Zero Liquid Discharge Ecology

In news: The Aqua Rejuvenation Pilot Plant (ARP) installed at CSIR-CMERI recently can help to reach towards a Zero Liquid Discharge Ecology

The Aqua Rejuvenation Pilot Plant (ARP) of CSIR

To remove the water contaminants & to purify the sewage water ,CSIR-CMERI developed innovative technology in combination with chemical & physical processes such as
- Mechanical segregation & filtration
- Coagulation-flocculation techniques and
- Chemical/physical adsorption.
It comprehensively treats WasteWater, based upon diverse purification parameters.
The approx. 24,000 litres of Water that can be rejuvenated using ARP, will be sufficient for almost 4 acres of Agricultural Land (barring seasonal variations in water requirements).
It is capable of removing all pollutants from sewage (below W.H.O recommended level) and based upon geographical variations they may be modified.
The filter media is also locally source-able so as to ensure that there would not be any stress in the supply chain for scaled-up manufacturing of ARP.

How does it purify sewage water?

The methods of purification applied by CSIR-CMERI in this technology are

Key benefits

The technology will help in solving two problems at one go:
- In one hand it converts sewage water to potable water which may be used for agricultural purposes thereby conserving the fresh water resources
- On the other hand it helps to reduce the burden of pollutant enriched grey water converting it into potable one.
An integrated mechanical and physico-chemical treatment processes based water purification system for effective removal of sewage water contaminants.
The technology is economical in terms of maintenance and affordable in terms of operation.
Sustainability towards healthy livelihood generation
Selective backwash without dismantling any part of the plant; less cumbersome approach.

Significance of the technology

ARP has maximum capacity to treat 40,000 litres/day in its scaled-up version. With this technology, CSIR-CMERI will incrementally reach towards a Zero Liquid Discharge Ecology.
The treated water processed from the ARP is preferable for agricultural purposes and with enhanced settling time it can be used for drinking purposes.
This treated water will help to improve the environment by fixation of carbon dioxide and will also provide food security.

What is a Zero Liquid DischargeZLD)?

It refers to a treatment process in which the plant discharges no liquid effluent into surface waters, in effect completely eliminating the environmental pollution associated with treatment.
It is a combination of technologies that work together to minimize wastewater as much as technically and economically practical, often resulting in a concentrated solid product and high-quality clean water for re-use or environmental discharge.
It is achieved by treating wastewater through recycling and then recovery and reuse for industrial purposes.

Components of ZLD

A systematic ZLD is made up of the following components:

How does it work?

ZLD systems employ advanced wastewater/desalination treatment technologies to purify and recycle virtually all of the wastewater produced

Benefits of ZLD

Following are the benefits of ZLD system

Wastewater discharge is avoided by recycling.
Recovery of water and salt aids in reducing the cost of operation of ZLD.
It promotes the sustainability of the industry and the environment at large.
There is less use of water by the textile industry, which means water is available for other purposes such as irrigation (agriculture) and domestic utilities.
ZLD helps recover the environment.
The sludge can be effectively used by the cement industry.