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Sewage and Wastewater Domestic households, industrial and agricultural practices produce wastewater that can cause pollution of many lakes and rivers. | |
* Sewage is the term used for wastewater that often contains faeces, urine and laundry waste.
* There are billions of people on Earth, so treating sewage is a big priority.* Sewage disposal is a major problem in developing countries as many people in these areas don’t have access to sanitary conditions and clean water.
* Untreated sewage water in such areas can contaminate the environment and cause diseases such as diarrhea.
* Sewage in developed countries is carried away from the home quickly and hygienically through sewage pipes.
* Sewage istreated in water treatment plants and the waste is often disposed into the sea.
* Sewage is mainly biodegradable and most of it is broken down in the environment.
* In developed countries, sewage often causes problems when people flush chemical and pharmaceutical substances down the toilet. When people are ill, sewage often carries harmful viruses and bacteria into the environmentcausing health problems.
Dumping of litter in the sea can cause huge problems. Litter items such as 6-pack ring packaging can get caught in marine animals and may result in death. Different items take different lengths of time to degrade in water:
* Cardboard – Takes 2 weeks to degrade.
* Newspaper – Takes 6 weeks to degrade.
* Photodegradable packaging – Takes 6 weeksto degrade.
* Foam – Takes 50 years to degrade.
* Styrofoam – Takes 80 years to degrade.
* Aluminum – Takes 200 years to degrade.
* Plastic packaging – Takes 400 years to degrade.
* Glass – It takes so long to degrade that we don’t know the exact time.
Industrial water and water pollution
Industry is a huge source of water pollution, it produces pollutants that areextremely harmful to people and the environment.
* Many industrial facilities use freshwater to carry away waste from the plant and into rivers, lakes and oceans.
* Pollutants from industrial sources include:
* Asbestos – This pollutant is a serious health hazard and carcinogenic. Asbestos fibres can be inhaled and cause illnesses such as asbestosis, mesothelioma, lung cancer, intestinalcancer and liver cancer.
* Lead – This is a metallic element and can cause health and environmental problems. It is a non-biodegradable substance so is hard to clean up once the environment is contaminated. Lead is harmful to the health of many animals, including humans, as it can inhibit the action of bodily enzymes.
* Mercury – This is a metallic element and can cause health andenvironmental problems. It is a non-biodegradable substance so is hard to clean up once the environment is contaminated. Mercury is also harmful to animal health as it can cause illness through mercury poisoning.
* Nitrates – The increased use of fertilizers means that nitrates are more often being washed from the soil and into rivers and lakes. This can cause eutrophication, which can bevery problematic to marine environments.
* Phosphates - The increased use of fertilizers means that phosphates are more often being washed from the soil and into rivers and lakes. This can cause eutrophication, which can be very problematic to marine environments.
* Sulphur – This is a non-metallic substance that is harmful for marine life.
* Oils – Oil does not dissolvein water, instead it forms a thick layer on the water surface. This can stop marine plants receiving enough light for photosynthesis. It is also harmful for fish and marine birds.
* Petrochemicals – This is formed from gas or petrol and can be toxic to marine life.
Nuclear waste – how it is produced
Nuclear waste is produced from industrial, medical and scientific processes that...