THE BIOFIL TOILET SYSTEM
The Toilet Facility that Makes Good Sanitation Sense
The Biofil Digester is a simple compact on-site organic waste treatment system that uniquely
combines the benefits of the flush toilet system and those of the composting toilets and
eliminates the disadvantages and drawbacks of both systems.
The Biofil Digester
How it works
The Biofil Digester technology mimics the decomposition found under forests’ floors and other
natural environments. Living organisms (both microorganisms and macro-organisms such as
earthworms) in an enclosed environment treats all organic degradable matter through the natural
process of aerobic decomposition.
Wastewater and fecal matter enter at the top of the Biofil Digester where rapid separation of
solids and liquid contents of the waste occurs. The digester is essentially a biological filter
consisting of a medium of soil and pervious concrete. Bacteria, other organisms degrade solid
fecal matter. All liquids are organically filtered out of the bottom of the digester and drained into
the soil where further and final decomposition occurs. Other solids (toilet paper & all degradable
anal cleaning material) are decomposed and converted into rich & safe soil.
When the Biofil Digester is used in the flush toilet situation, high nutrient biologically treated
water is made available for effective landscaping and beautification of the environment.
The design is simple, replicable, and affordable. It operates on very low maintenance
requirements. It suitable for all soil conditions including heavy clay soils, shallow or exposed
rock beds and soils with high water tables. The digester can be laid above ground or below
ground depending on the groundwater level of the location.
The digester operates as a filter via:
Rapid separation of solids and liquids
Aerobic composting of solids and
Bio-filtration of waste water
For maximum sanitation effect, the Biofil Microflush Toilet System is designed to integrate hand
washing.
Cross-section of the Biofil Digester System
Top co vers
Co ncre te Pane l ( P.V.C p ip e l)
Hum us Soil
( Conc ret Pa ne l)
Pervious
Co ncre te
(Pa vem ent Blo cks)
(Air Sp a ce )
Sa nd Sto ne s
Co ncre te Pane l
BiofilCom 13
The main drivers of the Biofil system
Good sanitation practice
Biofil Digester is completely aerobic. It requires minimum maintenance and needs no
mechanical or electrical aeration of solid mass to achieve decomposition. There is no need
for human contact with excreta. No odours or sludge are generated in the system to attract
insects that spread germs. Design considerations of the system (digester made of concrete)
make it impossible for rodents to burrow into Digester unlike conventional pit latrines.
Minimum land uptake
The basic digester is 2ft X 2ft X 6ft (600mm X 600mm X 1800mm) and so land-take is
minimized.
Number of Users
The typical digester (2ftX2ftX6ft or 600mm X 600mm X 1800mm) can accommodate 25
users in the micro-flush setting and 10 users when operated as a flush unit. These are average
typical usages the digester can tolerate occasion heavier use.
Environmental friendliness
Because the digester and effluent pipes are always installed above the ground water table,
water contamination is completely eliminated. Waste is treated under complete aerobic
conditions eliminating odour and air pollution. The system eliminate the possibility of costly
site remediation and clean-up (as in the case of failed septic / KVIPs)
Portable water savings
Bio-filtered water from digester is idea for landscaping in the case of flush toilets
Health impact mitigation,
The hazards of unsafe sanitation include diseases like cholera, dysentery, scabies and
intestinal worms, and environmental pollution. Biofil toilets are well ventilated, well
illuminated and meet the specific needs of user groups. Misuse of toilets and open defecation
is often avoided. Tiled interiors makes cleaning toilet easy. The digester provides a complete
barrier to insect vectors that spread diseases.
Ecological impact mitigation
The system eliminates ground/surface water and air contamination. It has a potential of
reducing greenhouse gas emissions through the avoidance methane emissions directly into
the atmosphere.
Environmental, Social and Technological Benefits
The system is technical, economic, social and environmental suitable for use in all situations,
especially where:
Water supply is an issue:
• Onsite well, or watercourse on the property where the danger of pollution of these
sources by runoff from waste and effluent is real
• Property is located in chronically drought-affected area
• Property has limited supply of fresh water
Service is an issue:
• No sewer, no water
• No septic hauling service
Property is an issue:
• Adverse soil conditions (clayey / solid rock sites )
• Poor drainage, high water table
• Low or seasonal use situations of sanitary facilities
• Crowded area/small land space
Designed in Africa for Africa, Biofil relies entirely on local manufacturers and local materials. It
is excellent in performance, affordable and replicable.
BIOFIL DIGESTER AS A FLUSH SYSTEM
When the Biofil Digester is use in homes offices and other commercial properties for treating
septic waste, it totally replaces the traditional septic tanks. It may be installed above ground or
buried depending on groundwater conditions. All the plumbing within the building remain
unchanged. For toilets located on the ground floors we recommend that P-trap WC toilet bowls
be used in areas with high groundwater tables or in areas where installation of the Biofil digester
will have to be above ground.
Septic Tank Biofil Digester
Groundwater pollution None
Cesspit emptying cost No need for Cesspit emptying
Not ideal for water logged areas Suitable for all soil conditions
BIOFIL STAND-ALONE TOILETS
Design Considerations
The Biofil Stand-Alone Toilet System consists of the digester and a super structure with a robust
microflush seat, a wash hand basin and tiled interiors. Design ensures well lit interiors with
natural lights. Units are precast and are typically installed within two days.
Stand-Alone units can be used as flush and microflush Units.
KVIP squatting Hole Tiled interiors of Biofil Microflush Toilet
Relative Advantage
KVIPs Vs. Biofil Digester
KVIP BIOFIL
System quickly becomes anaerobic Decomposition occurs under aerobic
releasing hydrogen Sulphide with conditions. NO odourous gas
its odour associated problems emissions
Groundwater pollution occurs. Not Ground water not affected; Water is
suitable for the rural areas where directed into top soils where
water supply is obtained almost microbial activities are most active.
Nutrients are removed by soil bacteria
exclusively from groundwater
decomposition
sources
Danger of spillage of pit contents Digester designed above ground and
during floods. typically has no more than a week of
undecomposed contents in digester
Special details required to control Not necessary – no odours or insects
of odour and flies in a KVIP latrine problem
Not suitable for every soil type – Suitable for every soil type
esp. rocky soils
Mosquitoes tend to breed in pits System largely dry and does not breed
mosquitoes
Toilets smell bad when water Designed for cleanliness. Rapid
washes into pit during raining separation of liquid and solids occurs
periods or when clean water washes at all times
into pit. Always a problem in
cultures where water for anal
cleaning is the norm.
Pit will eventually fill with fecal No sludge buildup. No need for
sludge and will require shut down emptying
for above a year for full
decomposition of waste before
contents are dug out for reuse of
pit. Two pits are always provided
for each seat to allow for
continuous use.
The sludge requires treatment
prior to re-use or disposal Solid residue can be immediately
used as manure
Potential Drawbacks and Maintenance
The Biofil Digester is an aerobic system and must never be subjected to flooding. In many
instances the digester must be installed above ground level and always above the highest ground
water table level.
When used as a flush unit blockage of effluent line can be a problem. This will usually manifest
as flooding or reduced draining rate of the digester. The system is easily restored when the
blockage is rectified. When use as a microflush system this problem does not arise.
Examples of Current Biofil System Applications in Ghana
Biofil Digester at Iduaprim Mines Estates Microflush Biofil Toilet system
Digester installed at new residential Biofil Digester installed at a School in Pokuase
Biofil Digester installed at a security post Biofil digester installed at Ghana Home Loans Office
block
Stand-alone toilet with Digester Biofil Toilet attached to a security post
