The use of reed beds for the treatment of sewage and wastewater

1. Presentation Topics: The use of reed beds for
the treatment of sewage and wastewater.
Department of Textile Engineering

2. Department of Textile Engineering
Submitted To: Submitted By
Toriqul Islam 2016000400047
Dipto Kumar Das 2016000400072
Faisal Ahmed 2016000400074
Zahidul Hasan 2016000400093
Rajib Miah 2015000400069
Israt zehrin
Lecturer
Dept. of Textile Engineering

3.  Wastewater = Good Water + impurities
What is wastewater?
Wastewater is any water that has
been affected by human
use. Wastewater is "used water
from any combination of domestic,
industrial, commercial or
agricultural activities, surface
or storm water, and any sewer
inflow or sewer infiltration

4.  Anaerobic In absence of O2
Sensitive to toxics
 Aeration not needed
 Easy To Operate
Lengthy startup periods, needs other treatments
 Septic tanks
 Biogas plants
 Anaerobic digesters
 Reed bed Treatment.
 Aerobic
In presence of O2 Needs care to maintain
O2 levels
 Aeration needed
Energy intensive
 Less Stink
But spreads aerosols
 Activated Sludge
 Trickling Filters
 RB Discs etc.
Wastewater Treatment Technology

5. Techniques of wastewater treatment
Conventional
•Variants of Activated Sludge
System
•Energy Intensive Mechanized
High O & M Difficult to maintain
•Medium foot print
Reed Beds
• Types of Constructed
Wetlands
• Simple O & M Easy to
operate Energy friendly
• Large Foot print
Membrane based
• Membrane Bio-Reactors
• Heavy costs Sophisticated
Automation
• Small Foot Print

6. Types of wastewater

7. Quality of wastewater
Bath water
• Simple
• No stink
• Soap Water
• Detergents
• BOD – 50
• COD – 200
• 40 %
Kitchen
• Not so simple
Develops stink
• Food waste, oils,
Soap, detergent
• BOD – 100
• COD – 200
• 20%
Toilets
• Difficult Stinks
• Human Waste
Pathogens
• BOD – 500
• COD – 900
• 40 %

8. What is reed Bed System?
Reed beds are aquatic
plant
based systems which
allow bacteria, fungi
and algae to digest the
sewage and clean the
water. There are two
basic types of reed
bed - vertical flow and
horizontal flow - and
the best system often
results from combining
the two

9. Salient Features of Reed Bed Systems
 No complicated setups
 No electricity wastage for aeration
 No costly imported equipment's
 No moving parts
 No need of highly trained manpower For
operations and maintenance
 Operationally Simple Natural systems
 Power saving systems
 Easy to Operate and maintain
 Rejuvenates ecosystems

10. The Treatment Train Process

11. the wastewater stored in reed
beds is treated and recycled.
The reed bed filters the water
just as the conventional
biological filter bed systems of
sewage treatment plants.
Earlier reed bed sewage
treatment systems used
horizontal flow reed beds,
where the liquid flows
horizontally
How Do Reed Beds Work?

12. Basic Reed Bed Design

13. Process of Reed Bed System?

14. How a Typical Reed Bed works

15. Reed bed life cycle stages
 Establishment
 Operation, and
 Biosolid disposal –
are shown below. Final Biosolids have a dry solid content of 25–
40%.

16. Application of Reed Bed System
Rural areas
Food processing industry
Breweries
Animal husbandry
Sewage from residential,
institutional and industrial
complexes.
Chemical industry

17. Types of Reed Bed
There are three different types of systems that have
been developed during the past 25 years for treating
wastewater and sewage effluent.
 Horizontal flow reed-beds
 Vertical flow reed-beds
 Down-Flow Reed-beds

18. Horizontal Flow Reed-Beds
Horizontal Flow systems only work
when the effluent is of low
strength. They are not to be
used to treat septic tank effluent,
as this is too strong. They are also
of no real use for reducing
ammonia levels, but they
can reduce the level of BOD
(Biochemical Oxygen Demand) and
SS (Suspended Solids) in sewage
treatment plant effluent.
Horizontal flow reed-beds
should only be considered for
tertiary treatment after a full
sewage treatment plant.

19. Vertical flow reed-beds
Vertical flow systems are
more efficient than
horizontal flow reed-beds
and can handle stronger
strength effluent. They can
reduce ammonia as well
as BOD and SS levels. It
is usual for there to be two
reed-beds installed, one
after the other down the
slope of the site. Vertical
flow ones can be used to
treat septic tank effluent.

20. Down-Flow Reed-beds
Multi-stage reed-bed systems, incorporating two stages of vertical flow.
They work on a 'fill and drain' system, where one bed fills over 12 hours
whilst the other one drains and vice versa. The idea is that as the effluent
drains out of the gravel, air is pulled in and helps to form an aerobic
bacterial colony on the gravel surface to digest the pollutants.
These systems invariably require the use of electric pumps, timers and
control panels as the effluent is switched from one bed to the other every
12 hours.
Down-flow reed-beds are normally used for treating septic tank effluent.

21. Factors influencing the purification process of reed
bed treatment systems
hydraulic loading rate (m³/[ha x d]) and hydraulic
detention time(d)
 temperature
influent pollutant concentration
oxygen supply
development stage of the reed ecosystem

22. Reed Bed Sludge Treatment Systems

23. How well do I need to treat my wastewater
How well you treat the wastewater is dependent on the method of disposal
e.g. Sub-surface irrigation, ETA beds, mini trenches. Sub-surface irrigation
systems require the highest level of treatment out of these three options.
Manufacturers of sub-surface irrigation systems, such as,, require that the
wastewater is treated to a secondary level with BOD 20mg/L and TSS
30mg/L. A 7day residence time in the reed bed will produce a secondary
treated effluent If you are installing an indexing valve and mini trenches or
ETA beds it is not so important to achieve a 20/30 BOD/TSS if nutrient
considerations have been met because the pipes used in the beds/trenches
have larger holes to allow solids to pass through. Therefore, in general, reed
beds used with sub-surface irrigation systems will be slightly larger, usually
in order to allow BOD levels to drop.

24. Reed-Bed Life Span
Reed beds are not a long term solution. They are a
relatively new idea and even when they are
designed and maintained properly, they will only be
viable for up to a maximum of 7 to 10 years for reed
beds that follow a full treatment plant as a final
polishing filter only. Severn Trent Water, with over
300 installed, is currently having to start a
refurbishment programme for reed beds which have
been in use for a few years

25. Reference
 www.researchgate.net
 www.wte-ltd.co.uk
 info.cat.org.uk
 www.canberragarden.com
 www.researchgate.net
 www.poplarnetwork.com
 www.reedbedtechnology.com
 www.slideshare.net
 www.oceans-esu.com