Olive mill wastewater: Treatment, valorization in the germination of tomato seeds and in the composting
Olive mill wastewaters represent a source of pollution for the environment, and hence there is a need for their treatment or their valorization. This study proposes the treatment of the olive mill wastewaters by electrocoagulation and their valorization, on the one hand, in the germination of the tomato seeds, and, on the other hand, in the humidification of compost. Raw olive mill wastewaters are acidic, with intense colour. They also have a high organic and mineral load. Electrocoagulation treatment increased their pH to neutrality and markedly reduced the intensity of their colour, which was reflected in a decrease in their polluting load of mineral and organic matter. The treated olive mill wastewaters acted very favourably on the germination of the tomato seeds, irrespective of the dilution rate. However, the application of raw olive mill wastewaters inhibited this activity. Using the olive mill wastewaters in the humification of compost contributed to the aerobic biodegradation of all substrates, as shown by monitoring physicochemical parameters over time until maturation after 12 weeks.