Water Polution

Water Pollution

Any physical, biological, or chemical change in water quality that adversely affects living organisms or makes water unsuitable for desired uses.

Point Sources

All industries that generate wastewater e.g. from factories due to use of water in manufacturing, power plants from their cooling and washing activities, and sewage treatment plants. They discharge pollution from specific locations, such as drain pipes, ditches, or sewer outfalls.

Nonpoint Sources

Scattered or diffuse, having no specific location where they discharge into a particular body of water. Include runoff from farm fields and livestock, golf courses, lawns gardens, construction sites, logging areas, roads, streets, and parking lots.

Pathogenic Organisms

The most serious water pollutants in terms of human health worldwide. The main source of these pathogens is untreated or improperly treated human wastes.

Biochemical Oxygen Demand (BOD)

The amount of dissolved oxygen that must be present in water in order for microorganisms to decompose the organic matter in the water, thus a useful test for the presence of organic waste in water.

Chemical Oxygen Demand (COD)

Uses a strong oxidizing agent (dichromate ion in 50% sulfuric acid) to completely breakdown all organic matter in a water sample.

Oxygen sag

The oxygen decline downstream. Upstream from the pollution source, oxygen levels support normal populations of clean-water organisms.

Oligotrophic

Rivers and lakes that have clear water and low biological productivity (oligo = little + trophic = nutrition).

Eutrophic

Waters that are rich in organisms and organic materials (eu + trophic = truly nourished).

Eutrophication

An increase in nutrient levels and biological productivity.

Effluent Sewerage

A hybrid between a traditional septic tank and a full sewer system. A tank near each dwelling collects and digests solid waste just like a septic system.

Constructed wetlands

Can cut secondary treatment cost to one-third of mechanical treatment costs, or less.

Containment methods

Confine or restrain dirty water or liquid in situ or cap the surface with an impermeable layer to divert surface water or groundwater away from the site and to prevent further pollution.

Extraction techniques

Pump out polluted water so it can be treated. Many pollutants can be destroyed or detoxified by chemical reactions that oxidize, reduce, neutralize, hydrolyze, precipitate, or otherwise change their chemical composition.

Bioremediation

Living organisms used effectively and inexpensively to clean contaminated water. This can be carried out in tanks or troughs.

Thermal Pollution

Raising or lowering water temperatures from normal levels, which can adversely affect water quality and aquatic life.

Infectious Agents

Bacteria, viruses, parasites. Source: Human and animal excreta. Causes health problems.

Organic Chemicals

Pesticides, plastics, detergents, oil and gasoline. Source: Industrial, household, and farm use. Causes health problems.

Inorganic Chemicals

Acids, caustics, salts, metals. Source: Industrial effluents, household cleansers, surface runoff. Causes health problems.

Radioactive Materials

Uranium, thorium, cesium, iodine, radon. Source: Mining and processing of ores, power plants, weapons. Causes health problems.

Plant Nutrients

Nitrates, phosphates, ammonium. Source: Agricultural and urban fertilizers, sewage manure. Causes ecosystem disruption.

Oxygen-demanding Wastes

Animal manure and plant residues. Source: Sewage, agricultural runoff, paper mills, food processing. Causes ecosystem disruption.

Cultural Eutrophication

Nutrient enrichment sewage, fertilizer run-off, even decomposing leaves in street gutters can produce human-caused increase in biological productivity.

Primary Treatment

The first step in municipal waste treatment. It physically separates large solids from the waste stream.

Secondary Treatment

Consists of biological degradation of dissolved organic compounds. The effluent from primary treatment flows into a trickling filter bed, an aeration tank, or a sewage lagoon.

Filtration

Water is passed through fine filters or membranes to screen out dissolved impurities.

Sediment

Soil, silt. Source: Land erosion. Causes ecosystem disruption.

Distillation

Involves heating or boiling water full of dissolved minerals. The water vapor driven off is pure water, while the minerals stay behind in what remains of the liquid.

Source Reduction

The cheapest and most effective way to reduce pollution is usually to avoid producing it or releasing it to the environment in the first place.

Philippine Clean Water Act of 2004

Republic Act No. 9275.

Coliform bacteria

any of the many types that live in the colon or intestines of humans and other animals.

Escherichia coli (E. coli)

The most common of these. Many strains of bacteria are normal symbionts in mammals, but some, such as Shigella, Salmonella, or Lysteria, can cause fatal diseases.

Dead zone

Further downstream, the water may become so oxygen-depleted that only the most resistant microorganisms and invertebrates can survive.

Trickling filter

simply a bed of stones or corrugated plastic sheets through which water drips from a system of perforated pipes or a sweeping overhead sprayer.

Activated sludge process

Effluent from primary treatment is pumped into the tank and mixed with a bacteria-rich slurry. Air pumped through the mixture encourages bacterial growth and decomposition of the organic material.