Environmental Engineering Reference
In-Depth Information
electrodes has been demonstrated to be an effective process since it does not require a
substantial investment, presents similar advantages as chemical coagulation, and reduces
disadvantages and produces minimum sludge.
EC is an electrochemical process that comprises chemical and physical processes involv-
ing many surface and interfacial phenomena. The technology lies at the DC required for
the electrolytic process, which is generated either by conversion of an alternating current
electric supply by a DC conversion unit of required capacity or by a solar photovoltaic
system consisting of solar panel, charge controller, and tubular battery. The solar panels as
per required power (watt) and time are mounted in a southeast direction at a place where
direct sunlight is received. The DC received through the solar panel is stored in the tubu-
lar battery through a charge controller and supplied to the aluminum electrodes through
a DC regulator.
The main reactions involved in the EC are as follows:
Al → Al
3+
+ 3e
−
at the anode
(17.1)
Al
3+
+ 3H
2
O → Al(OH)
3
+ 3H
+
(1 7. 2)
Al(OH)
3
+
x
F
−
→ Al(OH)
3−
x
F
x
+
x
OH
−
(17.3)
2H
2
O + 2e
−
→ H
2
+ 2OH
−
at the cathode
(17.4)
On the basis of the technology, solar-power-based electrolytic deluoridation demonstra-
tion units (Figure 17.4) were installed at Dongargaon in Chandrapur district, Maharashtra,
in 2002 and at Usarwara village in Durg district in Chhattisgarh state in 2010. The capacity
of these units is 600 and 2000 L per batch, respectively.
Three more plants were installed at Sargapur in Seoni district, Madhya Pradesh, in 2010;
at Malgaon in Balod district, Chhattisgarh, in 2011; and at Adiwasi Kanya Shiksha Parisar
in Chhindwara district, Madhya Pradesh, in 2012, keeping in view the successful perfor-
mance of earlier plants. These plants have a capacity to supply 2000 L per batch to a com-
munity of around 600-700 persons (Figure 17.5).
FIGURE 17.4
(See color insert.)
Electro-deluoridation ield units by CSIR-NEERI, Nagpur, India.
