Procedure for Dosing of Sodium Meta Bisulphite

Procedure for Dosing of Sodium Meta Bisulphite


To describe a procedure for Dosing of Sodium Meta Bisulphite.

  • SCOPE:

This SOP is applicable for Dosing of Sodium Meta Bisulphite for pre-treatment  in Water Treatment Plant


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.


Dosing of Sodium Meta Bisulphite                                                                 -Attachment I


6.1       Sodium Meta Bisulphate (SMBS) Dosing System:

Raw water chlorination dosing may contain some amount of chlorine as free chlorine. Therefore it is

essential to de-chlorinate water as free chlorine is injurious to resin of Sand and Carbon filters and

Ro membranes.

  • Chemical to be used is Sodium Meta Bisulphite (SMBS) available in market with 40% concentration         and dosage required is 3.0 to 4.0 ppm.
  • Calculation for 4.0 ppm dosing of SMBS :

6.4      Dosing Chemical rate (Ltrs /day)

=  ppm solution X Flow rate ( m3/hr) X Operating hours  / 1000

= 4 X 2 X 10

0.40X 1000

= 0.20 Kg/day


  • Now fix dosing rate, say typically 4 LPH.
  • Dosing pump shall dose 4 X 10 (Operating hours) = 40 Ltrs liquid per day.

6.7      Now take 0.20kg/day SMBS  and rest water (40 – 0.20 = 39.80 Ltrs) in dosing tank to prepare the Fresh solution for the day

6.8       Set and start dosing pump flow rate at 4 LPH.

6.9      Free chlorine content will be checked by QC department by taking sample to ensure the de- chlorination.

6.10   Above calculation is typical example; however dosing rate, calculation, concentration and SMBS 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.

  • Operator will update the consumption and stock of Dosing in log sheet

7.0        REFERENCES:



SMBS :Sodium Meta Bisulphite

ppm    :Parts per million.

LPH   :Litres per hour.

Kg      :Kilogram.

RO     :Reverse Osmosis.

m³/hr    :Cubic meter per hour.

Ltrs    : Litres


Quality Control

Quality Assurance



Version No.
Effective Date Reason for Revision


Dosing of Sodium Meta Bisulphite

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