FSTP at Khulna, Bangladesh

January 16, 2018

Location: Khulna (22°47'37.5"N 89°29'31.6"E)
Scale: City level (Population-1.5 million)
Implementing Organisation:
SNV, Bangladesh
Area: 1.3 Acres (site) 700 sq.m (plant)

Designed Capacity: 180 cum/day
Operational since: February, 2017
Capital Cost: 19,874,465 BDT
15,289,017 INR
O&M: N/A

 
 

In absence of any centralised sewerage network in Khulna city, the majority of population is dependent on onsite sanitation systems. The faecal sludge generated by the city was dumped anywhere and everywhere in the city. Moreover, a lot of these systems were desludged manually. Hence this plant was designed and implemented by SNV with the help of AIT Bangkok. Though the municipality has to still work on ensuring regular load to the plant, now at-least they have a dedicated disposal site

 
 

Planted drying bed: 6 units
Unplanted drying bed: 6 units
Constructed wetland: 1 unit with 2 chamber
Polishing tank: 1 unit

Unplanted drying bed:
Raw FS is emptied from the tanker into the screening chamber to remove any grit and debris. the sludge from the chamber is directed to the respective unplanted drying bed. The dried sludge from the unplanted drying bed is collected every 2 weeks and is further processed for composting. Leachate of the unplanted drying beds is then flooded to the polishing pond

Planted drying bed:
FS is emptied at the screening chamber and then loaded onto PDBs with up-to 20 cm of FS per loading, where the sludge accumulates for several years depending on the loading rate, the capacity of the system. Once the sludge accumulates to a height of around 0.9 m in the PDB (in 2-3 years), it is removed and can be used as an organic soil conditioner. The leachate is then flooded to the polishing pond as for the first process.

 
 

Treated water from the polishing pond after a retention of 10-15 days is transferred to the final collection tank which is finally discharged to a canal behind FSTP. Since the plant is recently established and is underutilised, SNV and municipality are looking out for ways and means to get truckloads of FS to the treatment planr.

 
 

SK Shaker Ahamed
Technical program officer, SNV Bangladesh
+088 01789441910
sahamed@snv.org