Abstract
Beverage production generates large quantities of wastewater with high organic and refractory content due to the material used in the manufacturing or cleaning processes. The present study investigates the treatment of wastewater from a beverage industry with an anaerobic membrane bioreactor (AnMBR) coupled with nanofiltration (NF). Because of the favorable climatic conditions of the Sahelian context, the production of biogas has also been evaluated. The study was conducted with a pilot-scale AnMBR fitted with an external ceramic ultrafiltration membrane. The AnMBR was fed with wastewater produced from the beverage industry. A hydraulic retention time of 1.5 days was employed for the study, whilst a solid retention time (SRT) of 60 days was set. The COD load varied from 0.8 to 5.7 g COD/L/d during 123 days of operation. The effluent from the AnMBR was fed in batch mode to the pilot-scale NF equipped with a composite spiral membrane of polyamide, polysulfone, and polyester. The results obtained showed a faster acclimation of the sludge due to its familiarity with the influent. The significant variations in alkalinity of the industrial wastewater used required buffering for better control of the biomass in the reactor. The AnMBR provided over 99% turbidity removal, whilst COD removal efficiency attained was 94%. NF resulted in almost complete rejection of most ions with removal rates ranging from 90 to 100%. The biogas produced was estimated at 0.21 L biogas/g COD removed.