Презентация Water pollution онлайн

Содержание слайда: Water pollution Greece, Spain and Germany have the cleanest coastal waters.

Содержание слайда: "Man is a complex being; he makes the deserts bloom and lakes die." — Gil Stern Pesticides are carried in rainwater from farm fields, suburban lawns, or roadside embankments into creeks. Results: affect and damage the nervous system; cause liver damage; damage DNA and cause a variety of cancers; cause reproductive and endocrine damage; cause other acutely toxic or chronic effects.

Содержание слайда: "Society, my dear, is like salt water, good to swim in but hard to swallow." — Arthur Stringer, author, The Silver Poppy Mercury comes through air pollution from industrial plants. In the water, the elemental mercury is converted to methylmercury by certain bacteria, after which it moves into food through a fish. Young children and fetuses (плод) are most at risk because their systems are still developing. Mercury causes neurological problems, including slower reflexes, learning deficits, delayed or incomplete mental development, autism, and brain damage. Mercury for adults is also a problem, causing: central nervous system effects like Parkinson's disease, multiple sclerosis, and Alzheimer's disease (разновидность пресенильного слабоумия); heart disease; death or irreversibly damaging areas of the brain.

Содержание слайда: PCBs, Dioxins, and Other POPs PCBs polychlorinated biphenyl - ПХД полихлорированные дифенилы dioxins - poisonous chemical by-products of the manufacture of certain herbicides and bactericides POP - persistent organic pollutants tend to collect in the fatty issues of animals.

Содержание слайда: Control of water pollution In urban areas, domestic sewage is typically treated by centralized sewage treatment plants. Plants are designed to control conventional pollutants(обычные загрязнит. в-ва) Well-designed systems can remove 90% or more of these pollutants.

Содержание слайда: Industrial Wastewater Treatment Some of these facilities remove the toxic components, and then send the partially-treated wastewater to the municipal system. Dissolved air flotation system for treating industrial wastewater.

Содержание слайда: Agricultural Wastewater Treatment Sediment (loose soil) washed off fields is the largest source of agricultural pollution Nutrients are typically applied to farmland as commercial fertilizer, materials left after the crop has been harvested, water irrigation, wildlife

Содержание слайда: Urban runoff (stormwater-ливневая вода) Effective control of urban runoff involves reducing flow of stormwater, as well as reducing pollutant discharges. Local governments use techniques (BMPs-best management practices) to reduce the effects of urban runoff : filters, clarifiers, biological reactors

Содержание слайда: Think about Water!!!