Bimbo – Ricolino candy manufacturing plant in Mexico City was discharging wastewater with high amount of fats oil and grease and dissolved sugars. Local regulatory agency requested that suspended solids, oil and grease and dissolved BOD be almost completely removed prior to discharge to municipal plant. The available real estate in Mexico City was very limited. A multistep treatment system was designed and installed. System includes self cleaning rotary drum screen, grease trap, flocculation – flotation, UASB anaerobic reactor, moving bed biofilm reactor, clarifier and multimedia filters. Most of the time system can remove TSS, FOG and BOD almost completely. Occasionally when chocolate candy is manufactured extremely high BOD’s are present in the waste stream. On such occasions, residual BOD’s are somewhat higher. Home made modifications to both bioreactors (combination of fixed and suspended media) increased the system performance during such high BOD episodes.
Keywords: candy manufacturing wastewater, GEM System, modified UASB reactor, modified MBBR, TSS, FOG, BOD removal
Advanced pretreatment enables MBBR treatment of high strength candy manufacturing wastewater