Group Title: Lake Alfred AREC research report
Title: A Key for determining the use of sodium hypochlorite (liquid chlorine) to inhibit iron and slime clogging of low pressure irrigation systems in Florida
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Permanent Link: http://ufdc.ufl.edu/UF00094251/00001
 Material Information
Title: A Key for determining the use of sodium hypochlorite (liquid chlorine) to inhibit iron and slime clogging of low pressure irrigation systems in Florida
Series Title: Lake Alfred AREC research report - Lake Alfred AREC ; HWF-100
Physical Description: 5 p. : ; 28 cm.
Language: English
Creator: Ford, Harry W., 1922-
Agricultural Research and Education Center (Lake Alfred, Fla.)
Donor: unknown ( endowment )
Publisher: Agricultural Research and Education Center
Place of Publication: Lake Alfred Fla
Lake Alfred Fla
Publication Date: May 17, 1979
Copyright Date: 1979
 Subjects
Subject: Irrigation water -- Quality -- Florida   ( lcsh )
Water -- Purification -- Chlorination -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
 Notes
Statement of Responsibility: Harry W. Ford.
General Note: Caption title.
General Note: "5/17/79-HWF-100."
 Record Information
Bibliographic ID: UF00094251
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 406543534

Full Text




Lake Alfred AREC Research Report-CS79-3
5/17/79-HWF-100



A Key for Determining the Use of Sodium Hypochlorite (Liquid Chlorine) to Inhibit
Iron and Slime Clogging of Low Pressure Irrigation Systems in Florida

Harry W. Ford
Professor (Horticulturist)
Agricultural Research and Education Center
Lake Alfred, Florida 33850


Terminology

EPA approved treatment. Only liquid sodium hypochlorite (NaOCI) is approved for use
in irrigation systems in Florida.

D.P.D. type chlorine test kit. A required purchase to measure free residual chlorine.
DO NOT use an orthotolodene swimming pool test kit which measures only total chlorine.

Free residual chlorine. The excess chlorine available to kill bacteria. Excess
chlorine cannot be present until chemical reactions with chlorine have been satisfied.

Injection system. A good quality variable rate injection pump is suggested. Increase
the rate of injection until the correct chlorine free residual is obtained.


Injection time. A 40 minute minimum injection of NaOC1 should occur early enough in
the irrigation cycle to permit 30 minutes of chlorine to reach the last emitter.

NaOC1. SEE: Sodium hypochlorite

Sodium hypochlorite (NaOC1). Liquid bleach or swimming pool chlorine either as
5.25% or 10%.

Water quality measurements are essential in order to use this key. Throughout the
irrigation season, changes in water quality will occur for iron, sulfides, and plI.
These should be checked at intervals and appropriate modifications made in the chlorine
injection procedure.

Water holding tanks with air spaces should not be used on low pressure systems. They
serve as chambers for bacterial slime growth particularly sulfur slime. The frequency
of chlorination must be increased. Certain precipitation reactions associated with
holding tanks have not been controlled in the range of pH 6.5-7.5.









A key for the use of sodium hypochlorite to inhibit slime clogging of low pressure irrigation
systems.
1. Surface water go to 2
1. Well water -to to 10
2. 0.2 to 2.0 ppm maximum of iron; lower than pH 6.5 go to 3
2. 0.2 to 2.0 ppm maximum of iron; higher than pH 6.5 go to 8
2. 0 to 0.1 ppm Fe; lower than pH 7.0 go to 3
2. O to 0.1 ppm Fe; higher than pH 7.0 go to 8
3. Visible greenish algal clumps in water go to 4
3. Water visibly free of biological growths go to 6
4. Chlorine injected on vacuum intake line before filter go to 5
4. Chlorine injected on pressure side after filter--
filter will clog from slimes. Unsatisfactory pro-
cedure. Otherwise go to 5
5. Sand filtration go to A
5. Screen filtration--may have frequent backflush problems.
Otherwise go to A
5. Slotted filtration--will not remove algae--use only for
larger than 7.0 gph spray jet nozzles. Keep daylight out
of the white PVC filter. Otherwise go to A
6. Inject NaOC1 (sodium hypochlorite) on intake side
of filter go to 7
6. Inject NaOC1 on pressure side after filter--unsatis-
factory; otherwise go to 7
7. Sand filter: more frequent backflushing during algal blooms, go to B
7. Screen filter; backflush problems during algal blooms.
Otherwise go to A
7. Slotted filter; will not trap algal blooms. Use only with
larger than 7.0 gph micro sprinklers. Keep out light.
Otherwise go to B

8. Trickle long path emitters--use only sand filtration.
Sludge precipitate may occur after 800 hrs even with
NaOCI. Otherwise go to A
8. Micro sprinkler system; 7 gph or greater each emitter:
May or may not accumulate sufficient sludge for block-
age: Use sand filtration. Otherwise go to A
8. Micro sprinkler system; emitters less than 7 gph. May
have sludge blockage, go to A

10. Well water contains iron but no sulfides go to 11
10. Well water with no iron and also no sulfides go to 19
10. Well water with no iron but contains sulfides go to 21
10. Well water containing iron and also sulfides go to 25
.11. pH less than 6.5 go to 12
11. pH 6.5 to 7.5 go to 16
11. pH 7.5 to 8.0 go to 18
11. pH higher than 8.0 Unsatisfactory for low pressure irrigation.
12. Open well with drop type suction inlet. Foot valve.
Centrifugal pump. NaOCl injection point deep into well. go to 13
12. Submergeable pump. Covered top. Injection point for NaOC1
as deep into well as possible. go to 13








12. Turbine pump.
Turbine pump.


NaOC1 injected below turbine
NaOCl injected just after pump on pressure side.


13. Water contains less than 3.5 ppm iron
13. Water contains more than 3.5 ppm iron. Unsatisfactory
14. No pressure holding tank on line
14. Pressure holding tank with air chamber. Unsatisfactory


15. If well is contaminated with
concentration is less than 2
15. If iron is more than 2 ppm.


iron deposits and iron
ppm
Unsatisfactory


16. Water almost free of suspended solids and/or organic-iron
completing agents.
16. Water contains suspended solids and organic-iron completing
agents. Less than 1 ppm iron. May clog from suspended
sludge particularly if iron is more than 1 ppm. Otherwise
17. Open well with centrifugal pump. Submerged pumps with
deep injection for NaOC1. Iron less than 2 ppm. More
than 2 ppm is Unsatisfactory
17. Turbine pump. Surface injection for NaOC1. No holding
tank. Iron less than 1.0 ppm. More than 1 ppm is
Unsatisfactory
17. Turbine pump. Deep injection for NaOC1. No holding
tank. Iron less than 2 ppm. More than 2 ppm is
Unsatisfactory


18. Open
deep
will


well with centrifugal pumps and submerged pumps with
NaOCl injection. Iron less than 2 ppm. Note: System
clog in 24 hours if chlorination stops. Otherwise


18. Turbine pump. As deep NaOCl injection as possible. Iron
less than 2 ppm. System will clog in 24 hours if chlorination
stops. Otherwise
19. Water almost free of suspended solids and/or organic
discoloration
19. Water contains suspended solids and/or discoloration
20. Open wells and/or other means of well contamination
20. No well contamination. MAY NOT NEED CHLORINATION. Otherwise
21. Sulfides less than 4 ppm
21. Sulfides more than 4 ppm may be toxic to plant roots
22. Artesian well
22. Well is not artesian


23. No leaks in well casing or other points on vacuum
side. Check valve. Positive artesian pressure during
irrigation season.
23. Any one of the following: Possible leaks in well casing
or other points on vacuum side. Old gate valve on
vacuum side. Pressure holding tank near pump. Artesian
pressure may be negative during dry season.
24. No leaks of air on vacuum side of pump gc
24. Possible leaks on vacuum side of pump. Pressure holding
tank in system. No check valve. Artesian pressure negative
during dry season. g
25. Sulfides 0.5 to 2 ppm and iron 0.1 to 3.0 ppm
25. Sulfides 2 to 4 ppm and iron less than 0.6 ppm
25. Sulfides 2 to 4 ppm and iron more than 0.6 ppm. Unsatisfactory
except with more than 12 gph microsprinklers. Otherwise


go to 13
go to 15



go to C


go to 14


go to C


go to 17


go to D


go to D


go to D


go to D


go to E



go to E


go to F
go to G



go to 23
go to 24


Sto I


o to J


go to 20
go to F



go to 22


go to G



go to H


go to 26
go to 26

go to 26








26. No air leaks in system. go to H
26. Air leaks on vacuum side of pump or there is a holding tank
near the pump. go to J
Chlorine Treatment
A. Less than pH 7.0: Use minimum of 1 ppm (Mg/L) free residual chlorine as measured at
the last emitter (Start with 3 ppm free residual as measured near the pump at the
first emitter). Inject for 40 min (minimum) each 6 hours of accumulative
irrigation time.

A. pH 7.0-7.5: Use minimum 1.5 ppm (Mg/L) free residual chlorine as measured at the last
emitter. (Start with 3.5 ppm free residual as measured near the pump at the first
emitter). Injected for 40 min (Minimum) each 6 hours of accumulated irrigation time.
A. pH 7.5-8.0: Use minimum 2.0 ppm (Mg/L) free residual chlorine as measured at the last
emitter. (Start with 4.0 ppm free residual as measured near the pump at the first
emitter). Inject for 40 min. (minimum) each 6 hours accumulated irrigation time.
B. pH 7.0: Use minimum of 1 ppm (Mg/L) free residual chlorine as measured at
the last emitter (Start with 3 ppm free residual as measured near the pump
at the first emitter). Inject for 40 min (minimum) each 12 hours of
accumulative irrigation time.
B. pH 7-7.5: Use minimum 1.5 ppm (Mg/L) free residual chlorine as measured at the
last emitter. (Start with 3.5 ppm free residual as measured near the pump at
the first emitter). Injected for 40 min (Minimum) each.l2 hours of accumulated
irrigation time.
B. pH 7.5-8: Use minimum 2.0 ppm (Mg/L) free residual chlorine as measured at the
last emitter. (Start with 4.0 ppm free residual as measured near the pump at
the first emitter). Inject for 40 min. (minimum) each 12 hours accumulated
irrigation time.
C. pH less than 6.3: Use minimum of 1 ppm (Mg/L) free residual chlorine as measured at
the last emitter (Start with 3 ppm free residual as measured near the pump at the
first emitter). Inject for 40 min (minimum) each 6 hours of accumulative irrigation
time.
D. pH 6.3-7.5. Use minimum 1 ppm (Mg/L) free residual chlorine as measured at last
emitter (Start with 3 ppm free residual as measured near the pump at the first
emitter). Inject NaOC1 for minimum of 40 minutes each 2 hours of accumulated
irrigation time.

E. pH 7.0-7.5. Use minimum of 2 ppm (Mg/L) free residual chlorine as measured at the
last emitter. (Start with 4 ppm free residual as measured near the pump at the
first emitter). Inject NaOCl CONTINUOUSLY.

F. Select the treatment and pH range of the water as indicated.
pH 7.0: Use minimum of 1 ppm (Mg/L) free residual chlorine as measured at
the last emitter (Start with 3 ppm free residual as measured near the pump
at the first emitter). Inject for 40 min (minimum) each 12 hours of
accumulative irrigation time.

pH 7-7.5: Use minimum 1.5 ppm (Mg/L) free residual chlorine as measured at the
last emitter. (Start with 3.5 ppm free residual as measured near the pump at
the first emitter). Injected for 40 min (Minimum) each 12 hours of accumulated
irrigation time.
pH 7.5-8: Use minimum 2.0 ppm (Mg/L) free residual chlorine as measured at the
last emitter. (Start with 4.0 ppm free residual as measured near the pump at
the first emitter). Inject for 40 min. (minimum) each 12 hours accumulated
irrigation time.








G. pH up to 7.5 use NaOCl with minimum of 0.75 ppm (Mg/L) free residual chlorine as
measured at the end of line (2.5 ppm free residual near pump).
Inject for a minimum of 40 minutes each 25 to 40 hours accumulative time.
Watch carefully for any sulfur slime formation in the area of the last emitter
in the system.

pH 7.5-8.0 increase treatment by 1 ppm of NaOC1.

H. pH up to 7.5 use NaOC1 with minimum of 0.75 ppm (Mg/L) free residual chlorine
as measured at end of line (2.5 ppm free residual near pump).
Inject for a minimum of 40 minutes each 10 hours of accumulative time.
Watch carefully for any sulfur slime formation in the area of the last emitter
in the system.
pH 7.5-8.0 increase treatment by 1 ppm of NaOCI.
I. pH up to 7.5 use NaOC1 with minimum of 0.75 ppm (Mg/L) free residual chlorine
as measured at end of line (2.5 ppm free residual near pump).
Inject for a minimum of 40 minutes each 10-20 hours accumulative time.
Watch carefully for any sulfur slime formation in the area of the last emitter
in the system.
pH 7.5-8.0 increase treatment by 1 ppm of NaOC1.

J. pH up to 7.5 use NaOCI with minimum of 0.75 ppm (Mg/L) free residual chlorine
as measured at end of line (2.5 ppm free residual near pump).
Inject for a minimum of 40 minutes each 6-8 hours accumulative time.
Watch carefully for any sulfur slime formation in the area of the last emitter
in the system.
pH 7.5-8.0 increase treatment by 1 ppm of NaOCI.




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