SANITATION SYSTEMS: PROCESSING, MANAGEMENT AND TREATMENT OF WASTEWATER

SANITATION SYSTEMS: PROCESSING, MANAGEMENT AND TREATMENT OF WASTEWATER

WHAT IS SANITARY WATER?

• Sanitary water refers to the water discarded after drinking and consuming through our food, cooking, cleaning ourselves and our homes, and washing clothes and utensils.
• Sanitation systems are meant to contain, convey, treat, and either dispose of or reuse the used water ensuring good public health and reducing environmental contamination.
• During ancient times, these systems were introduced as early as civilisations around 4000 BC.
• On the other hand, the modern sanitation system was built in London around the 1800s.

NEED OF MANAGING AND TREATMENT OF WASTEWATER:

• As per WHO, more than 2 billion people in the world are devoid of clean water for their daily use.
• Around 785 million people, many of whom live in the world’s least developed countries lack even basic water services.
• The India’s annual urban population is rising and is expected to reach about 600 million by 2030, making India more peri-urban than rural.
• More than 2 billion people in the world live without even basic sanitation.
• In the absence of sanitation system, contaminated drinking water can transmit serious illnesses like cholera, typhoid, dysentery, and polio.
• As per the study by WHO the wastewater management sustains many benefits, such as improving soil quality, providing nutrients for plants, and saving expenses of diverting freshwater for irrigation.

CONVENTIONAL METHOD OF MANAGING SANITATION WATER:

• Conventionally, twin pits and septic tanks are widely used in India based on your locality.
• Other on-site sanitation systems include bio-digester toilets, bio-tanks, and urine diversion dry toilets.
• These systems serve as collection and storage systems that naturally treat the used water and dispose the liquid into the soil.
• Twin pits are actually two pits separated by some distance.
• The pits used alongside have porous walls that allows the liquid part of used water to soak into the ground while solids collect and degrade at the bottom of the pit.

• When one pit fills to its capacity then it is covered and left unused for two years until its contents are dry, pathogen-free, and safe for reuse.
• During this period, the second pit is made to function and the cycle repeats.
• Similarly, in densely populated urban areas like cities that lack space within properties, have an underground network of pipes known as sewers.
• The sewer network collects and drains the used water to treatment facilities.
• Sewers have periodic machine-holes for maintenance and to remove blockages in case of clogging.
• Sewer network of interconnected pipes drains used water from toilets, bathrooms and kitchens to treatment facilities by gravity or with the help of pumps.

HOW WASTEWATER IS TREATED ? :

• Faecal sludge treatment plants (FSTPs) are used to treat wastewater.
• FSTPs can be either mechanical or gravity-based. Mechanised systems rely on equipment such as screw presses or centrifuges for dewatering while gravity-based systems use sand drying beds and sunlight.
• The treated solids is eligible for reuse in agriculture as a compost.
• Treated water is often reused in landscaping within the FSTP facilities.
• This process of containing, conveying and treating faecal sludge is also called faecal sludge management (FSM).
• STPs uses a series of physical, biological, and chemical processes to remove pollutants and contaminants from used water.

ADVANCED TREATMENT SYSTEM TO CLEAN SANITATION WATER:

• Solar-Powered Water Filtration: Researchers at Princeton University developed a Solar Absorber Gel for contaminated water.
• This solar gel absorbs water at room temperature, but it changes shape and releases the water when heated.
• It has a second layer consisting of polydopamine, which can transform the sun’s energy into heat. The third layer is made of alginate.
• When water passes through the gel, it purifies by filtering out pathogens, metals, and other molecules from the water.
• Other most common water purification techniques in the nanotech space is the carbon nanotube (CNT).
• CNT-based filtration systems remove organic, inorganic, and biological compounds from water to make it safe for drinking.
• Another process is desalination process.In this process, salt from saltwater is extracted to obtain freshwater, which can be used for several purposes.

WAY FORWARD:

• To realise SDG-6, the UN called for increased investment in management of freshwater ecosystems and sanitation facilities on a basin level in several developing countries within Sub-Saharan Africa, Central Asia, Southern Asia, Eastern Asia and South-Eastern Asia.
• Developing wastewater initiatives as part of a planning framework to maximize benefits, improve efficiency and resource allocation, and engage stakeholders.