Treatment of wastewater from Arabica coffee processing

5. 5. Khe Khe Sanh Sanh Pilot Pilot
Wastewater Wastewater Treatment Treatment
Plant Plant
5. 5. Khe Khe Sanh Sanh Pilot Pilot Water Water Treatment Treatment Plant
Plant
Waste Water type Required action Installation Remarks
Raw effluents from processing
(recycled water, demucilator
effluents, fermentation tank
effluents)
Fermentation,
Acidification and
sedimentation of mucilage
and pulp components diluted
in the water
Long and shallow acidification
tank
During acidification, a thick
crust of raw mucilage will
build up floating on the water.
The middle layer is clear acid
water, sediments will settle to
the bottom. Regular cleaning
is required.
Clear Acid water from Neutralisation with Mixing tank with trash pump Use powder or finely ground
acidification tank
limestone (CaCO3) to pH 6
limestone.
Neutralised water (pH around Reduction of BOD and - Biogas digester
Depending amount of
6)
COD, consumption fertilising - Wetland planted with reeds discharge water of the factory,
salts from reaction between and rushes
the most suitable options is to
acid and limestone (calcium - Anaerobic settlement pond be chosen.
acetate)
- Artificial aeration
Pre-treated waste water Final cleanup of water - Wetland planted with reeds Acidity and BOD/COD are
and rushes
under control, however water
- Water hyacinth pond might still be dark green to
- Final settle and infiltration
area
black in colour.
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