Capacitive membrane stripping for ammonia recovery (CapAmm) from

Subscriber access provided by UNIV OF NEW ENGLAND ARMIDALE

Letter

Capacitive membrane stripping for ammonia recovery (CapAmm) from dilute wastewaters Changyong Zhang, Jinxing Ma, Di He, and T. David Waite Environ. Sci. Technol. Lett., Just Accepted Manuscript • DOI: 10.1021/acs.estlett.7b00534 • Publication Date (Web): 21 Dec 2017 Downloaded from http://pubs.acs.org on December 24, 2017

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

Environmental Science & Technology Letters is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 18

Environmental Science & Technology Letters

1

Capacitive membrane stripping for ammonia recovery (CapAmm) from

2

dilute wastewaters

3

Changyong Zhang,a Jinxing Ma,a Di He,b,c and T. David Waite*a

4

a

5

Australia

6

b

7

Guangzhou 510006, China

8

c

9

Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China

School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052,

Institute of Environmental Health and Pollution Control, Guangdong University of Technology,

Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, School of Environmental

10 11

Email addresses: [email protected] (Changyong Zhang); [email protected]

12

(Jinxing Ma); [email protected] (Di He); [email protected] (T. David Waite)

13 14 15 16 17 18 19 20 21

Environmental Sciences & Technology Letters

22 23 24 25

__________________________________

26

*Corresponding authors: Professor T. David Waite; [email protected] 1 ACS Paragon Plus Environment


27

ABSTRACT

28

A novel cost-effective flow-electrode capacitive deionization unit combined with a

29

hydrophobic gas-permeable hollow fiber membrane contactor (designated as “CapAmm”) is

30

described here and used for efficient ammonia recovery from dilute synthetic wastewaters.

31

During operation, ammonia undergoes migration across a cation exchange membrane and

32

selective accumulation in the cathode chamber of a flow electrode followed by

33

transformation to dissolved NH3 with subsequent stripping via membrane contactor and

34

recovery as ammonium sulfate. Our results demonstrate that the CapAmm process can

35

achieve an ammonia removal efficiency of ~90% and recovery efficiency of ~60%. At current

36

densities of 5.8 and 11.5 A m−2 (normalized by effective cation exchange membrane area) and

37

hydraulic retention time of 1.48 min, the energies required for ammonia recovery were 9.9 and

38

21.1 kWh Kg−1 N respectively with these values comparable with other similar electrochemical

39

ammonia recovery systems. These findings suggest that the CapAmm technology described

40

here has the potential for the dual purposes of cost effective salt removal and ammonia

41

recovery from wastewaters, with greater stability, better flexibility and greater energy

42

efficiency than other methods.

43 44

KEYWORDS

45

Ammonia recovery, flow electrode capacitive deionization, membrane contactor, nitrogen

46

fertilizer, CapAmm

47

2 ACS Paragon Plus Environment

Page 2 of 18

Page 3 of 18


48

INTRODUCTION

49

A rapidly increasing world population and improvement in living standards have

50

resulted in the demand for greater food production with this production strongly dependent

51

on the utilization of fertilizers rich in nitrogen (N) and phosphorus (P) to maintain soil

52

fertility and increase crop yields.1, 2 However, the traditional Haber-Bosch process for the

53

production of ammonia, the key component in the synthesis of most popular N fertilizers

54

(including urea, ammonium nitrate and ammonium sulfate), is responsible for 1.5-2.5% of the

55

annual global energy consumption and more than 1.6% of global CO2 emissions.3-5

56

Considering that the demand for nitrogen fertilizer is expected to increase at an average

57

annual growth rate of 1.5% over the next decade,6, 7 the issue of how to produce ammonia in

58

a sustainable manner represents a global challenge.

59

While expenditure on ammonia production for fertilizer use is increasing, water

60

contamination has become increasingly severe, especially in recently industrialized countries

61

such as China and India, with ammonia nitrogen recognized to be one of the principal

62

contaminants. It has been reported that 2.5 million tonnes of ammonia nitrogen is discharged

63

annually to waterbodies in China2 with the injection of this major nutrient resulting in severe

64

eutrophication, acute and chronic toxicity to aquatic organisms and production of toxic

65

byproducts during drinking water disinfection.8,

66

technologies such as nitrification/denitrification, electrochemical oxidation and breakpoint

67

chlorination have been developed to remove ammonia from wastewaters,10-14 this practice

68

would seem unsustainable in view of the lifecycle of ammonia mentioned above. In light of

69

both the problems associated with removal of ammonia from waters and the increasing

70

demand for ammonia-based fertilizers, there is increased interest in ammonia recovery (and

71

production) from dilute wastewaters in view of the economic and environmental benefits.15-17

9

Though a great number of robust



72

The first step in the recovery of ammonia from low-strength wastewaters involves

73

pre-concentration of the ammonia. While ion exchange adsorption by zeolites and membrane

74

separation (e.g., reverse osmosis and nanofiltration) may be used to generate ammonia-rich

75

solutions,18,

76

quantities of chemicals for regeneration purposes and, as a result, are less feasible for

77

ammonia recovery from dilute waste streams. Recently, flow-electrode capacitive

78

deionization (FCDI) has attracted interest given its potential applications in seawater

79

desalination and energy storage.19-22 FCDI is particularly effective in accumulating ions in the

80

flow electrodes with cations such as Na+ and NH4+ concentrated in the cathode chamber and

81

anions such as Cl− concentrated in the anode chamber. In addition to this capacitive

82

mechanism, electron exchange at the surface of the flow electrodes may well result in the

83

consumption and/or production of protons.23 An increase in pH in the cathode chamber (as is

84

typical as a result, in part, of the reduction of oxygen)23,

85

speciation from NH4+ dominance at pH < pKa (of 9.3) for the NH4+-NH3 acid-base pair to

86

NH3(aq) dominance at pH > pKa. Equilibrium will rapidly be established between dissolved

87

and gaseous ammonia in the cathode chamber with the possibility of subsequent removal of

88

NH3(g) by interfacing the solution with a gas permeable membrane.

19

these technologies either suffer from high energy cost and/or require large

24

would result in change in

89

In this study, we develop a process for capacitive membrane stripping for ammonia

90

recovery (CapAmm) from dilute wastewaters (Scheme 1), in which ammonia undergoes

91

migration across a cation exchange membrane and selective accumulation in the cathode

92

chamber of a flow electrode followed by transformation to dissolved NH3 with subsequent

93

stripping via membrane contactor and recovery in acid solution (for example, as (NH4)2SO4).

94

A number of operational parameters associated with the performance of CapAmm are

95

investigated with specific consideration given to the mass flow of ammonia from the influent

96

wastewater to the acidic receiving solution. An overall evaluation of the operating cost and


Page 4 of 18

Page 5 of 18


97

economic benefit of the ammonia produced highlights the opportunities and challenges of

98

CapAmm in sustainable water, resource and energy management.

99

MATERIALS AND METHODS

100

Experiment Setup. The structure of the CapAmm apparatus is shown in Scheme 1a and

101

Figure S1. A silicone gasket and a nylon sheet (100-mesh) were bounded by two ion-

102

exchange membranes (CEM-Type I/AEM-Type I, FUJIFILM Europe) with the gap between

103

the ion exchange membranes acting as a spacer chamber (thickness of ~500 µm) through

104

which the wastewater flowed (Scheme 1b).21,

105

channels for flow electrodes were placed against the graphite current collectors (Scheme 1a).

106

The cross-section of each channel was 3 mm × 3 mm with an effective contact area between

107

the ion-exchange membrane and the flow electrodes of 34.9 cm2. These parts were held

108

together with the use of acrylic end plates (Scheme 1a and Figure S2). The flow electrodes

109

were continuously cycled between the flow channels and the circulation tanks, with the

110

polypropylene (PP) hollow-fiber membrane contactor (Schemes 1a and c) placed in the

111

negatively charged flow electrode circulation tank. The total length of the membranes used in

112

this work was 30 cm, with outer diameter of 2 mm, wall thickness of 0.1 mm, pore size of

113

0.45 µM and total effective surface area of 18.8 cm2.

25

Acrylic sheets with carved serpentine

114

Operating Conditions. Synthetic wastewater containing 1000 mg NaCl L−1 and 40 mg

115

NH4+-N L−1 was fed into the spacer chamber in single-pass mode. The effect of different

116

wastewater flow rates (of 0.85 to 2.55 mL min−1 with corresponding hydraulic retention time

117

(HRT) of 2.94 to 0.98 min) was evaluated in this study. The electrical conductivity of this

118

stream was continuously measured at the outlet with the use of a conductivity meter (CON-

119

BTA, Vernier) connected to a data acquisition system (SensorDAQ, Vernier). ). The flow

120

electrodes were composed of 10 wt% 100-mesh DARCO activated carbon (which, based on

121

SEM images, exhibited an average particle size on the order of 18.5 µm) and 90 wt% Milli-Q



122

water and were prepared in an identical manner to that described in our earlier studies.21 In all

123

experiments, the 65 mL flow electrodes were recirculated respectively using a dual-head

124

peristaltic pump (Longer pump, Baoding, China) at a constant flow rate of 50 mL min−1. In

125

one operating cycle, electrosorption was carried out at a constant current density (3.0-17.2 A

126

m−2) using a DC power supply (MP3840, Powertech). For ammonia recovery, the membrane

127

module was immersed in the cathode flow-electrode slurry while 65 mL of receiving solution

128

(0.5 M sulfuric acid) was continuously circulated (at 50 mL min−1) inside the hollow fibre

129

membranes.26, 27 The ammonia dissolved in the flow electrode slurry evaporates and diffuses

130

through the pores of the gas permeable membrane then reacts with sulfuric acid resulting in

131

formation of ammonium sulfate (the detailed mechanism is shown in SI text 1 and Figure S3).

132

The analytical methods and calculations are presented in Supporting Information.

133

RESULTS AND DISCUSSION

134

Ammonia Removal from the Dilute Wastewater. Results for salt removal

135

performance in the CapAmm system at different charging current densities and HRTs are

136

summarized in Figure S4 and Figure 1. Relatively stable effluent conductivity was observed

137

under all experimental conditions with higher current densities and longer HRTs resulting in

138

greater reduction in feed water conductivity (Figure S4). Meanwhile, increases in both

139

applied current densities and HRTs also exert positive effects on NH4+ and Na+ removal. It is

140

also revealed that CapAmm has a higher selectivity for NH4+-N compared to Na+ removal,

141

particularly at lower current density and/or HRT (Figure 1a and b). For instance, the ratio of

142

removal efficiency between NH4+-N and Na+ (i.e., RE(NH4+-N)/RE(Na+)) was 2.5 at a current

143

density of 3.0 A m−2 but gradually decreased to 1.8, 1.34 and 1.0 at higher current densities of

144

5.8, 11.5 and 17.2 A m−2. A similar trend was observed for the effect of change in HRT with

145

RE(NH4+-N)/RE(Na+) declining from 1.6 to 1.0 on increase in HRT from 0.98 to 2.94 min. The

146

change of current efficiency is described in the Supporting Information (see Figure S5).


Page 6 of 18

Page 7 of 18


147

It has previously been reported that ions with a smaller hydrated radius are transported

148

more rapidly from the feed water into the cathodic flow electrode under a fixed electrical field,

149

provided that they have the same valence charge.28 Additionally, smaller ions are more readily

150

electrosorbed by activated carbon particles than larger ions because of their easier access to the

151

micro-pores of these particle electrodes.29, 30 The fact that NH4+ has a slightly smaller hydrated

152

radius (3.31 Å) than Na+ (3.58 Å)31 may account for the observation that the electrosorption

153

process in our CapAmm system exhibits a higher selectivity towards NH4+ compared to Na+ at

154

lower current densities/shorter HRTs.

155

Ammonia Transformation in the Flow Electrode. Figure 1c and d indicate that the pH

156

of the cathode gradually changed from neutral to alkaline during operation. The shaded areas

157

represent the region where the pH was higher than the pKa of NH4+ (9.3). In this region,

158

almost all of the NH4+ will be deprotonated and transformed into dissolved NH3(aq), thereby

159

providing ideal prerequisites for ammonia separation and recovery from the bulk solution via

160

membrane stripping.

161

According to recent studies, Faradaic reactions such as oxygen reduction take place at

162

the cathode even when the cell voltage is relatively low (e.g. < 1.0 V), consuming H+ and

163

resulting in pH increase.23, 32-34 It is to be expected that higher current densities (and higher

164

charging voltages) will facilitate oxygen reduction leading to a more rapid rise in pH in the

165

cathode. In contrast, changing HRTs does not influence the duration for which the flow

166

electrode is exposed to a particular applied potential (as the flow electrode is recirculated at a

167

constant rate) and, as such, would not be expected to significantly influence the pH.

168

Ammonia Recovery and Energy Consumption. As shown in Figure 2, it can be

169

concluded that ammonium ions removed from the feed stream were effectively transferred to the

170

acidic receiving solution, with the recovered NH4+-N concentrations finally reaching 51.1 ± 1.2,

171

100.1 ± 9.6, 147.2 ± 0.6 and 174.9 ± 11.4 mg L−1 at 3.0, 5.8, 11.5 and 17.2 A m−2 respectively



172

(Figure 2a and b). The average ammonia recovery rate increased from 5.7 to 19.5 g N m−2 d−1

173

when the current density increased from 3.0 to 17.2 A m−2. In the first hour, the NH4+-N

174

concentration in the acid solution increased relatively slowly, presumably because the initial low

175

pH in the cathode chamber (Figure 1c and d) hindered the transformation of NH4+ into NH3(aq)

176

and the subsequent diffusion of NH3(g) across the gas membrane. On analysing the NH4+-N

177

concentration in the cathode solution, a sharp increase was observed in the first hour and then

178

reached a relatively stable concentration of 35-40 mg L−1 in the following three hours (Figure 2a).

179

Similar trends were observed when operated under different HRTs (Figure 2c and d).

180

From Figure 3a, we can clearly see that the applied current density plays an important role in

181

ammonia recovery. At current densities higher than 11.5 A m−2, 55-65% ammonia can be

182

recovered by the membrane contactor as ammonium fertilizer, while about 15% of the ammonia is

183

still present in the cathode and 20% was not detected (presumably either because it is electro-

184

absorbed on the carbon particles or because it has been air-stripped). It would be particularly

185

advantageous if the ammonia remaining in the cathode chamber (~35% of the total) could be

186

recovered. As is clear from Figure 3b, HRTs have a minor influence on the ammonia recovery

187

efficiency, especially when the HRT is longer than 1.48 min, with a similar recovery rate at these

188

long HRTs of 50~60%.

189

An overview of the effluent water quality, NH4+-N recovery efficiency, energy

190

consumption and average ammonia removal/recovery rate over a range of operating conditions is

191

provided in Table S1. Overall, the energy required for water desalination ranged from 0.05-1.95

192

kWh m−3, depending on the applied current densities and HRTs.

193

At applied current densities of 3.0, 5.8, and 11.5 A m−2 (for HRT fixed at 1.48 min), the

194

energies consumed for ammonia recovery were 6.1, 9.9 and 21.7 kWh Kg−1 N with recovery

195

efficiencies (respectively) reaching 18.7%, 38.1% and 55.1% and calculated average recovery

196

rates (respectively) of 5.7, 11.3 and 16.5 g N m−2 d−1. The energy consumption of the


Page 8 of 18

Page 9 of 18


197

CapAmm system is comparable with other electrochemical ammonia recovery systems. For

198

instance, an integrated system composed of a hydrogen gas (H2) recycling electrochemical cell

199

(recycling of the H2 generated at the cathode to the anode) and a gas permeable membrane

200

contactor was found to achieve an ammonia recovery efficiency of 60-73% and an average

201

ammonia recovery rate 110.2 g N m−2 d−1 at an energy requirement of 10.0 kWh kg−1 N. 35

202

However, this system required the injection of additional H2 and the application of a noble catalyst

203

to enable stable operation with these components representing an additional energy cost.

204

Another ammonia recovery system that combined an electrochemical cell (EC) and air-stripping

205

was able to recover 96% ammonia at a recovery rate of 120 g N m−2 d−1 and exhibited an energy

206

consumption of 20 kWh kg−1 N (with 13 kWh kg−1 N for EC and 9 kWh kg−1 N for air-stripping).

207

36

208

focussed on harvesting ammonia from high ammonia concentration (~3400 mg L−1 N) streams

209

(such as urine) with relatively low concentrations of competing ions (~1400 mg L−1 K+ and ~1600

210

mg L−1 Na+) with the competing cation and NH4+-N mole ratio as low as 0.43. However, the

211

influent of our CapAmm system contains 40-50 mg L−1 NH4+-N (~80 times lower than that in

212

urine) and ~390 mg L−1 Na+ (~1000 mg L−1 NaCl) resulting in a high Na+/NH4+-N mole ratio

213

of 5.7. This means that a larger part of the energy will be consumed for water desalination

214

(salt removal) thereby resulting in relatively lower ammonia recovery rate. In our future

215

studies, we will examine the applicability (and energy usage) of the CapAmm process to

216

recovery of ammonia from medium/high ammonia concentration waste streams.

35

More importantly, it should be noted that most of these ammonia recovery systems were

217

In contrast, bioelectrochemical systems (BES), which take advantage of electrochemically

218

active bacteria to degrade organic matter and generate electricity, can recover ammonia at much

219

lower energy demand compared to traditional EC systems and the CapAmm system introduced

220

here.37-40 In BES systems however, the ammonia recovery rate is relatively slow (3-5 g N m−2

221

d−1)17, 37 due to the limited current density produced by the anaerobic bacteria at the anode.



222

Additionally, the biological process is very sensitive to a range of environmental factors including

223

pH, carbon loading, chemical toxicity (e.g., ammonia present in the influent) and temperature,

224

restricting the practical application of these technologies. Indeed, the CapAmm process may have

225

an advantage over bioelectrochemical systems in view of its greater stability, predictability and

226

flexibility and the opportunity for automatic control of the reactor.

227

IMPLICATIONS

228

Our study demonstrates that the CapAmm process can be a very effective alternative for

229

ammonia removal and recovery from dilute wastewaters. Compared with other ammonia recovery

230

systems that require additional chemical dosing to adjust the pH and which use energy-intensive

231

air stripping to extract ammonia, CapAmm allows for the selective removal of ammonia from the

232

wastewater stream and preconcentration in the cathode chamber, with the elevation in pH that

233

occurs as a result of intrinsic Faradaic processes favoring the conversion of NH4+ into dissolved

234

NH3(aq). Given the rapidity with which solution phase ammonia equilibrates with gaseous

235

ammonia, NH3(g) will readily diffuse through a gas-permeable membrane into an acid solution

236

and may be recovered as an ammonium salt which can, potentially, be readily marketed as a

237

fertilizer.

238

configurations that utilize energy intensive air-stripping processes or require the use of multiple

239

absorption vessels. While sulfuric acid was used in this study for ammonia recovery, alternative

240

acids (such as phosphoric acid or nitric acid) could be used in order to produce higher-value

241

fertilizers.

In addition, our experimental setup is less complex than other experimental

242 243

AUTHOR INFORMATION

244

CORRESPONDING AUTHORS

245

*E-mail: [email protected]. Tel: +61-2-9385-5060;

246


Page 10 of 18

Page 11 of 18


247 248

ACKNOWLEDGEMENT

249

Support for Dr Jinxing Ma through a UNSW Vice Chancellor’s Postdoctoral Fellowship is

250

gratefully acknowledged.

251 252

SUPPORTING INFORMATION

253

Detailed information on the construction of the CapAmm cell, analytical methods and

254

calculations, mechanism of ammonia recovery by gas permeable membranes, variation of

255

effluent conductivity, variation of current efficiency and comparison of effluent water quality,

256

ammonia recovery efficiency, energy consumption and ammonia removal/recovery rate over a

257

range of operating conditions is available in the Supporting Information. The Supporting

258

Information is available at http://pubs.acs.org.

259 260



261

REFERENCES

262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319

1. Tilman, D.; Cassman, K. G.; Matson, P. A.; Naylor, R.; Polasky, S., Agricultural sustainability and intensive production practices. Nature 2002, 418, 671-677. 2. Jin, L.; Zhang, G.; Tian, H., Current state of sewage treatment in China. Water Res. 2014, 66, 85-98. 3. Agency, I. E., Tracking industrial energy efficiency and CO2 emissions. Organisation for Economic Co-operation and Development: 2007. 4. Zhou, F.; Azofra, L. M.; Ali, M.; Kar, M.; Simonov, A. N.; McDonnell-Worth, C.; Sun, C.; Zhang, X.; MacFarlane, D. R., Electro-synthesis of ammonia from nitrogen at ambient temperature and pressure in ionic liquids. Energy Environ. Sci. 2017. 5. Luther, A. K.; Desloover, J.; Fennell, D. E.; Rabaey, K., Electrochemically driven extraction and recovery of ammonia from human urine. Water Res. 2015, 87, 367-77. 6. Garcia-Gonzalez, M. C.; Vanotti, M. B., Recovery of ammonia from swine manure using gaspermeable membranes: effect of waste strength and pH. Waste Manag. 2015, 38, 455-61. 7. Heffer, P.; Prud’homme, M., Global nitrogen fertilizer demand and supply: trend, current level and outlook. 2016. 8. Ji, Y.; Bai, J.; Li, J.; Luo, T.; Qiao, L.; Zeng, Q.; Zhou, B., Highly selective transformation of ammonia nitrogen to N2 based on a novel solar-driven photoelectrocatalytic-chlorine radical reactions system. Water Res. 2017, 125, 512-519. 9. Kim, K. W.; Kim, Y. J.; Kim, I. T.; Park, G. I.; Lee, E. H., Electrochemical conversion characteristics of ammonia to nitrogen. Water Res. 2006, 40, 1431-41. 10. Zhu, G.; Peng, Y.; Li, B.; Guo, J.; Yang, Q.; Wang, S., Biological removal of nitrogen from wastewater. In Reviews of environmental contamination and toxicology, Springer: 2008; pp 159-195. 11. Gao, D.; Peng, Y.; Wu, W.-M., Kinetic model for biological nitrogen removal using shortcut nitrification-denitrification process in sequencing batch reactor. Environ. Sci. Technol. 2010, 44, 5015-5021. 12. Zhang, L.; Lee, Y. W.; Jahng, D., Ammonia stripping for enhanced biomethanization of piggery wastewater. J. Hazard. Mater. 2012, 199-200, 36-42. 13. Pressley, T. A.; Bishop, D. F.; Roan, S. G., Ammonia-nitrogen removal by breakpoint chlorination. Environ. Sci. Technol. 1972, 6, 622-628. 14. Kapałka, A.; Joss, L.; Anglada, Á.; Comninellis, C.; Udert, K. M., Direct and mediated electrochemical oxidation of ammonia on boron-doped diamond electrode. Electrochem. Commun. 2010, 12, 1714-1717. 15. Wang, Z.; Gong, H.; Zhang, Y.; Liang, P.; Wang, K., Nitrogen recovery from low-strength wastewater by combined membrane capacitive deionization (MCDI) and ion exchange (IE) process. Chem. Eng. J. 2017, 316, 1-6. 16. Ledezma, P.; Kuntke, P.; Buisman, C. J.; Keller, J.; Freguia, S., Source-separated urine opens golden opportunities for microbial electrochemical technologies. Trends Biotechnol. 2015, 33, 214-20. 17. Zhang, Y.; Angelidaki, I., Recovery of ammonia and sulfate from waste streams and bioenergy production via bipolar bioelectrodialysis. Water Res. 2015, 85, 177-84. 18. Booker, N.; Cooney, E.; Priestley, A., Ammonia removal from sewage using natural Australian zeolite. Water Sci. Technol. 1996, 34, 17-24. 19. Häyrynen, K.; Pongrácz, E.; Väisänen, V.; Pap, N.; Mänttäri, M.; Langwaldt, J.; Keiski, R. L., Concentration of ammonium and nitrate from mine water by reverse osmosis and nanofiltration. Desalination 2009, 240, 280-289. 20. Jeon, S.-i.; Park, H.-r.; Yeo, J.-g.; Yang, S.; Cho, C. H.; Han, M. H.; Kim, D. K., Desalination via a new membrane capacitive deionization process utilizing flow-electrodes. Energy Environ. Sci. 2013, 6, 1471-1475. 21. Ma, J.; He, D.; Tang, W.; Kovalsky, P.; He, C.; Zhang, C.; Waite, T. D., Development of redox-active flow electrodes for high-performance capacitive deionization. Environ. Sci. Technol. 2016, 50, 13495-13501. 22. Hatzell, K. B.; Hatzell, M. C.; Cook, K. M.; Boota, M.; Housel, G. M.; McBride, A.; Kumbur, E. C.; Gogotsi, Y., Effect of oxidation of carbon material on suspension electrodes for flow electrode capacitive deionization. Environ. Sci. Technol. 2015, 49, 3040-7. 23. Zhang, C.; He, D.; Ma, J.; Tang, W.; Waite, T. D., Faradaic reactions in capacitive deionization (CDI) problems and possibilities: A review. Water Res. 2018, 128, 314-330. 24. He, D.; Wong, C. E.; Tang, W.; Kovalsky, P.; Waite, T. D., Faradaic reactions in water desalination by batch-mode capacitive deionization. Environ. Sci. Technol. Lett. 2016, 3, 222-226. 25. Tang, W.; Kovalsky, P.; He, D.; Waite, T. D., Fluoride and nitrate removal from brackish groundwaters by batch-mode capacitive deionization. Water Res. 2015, 84, 342-9. 26. Darestani, M.; Haigh, V.; Couperthwaite, S. J.; Millar, G. J.; Nghiem, L. D., Hollow fibre membrane contactors for ammonia recovery: Current status and future developments. J. Environ. Chem. Eng. 2017, 5, 1349-1359. 27. Rezakazemi, M.; Shirazian, S.; Ashrafizadeh, S. N., Simulation of ammonia removal from industrial


Page 12 of 18

Page 13 of 18

320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353


wastewater streams by means of a hollow-fiber membrane contactor. Desalination 2012, 285, 383-392. 28. Tran, A. T. K.; Zhang, Y.; Lin, J.; Mondal, P.; Ye, W.; Meesschaert, B.; Pinoy, L.; Van der Bruggen, B., Phosphate pre-concentration from municipal wastewater by selectrodialysis: Effect of competing components. Sep. Purif. Technol. 2015, 141, 38-47. 29. Hou, C.-H.; Huang, C.-Y., A comparative study of electrosorption selectivity of ions by activated carbon electrodes in capacitive deionization. Desalination 2013, 314, 124-129. 30. Zhou, F.; Gao, T.; Luo, M.; Li, H., Preferential electrosorption of anions by C/Na 0.7 MnO 2 asymmetrical electrodes. Sep. Purif. Technol. 2018, 191, 322-327. 31. Nightingale Jr, E., Phenomenological theory of ion solvation. Effective radii of hydrated ions. The Journal of Physical Chemistry 1959, 63, 1381-1387. 32. Holubowitch, N.; Omosebi, A.; Gao, X.; Landon, J.; Liu, K., Quasi-steady-state polarization reveals the interplay of capacitive and Faradaic processes in capacitive deionization. ChemElectroChem 2017. 33. Nativ, P.; Badash, Y.; Gendel, Y., New insights into the mechanism of flow-electrode capacitive deionization. Electrochem. Commun. 2017, 76, 24-28. 34. Dykstra, J. E.; Keesman, K. J.; Biesheuvel, P. M.; van der Wal, A., Theory of pH changes in water desalination by capacitive deionization. Water Res. 2017, 119, 178-186. 35. Kuntke, P.; Rodriguez Arredondo, M.; Widyakristi, L.; Ter Heijne, A.; Sleutels, T. H.; Hamelers, H. V.; Buisman, C. J., Hydrogen gas recycling for energy efficient ammonia recovery in blectrochemical systems. Environ. Sci. Technol. 2017, 51, 3110-3116. 36. Desloover, J.; Woldeyohannis, A. A.; Verstraete, W.; Boon, N.; Rabaey, K., Electrochemical resource recovery from digestate to prevent ammonia toxicity during anaerobic digestion. Environ. Sci. Technol. 2012, 46, 12209-16. 37. Kuntke, P.; Smiech, K. M.; Bruning, H.; Zeeman, G.; Saakes, M.; Sleutels, T. H.; Hamelers, H. V.; Buisman, C. J., Ammonium recovery and energy production from urine by a microbial fuel cell. Water Res. 2012, 46, 2627-36. 38. Zamora, P.; Georgieva, T.; Ter Heijne, A.; Sleutels, T. H. J. A.; Jeremiasse, A. W.; Saakes, M.; Buisman, C. J. N.; Kuntke, P., Ammonia recovery from urine in a scaled-up Microbial Electrolysis Cell. J. Power Sources 2017, 356, 491-499. 39. Kuntke, P.; Sleutels, T. H. J. A.; Saakes, M.; Buisman, C. J. N., Hydrogen production and ammonium recovery from urine by a microbial electrolysis cell. Int. J. Hydrogen Energy 2014, 39, 4771-4778. 40. Ledezma, P.; Jermakka, J.; Keller, J.; Freguia, S., Recovering nitrogen as a solid without chemical dosing: bio-electroconcentration for recovery of nutrients from urine. Environ. Sci. Technol. Lett. 2017, 4, 119124.

354



355

TOC graphic

356 Freshwater out

+

NH4+ Cl-

Ammonium fertilizer out

High pH

Cl-

NH3

-

Cl-

Acid in

ClNa+

Na+

Gas permeable membrane module Flow electrode

357

AEM

Flow CEM electrode

Wastewater in

358


Page 14 of 18

Page 15 of 18


Anion exchange Cation exchange Graphite current membrane membrane collector Gasket Gasket Gasket

(a) End plate

Freshwater out

Ammonium fertilizer Membrane module Acid Flow electrode

Reservoir for electrically charged flow electrode (i.e., anode)

End plate

Wastewater in

+

Cl-

+

Current collector

Na+

Cl-

-

NH4

Cl-

NH4+

Na+

O2

OH−

Cl-

+

NH4+

Cl-

+

Na

+

Na

-

-

Na+

+

Cl-

-

Na +

NH4

+

Fertilizer

-

NH3 NH4

-

+

NH4

+

SO42-

+

NH3

-

Na+

Na+

+

Cl-

+

Na+

Carbo n

NH4

-

+ Cl- NH4

Gas permeable membrane

-

Cl-

Cl-

Cl-

+

359

Na+

Na+

-

Na+

+

+

Na+

Current collector

Cl-

+ Cl-

(c) -

+ Cl-

+

Cl-

Acrylic flow channel

Spacer

Graphite current Acrylic flow collector channel

(b)

Reservoir for electrically charged flow electrode (i.e., cathode)

NH4

+

NH3 NH4+

NH3 +

Na

+

Na

NH3

-

- Na+

NH3

H

SO42-

+

H

SO42-

+

H+ H

+

SO42-

Acid

360

Scheme 1 Schematic representations of (a) the capacitive membrane stripping for ammonia

361

recovery (CapAmm), (b) ammonia migration and transformation in the desalination unit and

362

(c) selective ammonia recovery from the negatively charged flow electrode.

363



+

+

+

+

NH4 -N

RE (NH4 -N)/RE (Na )

3.0

2.0

60

40

1.5

20

1.0

0

Ion removal efficiency (%)

2.5

80

0.5 3.0

5.8

11.5

+

+

RE (NH4 -N)/RE (Na )

2.5

80

2.0

60

40

1.5

20

1.0

0

0.5

17.2

0.98

-2

1.48

1.96

2.94

HRT (min)

13

13

(c)

(d)

12

12

11

11

pH

pH

+

(b)

Current density (A m )

10 9

10 9

-2

3.0 A m -2 5.8 A m -2 11.5 A m -2 17.2 A m

8

0.98 min 1.48 min 1.96 min 2.94 min

8

7

7 0

364

Na

3.0

100

(a) RE (NH4+-N)/RE (Na+)

Ion removal efficiency (%)

100

Na

RE (NH4+-N)/RE (Na+)

+

NH4 -N

Page 16 of 18

40

80

120

160

200

240

0

40

Time (min)

80

120

160

200

240

Time (min)

365

Figure 1. Average removal efficiencies for ammonium and sodium ions in the CapAmm

366

system (a) under different current densities (i.e., 3.0, 5.8, 11.5 and 17.2 A m−2) with a constant

367

HRT of 1.48 min, and (b) at a constant current of 11.5 A m−2 with HRTs of 0.98, 1.48, 1.96

368

and 2.94 min. The blue symbols are the ratio of removal efficiency of RE (NH4+-N)/RE (Na+)

369

with this ratio representing the selectivity of NH4+ compared to Na+. Temporal change of pH

370

in the cathode chamber of the CapAmm system operated (c) under different current densities

371

(i.e., 3.0, 5.8, 11.5 and 17.2 A m−2) with a constant HRT of 1.48 min, and (d) under a constant

372

current of 11.5 A m−2 with different HRTs (i.e., 0.98, 1.48, 1.96, and 2.94 min). The shade

373

area represents the pH range >9.3, indicating the deprotonation of NH4+ to NH3.

374


Page 17 of 18


200

(a) Cathode chamber -2

NH3-N (and NH4+-N) (mg L-1)

NH 3-N (and NH 4+-N) (mg L-1)

200 3.0 Am -2 5.8 Am -2 11.5 Am -2 17.2 Am

150

100

50

0

(b) Acid solution -2 3.0 Am -2 5.8 Am -2 11.5 Am -2 17.2 Am

150

100

50

0 0

40

80

120

160

200

240

0

40

Time (min)

160

200

240

200

240

160

(c) Cathode chamber



120

Time (min)

160 0.98 min 1.48 min 1.96 min 2.94 min

120

80

40

0

(d) Acid solution 0.98 1.48 1.96 2.94

120

min min min min

80

40

0 0

40

80

120

160

200

240

0

40

80

120

160

Time (min)

Time (min)

375

80

376

Figure 2. Temporal variation of ammonia concentrations in (a) the cathode chamber and (b)

377

acidic receiving solution of the CapAmm system operated under different current densities

378

(i.e., 3.0, 5.8, 11.5 and 17.2 A m−2) with a constant HRT of 1.96 min, and ammonia

379

concentrations in (c) the cathode chamber and (d) acidic receiving solution of the system

380

charged at a constant current density of 11.5 A m−2 with different HRTs (i.e., 0.98, 1.48, 1.96

381

and 2.94 min).



382 383

Figure 3. Fate and distribution of ammonia in the CapAmm system (a) at different current

384

densities (i.e., 3.0, 5.8, 11.5, and 17.2 A m−2) with a constant HRT of 1.96 min, and (b) at a

385

constant current of 11.5 A m−2 with different HRTs (i.e., 0.98, 1.48, 1.96, and 2.94 min).

386


Page 18 of 18

Capacitive membrane stripping for ammonia recovery (CapAmm) from

Recommend Documents