Procedure for Dosing of Sodium Hypo Chlorite

Procedure for Dosing of Sodium Hypo Chlorite


To describe a procedure for Dosing of Sodium Hypo Chlorite.

2.0) SCOPE:

This SOP is applicable for Dosing of Sodium Hypo Chlorite


Assistant Engineer/Above shall be responsible for implementation and compliance of this SOP.


Manager – Engineering/ Manager – Production/ Head-QA shall be accountable for implementation and compliance of this SOP.


Sodium Hypo Chlorite Consumption/Stock                                               -Attachment-I


6.1      Chlorine Dosing System :

Raw water contains organic, living micro organisms and iron which are undesireable, may cause iron

Fouling and  bio –organic fouling in resin and RO membrane. To oxidize the iron, disinfect raw water

and to break the organics, sodium hypo chlorite is used.

  • Chemical to be used for Chlorine Dosing is Sodium hypo-chlorite (NaOCl Concentration is normally

10% available in market) and dosage required is 1.0 to 2.0  ppm.

  • Calculation for 2 ppm Chlorination :

Dosing Chemical rate (Ltrs /day)

=  ppm solution X Flow rate ( m3/hr) X Operating hours


Concentration Fraction of NaOCl

= 2.0 X (1.0+1.0)X10

0.10 X 1000

=0.4 ltrs/day

= 400ml/day

  • Now fix dosing rate, say typically 4 LPH.
  • Dosing pump shall dose 4 x 10 (Operating hours) = 40 Ltrs liquid per day.
  • Now take 0.4Ltrs NaOCl (10%) and rest water (40 – 0.4 = 39.4 Ltrs) in dosing tank to prepare the fresh solution for the day
  • Set and start dosing pump flow rate at 4 LPH.
  • Chlorine content required will be checked by QC department by taking water from sampling point to ensure the required dosage of chlorine.
  • Above calculation is typical example; however dosing rate, calculation, concentration        and

chlorine dosage requirement may vary as per requirement. Also flow regulating      knob is available

on dosing pump to maintain flow rate and concentration of dosing chemical in line.

6.10      Operator will record the activity in respective attachment of SOP.

7.0        REFERENCES:



ppm     :Parts per million.

LPH    :Litres per hour.

Kg       :Kilogram.

m³/hr    :Cubic meter per hour


Quality Assurance




Version No.
Effective Date Reason for Revision

Attachment- I

Sodium Hypo Chlorite Consumption/Stock

    Date    Name of Chemical Initial Stock Receipt Consumption Final  Stock Sign.