Applicability Studies of Reactor Filled With Coffee Husk Blended with Wooden Chips as a Fixed Bed for Wastewater Treatment

Recent interest in environment-friendly materials for the treatment of wastewater leads to the creation of new composites. Organic matter can be effectively removed by packed materials such as plastic honey comb structures, corrugated sheets, stones, etc. in attached growth process. The use of naturally available fibrous materials, which is cost effective and also have characteristics of high specific surface area can be used as a support media in fixed film reactor. Several natural fibrous biomass support mediums are available for use; some of these are coffee husk and wooden chips. The present investigation aims to study the applicability of coffee husk blended with wooden chips as a fixed bed, and also to study the removal efficiency of chemical oxygen demand (COD), phosphate and ammonia nitrogen (NH₃-N) from the municipal wastewater. Two phases of operation were conducted to study the effects of hydraulic retention time (HRT), mixed liquor suspended solids (MLSS) and organic loading rates (OLR). In this study the experiment was conducted for a continuous mode of operation. The bioreactors were continuously aerated and fed with institutional wastewater having an initial average COD of 669 mg/L, ammonia nitrogen of 2.9 mg/L, phosphate of 19.83 mg/L, and TSS of 3600 mg/L. The reactor filled with coffee husk blended with wooden chips showed nominal amount of COD removal of 88-91%, ammonia nitrogen removal of 70-73% and phosphate removal of 91- 94% under different reactor conditions.