INTRODUCTION• Over two thirds of Earths surface is covered by water; less than a third is taken up by land. As Earths population continues to grow, people are putting ever-increasing pressure on the planets water resources.• In a sense, our oceans, rivers, and other inland waters are being "squeezed" by human activities.• Poorer water quality means water pollution.
HOW SERIOUS IS THE PROBLEM?• According to the environmental campaign organization WWF: "Pollution from toxic chemicals threatens life on this planet. Every ocean and every continent, from the tropics to the once-pristine polar regions, is contaminated."• Water pollution is a major problem in the global context. It has been suggested that it is the leading worldwide cause of deaths and diseases, and that it accounts for the deaths of more than 14,000 people daily.
WATER POLLUTION• Water pollution is the contamination of water bodies• Water pollution affects plants organisms living in these bodies of water; and, in almost all cases the effect is damaging either to individual species and populations, but also to the natural biological communities.• Water pollution occurs when pollutants are discharged directly or indirectly into water bodies without adequate treatment to remove harmful compound.
WATER POLLUTION• Water is typically referred to as polluted when it is impaired by anthropogenic contaminants and either does not support a human use.• “Water pollution can be defined in many ways. Usually, it means one or more substances have built up in water to such an extent that they cause problems for animals or people.”
WATER POLLUTION CATEGORIES• Sources of surface water pollution are generally grouped into two categories based on their origin.1) Point source pollution2) Non-point source pollution
1.Point source pollution• Point source pollution refers to contaminants that enter a waterway through a discrete conveyance, such as a pipe or ditch.• Examples- ▫ discharges from a sewage treatment plant, a factory, ▫ a city storm drain.
2. Non-point source pollution• Non-point source (NPS) pollution refers to diffuse contamination that does not originate from a single discrete source.• NPS pollution is often accumulative effect of small amounts of contaminants gathered from a large area• The leaching out of nitrogen compounds from agricultural land which has been fertilized is a typical example.
GROUNDWATER POLLUTION• By its very nature, groundwater aquifers are susceptible to contamination from sources that may not directly affect surface water bodies, and the distinction of point vs. non-point source may be irrelevant.• A spill of a chemical contaminant on soil, located away from a surface water body, may not necessarily create point source or non-point source pollution, but nonetheless may contaminate the aquifer below.• Analysis of groundwater contamination may focus on soil characteristics and hydrology, as well as the nature of the contaminant itself.
CAUSES OF WATER POLLUTION• Chemicals, pathogens, and physical or sensory changes such as elevated temperature and discoloration.• Other natural and anthropogenic substances may cause turbidity (cloudiness) which blocks light and disrupts plant growth.• Alteration of waters physical chemistry includes acidity (change in pH), electrical conductivity, temperature, and eutrophication.
CAUSES OF WATER POLLUTION1. Pathogens: ▫ High levels of pathogens may result from inadequately treated sewage discharges. ▫ This can be caused by a sewage plant designed with less than secondary treatment. ▫ Some harmful pathogens- Burkholderia pseudomallei, Cryptosporidiu parvum , Giardia lamblia, Salmonella, Novovirus and other viruses, Parasitic worms (helminths).
CAUSES OF WATER POLLUTION2. Chemical and other contaminants: ▫ Contaminants may include organic and inorganic substance. ▫ Organic- Detergents, Disinfection by-products, Food processing waste, Insecticides and herbicides, Petroleum hydrocarbons. ▫ Inorganic- Acidity caused by industrial discharges, Ammonia from food processing waste, Fertilizers containing nutrients, Heavy metals from motor vehicles .
CAUSES OF WATER POLLUTION3. Thermal pollution: ▫ Rise or fall in the temperature of a natural body of water caused by human influence. ▫ Caused out of use of water as a coolant by power plants and industrial manufacturers. ▫ Also caused by the release of very cold water from the base of reservoirs into warmer rivers. ▫ Elevated water temperatures decreases oxygen levels and affects ecosystem composition.
MEASUREMENT OF WATER POLLUTION• Methods- ▫ Physical ▫ Chemical ▫ Biological• Government agencies and research organizations have published standardized, validated analytical test methods to facilitate the comparability of results.
1. PHYSICAL TESTING• Common physical tests: ▫ Temperature, ▫ Solids concentration like total suspended solids (TSS) and, ▫ Turbidity.
2. CHEMICAL TESTING• Common Chemical Tests: ▫ pH testing, ▫ Biochemical Oxygen Demand (BOD), ▫ Chemical Oxygen Demand (COD), ▫ Nutrients (nitrate and phosphorus compounds), ▫ Metals (including copper, zinc, cadmium, lead and mercury), ▫ Oil and grease, ▫ Total petroleum hydrocarbons (TPH), and ▫ Pesticides.
3. BIOLOGICAL TESTING • Biological testing involves the use of plant, animal, and/or microbial indicators to monitor the health of an aquatic ecosystem.
CONTROL OF WATER POLLUTION• Water pollution is controlled by, preventing the entrance of sewage water & industrial water into main stream flow.• Nonpoint source controls- Erosion control to reduce runoff, reduce reliance on chemical pesticides, and protect water quality.• Point source wastewater treatment- Constructed wetlands are sometimes used to facilitate treatment of animal wastes, as are anaerobic lagoons
CONCLUSION• It is hard to imagine that one person can make a difference in protecting and conserving fresh water supplies on this planet, but each individual can really help the environment.• Water pollution is very serious problem and it can be controlled by providing proper escape to sewage and industrial waste water.• Also contaminated water can be treated and reused so as to reduce water pollution.