ammel process for the treatment of ammonia in low ... · the treatment of ammonia in low...

WaterTech 2011 Edmonton, AB

April 13‐15, 2011

Patented AmmEL Process for the Treatment of Ammonia in

Low Temperature Mine Wastewater;

Ammonia Converted to Environmentally–Friendly

Nitrogen Gas

Gene S. Shelp, Leonard P. Seed, Daren Yetman and John M. Motto

ENPAR Technologies Inc., Guelph, Ontario, Canada


April 13‐15, 2011

Introduction • Ammonia listed as a toxic substance by

Environment Canada

• One approach employed by the mining industry has been to lower the pH of the wastewater to render it less toxic (due to a shift in the NH3/NH4+ equilibrium)

• While this approach has assisted in meeting acute lethality discharge requirements, the total ammonia‐N released into the environment is not reduced

• Current technology for treating ammonia relies heavily on biological activity (e.g. nitrification) to convert ammonia to nitrate


April 13‐15, 2011

Introduction • Total nitrogen removal requires additional

biological processes to remove nitrate from wastewater prior to discharge

• Biological treatment systems are adversely affected by cold temperatures and changes in effluent composition

• A novel and patented ion‐exchange/electrochemical treatment technology (the AmmEL system) has been developed by Enpar Technologies, Inc. which is not adversely affected by low temperature


April 13‐15, 2011

The AmmEL Process

Electrochemical Reactor

IX

Wastewater (NH4)

Loading

(Phase 1)

Treated Effluent

Regeneration

(Phase 2)

Conversion

(Phase 3)

Regenerant Tank

IX

NH4 N2 NH4


April 13‐15, 2011

AmmEL Reactions

2NH4+ → N2 + 8H+ + 6e‐

2Cl‐ → Cl2 + 2e‐

Cl2 + H2O → HOCl + HCl

2NH4+ + 3HOCl → N2 + 3H2O + 5H+ + 3Cl‐


April 13‐15, 2011

The AmmEL Advantage

• Eliminates nitrogen loading by converting ammonia directly into innocuous N2

• Does not produce nitrate and the GHG nitrous oxide associated with biological treatment

• Not affected by low temperature

• Intermittent operation ‐‐ no start‐up delays

• Can be fully automated ‐‐ low maintenance


April 13‐15, 2011

System Applications

• Mining effluent or process streams containing ammonia derived from the use of ammonia based blasting powder and/or the oxidation of cyanide

• Tertiary treatment for municipal waste water treatment plants (MWTP) and lagoon systems

• Process streams related to steel, fertilizer and

chemical industries


April 13‐15, 2011

Pilot Study The AmmEL‐LC System


April 13‐15, 2011

AmmEL‐LC Pilot Unit Specifications

• 3‐20 cm x 3.05m fluidized bed IX columns, BV = 59.3L

• 1.5 kW electrochemical reactor

• pH adjustment station for the inlet water stream • The main operating conditions for the system were as

follows: – Wastewater flow rate: 18‐20 L/min – Recharge brine flow rate: 8‐10 L/min – Brine NaCl concentration: 3‐4% – Cell current: 150 A


April 13‐15, 2011

• Designed to allow for single column operation as well as series column operation

• Typical treatment mode was to operate the system with two columns in series in a lead‐lag arrangement

• Third column was either involved in a regeneration cycle or was in standby

• Following a regeneration cycle, the regenerated column was rinsed with a small amount of treated water to remove any extraneous brine

• The rinse stream was directed into a 200L holding tank for testing prior to release back into the holding pond


April 13‐15, 2011

IX 1 IX 1 IX 2 IX 2 IX 3 IX 3

Reactor Reactor


April 13‐15, 2011

Single Column Results

Breakthrough Curve at 18 L/min

99 98 97 9692

90 88 86 8479

75

67

5853

2728 28

29 29

27

3132

31 3130

2928

30

0.3 0.5 0.81.2

2.2 2.73.7 4.5

5.16.5

7.69.6

11.6

14.2

0

10

20

30

40

50

60

70

80

90

100

0

5

10

15

20

25

30

35

1 2 3 4 5 6 7 8 9 10 11 12 13 14

Amm

onia

Rem

oved

(%)

Amm

onia

Con

cent

ratio

n (m

g/L)

Run Time (h)

% Removed Inlet Ammonia Outlet Ammonia

99 98 97 9692

90 88 86 8479

75

67

5853

2728 28

29 29

27

3132

31 3130

2928

30

0.3 0.5 0.81.2

2.2 2.73.7 4.5

5.16.5

7.69.6

11.6

14.2

0

10

20

30

40

50

60

70

80

90

100

0

5

10

15

20

25

30

35

1 2 3 4 5 6 7 8 9 10 11 12 13 14

Amm

onia

Rem

oved

(%)

Amm

onia

Con

cent

ratio

n (m

g/L)

Run Time (h)



April 13‐15, 2011

Typical Single Column Results

Flow rate (L/min) 18.0 Total run time (h) 14 Total volume treated (L) 15,120 Water temperature (°C) 5.7 Inlet pH 7.76 Outlet pH 7.85 Avg inlet ammonia (mg/L) 29.1 Avg outlet ammonia (mg/L) 5.1


April 13‐15, 2011

Series Column Results

Ammonia Loading, Columns C2 & C1

96 96 96 96 94 92 9087

85 8480

76

6863

58

50

27

24

2725

2423

24

2021

2223

2120

2122 22

1.1 1.0 1.0 1.1 1.51.8 2.4

2.53.3 3.6

4.6 5.16.3

7.89.3

11.1

0

10

20

30

40

50

60

70

80

90

100

0

5

10

15

20

25

30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Amm

onia

Rem

oved

(%)

Amm

onia

Con

cent

ratio

n (m

g/L)

Time (h)


96 96 96 96 94 92 9087

85 8480

76

6863

58

50

27

24

2725

2423

24

2021

2223

2120

2122 22

1.1 1.0 1.0 1.1 1.51.8 2.4

2.53.3 3.6

4.6 5.16.3

7.89.3

11.1

0

10

20

30

40

50

60

70

80

90

100

0

5

10

15

20

25

30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Amm

onia

Rem

oved

(%)

Amm

onia

Con

cent

ratio

n (m

g/L)

Time (h)



April 13‐15, 2011



99 99 99 98 97 96 9491

88 90 8782

7872

6624

3032 32 32 32

3032

3032

3332

3332 32

0 .1 0 .3 0 .4 0 .6 0 .91 .3 1 .9

2 .8 3 .5 3 .24 .2

5 .77 .3

8 .710.8

0

10

20

30

40

50

60

70

80

90

100

0

5

10

15

20

25

30

35

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Ammonia Removed (%)

Ammonia Concentration (mg/L)

T im e (h )

% R em oved In le t Am m onia O utle t Am m onia

99 99 99 98 97 96 9491

88 90 8782

7872

6624

3032 32 32 32

3032

3032

3332

3332 32

0 .1 0 .3 0 .4 0 .6 0 .91 .3 1 .9

2 .8 3 .5 3 .24 .2

5 .77 .3

8 .710.8

0

10

20

30

40

50

60

70

80

90

100

0

5

10

15

20

25

30

35

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Ammonia Removed (%)

Ammonia Concentration (mg/L)

T im e (h )

% R em oved In le t Am m onia O utle t Am m onia


April 13‐15, 2011



96 97 96 95 9491 90

8582

7982

7673

32 32

35 35 3537

3534

37 37 3735

37

1.1 1.1 1.4 1.72.2

3.2 3.75.0

6.57.7 6.8

8.410.0

0

10

20

30

40

50

60

70

80

90

100

0

5

10

15

20

25

30

35

40

1 2 3 4 5 6 7 8 9 10 11 12 13

Amm

onia

Rem

oved

(%)

Amm

onia

Con

cent

ratio

n (m

g/L)

Time (h)


96 97 96 95 9491 90

8582

7982

7673

32 32

35 35 3537

3534

37 37 3735

37

1.1 1.1 1.4 1.72.2

3.2 3.75.0

6.57.7 6.8

8.410.0

0

10

20

30

40

50

60

70

80

90

100

0

5

10

15

20

25

30

35

40

1 2 3 4 5 6 7 8 9 10 11 12 13

Amm

onia

Rem

oved

(%)

Amm

onia

Con

cent

ratio

n (m

g/L)

Time (h)



April 13‐15, 2011

Series Column Results C2 & C1 C1 & C3 C3 & C2

Flow Rate (L/min) 18.2 18.1 18.3

Total Run Time (h) 16 15 13

Water Temperature (°C) 5.9 6.0 5.9

Inlet pH 7.79 7.84 7.82

Outlet pH 7.86 7.86 7.91

Average Inlet NH3 (mg/L) 23.0 31.0 35.3

Average Outlet NH3 (mg/L) 4.0 3.4 4.5


April 13‐15, 2011

Pilot Study Conclusions

• The AmmEL‐LC system can readily remove ammonia from mine waste water to below the discharge requirement of 10 mg/L

• No pretreatment of the stream was required

• The efficiency of the AmmEL‐LC was not affected by low water temperatures (>6°C)

• Operating costs were relatively low ($0.10/m3 of water treated)


April 13‐15, 2011

Full‐Scale Installation • Full‐scale installation commissioned March 10, 2010 in Timmins,

Ontario

• Three zeolite filled 30 cm (i.d.) x 6 m ion exchange columns

• Electrochemical reactor → 18 m2 of anode surface area; 16V, 2000A DC rectifier

• Chlorine gas scrubber to comply with Ontario MoE chlorine emission levels

• The system is designed to treat 400 m3 of mine waste per day containing an average of 30 mg of ammonia‐nitrogen/L

• Emission levels are 10 mg NH3‐N/L year round including during the winter months when mine water can reach temperatures slightly above freezing


April 13‐15, 2011

Ion Exchange Columns


April 13‐15, 2011

Electrochemical Reactor


April 13‐15, 2011

DC Rectifier Chlorine Gas Scrubber


April 13‐15, 2011

ammel process for the treatment of ammonia in low ... · the treatment of ammonia in low...

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