title: Biological activity during co-composting of sludge issued from the OMW evaporation ponds with poultry manure-Physico-chemical characterization of the processed organic matter.
abstract: Olive mill sludge (OMS), a by-product resulting from natural evaporation of olive oil processing effluent, poses a major environmental threat. A current cost-effective practice of OMS management is composting. A mixture of OMS (60%) with poultry manure (PM) was successfully composted for 210 days. During the process, effluents of olive oil mill and confectionary were used to keep moisture at optimal level (40-60%). Biological indicators reflecting stability of the compost (microbial biota respiration and enumeration, and germination index) were analysed for the assessment of the product quality. The composted mixture showed a high microbial activity with a succession of microbial populations depending on the temperature reached during the biodegradation. The pathogen content from PM decreased with composting as did phytotoxic compounds. Phenols and lipids were reduced, respectively, by 40% and 84% while germination index increased with composting progress. Fourier transform infrared (FTIR) spectroscopic analysis revealed that the final compost improved the aromatic content compared to the starting materials, with a decrease in aliphatic groups and a reduction in the easily assimilated components by the microflora acting during the biological process. The final compost was characterized by relatively high organic matter content (26.21%), a low C/N ratio (16.21), an alkaline pH (8.32), a relatively high electrical conductivity (9.21mS/cm) and a high level of nutrients. The germination index for Lepidium sativum L. was 87.71% after 210 days of composting, showing that the final compost was not phytotoxic.
authors.affiliation: UR Etude et Gestion des Environnements Urbains et Côtiers Ecole Nationale d'Ingénieurs de Sfax - LARSEN, 3038 Sfax, Tunisia.
authors.forename: Salma
authors.initials: S
authors.lastname: Hachicha
authors.forename: Fatma
authors.initials: F
authors.lastname: Sellami
authors.forename: Juan
authors.initials: J
authors.lastname: Cegarra
authors.forename: Ridha
authors.initials: R
authors.lastname: Hachicha
authors.forename: Noureddine
authors.initials: N
authors.lastname: Drira
authors.forename: Khaled
authors.initials: K
authors.lastname: Medhioub
authors.forename: Emna
authors.initials: E
authors.lastname: Ammar
mesh_terms: D000818:Animals; D002244:Carbon / Q000032:analysis; D002245:Carbon Dioxide / Q000032:analysis / Q000378:metabolism; D007220:Industrial Waste / Q000032:analysis*; D008372:Manure / Q000032:analysis* / Q000382:microbiology*; D019216:Metals, Heavy / Q000032:analysis; D008903:Minerals / Q000032:analysis; D009584:Nitrogen / Q000032:analysis; D000069463:Olive Oil; D010938:Plant Oils; D011200:Poultry; D012722:Sewage / Q000032:analysis* / Q000382:microbiology*; D012987:Soil / Q000032:analysis*; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D007220:Industrial Waste; D008372:Manure; D019216:Metals, Heavy; D008903:Minerals; D000069463:Olive Oil; D010938:Plant Oils; D012722:Sewage; D012987:Soil; D002245:Carbon Dioxide; D002244:Carbon; D009584:Nitrogen