Abstract:
Wet coffee processing, if not conducted properly, can harm the environment. Hence, a study
conducted in Ethiopia, Jimma Zone, Gomma and Mana wereda at Geruke, Gembe,
Omobeko and Bulbulo sites from four points (upper stream of the river, pulping,
fermentation tank, downstream). In order to characterize the wet coffee processing
wastewater on physicochemical qualities and the laboratory treatment of pulping
wastewater using effective microorganism activated solution at Jimma University
environmental health laboratory. Physicochemical characterization of water samples taken
from four points of all locations was done with three replication. The laboratory analysis
was in factorial arrangement of CRD designed with two factors and three replications. The
factors were pulping wastewater from four locations (Omobeko, Bulbulo, Gembe and
Geruke) and the effective microorganism with two types activation and five levels. EMAS1
with 0ml, 2ml, 4ml, 6ml, and 8ml and EMAS2 with 0ml, 3ml, 6ml, 9ml and 12ml. As a result,
the wastewater showed very high BOD (12150 mg/l), TSS (1805.8mg/l), TDS (1702),
turbidity (647.5 NTU), EC (568.5 µS/cm), NO3 (24.87 mg/l), NH3 (11.06 mg/l), PO4 (4.85
mg/l) and low pH (2.95) and DO (0.02 mg/l) values. The EMAS1 treated pulping wastewater
show a reduction of 49.5 - 60.5% BOD, 23.05 - 26.88% NO3, 41-46% NH3 36 - 52% PO4,
24 - 33% EC, 35 - 47% turbidity, 37.5 - 52.5% TSS and 41.7 - 49.1% TDS and increment
of pH by 1.27 - 1.69 and DO by 1.4 - 2.5mg/l amount for effluent treated with 4ml EMAS1.
Whereas EMAS2 pulping wastewater was show reduction of 40 - 45% NO3, 72 - 82%
NH3, 30 - 52% PO4 when treated with 9ml EMAS2 and 49.5 - 60.5% BOD5, 29 - 40% EC, 40
- 53% turbidity ,39.9% - 52.5% TSS and 47.8% - 56.6% TDS and increment of pH 1.1 -
1.59 and DO by 1.99 - 2.8 mg/l amount when treated with 6ml EMAS2. The quality of
wastewater improved by using EMAS; the relatively good improvement of wastewater was
on the use of EMAS2 6ml due to its economical benefit and better wastewater quality
improvement than EMAS1 of 4ml. So using 6ml EMAS2 advantageous to use for the
treatment of wet coffee processing wastewater as far as this study was concerned. The
wastewaters from four locations were highly polluted with the high pollution load on
pulping and fermentation wastewater. Hence, there should be strict environmental
regulation imposed on coffee processing stations not only during establishment but also
during subsequent operations. However, further multidisciplinary researches are imperative
on the impact of wet coffee processing wastewater and its treatment. It is advisable to do
confirmation of this research both on in-situ and ex-situ condition.
