what is sewage ? explain why it is harmful to discharge unteated sewage into rivers or ses
What is E. Coli? You need to do some google searching.
Sewage refers to a mixture of wastewater and waste materials generated from domestic, commercial, and industrial activities. It typically contains human waste (urine and feces), household chemicals, soaps, oils, food waste, and other pollutants. Sewage is harmful to discharge into rivers or seas without proper treatment due to several reasons:
1. Disease Transmission: Untreated sewage contains pathogens such as bacteria, viruses, and parasites that cause diseases like cholera, dysentery, hepatitis, and gastrointestinal infections. These diseases can spread through contaminated water, affecting both humans and aquatic organisms.
2. Oxygen Depletion: Sewage carries high levels of organic matter, which acts as a food source for bacteria. When untreated sewage enters water bodies, bacteria rapidly multiply and consume the oxygen present in the water. This process depletes the oxygen levels, leading to a condition called hypoxia. Low oxygen levels can suffocate fish and other aquatic organisms, leading to their death and disrupting the ecological balance.
3. Eutrophication: Sewage contains nutrients like nitrogen and phosphorus. When discharged into rivers or seas, these nutrients act as fertilizers, promoting excessive growth of algae and aquatic plants. This excess growth is known as eutrophication, which can harm marine life and disrupt the ecosystem. Algal blooms can create oxygen-deprived dead zones, where no marine life can survive.
4. Chemical Contamination: Sewage often contains harmful chemicals from household products, industries, and agriculture. These can include heavy metals, pesticides, pharmaceuticals, and personal care products. Discharging untreated sewage introduces these chemicals into water bodies, leading to pollution and potential harm to aquatic life and human health.
To prevent the negative impacts of untreated sewage, it is essential to treat wastewater before releasing it into rivers or seas. Proper treatment processes like primary, secondary, and tertiary treatment help remove contaminants, sterilize pathogens, and reduce the levels of nutrients and chemicals. This treated water can then be safely discharged or reused for irrigation or industrial purposes, minimizing the environmental and health risks associated with untreated sewage.