Involvement of Microbial Populations During the Composting of Olive Mill Wastewater Sludge

Abstract

Olive mill waste water sludge obtained by the electro-Fenton oxidation of olive mill waste water was composted in a bench scale reactor. The evolution of microbial species within the composter was investigated using a respirometric test and by means of both cultivation-dependent and independent approaches (Polymerase Chain Reaction-Single Strand Conformation Polymorphism, PCR SSCP). During the period of high respiration rate (7-24 days), cultivation method showed that thermophilic bacteria as well as actinomycetes dominated over eumycetes. During the composting process, the PCR-SSCP method showed a higher diversity of the bacterial community than the eukaryotic one. After 60 days of composting, the compost exhibited a microbial stability and a clear absence of phytotoxicity.

Electro-Fenton Process and Related Electrochemical Technologies Based on Fenton’s Reaction Chemistry

“…A greater reduction in the organic load of wastewater is feasible by coupling the ECP process with a more inexpensive biological post-treatment. However, this interesting bio-ECP remediation has only been tested for some real effluents such as landfill leachate and olive oil mill wastewater (OMW). – Figure a shows a flow process of three steps involving chemical coagulation, the ECP process, and a sequencing batch reactor (SBR), which was designed by Lin et al as an efficient and cost-effective treatment of a leachate effluent. It contained about 2000 mg L −1 COD, which was initially reduced by over 50% by chemical coagulation with addition of polyaluminium chloride, while its pH decreased from 8.1 to 4.1.…”

A comprehensive overview of elements in bioremediation

“…Generally in situ bioremediation is carried under mesophilic condition (20-40°C). Even for laboratory studies, bacteria with potential remediation value have focused on mesophilic species because of the species, of cultivation and relatively short doubling times (Kuntz et al 2008;Abid et al 2007). The rate of biochemical reactions in cells increases with temperature up to a maximum, above which the rate of activity declines as enzyme denaturation occurs and organisms either die or become less active (TrasarCepeda et al 2007).…”

Exploitation alternatives of olive mill wastewater: production of value-added compounds useful for industry and agriculture

“…However, there are still only a few reports in the literature on this topic. Abid et al (2007) published a study focused on the analysis of the microbial communities during the composting of an OMWW sludge (obtained by electro-Fenton oxidation of OMWW) in a bench-scale reactor. The dynamics of microbial diversity was followed through a respirometric test and by means of both cultivation-dependent and cultivation-independent techniques (PCR-singlestrand conformation polymorphism; SSCP).…”