Open Ponds for Effluent Storage, a Pertinent Issue to Olive Mill Wastewater (OMW) Management in a Circular Economy Context: Benefits and Environmental Impact

Abstract

AbstractThe olive oil production is focused in the Mediterranean countries, accounting around 98% of total olive oil production worldwide. The olive mill wastewater (OMW), an olive oil processing by-product, is considered as one of the major polluting effluent in the world, produced in a relatively short period with high polluting load. Among OMW valorizing-treatments, the effluent storage in evaporation ponds is one of the practiced solutions reducing its environmental negative impact. Therefore, the aim of the present work was to highlight the OMW physicochemical and microbial characteristics when stored in evaporation ponds, and to investigate first its disposal management considering the natural evaporation process and the environmental factors effect’, the effluent constituents, their biodegradation, gas emission as well as its infiltration and soil impact. Secondly, the storage in open ponds was considered with different potential valorization/reuse of the storage effluent, providing specific awareness on circular economy operationalization in the agri-food system of olive oil supply chain. The OMW impact on soil at long term was discussed compared to a control non-contaminated basin. Linear polluting economy migration to a circular economy by OMW storage in open ponds with economical incomes through the recycling/reuse will be developed.KeywordsOlive mill wastewaterEffluent managementEvaporation pondsPhysicochemicalMicrobial characteristicSoil impactCircular economy