Chemistry · Ch 14 — Environmental Chemistry
Water Pollution
14.3
Water Pollution
Why Water Quality Cannot Be Taken for Granted
Water is essential to all life, and we often assume it is pure — but pollution of water sources is a direct consequence of human activity, reaching surface water and groundwater through many different paths.
Point vs Non-Point Sources
- Point source — a pollution source that can be easily identified and located, e.g., a municipal or industrial discharge pipe emptying directly into a water body.
- Non-point source — a diffuse source that cannot be pinned to one location, e.g., agricultural run-off from farms, animal waste and cropland, acid rain, or storm-water drainage from streets, parking lots and lawns.
Major Water Pollutants and Their Sources
| Pollutant | Source |
|---|---|
| Micro-organisms | Domestic sewage |
| Organic wastes | Domestic sewage, animal excreta and waste, decaying animals and plants, discharge from food processing factories. |
| Plant nutrients | Chemical fertilizers |
| Toxic heavy metals | Industries and chemical factories |
| Sediments | Erosion of soil by agriculture and strip mining |
Table 14.1Major Water Pollutants
| Pollutant | Source |
|---|---|
| Micro-organisms | Domestic sewage |
| Organic wastes | Domestic sewage, animal excreta and waste, decaying animals and plants, discharge from food processing factories. |
| Plant nutrients | Chemcial fertilizers |
| Toxic heavy metals | Industries and chemical factories |
| Sediments | Erosion of soil by agriculture and strip mining |
| Pesticides | Chemicals used for killing insects, fungi and weeds |