Nitrogen and Phosphorus Harvesting from Human ... - ACS Publications

Subscriber access provided by University of Newcastle, Australia

Article

Nitrogen and phosphorus harvesting from human urine using a stripping, absorption, and precipitation process Surendra K Pradhan, Anna Mikola, and Riku Vahala Environ. Sci. Technol., Just Accepted Manuscript • DOI: 10.1021/acs.est.6b05402 • Publication Date (Web): 14 Apr 2017 Downloaded from http://pubs.acs.org on April 14, 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 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 27

Environmental Science & Technology

Ammonium sulfate

Human urine

Phosphate compound

ACS Paragon Plus Environment


1

Nitrogen and phosphorus harvesting from human urine using a stripping,

2

absorption, and precipitation process

3

*Surendra K Pradhan, Anna Mikola, Riku Vahala

4

Department of Built Environment, School of Engineering, Aalto University, P.O. Box 14100

5

FI-00076 AALTO, Finland

6

*corresponding author: - Surendra K Pradhan, [email protected], +358400973372

7

8

ABSTRACT

9

Human urine contains significant amounts of N (nitrogen) and P (phosphorus); therefore it has

10

been successfully used as fertilizer in different crops. But the use of urine as fertilizer has several

11

constraints, such as, the high cost of transportation, an unpleasant smell, the risk of pathogens,

12

and pharmaceutical residue. A combined and improved N stripping and P precipitation technique

13

is used in this study. In this technique, Ca(OH)2 is used to increase the pH of urine which

14

converts ammonium into ammonia gas and precipitate P as Ca-P compound. The ammonia gas is

15

stripped and passed into the sulfuric acid where ammonium sulfate and hydrogen triammonium

16

disulfate is formed. The experiment was performed using 700 ml of urine and the pH of the urine

17

was increased above 12. Our results showed that 85-99% of N and 99% of P (w/w) can be

18

harvested from urine in 28 h at 40 oC and in 32 h at 30 oC. The harvested N (13% N w/w) and P

19

(1.5% P w/w) can be used as mineral fertilizer. The economic assessment of the technique

20

showed that the extraction of N and P from 1 m3 of pure urine can make a profit of €2.25.

21

Keywords: - mineral fertilizer, nitrogen, phosphorus, sanitation, urine 1 ACS Paragon Plus Environment

Page 2 of 27

Page 3 of 27


22

23

1. INTRODUCTION

24

The urine-separating toilet is an established concept to collect urine separately from feces for

25

further use as a fertilizer. One person excretes about 550 L urine/year, which is equal to 4 kg of

26

nitrogen (N) 0.4 kg of phosphorus (P) and 0.9 kg of potassium (K) per year.1 Recovery and reuse

27

of these nutrients improve the sustainable environment. The recycling of P is even more

28

important because today most of P fertilizers are produced by mining and which may be depleted

29

in 50 – 100 years.2 Therefore, urine as a fertilizer is receiving increasing research attention and

30

has already been successfully used in agriculture.3,4 Although urine can be collected separately in

31

big buildings or public places like airports and universities, the use of urine itself as a fertilizer is

32

not feasible on a large scale. There are several constraints that make urine unattractive. For

33

example: (1) it is expensive to transport large volumes of urine to farms,5 (2) urine has an

34

unpleasant smell,6 (3) urine is not acceptable in many societies7 and (4) urine can contain

35

pharmaceutical residues and pathogens8. This study aimed to address these issues by harvesting

36

nutrients from urine.

37 38

One of the common techniques of nutrient recovery from urine is the formation of struvite

39

(MgNH4PO4·6H2O) using different Mg2+ sources including wood ash,9 MgO and NaOH,10

40

MgO11 and brine12. Struvite precipitation is principally based on the chemical equilibrium of

41

constituent ions in the solution and it needs the correct ratios of Mg2+:NH4+:PO43- (close to 1:1:1

42

and up to 2.5:1:1).11 Ostara in Virginia (USA) and Multiform Harvest in Yakima, Washington

43

(USA) are successfully producing struvite at full-scale operation with 80-90% P recovery.13 In

44

general, the struvite precipitation process recovers mainly P with about 10% of N and it is a P2 ACS Paragon Plus Environment


45

based slow nutrient releasing compound.14 In the struvite formation technique N recovery can be

46

enhanced by adding more Mg2+ and PO43− to achieve the appropriate ratio of Mg, P and N.15

47

Another technique of nutrient recovery from urine is ammonia stripping.10,16-18 Residual

48

ammonium from urine was stripped and recovered in H2SO4 after the recovery of struvite.10,16

49

Furthermore, N was stripped and recovered from diluted urine17 and manually hydrolyzed (using

50

urease) fresh urine18. Both of these studies17,18 recovered only N. Some other techniques to

51

recover nutrients from liquid waste are: nutrient recovery using zeolite,19 recovery of

52

concentrated nutrients using RO (reverse osmosis)20.

53

Although there are several existing techniques to recover N and P from urine, new approaches

54

are needed to make the nutrients recovery process more economical and feasible. We realized

55

that the recovery of N and P separately can be better, so an N or P fertilizer can be used

56

separately. The earlier stripping study was conducted either combined with the struvite process

57

or they only recovering N using NaOH as alkali. Here, we are developing a new approach by

58

using Ca(OH)2 instead of NaOH in the stripping process as Ca(OH)2 increase the urine pH as

59

well as precipitates the P. In this study, we have actually improved the stripping technique by

60

combining N stripping with the P precipitation technique. The process of our technique is based

61

on increasing the pH of urine and the precipitation of P (Equation 1) using Ca(OH)221 followed

62

by the stripping and capturing of the resulting ammonia as ammonium sulfate and hydrogen

63

triammonium disulfate using H2SO4 (Equation 2). Equations 1 and 2 describe the main reactions,

64

but additional products can also form in these reactions.22 Our approach is the first technique

65

where the extraction of N and P from human urine takes place simultaneously, i.e., the stripping

66

of ammonia and P sedimentation in the same reactor and production of the ammonium

67

compound in another reactor (reactor containing H2SO4) but all at the same time. Dry and wet

3 ACS Paragon Plus Environment

Page 4 of 27

Page 5 of 27


68

urinals are used for collecting urine; therefore the influence of the urine concentration was

69

studied.

70

10Ca2+ + 6PO43- + 2OH- → Ca10(PO4)6(OH)2 ↓

Equation 1

71

2NH3 + H2SO4 → (NH4)2SO4

Equation 2

72

The main aim of this study is to recover nutrients from human urine and produce a mineral

73

fertilizer. The objectives of the study are; (1) to determine the effect of temperature and the

74

concentration of urine on the performance of the N and P harvesting process, (2) to determine the

75

quality and quantity of the produced NH4 compound, and (3) to determine the quality and

76

quantity of the produced Calcium + P compound fertilizer. According to our study hypothesis;

77

(1) N and P can be harvested from urine using our technique and (2) the temperature and pH will

78

be positively correlated with the N harvesting process.

79

2. MATERIALS AND METHODS

80

2.1. Urine handling and analytical methods. Urine was collected from a waterless urinal

81

placed at the Helsinki Festival in the summer of 2014 and stored for about a year by Dodo (an

82

NGO). About 90 L of urine in 30 L jerry cans were transported to the water lab at the

83

Department of Built Environment, Aalto University, and kept in a cold room (4 oC) until used for

84

the experiment. A physiochemical analysis was done before and after N and P harvesting (Table

85

1). Total-N was analyzed using the Finnish standard corresponding to the ISO standard (SFS-EN

86

ISO 11905-1), the automatic analyzer was equipped with an autoclave and an Ultraviolet

87

Spectrophotometric Screening Method Ganimede N (Lange), Germany. NH4-N (Ammonium-N)

88

was analyzed using the ISO 11732 method. The analysis was done using a Tecator 5042

89

Detector/5012 Analyzer from Foss Höganäs, Sweden. NH4-N was also determined using the NH3 4 ACS Paragon Plus Environment


90

gas sensing electrode Orion 900/200 (Thermo Electron Corporation, Beverly, MA, USA) after

91

adjusting the sample to pH > 11. Total P was analyzed by FIA (flow injection analyzer), using a

92

FiaStar 5000 analyzer from Foss, Höganäs, Sweden, following the standard method SFS-EN ISO

93

6878. PO4-P was determined using the Finnish standard SFS-EN ISO 15681-1 by the FIA

94

method using a FiaStar 5000 analyzer from Foss, Höganäs, Sweden. For sediment, total P and K

95

was analyzed using FAAS (flame atomic absorption spectroscopy). Suspended solid (SS) was

96

determined using a Whatman membrane (pore size 0.4µm) with a drying method at 105 oC for 2

97

hours (SFS-EN 872, year 2005). The harvested ammonium sulfate and phosphorus compounds

98

(sediment) were determined or confirmed by XRD (X-ray diffraction) using an X-ray powder

99

diffractometer (PANalytical X'Pert Pro MPD α1). Quantification was based on semi-quantitative

100

results performed using the “Match!” (crystal impact) program using the ICDD-PDF-4 +2014

101

RDB database. XRD and FAAS analysis was done in the Department of Chemistry, and the rest

102

of the analyses were done in the water laboratory at the Department of Built Environment, Aalto

103

University.

104

105

2.2. Process optimization. Increase the air flow rate17,18 and temperature18 increase the NH3

106

stripping, but these parameters need to be optimized according to the experimental setup. In our

107

experiment, the airflow rate was optimized at 1.1 ± 0.1 L/min because higher than 1.1 ± 0.1 L

108

airflow caused a foaming issue. The amount of Ca(OH)2 was determined based on the potential

109

to increase the pH (here, pH was determined by measurement) of urine, and the amount of 1M

110

H2SO4 was determined by calculating the amount of ammonium-N and its molecular weight in

111

urine. The dilution factor of urine was selected based on the commonly used urine separating

112

flush toilet which uses about 1:4 portion of water. In order to study the effect of temperature, our 5 ACS Paragon Plus Environment

Page 6 of 27

Page 7 of 27


113

technique was first tested at room temperature (i.e., 21 ± 1 oC), but the NH3 stripping process

114

was slower (i.e. 0.05) when the pH of the pure urine was

209

maintained than when the pH was not maintained (Table 2). When the pH was maintained above

210

11, NH4-N harvesting was more than 99%, which is similar to the results presented by

211

Basakçilardan-Kabakci et al.17 In contrast, Liu et al.18 showed that ammonia stripping was not

212

increased, while the urine pH increased above 10. The temperature did not greatly affect the N

213

harvesting percentage when the pH was maintained above 11 (Table 2) but the urine pH and

214

ammonia reduction were positively correlated (p = 0.0001, r = 0.59). This result showed that if

215

the urine pH is kept above 11, the N harvesting percentage will be similar at 30 oC and at 40 oC.

216

This means that a 10 oC increase in temperature is not required after increasing the urine pH

217

which results in a significant amount of saved energy. The results in efficiency of our technique

218

at 30 oC will be very useful and energy-efficient in tropical countries, where the ambient

219

temperature is about 30 oC all year around. The use of our technique at 30 oC seems reliable as

220

Quan et al.31 and Siegrist et al.25 also reported that NH3 stripping needs to be performed at > 25

221

o

C. On the other hand, the harvesting process was 8 hours faster at 40 oC when the pH was



222

maintained (Figure 2). Furthermore, Ca(OH)2 is a commonly available chemical and this is re-

223

useable as lime + phosphorus in agricultural soil even after used in our technique compared to

224

NaOH used in previous studies.17,18 However, it is clear that the temperature, pH, and

225

experimental duration need to be optimized to make this technique as economic as possible. A

226

similar conclusion is presented by Liu et al.18

227

3.3. Ammonium concentration and nutrient harvesting process. Our technique harvested 95-

228

99% of NH4-N from pure and diluted urine at 40 oC when the pH was maintained >11 for the

229

entire harvesting period (Figure 2 (D,F)). The NH4-N harvesting rate from the high NH4-N

230

content urine or pure urine was slightly higher compared to the low NH4-N content urine or

231

diluted urine. Pearson’s correlation also showed a weak but positive correlation between NH4-N

232

harvesting and NH4-N concentration in urine (p = 0.047, r = 0.583). Liu et al.18 also reported that

233

dilution of urine does not have a significant effect on NH4-N harvesting but it has some

234

influence. These results suggested that it would be more economical (saving energy and time) to

235

apply this technique to harvest N and P from pure urine than from diluted urine. However, the

236

cost of chemicals will not be very different as the consumption of H2SO4 and Ca(OH)2 mainly

237

depends on the ammonium concentration in the liquid waste. For example; in an estimated

238

calculation assuming a linear scale up of our work, only 43 L of 1M H2SO4 can be used to

239

harvest NH4-N (i.e. about 0.85 g of NH4-N) from 1m3 of diluted urine (1:4 times dilution) while

240

214 L of 1M H2SO4 is needed to harvest NH4-N (i.e., about 4.4 g of NH4-N) from 1m3 of pure

241

urine. Similarly, a smaller amount of Ca(OH)2 was used to increase the pH of diluted urine

242

compared to the amount used for pure urine. Variations in Ca(OH)2 consumption and phosphorus

243

removal efficiency are mainly dependent upon the presence of NH4+ and CO32- in the solution.32


Page 12 of 27

Page 13 of 27


244

Although the stored urine contained 4.5 g/L of NH4-N (Table 1), some of the ammonia

245

volatilized during the preparation of the experiment or before the stripping process. We noticed

246

that there is a risk of ammonia evaporation while urine is mixed with Ca(OH)2 and the pH is

247

increased to >12. There was an NH4-N loss of 0.5-6% during the N and P harvesting process

248

(Table 2). This might be due to evaporation during sampling, air flow and pH adjustment. N loss

249

was comparatively lower in the pH-maintained pure urine compared to the others (Table 2). The

250

experiment with pH-maintained pure urine had lower residual NH4-N, so there was less ammonia

251

to evaporate compared to urine from other treatments. However, the NH3 loss was not due to

252

nitrification, as a high pH inhibits the nitrification process33 and a high temperature of 40 oC is

253

not a favorable condition for nitrification. Furthermore, there was about 10% of NH4-N loss

254

during the drying/crystallization of the acid solution which is similar to the results presented by

255

Basakçilardan-Kabakci et al.17 This might be because some ammonium ions remain in the acid

256

solution and they evaporate during the drying/crystallization process. In fact, if (NH4)2SO4 is

257

already formed, N will not evaporate in this temperature.34 The loss of ammonia might have

258

influenced the result of the total N content being only 13%. The ammonia loss during the

259

experiment can be controlled in a pilot plant where the possible evaporation points can be

260

mitigated.

261

3.4. Characteristics of the products. The ammonium sulfate production was similar in both

262

temperatures when urine pH was maintained above 11 whereas Liu et al.18 found that recovery

263

increases when the temperature increases. This might be because our experimental duration was

264

28 hours and pH was >11 while Liu et al.18 conducted an experiment for 24 hours and pH was

265

99% P,

294

as reported by Fernandes et al.21 As pH is the main factor for P precipitation, the experimental

295

temperature did not affect the P harvesting rate. But the concentration of P was positively

296

correlated to the P harvesting percentage (p < 0.0001, r = 0.912). Most of the P in urine was in

297

the form of PO4-P (Table 1); similarly, most of the P in the sediment was also PO4-P. This

298

sediment containing about 1.5 % P containing sediment can be used as fertilizer + lime in forest

299

soil37 and agricultural soil37 especially with low pH soil to increase productivity. Although we

300

have not done any specific treatment to remove pharmaceutical residues and heavy metals from

301

our sediment, the previous study showed a low risk of using sediment from urine. For example,

302

Ronteltap et al39 showed that the heavy metals contained in urine sediment are lower than even

303

the European standard, and only 9 reduces a significant amount of pathogens40 and



41

312

inactivates Ascaris eggs.

E coli and Salmonella spp can be reduced 8 logs at pH 12 for 15

313

seconds of contact time.42

314

3.6. Economic assessment. In general, 1 m3 of urine contains 4.5 kg of NH4-N and 0.35 kg of

315

total P.1 Among them, 4.2 kg of NH4-N and 0.35 kg of total P can be harvested using 20.9 kg of

316

H2SO4 (98%) and 22 kg of Ca(OH)2. Based on the calculation the harvesting of N and P from 1

317

m3 of urine can make a profit of €2.25 (Table 3). The economic assessment was based on a

318

theoretical calculation of the upscale 1 m3 controlled pilot plant assuming a linear increase in the

319

chemical dose from a 1 L reactor. However, additional studies are needed to convert the

320

hydrogen triammonium disulfate mixture into ammonium sulfate and to produce pure CaCO3

321

and phosphate precipitates. The revenue gain assumes that pure compounds were produced

322

without the additional cost.

323

ACKNOWLEDGEMENTS

324

We would like to thank the Kone Foundation for funding the study upon the decision of 2014.

325

We would also like to thank Mr. Taneli Tiittanen for the XRD analysis and Mr. Kirmo Kivela

326

from Dodo.org for providing urine for the experiment.

327

REFERENCES

328

1.

329

faeces in crop production. EcoSanRes publication, Stockholm Environmental Institution (SEI):

330

Stockholm, Sweden, 2004.

331

2.

332

Phosphorus Management, A Global Transdisciplinary Roadmap. Springer Dordrecht Heidelberg

333

New York London, 2014 DOI 10.1007/978-94-007-7250-2,

Jönsson, H.; Stintzing, R.; Vinnerås, B.; Salomon, E., Guidelines on the use of urine and

Scholz, R.W.; Roy, A.H.; Brand, F.S.; Hellums, D.T.; Ulrich, A.E., Eds. Sustainable


Page 16 of 27

Page 17 of 27


334

3.

Heinonen-Tanski, H.; van Wijk-Sijbesma, C. Human excreta for plant production.

335

Bioresour. Technol. 2005, 96 (4), 403-411; 10.1016/j.biortech.2003.10.036.

336

4.

337

human urine fertilizer in cultivation of cabbage (Brassica oleracea)- Impacts on chemical,

338

microbial, and flavor quality. J. Agric. Food Chem. 2007, 55 (21), 8657-8663;

339

10.1021/jf0717891.

340

5.

341

the Use of Urine in Crop Production. Stockholm Environment Institute (SEI): Sweden, 2010.

342

6.

343

willingness to use urine in agriculture: a case study from rural areas of eThekwini municipality,

344

South Africa. J. Water Sanitation and Hygiene for Develop. 2013, 3 (4), 582-591;

345

10.2166/washdev.2013.036.

346

7.

347

central Nepal: a questionnaire survey. Environ. develop. sustain. 2010, 12 (5), 713-726;

348

10.1007/s10668-009-9220-5.

349

8.

350

assessment of 42 pharmaceuticals considering human metabolism and excretory routes. Environ.

351

Sci. Technol. 2007, 41 (12), 4471-4478; 10.1021/es0627693.

352

9.

353

recovery

354

10.1016/j.scitotenv.2011.12.065.

Pradhan, S.K.; Nerg, A.; Sjoeblom, A.; Holopainen, J.K.; Heinonen-Tanski, H. Use of

Richert, A.; Gensch, R.; Jönsson, H.; Stenström, T.; Dagerskog, L. Practical Guidance on

Okem, A.E.; Xulu, S.; Tilley, E.; Buckley, C.; Roma, E. Assessing perceptions and

Pradhan, S.K.; Heinonen-Tanski, H. Knowledge and awareness of eco-sanitation in

Lienert, J.; Gudel, K.; Escher, B.I. Screening method for ecotoxicological hazard

Sakthivel, S.R.; Tilley, E.; Udert, K.M. Wood ash as a magnesium source for phosphorus from

source-separated

urine. Sci.

Total


Environ. 2012, 419,

68-75;


Page 18 of 27

355

10.

Antonini, S.; Paris, S.; Eichert, T.; Clemens, J. Nitrogen and phosphorus recovery from

356

human urine by struvite precipitation and air stripping in Vietnam. Clean-Soil Air Water 2011,

357

39 (12), 1099-1104; 10.1002/clen.201100036.

358

11.

359

separated urine in Nepal. Water Res. 2011, 45 (2), 852-862; 10.1016/j.watres.2010.10.007.

360

12.

361

struvite formation from source-separated urine using seawater and brine as magnesium sources.

362

Chemosphere 2013, 93 (11), 2738-2747; 10.1016/j.chemosphere.2013.09.025.

363

13.

364

from centralised sewage treatment in a transitioning economy context. Masters, Department of

365

Chemical Engineering, University of Cape Town, South Africa, 2015.

366

14.

367

Recovery. Environ. Sci. Technol. 2013, 47 (10), 4965-4966; 10.1021/es401140s.

368

15.

369

struvite precipitation process using unconventional reagents. Environ. Technol. 2014, 35 (7),

370

841-850.

371

16.

372

from urine by struvite precipitation followed by combined stripping with digester sludge liquid at

373

full scale. Water 2013, 5 (3), 1262-1278; 10.3390/w5031262.

374

17.

Basakcilardan-Kabakci, S.; Ipekoglu, A.N.; Talini, I. Recovery of ammonia from human

375

urine

by

376

10.1089/ees.2006.0412.

Etter, B.; Tilley, E.; Khadka, R.; Udert, K.M. Low-cost struvite production using source-

Liu, B.; Giannis, A.; Zhang, J.; Chang, V.W.-.; Wang, J. Characterization of induced

Mikosana, M. A technological, economic and social exploration of phosphate recovery

Hao, X.; Wang, C.; van Loosdrecht, M.C.M.; Hu, Y. Looking Beyond Struvite for P-

Siciliano, A.; De Rosa, S. Recovery of ammonia in digestates of calf manure through a

Morales, N.; Boehler, M.A.; Buettner, S.; Liebi, C.; Siegrist, H. Recovery of N and P

stripping

and

absorption.

Environ.

Eng.


Sci.

2007,

24

(5),

615-624;

Page 19 of 27


377

18.

Liu, B.; Giannis, A.; Zhang, J.; Chang, V.W.; Wang, J. Air stripping process for

378

ammonia recovery from source-separated urine: modeling and optimization. J. Chem. Technol.

379

Biotechnol. 2015, 90 (12), 2208-2217; 10.1002/jctb.4535.

380

19.

381

struvite crystallisation and zeolite adsorption. Environ. Technol. 2004, 25 (1), 111-121.

382

20.

383

nutrients from urine and reject water from anaerobically digested sludge. Water Sci.

384

Technol. 2006, 54 (11-12), 437-444; 10.2166/wst.2006.924.

385

21.

386

Flores, E.M.; Dressler, V.L. Chemical phosphorus removal: a clean strategy for piggery

387

wastewater management in Brazil. Environ. Technol. 2012, 33 (14), 1677-1683.

388

22.

389

Phosphates precipitated from solutions of high to medium concentrations. J. Cryst. Growth 1986,

390

74 (3), 581-590; 10.1016/0022-0248(86)90205-8.

391

23.

392

percent

393

http://nepis.epa.gov/Adobe/PDF/30000I7U.PDF

394

24.

395

Inhibition by ammonia. Water Res. 1998, 32 (1), 5-12; 10.1016/S0043-1354(97)00201-7.

396

25.

397

Transfer into the gas phase: ammonia stripping, 2013, 337-349, IWA Publishing, London, UK

Ban, Z.; Dave, G. Laboratory studies on recovery of N and P from human urine through

Ek, M.; Bergstrom, R.; Bjurhem, J.-.; Bjorlenius, B.; Hellstrom, D. Concentration of

Fernandes, G.W.; Kunz, A.; Radis Steinmetz, R.L.; Szogi, A.; Vanotti, M.; de Moraes

Abbona, F.; Madsen, H.E.L.; Boistelle, R. The initial phases of Calcium and Magnesium

Thurston, R.V.; Russo, R.C.; Emerson, K. Aqueous ammonia equilibrium- tabulation of un-ionized

ammonia;

1979,

EPA-600/3-79-091,

EPA:

USA;

Hansen, K.H.; Angelidaki, I.; Ahring, B.K. Anaerobic digestion of swine manure:

Siegrist, H.; Laureni, M.; Udert, K.M. Transfer into the Gas Phase: Ammonia Stripping



Page 20 of 27

398

26.

Gulyas, H.; Zhang, S.D.; Otterpohl, R. Pretreating stored human urine for solar

399

evaporation by low-technology Ammonia stripping. J. Environ. Protec. 2014, 5, 962-969;

400

http://dx.doi.org/10.4236/jep.2014.511097.

401

27.

402

Calculations - Effect of pH and Temperature. J. of the Fisheries Res. Board of Canada 1975, 32

403

(12), 2379-2383.

404

28.

405

treatment- chapter 6, In Reclamation of Drastically Disturbed Lands, 2000th ed.; John

406

Sencindiver,

407

http://anr.ext.wvu.edu/resources/295/1254842045.pdf

408

29.

409

for stabilizing fresh urine by calcium hydroxide addition. Water Res. 2016, 95, 361-369;

410

10.1016/j.watres.2016.03.007.

411

30.

412

York: 2007.

413

31.

414

sparged

415

10.1016/j.jhazmat.2009.05.083.

416

32.

417

Qual. 2009, 38 (2), 576-586; 10.2134/jeq2007.0641.

418

33.

419

Works Association 2002, 94 (7), 73-83.

Emerson, K.; Russo, R.; Lund, R.; Thurston, R. Aqueous Ammonia Equilibrium

Skousen, J.G.; Sexstone, A.; Ziemkiewicz, P.F. Acid mine drainage control and

K.G.,

Ed.;

West

Virginia

University:

US,

2000;

pp.

1-42.

Randall, D.G.; Krahenbuhl, M.; Kopping, I.; Larsen, T.A.; Udert, K.M. A novel approach

Perry, R.H.; Green, D.W. Perry's chemical engineers' handbook. McGraw-Hill: New

Quan, X.; Wang, F.; Zhao, Q.; Zhao, T.; Xiang, J. Air stripping of ammonia in a wateraerocyclone

reactor.

J.

Hazard.

Mater.

2009,

170

(2-3),

983-988;

Szogi, A.A.; Vanotti, M.B. Removal of Phosphorus from Livestock Effluents. J. Environ.

Skadsen, J. Effectiveness of high pH in controlling nitrification. J. American Water


Page 21 of 27


420

34.

Zapp, K.; Wostbrock, K.; Schäfer, M.; Sato, K.; Seiter, H.; Zwick, W.; Creutziger, R.;

421

Leiter, H. Ammonium Compounds, In Ullmann's Encyclopedia of Industrial Chemistry,

422

Anonymous ; Wiley-VCH Verlag GmbH & Co. KGaA: 2000; 2013.

423

35.

424

(ND4)(3)D(SO4)(2) in high temperature phase. Solid State Ionics 1997, 98 (1-2), 105-111;

425

10.1016/S0167-2738(97)00105-7.

426

36.

427

inherent Ca2+ in phosphorus removal from wastewater system. Water Sci. Technol. 2016, 73 (7),

428

1644-1651; 10.2166/wst.2015.642.

429

37.

430

properties of soil, needle nutrients and growth of Scots pine transplants. For. Ecol. Manage.

431

2011, 262 (2), 278-285; 10.1016/j.foreco.2011.03.033.

432

38.

433

Nascente, A.S. Tillage system and lime application in a tropical region: Soil chemical fertility

434

and corn yield in succession to degraded pastures. Soil & Tillage Res. 2016, 155, 437-447;

435

10.1016/j.still.2015.06.012.

436

39.

437

metals during struvite precipitation in urine. Water Res. 2007, 41 (9), 1859-1868.

438

40.

439

coliphage MS2 in pure human urine. J. Appl. Microbiol. 2009, 107 (5), 1651-1657;

440

10.1111/j.1365-2672.2009.04353.x.

441

41.

442

Technol. 2005, 39 (20), 7909-7914; 10.1021/es050659a.

Fukami, T.; Ninomiya, H.; Chen, R. Crystal structure and a new phase transition of

Han, C.; Wang, Z.; Wu, Q.; Yang, W.; Yang, H.; Xue, X. Evaluation of the role of

Saarsalmi, A.; Tamminen, P.; Kukkola, M.; Levula, T. Effects of liming on chemical

Tiritan, C.S.; Buell, L.T.; Crusciol, C.A.C.; Carmeis Filho, A.C.A.; Fernandes, D.M.;

Ronteltap, M.; Maurer, M.; Gujer, W. The behaviour of pharmaceuticals and heavy

Chandran, A.; Pradhan, S.K.; Heinonen-Tanski, H. Survival of enteric bacteria and

Pecson, B.; Nelson, K. Inactivation of Ascaris suum eggs by ammonia. Environ. Sci.



443

42.

Mendoca, A.; Amoroso, T.; Knabel, S. Destruction of Gram-Negative Food-Borne

444

Pathogens by High Ph Involves Disruption of the Cytoplasmic Membrane. Appl. Environ.

445

Microbiol. 1994, 60 (11), 4009-4014.

446

43.

447

using flat gas permeable membranes. Waste Manage. 2013, 33 (6), 1531-1538.

448

44.

449

USGC: US, 2012; Vol.1 pp. 43.1-43.13.

Rothrock, M.J.,Jr.; Szoegi, A.A.; Vanotti, M.B. Recovery of ammonia from poultry litter

Miller, M. Metals and minerals, Lime statistics and information, In Minerals year book,


Page 22 of 27

Page 23 of 27

450


Table 1. Physico-chemical properties of urine, effluent and sediment. Parameters

Before N and P

Effluent after N and P harvesting

harvesting pH not maintained pure

pH maintained pure urine

pH maintained diluted urine

urine At 30 oC

At 40 oC

At 30 oC

At 40 oC

At 30 oC

At 40 oC

pH

9.3 ± 0.1

8.8 ± 0.2

8.5 ± 0.2

11.9 ± 0.3

11.8 ± 0.2

10.5 ± 0.8*

10.7 ± 3*

Conductivity

27.3 ± 4.5

13.5

13.5 ± 1

16.1 ± 4

15.5 ± 3.4

2.9 ± 0.4

3.2 ± 0.5

NH4-N (g/L)

4.5± 0.2 (0.9)**

0.6 ± 0.2

0.8 ± 0.4

0.3 ± 0.01

0.1 ± 0.02

0.02± 0.001

0.01± 0.001

Total-N (g/L)

5.0 ± 0.2 (1)**

0.6±0.06a

0.4±0.04b

0.2±0.07c

0.2±0.07c

0.06±0.01d

0.03±0.01d

Total-P (mg/L)

328±1.1(66)**

1.5 ± 6

1.03 ± 0.6

1.8 ± 0.8

1.2 ± 0.1

1.6 ± 0.6

0.9 ± 0.3

PO4-P (mg/L)

309± 10 (62)**

0.1

0.1

0.1

0.1

0.02

0.02

Total-K (g/L)

1.7 (0.2)**

1.33 ± 0.04

1.38 ± 0.1

1.38 ± 0.04

1.37 ± 0.05

0.29 ± 0.01

0.3 ± 0.01

SS (mg/L)

180 (36)**

44 ± 34

30 ± 24

5±2

1±3

2±1

4±1

Cl (g/L)

4.5

NA

NA

NA

NA

NA

NA

Total-N (%)

-

0.23 ± 0.03

0.1

0.34 ± 0.01

0.22 ± 0.01

0.15 ± 0.04

0.2 ± 0.02

Total-P (%)

-

1.6±0.05a

1.6±0.04a

1.6±0.03a

1.4±0.07a

1±0.05b

0.9±0.05b

PO4-P (%)

-

1.6±0.12

1.6±0.1

1.3±0.06

1.4±0.1

0.60.5

0.9±0.04

Total-K (%)

-

0.4 ± 0.07

0.42±0.15

0.42± 0.07

0.42±0.13

0.06 ± 0.01

0.09 ± 0.01

(mS/cm)

In sediment

451

Mean ± Stdev (N = 6). *Although the pH of the urine was maintained at >11 it was a little lower

452

at the end of the experiment. ** The value in the parenthesis is for diluted urine. NA= not

453

analyzed. Different letters in the same row mean significantly different results (P > 0.05) but the

454

analysis did not include the row “Before N and P harvesting”. The result presented as a

455

percentage was calculated based on weight (W/W).

456



Page 24 of 27

457

Table 2. N and P harvesting efficiency, production of (NH4)2SO4 compound, and P sediment in

458

different experiments. Experimental conditions

NH4-N

NH4-N

P

NH4-N

(NH4)2SO4

Sediment

removed %

harvested

harvested

loss %

compound (DW

(DW

%

%

kg/m3 urine)

urine)

kg/m3

At 30 oC (pure urine)

87 ± 1a

85 ± 2a

99

2 ± 1a

24 ± 0.5a

26.9 ± 0.4a

At 40 oC (pure urine)

92 ± 4 ab

86 ± 4a

99

6 ± 3b

25.5 ± 1.1ab

25.6 ± 1.1a

At 30 oC (pH maintained

94 ± 2b

96 ± 3bc

99

0.5 ± 1c

25.8 ± 0.8ab

32.4 ± 0.3b

98 ± 2cd

99 ± 1c

99

1 ± 1c

25.6 ± 0.4b

29.5 ± 0.9c

96 ± 1c

92 ± 5ab

99

5 ± 5abc

4.5 ± 0.4c

9.1 ± 0.1d

99 ± 1d

95 ± 4bc

99

4 ± 3abc

5 ± 0.2c

8.9 ± 0.2d

pure urine) At 40 oC (pH maintained pure urine) At 30 oC (pH maintained diluted urine) At 40 oC (pH maintained diluted urine)

459

Mean ± SD, (N = 6). Different letters in the same column mean significantly different results (P

460

> 0.05), DW = dry weight. The % result was calculated based on W/W.

461 462 463 464 465 466 467 468 469


Page 25 of 27

470


Table 3. Theoretical economic assessment of N and P harvesting using our technique. Treatment

Used amount

Cost/price (€)

References

H2SO4

20.9 kg

6

(€290/ton)43

Ca(OH)2

22 kg

2

(€93/ton)44

Energy for aeration

0.025 kWh/nm3

0.10

(calculated

as

€0.072/kWh

in

as

€0.072/kWh

in

Finland) Energy for drying the acid

1

(calculated

and sediment H2SO4

for

Finland) effluent

1.47 kg

(€290/ton) 43

0.4

neutralization Total treatment cost

9.50

Revenue Revenue from (NH4)2(SO4)

25.2 kg of

(€461/ton of (NH4)2SO4 of 21% N)

7.3

+ H(NH4)3(SO4)2 mixture

(Cemagro Finland)

(13% N) Revenue from CaCO3 + P

4.45 (4.05+0.4)

(€1363/ton of phosphate, USDA 2013),

(€135/ton

of

36%

Ca,

Nordkalk) Total revenue

11.75

Total profit

2.25

471

Note:- The price of produced (NH4)2(SO4) + H(NH4)3(SO4)2 mixture is calculated as the price of the N

472

content in it and the price of Ca(OH)2 is calculated as the price of calcium. Investment and labor

473

costs are not included in the calculation.

474



475

45.

476

Experimental design.

477 478

Figure 1. Experimental setup. (Volume of the urine bottle was 1L, volume of the acid bottle

479

1 was 250 mL and the volume of acid bottle 2 was 100 mL).

480

481


Page 26 of 27

Page 27 of 27


482 483

484 485

Figure 2. The relation between NH4-N removal from urine, NH4-N harvested in sulfuric acid,

486

and the pH of urine. (A,B) pH not maintained pure urine, (C,D) pH maintained pure urine, (E,F)

487

pH maintained diluted urine. Standard deviation is shown as an error bar. The nutrient harvesting

488

experiment at 30 oC was conducted for 32 h (A,C,E) and at 40 oC for 28 h (B,D,F). The NH4-N

489

results are shown on the primary axis and the pH result is shown on the secondary axis.

490


Nitrogen and Phosphorus Harvesting from Human ... - ACS Publications

Recommend Documents