RO Cleaning Procedure

Cleaning procedure Recommended by Dow. Organic Cleaning Procedure There are eight steps in cleaning elements fouled with organics, but the six steps are conducted first with a high pH cleaning solution and then repeated with a low pH cleaning solution. 1. Make up the desired high pH cleaning solution selected Table 6.7. 2. ntroduction of the cleaning solution. !. "ec#cle the cleaning solution for !$ minutes. f a color change occurs, dispose of the cleaning solution and prepare a fresh solution. %. &oak. '. High(flow pumping. 6. )lush out. 7. "epeat steps 2 through 6 with cleaning solution of H*l at pH 2. +. "estart.

Cleaning solutions referred

referred

3lternate

Solution $.1 wt - a/H pH 12, !$0* maximum, followed b# $.2- H*l pH 2, %'0* maximum $.1 wt - a/H $.$2' wt - a(& pH 12, !$0* maximum, followed b# $.2- H*l pH 2, %'0* maximum $.1 wt - a/H 1.$ wt - a%4T3 pH 12, !$0* maximum, followed b# $.2- H*l pH 2, %'0* maximum

*leaning chemical formula in order used a/H is sodium h#droxide5 H*l is h#drochloric acid muriatic acid5 a(& is sodium salt of dodec#lsulfate5 sodium laurel sulfate5 a %4T3 is the tetrasodium salt of eth#lene diamine tetraacetic acid and is a8ailable from The ow *hemical *ompan# under the trademark 94"&44 1$$ and 94"&44 22$ cr#stals.

Note: Instead of HCl, citric acid ( food grade) should be used. As HCl is aggressive cleaner which will increase the permeate !". Biofouling Cleaning procedure The following cleaning procedure is designed specificall# for a s#stem that has been fouled with biological matter. Cleaning Procedure There are se8en steps in cleaning elements with biofouling. 1. Make up the cleaning solution listed from Table Table 6.+. 2. ntroduction of the cleaning solution. !. "ec#cle for !$ mins %. &oak for !$ mins '. *ontinue for 2 hours 6. High(flow pumping. 7. )lush out. +. "estart.

Table 6.8 Bio fouling cleaning solutions Cleaning solutions referred referred

3lternate

Solution $.1 wt - a/H pH 12, !$0* maximum $.1 wt - a/H $.$2' wt - a(& pH 12, !$0* maximum $.1 wt - a/H 1.$ wt - a%4T3 pH 12, !$0* maximum

*leaning chemical formula in order used a/H is sodium h#droxide5 a(& is sodium salt of dodec#lsulfate sodium laur#l sulfate5 a%4T3 is the tetrasodium salt of eth#lene diamine tetraacetic acid and is a8ailable from The ow *hemical *ompan# under the trademark 94"&44 1$$ and 94"&44 22$ cr#stals.

Flushing with SMBS solution: 1. 2. $. ). 5. +.

Flush the system till the pH is normal Add 1-1.5% SMBS  !ood grade" to the #leaning solution  permeate water" ir#ulate !or $& M'(S *rain Flush with permeate water till pH is normal ,estart.

r Flushing with  11 solution: 1. 2. $. ). 5. +.

Flush the system till the pH is normal Add 5&& ppm o!  11 to the #leaning solution  permeate water" ir#ulate !or $& M'(S *rain Flush with permeate water till pH is normal ,estart.