photo.jpg

# Dealing with Waste Water ## Know these before you start - We use water for drinking, cleaning, bathing, washing clothes, etc. - Tap water comes from rivers, lakes or wells. - Sewage includes garbage, human waste and water that has been used for cleaning, washing, and bathing. - Sewage contains di...

# Dealing with Waste Water ## Know these before you start - We use water for drinking, cleaning, bathing, washing clothes, etc. - Tap water comes from rivers, lakes or wells. - Sewage includes garbage, human waste and water that has been used for cleaning, washing, and bathing. - Sewage contains dissolved and suspended impurities called contaminants. - Sewage contains organic, inorganic impurities, nutrients, and microorganisms. - Before draining sewage into rivers or lakes, it needs to be treated in sewage treatment plants. - Waste water treatment processes include: screening, grit tanks, sedimentation, aeration, and disinfection. - Dispose of hazardous and nonbiodegradable waste properly - Do not litter at public places; dispose of waste properly after fairs, weddings, or processions. ## Learning objectives - Understand the various uses of water. - Know what sewage is - Understand the processes involved in the treatment of sewage. - Understand how to reduce water pollution at home. ## Water Water is the most common liquid on Earth. Everything needs water to survive. People use water for drinking, cleaning, bathing, and washing clothes. Even plants cannot survive without water. Clean water that is fit for drinking is called **potable water**. Even though three-fourths of the Earth's surface is covered with water, it is not equally distributed. In many places, people have to rely on unsafe water sources.