Wet processing of Arabica coffee (Coffea Arabica) produces higher quality and
receives higher prices on the world market compared to coffee prepared via dry
method. Behind the background of depressed world market prices, countries with
comparatively low production costs like Vietnam will increasingly switch their
production to high quality and higher priced washed Arabicas in order to
enhance competitiveness and revenues.
However, wet coffee processing requires a high degree of processing know how
and produces large amounts of processing effluents which have the potential to
damage the environment. Characteristics of waste water from coffee processing
is a Biological Oxygen Demand (BOD) of up to 20.000 mg/l and a Chemical
Oxygen Demand (COD) of up to 50.000 mg/l aswell as an acidity of below pH 4.
In order to treat coffee processing waste waters, the constitution of waste water
is presented and technical solutions for waste water treatment in a pilot case are
presented.