Reed bed technology

Reed bed technology

1. Reed Bed Technology



SATPAL
ENVIRONMENTAL ENGINEERING Civil Engineering Department
S V NATIONAL INSTITUTE OF TECHNOLOGY, SURAT

2. Topics
Introduction
Working of reed beds
Types of reed beds
Factor Influencing the purification process of reed beds
Features of reed bed system
Application
Benefits
Conclusion
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3. INTRODUCTION
Reed beds are gravel filled, contained, shallow beds, planted
with plants (e.g. reeds), and specially design to treat
wastewater including sewage, agricultural, industrial and road
wastewaters.
Wastewater, black or grey, is passed through the root zone of
the reeds where it undergoes treatment.
Primary treated effluent from the house is initially filtered
prior to entering the reed bed through an effluent filter fitted to
the grey-water collection tank or septic tank outlet pipe then it
is passes through reed bed system.
Reed beds are generally designed to detain the wastewater for
a period of 5 to 7 days and the quality of treated effluent
improves with increased residence time
(1)
.
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4. WORKING OF REED BEDS
Fig.1. http://www.permaculturenews.org/images/how-reed-bed.jpg 4/25

5. The Phragmite is one of the most widespread flowering plants in
the world. It is a tough adaptable plant, which can grow in polluted
waters and find sustenance in sludge.
Reed beds perform three basic functions
(3)
:
(1) Dewater the sludge: - Dewatering is accomplished
through evaporation (as in a normal sludge drying bed operation).
(2)Transform it into mineral and humus like components:
- transpiration through the plants roots stem, and leaf structure.
(3) Store sludge for a number of years: - filtration through
the bed's sand and gravel layers and the plant's root system

Continue………….
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6. Fig.2. http://www.nireedbeds.co.uk/images/general/diagram2.gif 6/25

7. TYPES OF REED BEDS
Horizontal Flow Reed Beds
The effluent enters at one end and travels horizontally through the
reeds root zone, before being discharged on the far side of the bed.
These reed beds works particularly well for low strength effluents, or
effluent that have been pre-treated.
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. They are
particularly useful in converting nitrates into nitrogen.
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8. Fig.3 - www.ecotechnologies-international.com
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9. Vertical Flow Reed Beds
The reed beds are lined with deeper structures made up of
layers of various sized gravels planted with reeds. In this
system effluent is delivered to the top of the bed in
batches, floods the surface of the bed and drains through.
Each batch traps oxygen in the bed leading to an aerated
system.
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.

TYPES OF REED BEDS
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10. Fig.4. http://www.ecodesigns.co.uk/resources/vf%20reed%20bed%20section.jpg
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11. FACTORS INFLUENCING THE PURIFICATION
PROCESS OF REED BEDS
Life of Reed beds
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
(3)
.
Power Requirement and System Costs
Unless the site has a decent gradient, it is not usually possible
to avoid the need for electrical power when designing a reed
bed system. Reed bed systems for treatment of wastewater is
very low cost treatment method only a very low initial and
maintenance cost is required for construction and operation of
reed beds.

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12. Maintenance and Replacement of the system
Reed bed systems are not low maintenance and a regular
maintenance programme is required to keep them
working properly.
The owner will also require several injections every year
against leptospirosis, Hepatitis, etc. so fear of needles is
also a nuisance
Continue………….
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13. The Role of Plants

The specially selected plant species (Phragmite species
e.g. Phragmite karka and Typha angustus) is used.
The roots of the aquatic plant introduce atmospheric
oxygen down into the body of soil, facilitating the diversity
of microorganisms to flourish around the plant roots. It is
essential for the effective breakdown of various organic
and inorganic compounds.
The plants are capable of taking up a certain amount of
nutrients from the wastewater itself.

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14. Fig.5. sources:http://tcpermaculture.com/site/wp-content/uploads/2013/05/Reeds03.jpg
Phragmite karka
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15. Factors influencing the purification process of reed bed
treatment systems

The main factors that typify the treatment characteristics are:
 Hydraulic loading rate (m³/[ha x d]) and hydraulic detention
time(d)
 Temperature
 Influent pollutant concentration
 Oxygen supply
 Development stage of the reed ecosystem (this sequence is in
random order, not according to quantitative importance)

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16. The basic features of reed bed technology are given below:-
 Operation and maintenance free
 Can handle difficult effluents
 Self-sustaining
Adaptability
 Clean and
 Cost efficient

FEATURES OF THE REED BED SYSTEM
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17. The reed bed system is effective in treating effluent from
 Rural areas
 Food processing industry
 Breweries
 Animal husbandry
 Sewage from residential, institutional and industrial
complexes.
 Chemical industry
Applications
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18. It offers a low cost, low maintenance and sustainable solution to
effluent problems.
A single reed bed system is able to treat effluents from a number
of sources.
The operational cost of this mode is also less, as no trained staffs
is required for its operation.
The treated effluent can be safely used for irrigation and
the crops grown have higher yield and do not create any
health problem.

Benefits
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19. CASE STUDY
Case study from Ujjain city named “Performance
Evaluation of Reed Grass (Phragmites karka) in Constructed Reed
Bed System (CRBs) on Domestic sludge, Ujjain city, India
(3)
”.
Material and Methods
A field scale unit of Reed bed system was established at IEMPS,
Vikram University in the southern area of Ujjain in the state of
Madhya Pradesh, India.
The average temperature varies between 7ºC to 38ºC.
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20. 20/25
Continue………….
Physico-chemical Characteristic of reed bed complex after treatment in domestic sludge of Mahanandra Nagar
Parameter Initial 15Days %TP 30days %TP 45Days %TP 60Days %TP
pH 7.90 7.70 2.53 7.50 5.6 7.40 6.33 7.20 8.86
Conductivity(mMho) 1.25 1.20 4.00 1.00 20.00 0.80 36.00 0.55 56.00
Salinity 12.50 12.00 4.00 10.00 20.00 8.00 36.00 5.50 56.00
%Organic Carbon 38.00 37.00 2.63 33.00 13.16 30.00 21.05 28.00 26.32
%Organic Content 65.51 63.79 2.63 56.89 13.16 51.72 21.05 48.27 26.32
%Moisture content 70 58.00 17.14 35.00 50.00 22.00 68.57 11.00 84.29
Bulk density (%) 1.75 1.71 2.29 1.62 7.43 1.53 12.57 1.41 19.43
Total nitrogen (TKN) 37.10 35.70 3.77 25.90 30.19 20.60 44.47 12.17 67.20
Nitrate nitrogen 2.96 2.85 22.58 2.16 49.47 1.95 64.31 1.72 69.13
Ammonium Nitrogen 41.00 39.20 4.39 28.60 30.24 19.80 51.71 11.20 72.68
Organic nitrogen 22.40 20.60 8.04 15.40 31.25 9.62 57.05 5.14 77.05
Available Phosphorus 6.40 5.90 7.81 4.10 35.94 3.50 45.31 2.70 57.81
Total Phosphorus 7.70 7.50 2.60 5.60 27.27 3.10 59.74 1.20 84.84

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Continue………….
Physico-chemical Characteristic of reed bed complex after treatment in domestic sludge of Ravindera Nagar
Parameter Initial 15Days %TP 30days %TP 45Days %TP 60Days %TP
pH 8.10 7.90 2.47 7.70 4.94 7.60 6.17 7.40 8.64
Conductivity(mMho) 1.30 1.20 7.69 1.00 23.08 0.75 42.31 0.60 53.85
Salinity 13.00 12.00 7.69 10.00 23.08 7.50 42.31 6.00 53.85
%Organic Carbon 42.50 41.40 2.59 38.50 9.41 30.10 29.18 23.70 44.24
%Organic Matter 73.27 71.37 2.59 66.37 9.41 51.89 29.18 40.86 44.24
%Moisture content 80.00 71.00 11.25 58.00 27.50 35.00 56.25 14.00 82.50
Bulk density (%) 1.95 1.90 2.56 1.65 15.38 1.32 32.31 0.90 53.85
Total nitrogen (TKN) 40.60 39.90 1.72 33.10 18.47 21.00 48.28 15.00 63.05
Nitrate nitrogen 3.50 3.30 27.59 2.29 44.44 2.20 51.39 1.90 60.53
Ammonium Nitrogen 42.70 41.30 3.28 34.80 18.50 24.90 41.69 13.20 69.09
Organic nitrogen 24.60 22.90 6.91 15.80 37.77 10.10 58.94 4.60 81.30
Available Phosphorus 6.80 6.60 2.94 5.10 25.00 4.30 39.76 2.70 60.29
Total Phosphorus 7.50 7.20 4.00 5.10 32.00 2.50 66.67 1.00 86.67

22. CONCLUSIONS
The aim of this study was to know about the working of
Reed bed treatment system and their performance and there
type. From the above study we conclude that reed bed
treatment system is a environmental friendly cost effective
and efficient method for the treatment of the waste water
which is coming through the various industries, domestic
sectors, institutional activities.
After the treatment of water if water is reused then a
tertiary treatment is required for reducing their
contamination.

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23. Reed bed treatment systems have been successfully used
for treating a wide range of wastewater concentrations,
They can also handle a wide range of effluent throughputs
ranging from small and intermittent flows of about 1 m3/d to
several 10,000 m3/d.
The main benefits of the reed bed treatment system is it offers a
low cost, low maintenance and sustainable solution to effluent
problems.


Continue………….
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24. References
 http://www.alvinmorrow.com/
Lismore city council, May 2005, The Use of Reed Beds for the Treatment
of Sewage & Wastewater from Domestic Households.
 Smeal C, P. Truong, J. Biala and A. Butler, Gelita APA, Beaudesert 4285,
Australia, ”APPLICATION OF VETIVER GRASS IN SOIL BASED
REED BEDS FOR EFFLUENT TREATMENT AT GELITA APA,
AUSTRALIA”.
Fact sheet, June 2006, “Reed Beds- A brief guide”
Sushil Manderia, January 2012, Performance Evaluation of Reed Grass
(Phragmites karka) in Constructed Reed Bed System (CRBs) on Domestic
sludge, Ujjain city, India,
Mohammed Al-Saad, The 1stRegional Conference of Eng. Sci. NUCEJ
Spatial ISSUE vol.11, No.3, 2008 pp 494-505”Municipal Wastewater
Treatment Using Reed Bed Eco Technology”
Ecotechnologies International, Reed Bed Technology.
(www.ecotechnologies-international.com).
http://www.wte-ltd.co.uk/reed_bed_sewage_treatment.html

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