Wastewater recycling is emerging as an integral part of water demand management. Promoting as it does the preservation of high-quality fresh water supplies as well as potentially reducing the pollutant in the environment and reducing overall costs.

1. Waste water
RecyclingS.Vignesh, BTG-12-037
Dr.A.Valliammai,
Assistant Prof.,(WTC)

2. Waste Water
 It is any water that has been adversely affected in
quality by naturally or anthropogenic influence.
 Wastewater is water containing wastes from
residential, commercial, and industrial processes.
 Municipal wastewater contains sewage, gray water.
 Wastewater requires treatment to remove
pollutants prior to discharge.

3. Wastewater Recycling
 Wastewater recycling is emerging as an integral part of
water demand management.
 Promoting as it does the preservation of high-quality fresh
water supplies as well as potentially reducing the pollutant
in the environment and reducing overall costs.

4. Motivational Factors
 Opportunities to augment limited primary water sources.
 Prevention of excessive diversion of water from alternative
uses, including the natural environment.
 Possibilities to manage in-situ water sources.
 Reduction and elimination of discharges of wastewater
(treated or untreated) into receiving environment.
 Scope to overcome political, community & institutional
constraints.

5. Reuse
 Potential reuses of wastewater depends on the hydrau.
and biochemical characteristics of wastewater, which
determine the methods and degree of treatment req.
 It can be recycled/reused as a source of water
for a multitude of water-demanding activities such as
agriculture, aquifer recharge, aquaculture, fire fighting,
 flushing of toilets, snow melting, industrial cooling,
parks and formation of wetlands for wildlife habitats,
recreational impoundments.

6. Quality of Wastewater
Wastewater, if treated appropriately, has the potential to be
recycled in a number of sectors. Recycled water can be
treated to a number of different standards using different
technologies depending on the quality req.
Broadly, wastewater is treated to three levels, namely
primary, secondary and tertiary levels. According to the
Environment Protection Agency (EPA), they are defined as
follows:

7. Methods
 Wastewater treatment is closely related to
the standards and/or expectations set for the
effluent quality.
 Suspended solids (physical particles that can clog
rivers or channels as they settle under gravity)

8. Biodegradable Organics
Microorganisms combine this matter with oxygen from the
water to yield the energy they need to thrive and multiply;
Unfortunately, this oxygen is also needed by fish and other
organisms in the river. Heavy organic pollution can lead to
“dead zones” where no fish can be found; sudden releases
of heavy organic loads can lead to dramatic “fish kills”.

9.  Pathogenic Bacteria
These are most relevant where the receiving
water is used for drinking, or where people
would otherwise be in close contact with it.
 Nutrients
These nutrients can lead to high concentrations
of unwanted algae, which can themselves become
heavy loads of biodegradable organic load
Treatment processes may also neutralize or removing
industrial wastes and toxic chemicals.

10. 1.Primary treatment:
Treatment involving sedimentation (sometimes preceded by screening and grit
removal) to remove gross and settle able solids. The remaining settled solids,
referred to as sludge, are removed and treated separately.
2.Secondary treatment:
Generally, a level of treatment that removes 85% of Biological Oxygen Demand
[BOD] and suspended solids via biological or chemical treatment process.
Secondary treated reclaimed water usually has a BOD of <20 milligrams per liter
(mg/L) and suspended solids of <30 mg/L, but this may increase to >100 mg/L
due to algal solids in lagoon systems.

11. 3.Tertiary treatment:
The treatment of reclaimed water beyond the secondary
biological stage. This normally implies the removal of a high
percentage of suspended solids and/or nutrients, followed
by disinfection. It may include processes such as coagulation,
flocculation and filtration.

12. Wastewater Sludge Reuse
 Wastewater sludge is the solid/semi-solid substance,
concentrated form of mainly organic, and inorganic
impurities, generated as a result of treatment of
wastewater.
 It can be reused to reclaim parched land by application
as soil conditioner, and also as a fertilizer in agriculture.
 Deteriorated land areas, which cannot support the plant
vegetation due to lack of nutrients, soil organic matter,
low pH and low water holding capacity, be reclaimed
and improved by the application of sludge…Etc.

13. Economic Characters
 Centralized wastewater treatment systems, the location of the
treatment plants, the availability of space in and around cities and the
topography – all of these factors restrict the use of wastewater to
certain areas and for specific purposes.
 There are both positive and negative externalities associated with
wastewater recycling. The positive externality is: environmental
benefits from reduced discharge of saline wastewater into natural
water bodies. The negative externalities include potential groundwater
pollution and increase in soil salinity if used for irrigation and potential
unknown ill effects on human health if used for potable uses

14. Government / Institutions roles
I. Environmental Protection Agency
Responsible for the developing and applying of best practice
management guidelines for reclaimed water irrigation
II. Department of human services
Responsible for ensuring that, reuse schemes do not
pose a risk to public health
III. Council/Local Government
Councils control development zoning, minimum subdivision
size, infrastructure size, infrastructure provision, and land use
controls

15. Conclusion
Today, these methods are most widely used in
wastewater treatment process.
An economic and reliable way of using solar energy for
effluent treatment is a very attractive option for Indian
industries since the life of the catalyst is long.
Also many possible synergism of these techniques
promise a good pollutant destruction rate that helps in
maintaining the environment clean.

16. Reference
• ABS. 2005. Annual Report 2005-06.
http://www.ausstats.abs.gov.au/ausstats/subscriber.nsf
• am (Canberra Time) 28 November 2006. Australian Bureau of Statistics.
Commonwealth of Australia.
• http://www.tn.gov.in
• ACIL Tasman Pty Ltd. 2005. Economics Policy Strategy. Research into access to
recycled water and impediments.
• recycled water investment. Report prepared for the Australian Government
Department of Agriculture, Fisheries.
• and Forestry on behalf of the Natural Resource Policy and Programs
Committee. June 2005.

17. Thank You