ELECTROCHEMICAL GENERATION OF CHLORINE FOR DISINFECTION IN CONTINUOUS FLOW PROCESS

In-situ generation of chlorine was obtained by electrochemical process using Metal
Oxides - coated titanium as anode and Titanium as cathode. In this process, its effect
will be mainly based on the electrochemical production of hypochlorite and/or
hypochlorous acid from the chloride content of the water. Brine solutions which
consist of different concentration of sodium hydroxide (NaCI) were being prepared
for electrolysis at different conditions such as flow rate of brine solution entering
reactor (4 mL/min - 12 mL/min), electrodes configurations, brine solution pH (2 - 7),
chloride concentrations (3.6 mg/L - 100 mg/L) and current densities (1.33 mA/cm2-
4 mA/cm2) in a continuous flow process. The system was running for 5 minutes
before the 1 litre of sample taken so that the system was stabilized. Two conditions
that have been identified to produced optimum value of free available chlorine (FAC)
was at pH 5 which yield as high as 800 mg/L and electrodes configuration that
produce optimum FAC was arrangement B, which produced 640 mg/L of FAC. From
the 3D surface plot, it was found that FAC production increases with increase in
chloride concentration and current density but reduces with increase in flow rate.
Furthermore at 3.6 mg/L chloride concentration, sufficient amount of FAC was
produced for disinfection where 0.23 mg/L, 1.98 mg/L and 2.38 mg/L of FAC was
produced at current densities of 4 mA/cm2 and flow rate of 4 mL/min, 8 mL/min and
12 mL/min respectively.