D1-Fecal-Sludge-Management-Planted-Sludge-Drying-Bed

7/28/2019 D1-Fecal-Sludge-Management-Planted-Sludge-Drying-Bed

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• All organic degradation process produce sludge.

• Sludge has a total solid content of 2 to 10 % and can not be transportsimple equipment.

• Apart from this, sludge is contaminated and occupies large volumes for

• Therefore it is better to dry or sludge (dewatering) before further use or

• Anaerobic sanitation systems (e.g. latrines, septic tanks, aqua privies, anreactors, biogas reactors) produce less sludge than aerobic treatme

trickling filters, activated sludge) and anaerobic sludge also dries better

less odour as it is more stabilised.

Background



Fecal Sludge

Fecal Sludge is the general term for the raw (or partially digeste

solid that results from the storage of blackwater or excreta. The c

of Fecal sludge varies significantly depending on the location

content, and the storage. For example, ammonium (NH4-N) can

300–3000 mg/L while Helminth eggs can reach up to 60,000 e

composition will determine the type of treatment that is possible a

use possibilities.



Sludge Drying Bed

Sludge drying beds are one of the simplest and oldest techniquesdewatering.

They are impermeable beds filled with different layers of gravsand.

Draining pipes are in incorporated in the bottom of the beds.

Sludge is applied in layers on the top filter beds. Drying is achieved by evaporation and gravity percolation. In

drying bed, the removal of humidity is enhanced by evapotrans

Dried sludge is not stabilized, but additional composting (e.g. cocomposting) will allow to recycle nutrients and organic matter inagriculture.



Sludge Treatment process with drying beds

• Unplanted

• Planted

Unplanted sludge drying beds

• Design similar to unplanted filters sand/gravel filters

• Require desludging after every cycle of drying (manpower required)

Planted sludge drying beds • Design similar to reed beds or constructed wetlands

• Do not need desludging after every cycle:

◦ Porosity is maintained by the root systems of the plants.

◦ Sludge is transformed into biomass (plants) and can be harvested.



Example: Unplanted Drying Bed



Example: Planted Drying Bed



Fertiliser for

agriculture

Septic tank

Co-composting

Conveyance

Filter

Process Flow Diagram Sludge dry



Project Works



Project Plant Components

• Filter media i.e Different layers of coarse gravel, gravel, sand.

•

Drying Beds• Under drain piping in the bed bottom

• Ventilation pipes

• Sludge Loading & inlet pipes

•

Sludge unloading chamber• Planting of Phragmites (Karka) reeds.

• Percolate collection pond

• Access road for tractor with vacuum pump

• Portable Diesel water pump



Trench cutting for foundation at Jhenaidah Pourashava



Construction works of Fecal sludge treatment plant at Narsingdi P



Construction works of Fecal sludge treatment plant at Jessore Pou



Piping arrangement of Fecal sludge treatment plant at Jhenaidah P



Inlet chamber and walkway at Jhenaidah Pourashava



HBB road at Jhenaidah Pourashava



Pond side protection at Jhenaidah Pourashava



Materials for Filter media



Filter Media

•Large gravel : d=20 -40 mm

•Fine gravel : d=5-10 mm

•Sand : d = 0.3 – 0.6 mm

Total thickness of filter media 700mm



Growth of Reed bed at Laxmipur Pourashava



Sludge collection from septic tank with

Laxmipur Pourashava



Sludge disposing from Vacutug at Laxmipur Pourashava



Treated water from Fecal sludge treatment plant at

Laxmipur Pourashava



BUET Laboratory Test Repor

Raw Water

Si.

No.Water Quality Parameters Unit Cons. Present

ECR 199Discharge in

Inland Water

Discharge

Public Sew

1 pH - 7.34 6-9 6-9

2 Fecal Coliform (FC) mg/L 160000 - -

3 Chemical Oxygen Demand (COD) mg/L 28100 200 400

4 Biological Oxygen Demand (BOD) mg/L 5000 50 250

5 Total Suspended Solid (TSS) mg/L 59036 150 500

6 Total Dissolved Solid (TDS) mg/L 450 2100 2100

7 Ammonia Nitrogen (NH3-N) mg/L 153.5 50 75



Si.

No.Water Quality Parameters Unit Cons. Present

ECR 199Discharge in

Inland Water

Discharge

Public Sew

1 pH - 8.09 6-9 6-9

2 Fecal Coliform (FC) mg/L 100 - -

3 Chemical Oxygen Demand (COD) mg/L 45 200 400

4 Biological Oxygen Demand (BOD) mg/L 12 50 250

5 Total Suspended Solid (TSS) mg/L 17 150 500

6 Total Dissolved Solid (TDS) mg/L 244 2100 2100

7 Ammonia Nitrogen (NH3-N) mg/L 1.69 50 75


Treated Water



Si.No. Water Quality Parameters Unit Cons. Raw Water Cons. Treat. W

1 pH - 7.34 8.09

2 Fecal Coliform (FC) mg/L 160000 100

3 Chemical Oxygen Demand (COD) mg/L 28100 45

4 Biological Oxygen Demand (BOD) mg/L 5000 12

5 Total Suspended Solid (TSS) mg/L 59036 17

6 Total Dissolved Solid (TDS) mg/L 450 244

7 Ammonia Nitrogen (NH3-N) mg/L 153.5 1.69


Treatment Achievement



Operation and Maintenance

Laxmipur Pourashava-

•Desludging starts from March 2013

•Operating Vacutug collection size - 2m3 Volume

•Desludging frequency- 2 septic tank in 1 week (2 separate days

days rest)

•3 persons working for operation & revenue collection

•All the persons are Pourashava employee



Revenue collection

Laxmipur Pourashava-

•68000.00 BDT already collected in 3 months (March to May)

•Charge imposed- 1000 BDT per 2m3 Sludge/Per Trip

•Cost for operation- 2500.00 BDT per week (Approximate)

•Revenue collection- 5666.00 BDT per week (Approximate)



Presented By

Md.Shafiqul HassanDeputy Project Director

Shishir Kumar BiswasAssistant Engineer

Secondary Town Water Supply & Sanitation Sector (GOB-AD

Department of Public Health Engineering



For Fu

shass

shish

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D1-Fecal-Sludge-Management-Planted-Sludge-Drying-Bed