Solutions of 5 vol% of HCl and 0.1 vol% of NaOH each in 100 mL distilled water were prepared. The cation tube was filled with the 5% HCl solution and the anion tube with the 0.1% NaOH solution; each containing 20 g polymeric resin. The process started by pumping the hard water through the column, and water was allowed to pass through the outlet tubes. Once a steady flow is passing through the outlet, the conductivity of the water at the outlet was recorded at time intervals of 10 seconds. The pump turned off when the conductivity values start to increase until reaching a steady state. The experiment was repeated with other concentrations of HCl and NaOH with 0.5 and 0.1 increments, respectively.
For the purpose of studying the effect of amount of water treated, the process was repeated at certain concentrations of HCl and NaOH with the tubes filled with different amounts of hard water. Also, the effect of amount of resin used was studied by pacing different amounts of resin at the different runs for given concentrations of HCl and NaOH.
In the regeneration process, acid or
caustic is fed into the ion exchangers from below using the same pump. The acid and
caustic used is collected in the collecting tank. The flow rate of the pump is adjustable, and can be read from a flow meter before it enters the first ion exchanger. For
continuous evaluation of the process, a conductivity sensor is installed upstream of
the inlet into the collecting tank. The measured values can be read from a conductivity meter. Samples can be taken at all relevant points. Tap water can be used as
raw water.
or continuous evaluation of the process, a conductivity sensor is installed upstream of the inlet into the collecting tank. The measured values can be read from a conductivity meter. Samples can be taken at all relevant points. Tap water can be used as raw water.
as the amount of resin decreases, the conductivity of water increases indicating that fewer ions were removed. So, resin volume should be high.
lowest conductivity is achieved when using 1-vol% NaOH and 5-vol% HCl in the cathodic and anodic resin tubes, respectively.