Abstract:
Arabica coffee is cultivated by smallholder farmers for commercial purposes, and it is mainly processed using wet Coffee Processing Technology. Burundi has more than 250 Coffee Processing factories owned by private, cooperative and government which discharge effluents to the receiving water bodies. The aim of this study was to determine the physico-chemical properties of wet coffee processing plants effluent and environmental effects in Burundi. Levels of physico-chemical parameters in wastewater from Coffee Processing factories were studied, and the impact of wet coffee processing effluents on water quality of receiving water bodies were studied in Kayanza, Gitega and Makamba. The dynamic simulator Sewage Treatment Operational Analysis Overtime was used to simulate and optimize treatment design. The samples were collected from the effluent released from the selected wet coffee processing factories and Upstream and downstream of discharge points in the receiving rivers/Streams using pre-cleaned plastic bottles. pH, TDS, EC, DO, Salinity, were analyzed onsite by using Trace2o Hydrocheck HC1000 multi-parameter. Samples were prepared and analyzed using standards methods as described in AFNOR and APHA. Various simulation models were implemented using STOAT to simulate treatment processes in studied design approaches such as ASAL 1 model; BOD model; and SSED 1 model. Data were analyzed using Rstudio-1.0.153, GenStat 64-bit Release 14.1 and SPSS. The study found that coffee wastewater does not meet Burundi Effluent Discharge standards for TSS, COD, BOD5 and pH. However, Nitrates, Nitrites, DO, Phosphates, salinity, EC, TDS, Chlorides, Pb, Cu and NH4+ were in conformity with the set standards. All sites downstream had COD, BOD5 and TSS values above recommended standards while pH was below the allowable limits set by WHO and Burundi standards. The result from WCPTP designed by STOAT met the required standards for discharge in surface water bodies.
