic matter exceeds the capacity of microorganisms to decompose them
- This results in rapid growth of algae called Algal blooms, causing further increase in organic matter
- Water becomes deficient in oxygen and anaerobic organisms thrive in water
- They attack organic matter releasing gases such as methane and H 2S producing foul smell.
Waste water quality indicators
Various tests measure the physical, chemical and biological characteristics of waste water
- Temperature : There is a specific temperature required for growth of microorganism
- Solids : Total dissolved or suspended solids give indication of the level of pollution
- pH : Indicates the level of acidity of water.
- Dissolved oxygen content is a crucial factor determining quality of water in rivers and lakes
- Oxygen content in water expressed as
- Dissolved O2 concentration
Biochemical O2 demand (BOD) : Amount of oxygen required by microorganisms to decompose organic matter in water.
It is defined as the amount of O2 consumed (mg) for decomposing organic substance in 1L of water. Expressed in mg/L or ppm.
- Nitrogen in the form of organic matter, ammonia and nitrates act as nutrients for growth of plants
- Excess Nitrogen results in eutrophication
- Chlorine comes as residues of water purification
- Remaining hypochlorous acid and hypochlorite ion concentration in water is estimated
- Quality of water tested by growing aquatic test species in polluted and normal water
Presence of pathogenic microorganism especially Coliform seen in intestine of animals is checked (Coliform index).
About Author / Additional Info:
PhD research scholar (Plant biotechnology), interested in genetic engineering and molecular biology studies