Water and Wastewater

• All people use water in their homes, which makes it dirty.
• Wastewater is dirty water rich in lather, mixed with oil, and black-brown in color.
• Wastewater from sinks, showers, toilets, and laundries should not be wasted.
• Wastewater should be cleaned by removing pollutants.

Water, Our Lifeline

• Clean water is a basic human need
• Unfortunately, clean water is not available to all, with over one billion people lacking access to safe drinking water.
• This lack of access leads to water-related illnesses and deaths.
• In some instances, people, including children, walk kilometers to obtain clean water.
• The scarcity of fresh water is increasing due to population growth, pollution, industrial development, and mismanagement.
• The United Nations General Assembly declared 2005-2015 as the "Water for Life" International Decade for action on the situation.
• All efforts during that decade aimed to halve the number of people without safe drinking water access.
• Cleaning water removes pollutants before it enters a water body or is reused, also known as “Sewage Treatment”.

What is Sewage?

• Sewage is wastewater released by homes, industries, hospitals, offices, and other users.
• Sewage includes rainwater running down streets during storms, which carries harmful substances from roads and rooftops.
• Sewage is a liquid waste composed mostly of water with dissolved and suspended impurities.
• Sewage contains suspended solids, organic and inorganic impurities, nutrients, saprophytes, disease-causing bacteria, and other microbes like protozones that cause dysentery.
• Organic impurities include human waste and animal waste
• Inorganic impurities include Nitrates, Phosphates, metals
• Nutrients include - Phosphorus and Nitrogen. _ Bacteria include vibrio cholera which causes cholera and salmonella paratyphi which causes typhoid.

Water Freshens Up – An Eventful Journey

• Buildings use one set of pipes to bring in clean water and another to remove wastewater.
• Sewers form the sewerage; a transport system carrying sewage from its origin to a treatment plant.
• Manholes are located every 50 to 60 meters in the sewerage system, at junctions, and where there are changes in direction.

Treatment of Polluted Water

• A process is done to help you understand the processes that take place at the wastewater treatment plant.
• Dirty organic matter like grass, orange peels, detergent, and a few drops of ink are added to water, shaken, and left in the sun for two days.
• First sample is called Before treatment; Sample 1
• Air is bubbled through the mixture for aeration
• Next sample is called After aeration; Sample 2”
• Filtration is done in layers of sand, fine gravel, and medium gravel are placed in a funnel
• Next sample is called "Filtered; Sample 3".
• Another sample of the filtered water with a little chlorine is added, and called "Chlorinated; Sample 4".

Wastewater Treatment Plant (WWTP)

• Treats wastewater using physical, chemical, and biological processes
• These processes remove physical, chemical, and biological matter that contaminates the wastewater.
• Wastewater goes through bar screens to remove large objects like rags, sticks, cans, and plastic packets.
• Second, water goes to a grit and sand removal tank, where the speed is decreased to allow sand, grit, and pebbles to settle.
• Third, the water settles in a large tank sloped towards the middle.
• Solids like faeces settle at the bottom and are removed with a scraper, known as sludge.
• A skimmer removes floatable solids like oil and grease, and the remaining water is called clarified water.
• Fourth, sludge is transferred to a separate tank and decomposed by anaerobic bacteria.
• Biogas produced in this process can be used as fuel or to produce electricity.
• Air is pumped into the clarified water to help aerobic bacteria grow
• Bacteria consumes any human, food, or soap waste.
• The water is then removed from the top resulting in activated sludge.
• The activated sludge content is about 97% water.
• The water is removed by sand drying beds or machines.
• Dried sludge is used as manure to return organic elements and minerals to the soil.
• The treated water with very low levels of organic material and suspended matter, is discharged into a sea, a river, or the ground.
• Additional disinfection with chemicals like chlorine and ozone is used before releasing it into the distributions.

Better Housekeeping Practices

• Minimize or eliminate waste and pollutants at the source.

• Cooking oil and fats should not be thrown down the drain because they harden and block pipes.

• Open drains get clogged, reducing the effectiveness of filtering throw oil and fats in the dustbin

• In 2016, the Government of India started the “Swachh Bharat” initiative with proper sewage disposal and providing toilets.

• Vermi-processing toilets treat human excreta with earthworms, a water toilet for safe processing of human waste

• Human excreta is converted to vermi cakes to convert resources needed for soil completely.

• Poor sanitation and polluted drinking water are leading causes of disease.

• Many people do not have sewerage facilities and commonly defecate in the open resulting in untreated human excreta which is a health hazard

• It may cause water pollution and soil pollution that includes waterborne diseases like cholera, typhoid, polio, meningitis, hepatitis, and dysentery

Alternative Arrangements for Sewage Disposal

• Septic tanks are the preferred alternative
• Septic tanks are suitable for hospitals, isolated buildings, or a cluster of 4 to 5 houses
• Some organizations offer hygienic on-site human waste disposal technology.
• Excreta from the toilet seats flow through drains into a biogas plant that generates biogas to use.
• Many People go to railway stations, bus depots, airports, and hospitals daily
• The government creates standards of sanitation but are not strictly enforced unfortunately.
• Everyone can contribute to sanitation at public places, like by avoiding scattering litter, and using bins when available.