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

Amal Aitcheikh,Nadia Boutaleb,Said Lazar,Said El Antri,Mohammed Bennani,Bouchaib Bahlaouan

doi:10.19026/rjaset.15.5975

Abstract

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 <em>Aspergillus niger</em> and <em>Penicillium chrysogenum</em>. 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.

Highlights

The dairy industries consume large amounts of water daily during their processes, especially to maintain the hygienic and sanitary conditions required (El Jaâfari et al, 2015; El Jaafari et al, 2016) which generates waste water with a high content of organic matter, as well as waste production and management
The present study aims to study these new supports by comparing them with those used on an industrial scale, as well as to study their surfaces after the biological treatment to confirm the presence of biofilm at the end of the treatment
The abatement of COD increases with time because of the use of organic compounds by microorganisms, we noted that the presence of supports promotes biodegradation; a difference of more than 30% in the COD abatement is recorded between the processes using a garnishing and the process without garnishing

Summary

Introduction

The dairy industries consume large amounts of water daily during their processes, especially to maintain the hygienic and sanitary conditions required (El Jaâfari et al, 2015; El Jaafari et al, 2016) which generates waste water with a high content of organic matter, as well as waste production and management. The mobile bed reactors are among the designs that can implement a biological treatment; it has been proven that it effectively reduces the rejections of dairies to the regulations in force before they are discharged in the sewers or in the environment (Djelal et al, 2007; El Jaafari et al, 2014b; Aitcheikh et al, 2014; Bassin and Dezotti, 2018) Since these bioreactors are a design that require the use of colonization supports, the objectives of this study is to substitute the conventionally used synthetic supports (usually made of plastics) with other natural supports able to ensure optimal colonization of biofilm, in the presence of Aspergillus niger and Penicillium chrysogenum as biomass, their capacity and resistance in a stressful environment such as the presence of acid or phenolic products has been demonstrated in many studies (Esteban et al, 2006; Djelal et al, 2007; Wolski et al, 2012; Aitcheikh et al, 2014; El Jaâfari et al, 2014a; El Jaafari et al, 2014b; Ladeira Ázar et al, 2018; Bassin and Dezotti, 2018). In Corresponding Author: Nadia Boutaleb, Laboratory of Biochemistry, Environment and AgriFood, (URAC36), University Hassan II of Casablanca 20650, Morocco, Tel.: (+212) 6.61.38.93.85

Objectives

Methods

Results

Conclusion