Method of controlling the amount of sanitizing agent in an aqueous medium

A method of controlling the amount of free available halogen present in an aqueous stream, comprising the steps of:

• (a) providing a halogenation unit having therein a source of free available halogen;
• (b) providing an aqueous stream;
• (c) splitting said aqueous stream into a first aqueous stream and a second aqueous stream;
• (d) introducing controllably said first aqueous stream into said halogenation unit and into contact with said source of free available halogen;
• (e) removing a third aqueous stream from said halogenation unit, said third aqueous stream containing free available halogen;
• (f) combining said third aqueous stream with said second aqueous stream to form a fourth aqueous stream;
• (g) determining the electrical conductivities of the aqueous stream of step (b) and of said fourth aqueous stream;
• (h) comparing the conductivities determined in step (g);
• and
• (i) adjusting in response to the comparison of step (h) the introduction of said first aqueous stream into said halogenation unit, thereby controlling the amount of free available halogen present in said fourth aqueous stream.

A method of sanitizing a surface comprising:

• (a) controlling the amount of free available halogen present in an aqueous stream by the steps of:
• (i) providing a halogenation unit having therein a source of free available halogen;
• (ii) providing an aqueous stream;
• (iii) splitting said aqueous stream into a first aqueous stream and a second aqueous stream;
• (iv) introducing controllably said first aqueous stream into said halogenation unit and into contact with said source of free available halogen;
• (v) removing a third aqueous stream from said halogenation unit, said third aqueous stream containing free available halogen;
• (vi) combining said third aqueous stream with said second aqueous stream to form a fourth aqueous stream;
• (vii) determining the electrical conductivities of the aqueous stream of step (a)(ii) and of said fourth aqueous stream;
• (viii) comparing the conductivities determined in step (a)(vii);
• and
• (ix) adjusting in response to the comparison of step (a)(viii) the introduction of said first aqueous stream into said halogenation unit, thereby controlling the amount of free available halogen present in said fourth aqueous stream;
• and
• (b) applying said fourth aqueous stream to a surface to be sanitized.