India is home to 17.8% of the global population with only 4% of the world’s freshwater, leaving over 1,95,813 of its inhabitants with unsafe drinking water.
Additionally, urbanization, agriculture and raw sewage all strain India's limited freshwater resources as untreated wastewater pollutes rivers, lakes and groundwater.
Turning sewage into clean water eases pressure on freshwater and safeguards natural resources.
How does sewage treatment work?
Wastewater treatment includes a series of systematic steps that result in clean drinking water that’s safe to drink.
Pre-treatment: Screens remove large debris, while grit tanks filter out sand and gravel.Primary treatment: Heavier solids settle, oils are skimmed, removing 60% of impurities.Secondary treatment: Microbes break down organic matter. Sludge is separated and treated.Tertiary treatment: Removes any remaining contaminants.Disinfection: Kills harmful bacteria and viruses.Sludge treatment: Leftover waste undergoes further processing before disposal.Testing: Ensures water meets drinking water quality standards.5 key technologies in wastewater recycling
The following key technologies in the multi-stage wastewater recycling process eliminate contaminants and pathogens completely:
Membrane filtration (microfiltration, ultrafiltration, nanofiltration): Filters fine particles, bacteria, viruses, and other contaminants.Reverse osmosis: Forces water through semi-permeable membranes to remove salts, molecules, and other small contaminants.Disinfection (chlorination, ozonation, UV radiation): Inactivates and destroys disease-causing microorganisms.Advanced oxidation processes: Oxidizing agents like ozone, hydrogen peroxide, and UV light destroys resistant chemical contaminants.Activated carbon filters: Removes residual disinfectants like chlorine as well as absorbing other pollutants.In addition to this, safety procedures for chlorinated water involve continuous monitoring of chlorine levels and controlling dosage to prevent exceeding limits, ensure microbial safety and reduce by-products. Adequate dosage achieves thorough disinfection and minimizes residual chlorine.
The cost of recycling water in India varies significantly with the type and capacity of the system.
Wastewater treatment plants for 8-10 KLD capacity cost ₹2.5-3 lakhs.
Residential septic tanks (10,000 liters) range ₹1.6-1.8 lakhs.
Wastewater recycling tanks like Biocleanser or Biofilm Septic Tanks cost ₹1.25-1.65 lakhs.
Sewage treatment plants for apartments (<200 people) cost ₹5-12 lakhs.
Evidently, developing and implementing innovative, low-cost solutions can help scale wastewater treatment across the country. Climate tech are actively working to cater to this need for advanced technologies in order to have a transforming impact on water management.
However, achieving this vision won't happen overnight. It requires collective responsibility and action from everyone to improve water quality monitoring, advance purification technologies, and follow sustainable water management practices to safeguard public health and preserve natural resources.
With every drop recycled, we move closer to a day where water issues are a thing of the past, and everyone has access to safe drinking water.
(Author: Abhijeet Gan, MD & CEO of Rite Water Solutions)
