with the permeate flux of 30–80 L/m
2 h. Mondal and Wickramasinghe (2008) treated
the oily wastewater of high concentrations of total organic carbon (136.4 mg/L) and
total dissolved solids (2090 mg/L) using the reverse osmosis membrane at the
pressure of 1.4–7 bar. The membrane successfully reduced the total organic carbon
and total dissolved solids concentrations to 45.2–1090 mg/L, respectively. In addition, a study conducted by Murray-Gulde et al. (2003) showed the outstanding
performance of the polymeric reverse osmosis membrane in treating oily wastewater. The membrane attained outstanding total dissolved solids and total organic
carbon removal performances of 95.5% and 76.2%, respectively with the flow
rates of 0.006–0.028 L/s at a pressure of 18.6 bar.
11.4 Electrochemical Treatment
Electrochemical treatment is arguably the most effective technique for the treatment
of oily wastewater. Electrochemical treatment offers several advantages, such as
(a) energy saving as the process operates at the ambient temperature and pressure,
(b) robust performance with the capability to adjust to the process variations such as
influent flow rate and concentration, (c) versatile and can be easily incorporated with
other technologies, and (d) ease of control as the process kinetics can be easily
controlled through the adjustment of working potential and/or current density
(Santos et al. 2006; Radjenovic and Sedlak 2015; Yavuz et al. 2010). However,
the electrochemical technique suffers from relatively high costs of electrodes and the
generation of toxic side products in the treated water (Radjenovic and Sedlak 2015).
There are two types of electrochemical processes, namely (a) electro-Fenton
(achieved from several electrodes) and (b) oxidation processes, which can be used
to treat oily wastewater of different sources. The electrodes used in the electrochemical technique are made from aluminum, platinum–iridium, boron-doped diamond,
and titanium–rubidium (Jamaly et al. 2015).
11.4.1 Electro-Fenton Process
In the electro-Fenton process, the Fenton’s reagent consisting of iron (II) ions and
hydrogen peroxide can be electrochemically generated on-site. Iron (II) ions can be
produced through two different ways, as such, (a) the reduction of iron (III) ions
(Eq. 11.4) and (b) the oxidation of a sacrificial iron anode (Eq. 11.5) (Yavuz 2007).
And, hydrogen peroxide can be generated via the reduction of dissolved oxygen as
demonstrated in Eq. 11.6 (Bellakhal et al. 2006).
370
M. H. D. Othman et al.
2 h. Mondal and Wickramasinghe (2008) treated
the oily wastewater of high concentrations of total organic carbon (136.4 mg/L) and
total dissolved solids (2090 mg/L) using the reverse osmosis membrane at the
pressure of 1.4–7 bar. The membrane successfully reduced the total organic carbon
and total dissolved solids concentrations to 45.2–1090 mg/L, respectively. In addition, a study conducted by Murray-Gulde et al. (2003) showed the outstanding
performance of the polymeric reverse osmosis membrane in treating oily wastewater. The membrane attained outstanding total dissolved solids and total organic
carbon removal performances of 95.5% and 76.2%, respectively with the flow
rates of 0.006–0.028 L/s at a pressure of 18.6 bar.
11.4 Electrochemical Treatment
Electrochemical treatment is arguably the most effective technique for the treatment
of oily wastewater. Electrochemical treatment offers several advantages, such as
(a) energy saving as the process operates at the ambient temperature and pressure,
(b) robust performance with the capability to adjust to the process variations such as
influent flow rate and concentration, (c) versatile and can be easily incorporated with
other technologies, and (d) ease of control as the process kinetics can be easily
controlled through the adjustment of working potential and/or current density
(Santos et al. 2006; Radjenovic and Sedlak 2015; Yavuz et al. 2010). However,
the electrochemical technique suffers from relatively high costs of electrodes and the
generation of toxic side products in the treated water (Radjenovic and Sedlak 2015).
There are two types of electrochemical processes, namely (a) electro-Fenton
(achieved from several electrodes) and (b) oxidation processes, which can be used
to treat oily wastewater of different sources. The electrodes used in the electrochemical technique are made from aluminum, platinum–iridium, boron-doped diamond,
and titanium–rubidium (Jamaly et al. 2015).
11.4.1 Electro-Fenton Process
In the electro-Fenton process, the Fenton’s reagent consisting of iron (II) ions and
hydrogen peroxide can be electrochemically generated on-site. Iron (II) ions can be
produced through two different ways, as such, (a) the reduction of iron (III) ions
(Eq. 11.4) and (b) the oxidation of a sacrificial iron anode (Eq. 11.5) (Yavuz 2007).
And, hydrogen peroxide can be generated via the reduction of dissolved oxygen as
demonstrated in Eq. 11.6 (Bellakhal et al. 2006).
370
M. H. D. Othman et al.