Reverse Osmosis Technology – Tata Projects

Reverse Osmosis (RO), also known as hyper-filtration, is a purification process used in desalination plants to eliminate concentrated solutions like dissolved minerals and salts in water. We partnered with Tata Projects^* whose RO technology helps us in providing chemical contamination free drinking water to villagers. This technology offering can be customised to address arsenic, nitrate, sulphate and other chemical contamination.

The model has been initiated with active cooperation from several districts in AP, Punjab and Haryana that have chemical contamination in their water sources. 

How the RO technology works

RO technology uses a membrane that is semi-permeable, which allows only pure water to pass through it. During the process it rejects large contaminants passing through the membrane. Quality RO systems use a process known as ‘crossflow’ which allows the membrane to continually clean itself. RO requires a driving force to push the fluid through the membrane and as some of the fluid passes through, the rest continues downstream, thereby sweeping the rejected contaminants away from the membrane.

The unit that is skid-mounted and designed for indoor installation comprises a raw water pump that supplies water to the micron cartridge water filtration system and to the high pressure pump. Micron cartridge filters control the silt density before water enters into the membrane whereas high pressure pump exists to boost water pressure as required.

Pictorial representation of the technology:

The RO unit of 500 LPH Model

Advantages:

• RO technology has a proven record to reduce/treat contamination related to fluoride/salinity and other chemicals.
• It eliminates water from suspended solids, major inorganic pollutants like acids, salts, toxic metals and most of the organic micro pollutants including aromatic hydrocarbons, organochlorine pesticides and toxins.
• The model has a throughput of 200 litres to 2,000 litres per hour and ensures quality safe drinking water for a village size of 2,000 to 10,000 population (the capacity can further go up).
• Incurs low maintenance costs.
• Easy to operate and maintain.

* Tata Projects has emerged as an Engineering, Procurement and Construction (EPC) contracting company since its humble operations 25 years ago with focused operations in core sectors of Power Generation, Transmission & Distribution, and Industrial infrastructure. The company is one amongst the few constructions companies in India having all the three certifications ISO 9001, ISO 14001 and OHSAS 18001. It is being part of the Tata Corporate Group, the most trusted in India, gives it offerings a high degree of acceptance amongst the consumers/clients/ beneficiaries.

Ultraviolet Waterworks ^TM- WaterHealth International, Inc

Ultraviolet (UV) Waterworks^TM technology is a unique system where ultraviolet light inactivates microorganisms in water through disruption of their DNA processes. We tied up with WaterHealth International whose technology will help us make drinking water free from pathogen contamination.

Developed by renowned Indian scientist Dr Ashok Gadgil, at the Lawrence Berkeley National Laboratory, USA, the technology was first piloted in Bomminampadu village, Krishna district. The village had a history of waterborne diseases and contaminated water-linked debilities and for generations, residents of the village have been dependant on pathogen contaminated village water sources such as wells, tanks and canals.

How the UV Waterworks^TM technology works

There are more than a thousand products to disinfect water using UV light of 254 nanometer wavelength. All these products are designed with a UV lamp encased in a quartz tube, which is then placed in a cylindrical container. Water flows in the space between the walls of the quartz tube and the cylindrical container. All these designs suffer from two major problems. Firstly, they require a source of pressurized water – or a pump to pressurize the water. Secondly and much more seriously, the walls of the quartz tube get fouled with deposits of calcium and magnesium salts from hardness in the water, and also permit a surface for growth of algae on the quartz tube. This fouling substantially reduces the transmittance of UV through the quartz tube in a matter of weeks. Thus, these designs require frequent and careful maintenance to open the seals, remove the quartz tube, clean the deposits with acids or mechanical scrubbing, replace it, and seal it back with seals. This is expensive and delicate operation to perform in the field where trained technical help (and even tools) are not easy to find.

Conventional UV disinfection technology uses a submerged UV source encased in quartz sleeve. Such equipment is prone to “fouling”, and is expensive to maintain

Complex designs existing in conventional UV systems’ make them inappropriate in rural settings. Contrastingly, in WaterHealth’s design, the UV lamp is suspended in air above a free surface of water flowing under the lamp in a shallow (max depth 4 cm) channel. There is no solid surface between the water and the lamp that can be fouled even under the worst conditions. Also, the pressure drop across the device is reduced so much that simple gravity drop of 10 cm of water column is adequate for the flow. This non-submerged makes UV Waterworks^TM a unique and distinct model from others.

Advantages:

• High efficacy in pathogen removal; upto 99.99 per cent bacterial and viral load elimination
• High quality treated water output of upto 3,000 litres/hour per disinfection unit
• Purified water can be stored for longer without need for re-purificaiton
• Low energy usage renders it appropriate for villages with irregular electricity supply
• Low operating costs to keep treated water affordable for all
• Low maintenance requirements make it ideal for remote villages where qualified engineers are hard to come by.
• Can be run and operated by community members
• Robust and versatile design to withstand the vagaries of nature and changing levels of demand

WaterHealth International, Inc. (WHI) provides innovative business solutions to one of the world’s most desperate health crises, the lack of safe, clean and affordable water for the more than two billion people who have little or no access to it. WHI’s award winning water purification and disinfection technology, combined with creative and unique business approached, enables the delivery of highly affordable, clean water to even the most remote and underserved communities. WHI invests in health and hygiene education programs as part of its normal business practices to combat waterborne diseases in the communities it serves.