**5. Anaerobic treatment of olive oil mill wastes**

#### **5.1 Three-phase olive mill wastes**

#### **5.1.1 Three-phase olive mill solid wastes (3POMSW)**

The heterogeneous cellulosic and lignocellulosic structures of the husk make the anaerobic digestion of this waste impossible because the microorganisms are unable to attack these

The microbial fuel cell (MFC) is a new energy technology in which microorganisms produce electricity directly from renewable biodegradable materials (Logan et al., 2006). During microbial oxidation of biodegradable matter, not only are protons and oxidized products formed but electrons are remarkably transferred from the bacteria towards a solid electrode. The electrons flow through an electrical circuit towards the cathode where a final electron

Although interest in microbial fuel cells was relatively high in the 1960s, research has been limited as the cost of other energy sources remained low and the available microbial fuel cells lacked efficiency and long term stability. However, in the past seven to eight years there has been a resurgence in microbial fuel cell research. In fact, the efficiency of this energy conversion is potentially higher than the actual waste treatment technology for

Microbial fuel cells have been validated at lab-scale with simple organic substrates, pure culture and highly controlled experimental conditions. Organic substrates as volatile fatty acids and more recently wastewater have generated high energy production (Catal et al., 2008; Clauwaert et al., 2007; Clauwaert et al., 2008; Rabaey et al., 2003; Rabaey & Verstraete, 2005). Over the last 10 years, the improvement in the design of microbial fuel cells has increased electrical generation 10,000 times (Debabov, 2008). However, full scale application

acceptor is reduced resulting in generation of electrical power (Figure 3).

energy recovery, such as anaerobic digestion or incineration (Logan et al., 2006).

**Organic matter**

**e-**

**Biofilm**

**CO2**

**H+**

The heterogeneous cellulosic and lignocellulosic structures of the husk make the anaerobic digestion of this waste impossible because the microorganisms are unable to attack these

**Membrane**

**O2**

**H2O**

**4.3 Microbial fuel cell technology** 

has not yet been developed.

Fig. 3. Microbial Fuel Cell (MFC) set up

**5.1 Three-phase olive mill wastes** 

**5. Anaerobic treatment of olive oil mill wastes** 

**5.1.1 Three-phase olive mill solid wastes (3POMSW)** 

complex structures. Therefore, anaerobic digestion is not a suitable technology for the treatment of 3POMSW.
