Time-dependent evolution of olive mill wastewater sludge organic and inorganic components and resident microbiota in multi-pond evaporation system

• Published in: Bioresource technology 2010-08, Vol.101 (15), p.5749-5758
• Main Authors: Jarboui, Raja, Chtourou, Mohamed, Azri, Chafai, Gharsallah, Néji, Ammar, Emna
• Format: Article
• Language: English
• Subjects: Agriculture - methods; Applied sciences; Ashes; Autochthonous microbial flora; Bacteria; Biological and medical sciences; Computer Simulation; Evaporation; Evaporation ponds; Exact sciences and technology; Food industries; Fresh Water - chemistry; Fresh Water - microbiology; Fundamental and applied biological sciences. Psychology; Industrial Waste - prevention & control; Inorganic Chemicals - chemistry; Inorganic Chemicals - metabolism; Mathematical models; Microorganisms; Modelling; Models, Biological; Olea - chemistry; Olea - microbiology; Olive mill wastewater sludge; Organic Chemicals - chemistry; Organic Chemicals - metabolism; Pollution; Ponds; Principal component analysis; Sewage - chemistry; Sewage - microbiology; Sludge; Use and upgrading of agricultural and food by-products. Biotechnology; Waste water; Wastes; Wastewaters; Water Purification - methods; Water treatment and pollution
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2010.02.069

The physico-chemical and microbiological characterizations of olive mill wastewater sludge (OMWS) were investigated in five OMW evaporation ponds of the open-pond system in Sfax (Tunisia), during the olive oil production period in 2004. Time-dependent changes in both physico-chemical parameters and the microbiota were investigated. Mathematical models and principal component analysis (PCA) were used to establish the correlations between the studied parameters. During the effluent time-dependent changes in the ponds, the result of OMWS analysis showed an increase of sludge index (SI), ash content, total solids (TS), volatile solids (VS), ethyl acetate extractive (EAE) and total phosphorus (Total P), as well as microbial flora especially the yeasts and moulds. The SI, TS, VS and Total P changes with time fit a simple linear equation, while EAE, phenols and NH4+ fit a second-degree polynomial model. The PCA analysis exhibited three correlated groups. The first group included temperature, ash content, evaporation, SI, TS, VS, Total P, EAE, yeasts and moulds. The second group was made by bacteria and moisture; and the third group by NH4+, oil and phenol. Such modelling might be of help in the prediction of OMW changes in natural evaporation ponds.