Treatment of Dairy Effluents in Biological Fluidized-Bed Reactors using Oyster Shells as Ecological Garnishing

We investigated the effectiveness of a new ecological garnishing of natural origins in MBBR reactors: The shells of oysters, used for the biological treatment of dairy effluents, in the presence of fungi Aspergillus niger and Penicillium chrysogenum. The abatement performance of organic matter was compared with the same bioreactor design in the presence of a common reference support (Kaldnes K3), conventionally used on an industrial scale. Pollution parameter monitoring results (Chemical Oxygen Demand COD, total nitrogen soluble NKT, phosphorus P, suspended matter SM and biochemical oxygen demand BOD5) obtained using oyster shells as garnishing media, are favorable after only 24 h of biological treatment. Organic matter removal efficiencies are comparable sometimes even better than K3 media. All the results show that oyster shells can provide an ecological support for biofilm colonization in MBBR reactors and allow for a satisfactory pollution abatement rate.