Proceedings available at: http://www.extension.org/67656 The objective of this research was to evaluate electrolyzed water as a solution for a lab-scale spray scrubber for removing NH3 from air. A one-stage spray scrubber was fabricated to treat 50 cfm (1.42 m3/min) of introduced mixed NH3-air with an approximate NH3 concentration of 20 ppm. The mixed air was blown, countercurrent, to the 5-ft vertical scrubber body using a fan. Eight scrubber design variables were studied including contact times, nozzle types and scrubber solutions. Three contact times were 0.3, 0.6 and 0.9 s. The two narrow and standard nozzles sprinkled in a full-cone spray pattern but at different angles of 26ᴼ and 52ᴼ, respectively. The scrubber solutions variables tested were reverse osmosis (RO) water and two types of electrolyzed water (50 ppm of total chlorine) with pH = 9.0 and pH = 6.5. The 18 combinations of treatments were tested in three replications and statistically analyzed to investigate the objective. The result showed that all of the experiments were able to mitigate the NH3, but at different efficiencies. The maximum efficiency of 53% was acquired with the narrow nozzle, 0.9s contact time and electrolyzed water with pH = 6.5. Therefore, it was concluded that increasing the contact time, decreasing the pH of electrolyzed water and using the narrow angle, higher flow rate nozzle increased the scrubber efficiency.

1. Ammonia (NH3) Mitigation Using an
Electrolyzed Water Spray Scrubber
Gerald Riskowski, Professor,Texas A&M University, Bio. Ag. Eng. Dept.
Saqib Mukhtar, Professor,Texas A&M University, Bio. Ag. Eng. Dept.
Ahmad Kalbasi, Researcher,Texas A&M University, Bio. Ag. Eng. Dept.
Amir M. Samani Majd, PhD Candidate,Texas A&M University, Bio. Ag. Eng. Dept.
Waste to Worth Conference, Hyatt Hotel, Denver, CO. April 1-5, 2013

2. Introduction
 NH3 emission from AFOs
 Adverse effects on animal and worker health
 Source of Odor and Environmental Pollution
Contribute to fine particulate matter formation
Eutrophication of water bodies
Contamination of groundwater
Constituent of nitrous oxide, a potent greenhouse gas
 NH3 emission into the atmosphere results in a loss of
nitrogen, an essential plant nutrient.

3. Introduction
 U.S.EPA regulation
- Environmental Planning and Community Right-to-Know
Act (EPCRA)
-NH3 and H2S emissions exceeding 45.4 kg (100 lb) in any
24 hour time period are considered a “reportable
Quantity.”

4. Introduction
Abatement Technologies
 Chemical amendments
 Hollow fiber mitigation technologies
 Bio-filters
 Exhaust air scrubber
 Packed bed scrubbers
 Impingement plates scrubbers
 Fiber beds Higher pressure drops and
operating costs compared
 Cyclonic spray scrubber, to spray scrubbers
 Venturi scrubbers
 Rotating beds

5. Objective
To develop and evaluate a lab-
scale spray scrubber that
uses an electrolyzed water
scrubber solution.

6. Materials and Methods
The main set-up
A one-stage spray
scrubber
5-ft vertical
scrubber body

7. Materials and Methods
The main set-up
A fan blew 50 cfm
of mixed NH3& air
into the scrubber
stream
 Approximate NH3
concentration in
simulated exhaust
air was 20 ppm

8. Materials and Methods
Two Types of Nozzles Used for Scrubbing
Exhaust Air
 Narrow-Angle Full Cone Nozzle
 Standard Type Full Cone Nozzle

9. Materials and Methods
The main set-up
 Two types of nozzles:
A Narrow-Angle Full Cone Nozzle
A Standard Type Full Cone Nozzle
Nozzle Narrow-angle Standard Type
Spray pattern Full cone Full cone
Spray angle 26o 45o
Height of spray 30 cm (12”) 15 cm (6”)
Droplet size 700-900 µm 200-300 µm
Pressure 190-200 kPa 190-200 kPa
(27.6-29 psi) (27.6-29 psi)
Scrubbing solution 5.2 L/min 0.95 L/min
flow rate (~1.38 gal/min) (~0.252 gal/min)

10. Exhaust
Air
2
Contact
NH3 Preheating chamber
Analyzer System
Exhaust nozzle
Air P
Manometer
Spray F
P
cone
F 1
Air Air duct
Air Pump
Fan Nozzle
NH3 Cylinder
Drainage
Valve Scrubbing
Flowmeter F Solution
Pressure Gage P

11. Contact
chamber
Spray nozzle
Manometer
Air
duct NH3
NH3 flowmeter
diffuser
NH3
Air
nozzle cylinder
Centrifugal fan

13. Production of Electrolyzed water
 Membrane less Electrolyzed water
 Electrolyzing regular NaCl solution
In an EW solution, the most effective form of chlorine
compounds include hypochlorous acid (HOCl) and
hypochlorite ion (OCL-)
HOCl OCl- + H+

14. Materials and Methods
Experiments
 Eight Variables:
 54 experiments: 18 scenarios in three replications
- Contact times: 0.3, 0.6 and 0.9 second
- Nozzle types: Narrow and Standard
- Scrubber solutions: Reverse osmosis (RO)
water, two types of electrolyzed water (50 ppm of
total chlorine) with pH = 9.0 and pH = 6.5.

15. Materials and Methods
Measurements
 TEImodel 17C
chemiluminescence NH3 analyzer
Ion Selective Electrode
NH3 probe & pH probe

16. Results and Discussion:
Treatment Variables
Efficiency
Treatment #
(%)*
contact time
Nozzle type Scrubbing solution
(s)
1 0.3 37.9 (1.6)
2 EW, pH 6.5 0.6 51.9 (3.8)
3 0.9 56.0 (2.7)
4 0.3 34.7 (5.5)
5 Narrow-angle RO 0.6 43.9 (3.6)
6 0.9 49.5 (5.6)
7 0.3 39.0 (0.8)
8 EW, pH 9.0 0.6 47.1(2.0)
9 0.9 51.3(3.6)

17. Results and Discussion:
Treatment Variables
Efficiency
Treatment #
(%)*
Scrubbing
Nozzle type contact time (s)
solution
10 0.3 37.9 (0.7)
11 EW, pH 6.5 0.6 46.7 (3.3)
12 0.9 43.9 (4.4)
13 0.3 32.1 (2.5)
Standard
14 RO 0.6 36.7 (4.8)
Type
15 0.9 39.3 (2.8)
16 0.3 34.2 (7.7)
17 EW, pH 9.0 0.6 39.9 (3.9)
18 0.9 40.6 (0.7)

18. Results and Discussion:

19. Conclusions
 The ammonia removal efficiency of the scrubber ranged
from 34% to 56%.
 Increasing the contact time, decreasing the pH of
electrolyzed water and narrow spray pattern mostly
increased the efficiency of the scrubber.
 The maximum efficiency of 56% was for:
narrow nozzle,
0.9s contact time,
Electrolyzed water with pH = 6.5

20. Future Plan
A Wet scrubber will be designed from
the knowledge gained in laboratory
studies will be scaled-up for Field studies

21. Acknowledgements & Questions
Funding for this study was made possible by the State of Texas Air
Quality Initiative.