Abstract:
Ion-exchange water softener used in commercial and industrial applications to reduce hardness.
The water is passed through a negatively-charged resin initially containing sodium ions in the
softening cycle, after avoid a sufficient quantity of hardness ions, regeneration of the resin back
to sodium ion form is required. Regeneration involves contacting the resin bed with concentrated
sodium chloride (NaCl) solution.
The key objectives of this study is to increase the shelf life of IEX sulfonated resine using the
lpcal salt to provide a highly concentrated and purified NaCl solution that is fed to the softener
regeneration step on the selected industry. Experimental work was conducted by using chemical
treatment process, the chemicals used in this process were sodium hydroxide, sodium carbonate,
and barium chloride. The result from the purification proce ss depends on the rate of reaction
between the chemical used to treat salt impurities & its precipitation.
Response surface methodology based on CCD was employed to study the influence of variables
and to optimize the improved response Variables (Mg(OH)
2, CaCO
3
, total alkalinity & purity).
A response surface methodology was used to evaluate the effect of varibles (NaOH
concentration, Na2CO3
concentration, BaCl2
concentration, temperature and time on the response
variables i.e. Mg(OH)2,CaCO
3
, total alkalinity purity and on the IEX regeneration the hardness
leakage, treatement capacity .
The ANOVA result for all responses showed that the significance of all variables (P< 0.05)
showing that the model accurately includes most of the data in quadratic polynomial regression.
The newly developed approach was developed that integrates all parameters (NaOH, Na
2CO3
,
BaCl2, temperature and time) on optimization constraints. The optimization goal w ere obtaining
responses with a low Mg(OH)
2, low CaCO
3
, low total alkalinity and high Purity and on the hand
IEX regeneration the hardness leakage, treatement capacity.
The optimal value were Mg(OH)2, CaCO
3
, Total alkalinity and Purity values and on the IEX
regeneration using treated afdera brine low leakage (Co/C) & high Treatment capacity (BVs)
values of 0.081 mg/L, 0.050 mg/L, 0.116 mg/L, 98.52% ,67.09 % and 10.67 % respectively.
Key words: Ion exchange, NaCl,Water Softener, Response Surface Method, Central Composite
Design.