SEPARATION OF WASH/SPILLAGE WATER FROMDEFECATED MANURE

Final Report Submitted to

Manitoba Livestock Manure Management Initiative Inc.

By

DGH Engineering Ltd.

March, 2002

Acknowledgements

DGH Engineering Ltd. would like to express its gratitude to Manitoba Livestock ManureManagement Initiative Inc. (MLMMI) as well as the Agri-Food Research & DevelopmentInitiative (ARDI) for the financial support and co-operation provided during the course ofthis study. Additionally, DGH Engineering Ltd. would like to thank Clearwater ColonyFarm for allowing use of and access to their hog barn and ongoing co-operation andassistance throughout the study. The advice and co-operation of Dr. Q. Zhang,University of Manitoba is also gratefully acknowledged.

Executive Summary

A technology to separate defecated manure and urine from spillage water in hogfarrowing barns has been developed in the Netherlands to reduce ammonia emissionsup to 50 to 65 percent. A project was undertaken at a local Manitoba farm to evaluatethe potential for this technology to reduce odour emitted from a farrowing barn.

A test room with ten sows had the manure pit divided into a defecated manure (manure)channel and a spillage water (water) channel. The manure channel comprisedapproximately 33 percent of the total pit area. There was 1.3 m2 of manure surface areaper sow. A control room with 28 sows was used for comparative purposes. Allcomparative data was analyzed on a per sow or a unit ventilation rate basis.

The total nitrogen, ammonia, pH, electrical conductivity, phosphorous, potassium,sulphur, and total solids in the manure channel were significantly higher than the waterchannel. The values of these parameters were approximately two to 15 times higher inthe manure channel than the water channel.

The odour emission rate in terms of per sow from the test room was approximately 17percent lower than the control room. The mean emission rate from the test room was60.6 OU*m3/sow/s, while the control room was 73.4 OU*m3/sow/s.

The hydrogen sulfide emission rate from the test room (0.92 L/sow/day) wasapproximately 27 percent lower than the control room (1.26 L/sow/day).

The ammonia emission rate from the test room was approximately 25 percent lower thanthe control room. The mean ammonia emission rates were 19.8 and 26.3 L/sow/dayfrom the test room and control room, respectively.

Since odour is emitted from sources other than the manure surface, the reduced impacton the odour emission rate as compared to hydrogen sulfide and ammonia is to beexpected. Hydrogen sulfide and ammonia can be emitted only from the manure surface,while odour is emitted from sources other than open manure, diluting the effect ofmanure surface treatments.

The test room released approximately 1.5 kg less nitrogen per sow per year than thecontrol room.

The separated spillage water, up to six cubic metres per sow per year, is suitable for useas flush water in other rooms in the barn, which would result in a significant reduction inwater consumption and wastewater production.

The total potential saving due to nitrogen retention and reduced water consumption isapproximately $13.00 per sow place per year. The cost of an imported gutter from theNetherlands is $375.00, however this cost should be reduced substantially if they wereto be manufactured in Manitoba.

Practical applications of the research results to existing building systems are discussedfor farrowing, dry sow, weanling and grower/finisher production areas.

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1.0 INTRODUCTION

Odour is a concern to neighbors of hog barns. Hog barn odours emanate from thesurfaces of floors, walls and pens; as well as from manure collection, storage andspreading; feed storage; dead storage and disposal; and from the hogs themselves.

Ammonia (NH3) and hydrogen sulfide (H2S) are two major odorous gases emitted fromanimal operations (Xue and Chen, 1999). These gases are generated while manureundergoes microbial degradation. Ammonia is produced by the decomposition ofnitrogen-containing compounds in the excreta, especially in urine. Hydrogen sulfide istypically the result of the anaerobic decomposition of sulfur-containing amino acids in adung/urine mixture (Overcash et al., 1983).

To reduce odour, intensive research has been undertaken on the emissions frommanure storage and application. The result has been new technologies such assynthetic manure storage covers and methods of injecting manure directly into the soil,which can reduce the odour level dramatically during manure storage and application.Technologies to reduce barn odour, however, have not been readily available.

A concept to modify manure collection pits has been developed in the Netherlands. Theidea is to confine the majority of the feces and urine in a customized gutter thatminimizes the surface of this “strongest” portion of the total wastes. This approach canbe implemented to maximum effect in a farrowing room where all the feces and urinefrom the sow can be collected beneath as little as 15 to 20 percent of the pen area.Similar but less dramatic reductions in the surface area of the “highest strength” wastescould be achieved in other areas of modern swine facilities. Some gutter manufactures inthe Netherlands claim that their products can reduce ammonia emission up to 65 percent(IC-W, 2001).

The potential for separation to control odour is based on the principal that manure odourrelease is a mass transfer process occurring at the liquid-air interface. When passingover the free surface of a liquid, air tends to sweep away any gases and vapors emittedfrom the liquid phase. Miner (1973) and Card (1998) believed that mass transfercoefficients could be used to characterize the transfer rate of a gas through an interfacialboundary layer. The emission rate of a compound from an aqueous phase into gasphase is defined by

Rv = Kt (Cl - Cg/Hc) A (1-1)

Where Rv = mass transfer rateKt = overall mass transfer rateCl = liquid-phase concentrationCg = gas-phase concentrationHc = henry’s law coefficientA = surface area

The emission rate is a function the surface area of the gas/liquid interface and theconcentration of the compound in the liquid and gas phases. Reducing the surface area

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potentially slows down the emission rate and eventually reduces the total amount of thecompound emission during a certain period of time. Since manure slurry is not an idealsolution, the real emission model of this odorous material would be much more complexthan expressed in the Eq. 1-1.

2.0 OBJECTIVES

The objective of this study was to determine the effect that the separation of spillagewater from defecated manure has on the reduction of odour, ammonia and hydrogensulfide emissions from swine barns. The nitrogen conservation effect resulting fromammonia emissions was to be evaluated. As well the extent to which the reuse of spilledwater could reduce water consumption was to be estimated.

3.0 MATERIALS AND METHODS

3.1 Site Description

The study took place on Clearwater Colony Farm located in the Rural Municipality ofRockwood, Manitoba. The farm provided two farrow rooms for this study. One of therooms was used as a test room to demonstrate the effect of waste separation, while theother was used as a control room.

The test room had an area of 887 square feet, with a holding capacity of 10 sows. Aconcrete divider was constructed in the manure pit to divide the pit into two channels: aspillage water (water) channel and a defecated manure (manure) channel. The surfaceareas of the water and manure channels were 280 and 140 square feet respectively.The test room was equipped with a 24 inch exhaust fan. The characteristics of theserooms are outlined in Appendix A.

The area of the control room was 2045 square feet with a holding capacity of 28 sows.There were two identical pits (east pit and west pit) in the control room. The surface areaof a single pit was 630 square feet. The room was equipped with two 24 inch exhaustfans (west and east). The west fan was in operation for the full duration of the study(April to October), while the east fan ran periodically from June to September accordingto the variation of the ventilation demand.

A farrow cycles in farrow room starts with filling the entire room with predeliver sows.The sows stay and deliver in the room. The sows and their offspring are held in the roomfor an average of 20 days after farrowing. The rooms are emptied all on the same day atthe end of the farrow cycle. The room is then soaked, pressure washed, disinfected andallowed to dry before refilling with the next batch of sows.

At the beginning of a farrow cycle, the discharge hole of the manure pit was plugged.The pit is filled with two to four inches of water. During the farrow cycle, manure andurine and spillage water are stored in the pit. The manure pit was emptied and washedafter the room is emptied. There was no drainage before the room was emptied. Theliquid samples were collected immediately after the rooms were emptied and before thepressure washing.

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3.2 Sampling and Laboratory Testing

3.2.1 Liquid testing

A period of two months was allowed to acclimatize the newly installed divided pit system.Liquid samples were then collected from the pits in the control room, and the water andmanure channels in the test room. These samples were collected following the end offour successive farrow-lactation cycles in each room. The initial sample set wassubmitted to Enviro-Test Laboratories in Winnipeg, Manitoba, to evaluate total solids(TS), total Kjeldahl nitrogen (TKN), ammonia, electrical conductivity (EC), sodium,potassium, sulfur and pH. The subsequent three sample sets were only tested for TKNand ammonia.

The measurement of TKN provided the basis from which to determine the effect that pitseparation had on nitrogen conservation. The TKN concentration multiplied by thevolume of liquid in the pit yields the total nitrogen in the room during one farrow-lactationcycle. This value was to be used to estimate nitrogen accumulation per sow per day.

3.2.2 Air sampling for odour testing

Originally, odour sampling was scheduled to occur on the same day that liquid samplingwas conducted. In practice, however, it was found that this schedule was not practical,as weather conditions and laboratory scheduling were problematic. On days with strongwinds, which can greatly influence sample quality, sampling had to be postponed. Aswell, the odour samples had to be analyzed within 24 hours of collection. In some cases,laboratory analysis could not be scheduled for the sampling day. As a result, odoursampling was conducted on a different day than liquid sampling.

The air samples for odour testing were collected both inside and outside of the barnrooms. The samples from inside the rooms were collected around the pits approximatelyfour inches below the slatted floor. The exterior samples were collected at the exhaustfan’s outlet. The air flow rates were measured while air sampling took place.

The samples were collected with Tedlar bags and an AC’SCENT Vacuum Chamber. Anair sampling was completed in two steps: filling the bag for conditioning and collecting asample for testing. In the first step, a Tedlar bag was placed in AC’SCENT VacuumChamber. The bag was filled with air sample ¼ to ½ full and then was evacuated. Thisfirst step is also known as coating the bag. The actual sample collection was completedin the second step. In this step the bag was filled ¾ full. The air samples were sent to theUniversity of Manitoba where they were tested within 24 hours of their collection. In thelaboratory, samples were analyzed for odour with a dynamic olfactometer. In order toobserve hydrogen sulfide concentration change in the storage period (from sampling totesting), hydrogen sulfide concentration was also tested in the lab at the beginning ofthis study.

3.2.3 Hydrogen sulfide field measurement

Hydrogen sulfide (H2S) concentration was also measured in the field using a Jerome631-X Hydrogen Sulfide Analyzer that provided a range of measurement spanning from0.003 parts per million (ppm) to 50 ppm. The hydrogen sulfide concentration, in ppm,was displayed on a digital meter following the measurement cycle.

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The hydrogen sulfide concentrations were measured at the outlet of the exhaust fans inconjunction with the measurement of air flow rate through the fans.

3.2.4 Ammonia field measurement

Ammonia (NH3) concentration was measured with a Dräger Gas Detector providing astandard range of measurement varying from 5 ppm to 70 ppm. Dräger 5/a ammoniatubes were used. The standard number of stokes of the Dräger gas detector pump is10. In this study, however, the number of stokes were adjusted according to theammonia concentration to minimize the relative error caused by diffusion of thediscoloration scale.

The ammonia measurement was always conducted at the same time and location as thehydrogen sulfide measurement.

3.2.5 Ventilation rate measurement

To evaluate the odour, hydrogen sulfide and ammonia emission rates, the ventilationrates were measured while sampling was conducted. The instrument employed forventilation measurement was an ALNOR® Electronic Balometer, with an APM 150 Meter,capable of measurements from 50 to 2000 CFM (24 to 940 L/s). The meter is able toshow the instantaneous flow rate on the digital screen, store several readings during thesampling period, and give the average flow rate for the period.

3.2.6 Odour, ammonia and hydrogen sulfide emission rate calculation

The unit emission rate of the tested criteria was calculated as:

Volume Concentration of the criteria X Air FlowrateUnit emission rate = (2-1) Number of sows in barn

The effect of manure channel separation on emission reduction can be observed bycomparing the unit emission rates between the test room and the control room.

3.2.7 Environmental Controls

The operating environments in the control and test rooms were monitored by membersof Clearwater Colony Farm in an effort to maintain as much similarity between the tworooms as possible. The items monitored included temperature, humidity, waterconsumption, feed consumption as well as fill and empty dates. The monitoring data isattached in Appendix B.

4.0 RESULTS AND DISCUSSION

4.1 Results of Liquid Sample Analysis

The concrete divider that provided the separation of wash/spillage water from defecatedmanure, had a substantial effect on the total solids (TS), total sulfur (S), total potassium

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(K), total sodium (Na), electrical conductivity (EC), pH level, ammonia and total Kjeldahlnitrogen (TKN) concentrations. The test results are listed in Table 1. The separatedmanure was approximately 2.6 to 15.9 times more concentrated than the separatedwash/spillage water. Among them, the ratios in ionized matters, such as EC (closelyrelated to total dissolved solids), Na, and K, 2.6, 3.0 and 5.2 respectively, were smallerthan in the other matters which from 8.0 to 15.9. The reason causing this is not clear,however, the sodium chloride in the feed spilled in water channel definitely contribute tothe increase of Na concentration and affect the Na ratio of manure channel to waterchannel.

The separated manure was approximately 1.6 to 2.1 times more concentrated than thecontrol sample for all criteria except sodium. Figure 1 provides a graphicalrepresentation of the data in Table 1. pH values are not represented in the figure, asseparation has a minimal effect on pH. EC is presented in Figure 1 in terms of TotalDissolved Solids (TDS), since the EC of liquid waste is based on the TDS change(Metcalf and Eddy, 1991).

Table 1 Characteristics of the liquid samples from water channel and manurechannel in the test room and from manure pits in the control room

Samples TKN(mg/L)

NH3

(mg/L)pH EC

(mS/cm)Na (mg/L) P (mg/L) K (mg/L) S (mg/L) TS (mg/L)

separated water 500 300 6.7 5 99 186 204 43 9000separated manure 4000 2700 7.3 13 298 2960 1070 497 86000

control sample 2500 1600 7.1 8 301 1480 615 260 41000Manure/water 800% 900% 260% 301% 1591% 525% 1156% 956%Water/control 20% 19% 63% 33% 13% 33% 17% 22%

Rat

io

Manure/control 160% 169% 163% 99% 200% 174% 191% 210%

Table 1 indicates that a certain amount of the impurities in the water channel can beattributed to the feces and urine production from the piglets, as well as spilled feed.

Sodium and potassium concentrations proved to be affected less by the separationtechnique, than were other the test criteria.

4.2 Odour, Hydrogen Sulfide and Ammonia in the Barn Rooms

The odour samples obtained inside the barn were collected at three points along each ofthe water channel and manure channel in the test room and six points around themanure pits in the control room, approximately four inches below the slatted floor.Hydrogen sulfide concentration and ammonia concentration were each measured 12times.

A significant difference in odour levels above the manure pits was observed between thecontrol room and the test room. The mean odour levels were 2705 odour units (OU) witha standard deviation (SD) of 574 in the control room and 1627 OU with a SD of 461 inthe test room. The mean odour concentration measured above the test pit was 40% lessthan that above the control pit. Figure 2 shows the odour levels of the individualsamples.

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Figure 1: Comparison of Chemical Characteristics of Liquid Samples fromControl Room Manure Pits and Test Room Manure Channel andWater Channel

Figure 2: Odour Concentration in Air Immediately Above Manure Pits

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No significant difference in odour levels was detected between the samples collectedabove the water and manure channels. The mean odour levels were 1603 with a SD of663 in the water channel and 1650 with a SD of 298 OU in the manure channel (Table2). This was not expected as it was predicted that the odour concentration above thewater would be less than that above the concentrated manure. A possible explanationfor this phenomenon is that the concrete pit divider has little to no effect on thecontainment of odour. Thus, odorous molecules are free to flow over the divider from themore concentrated manure to the less concentrated water channel and elevate theodour concentration. At the same time, the air molecules flow from the water channel tothe manure channel and dilute the odour concentration above the manure. Odourconcentration and airflow caused by ventilation are the two driving forces behind thisodour equalization. As a result, the difference in odour concentrations between thewater and manure channels was very limited.

Table 2 Odour Levels in Test Room Manure Pit (OU)Sample position Door side

(north)Middle Fan side

(south)Mean SD

Water channel 1986 837 1986 1603 663Manure channel 1980 1574 1397 1650 299

Theoretically, when the odour molecule equilibrium point is reached, the odourconcentration on the manure side should be somewhat higher than that on the waterside, because odour is continuously released from the manure. However, this differencein odour concentration was not significant enough to be identified by humanolfactormeter panelists.

Twelve hydrogen sulfide measurements were conducted in each room, with six fromeach of the water and manure channels in the test room, and six from each pit in thecontrol room. The results of hydrogen sulfide measurement show that the average H2Sconcentration in the control room was 2.3 times higher than that in the test room (Table 3& Figure 3).

Table 3 H2S concentration in the air above the pitsSampled at from 13:30 to 14:45 Sampled from 16:20 to 17:40Sample position

Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Sample 6Average

manure channel 1.5 1.7 1.7 1.04 1.1 0.91 1.325testroom water channel 1.1 0.99 1.3 0.52 0.62 0.71 0.873

east pit 2.9 2.8 2.1 2.5 2.4 1.9 2.433controlroom west pit 2.1 2.8 2.5 2.6 2.0 2.2 2.367

Table 3 also shows that hydrogen sulfide concentrations were lower directly above thewater channel than directly above the manure channel. This difference was more readilyidentified than the odour tests because of the JEROME meter is more sensitive thanhuman odour panelists. In addition, H2S is dense molecule and likely diffuses moreslowly than other constituents of odour increasing the gradient immediately above theemitting surface.

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Figure 3: Hydrogen Sulfide Concentration in Air Immediately Above ManurePits

Figure 4: Ammonia Concentration in Air Immediately Above Manure Pits

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The ammonia concentrations in the test and control room were compared as shown inTable 4 and Figure 4.

Table 4 Ammonia concentration in the air above the pits (ppm)Control room Test room

Samplingtime

SampleID

controlroom east

pit

test roomwest pit

test roommanurechannel

test roomwater

channel13:00-14:45 Sample 1 15 10 5 413:00-14:45 Sample 2 6 11 3 513:00-14:45 Sample 3 10 10 3 216:20-17:40 Sample 4 10 8 2 216:20-17:40 Sample 5 12 16 7 216:20-17:40 Sample 6 11 12 3 3

Average 10.7 11.2 3.8 3.0

The comparison of the criteria in the rooms only partially reflects the effectiveness of thewater and manure separation. Since the test room and the control room used in thisstudy have different sizes and different holding capacities, it is necessary to investigatethe emission rates of odour, hydrogen sulfide and ammonia from the rooms.

4.3 Odour, Hydrogen Sulfide and Ammonia Emission Rates

Figure 5 compares the odour emission rate from the test and control rooms as measuredin the discharge ventilation air. The average emission rates from the test and controlrooms were 60.6 with a SD of 35.8 and 73.4 with a SD of 37.0 OU*m3 per sow persecond, respectively. The average odour emission rate from the test room wasapproximate 17 percent lower than the control room.

The overall hydrogen sulfide emission rate from the test room was 0.92 with a SD of0.04 litres per sow per day, approximately 27 percent lower than the control room with avalue of 1.26 with a SD of 0.17 litres per sow per day.

Comparing 14 samples collected from the test room exhaust fan and 22 samplescollected from the control room exhaust fans, the ammonia emission rate from the testroom was approximately 25 percent lower than the control room. This ammoniareduction is lower than the 50 to 65 percent reduction obtained in the Netherlands. In thesystems used in the Netherlands, the defecated manure surface for one sow is reportedas low as 0.8 m2 (8.6 ft2) and the water channel comprises 80 percent of the pit surface.In this study, the geometry of the installation was limited by the need to retrofit thesystem to an existing barn. The water channel occupied 67 percent of the pit area andeach sow had 1.3 m2 (14 ft2) manure channel.

The ammonia average emission rates were observed as 19.8 L/sow/day with a SD of2.20 from the test room and 26.3 L/sow/day with a SD of 2.95 from the control room interms of litre per sow per day. The equivalent emission rates were 5.5 and 7.3 kgammonia (4.5 and 5.9 kg nitrogen) per sow per year from the test or the control room,respectively.

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Figure 5: Odour Emission Rate Comparison

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Figure 6: Hydrogen Sulphide Emission Rate Comparison

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Figure 7: Ammonia Emission Rate Comparison

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The reduction in hydrogen sulfide emission rate is very close to the reduction inammonia emission. The reduction in odour emission rate is lower than the reduction ineither H2S and NH3. Hydrogen sulfide and ammonia can only come from manure, butodour may result from other sources besides manure.

4.4 Nitrogen Conservation

Nitrogen levels were determined in both liquid and air samples in an effort todemonstrate the effect separation had on nitrogen conservation. This analysis, however,was clouded by some questionable laboratory test results with respect to TKN andammonia. The laboratory reports indicated that two of the four manure samples hadammonia concentrations in excess of the TKN concentration. This data is assumed tobe incorrect as ammonia is a component of TKN, and therefore cannot exceed the TKNlevels. Based on previous studies, the percentage of ammonia to TKN in manure pitsshould be approximately 60 to 70 percent (DGH, 2001). The Farm Practice Guidelines(Manitoba Agriculture, 1998) also reported that the typical ratio is 67 percent, and rangeof ratios is from 40 to 78 percent. The ammonia to TKN ratio indicates the degree ofmineralization of organic nitrogen in the manure. The average retention time of themanure in the collection pits was approximately 10 to 15 days. The organic nitrogencould not be thoroughly mineralized during this period.

Based on the difficulties mentioned above in the nitrogen analysis of the liquid samples,the nitrogen conservation was estimated from the difference in ammonia emission ratebetween the control and the test room.

5.0 COST/BENEFIT ESTIMATION

Besides the environmental benefit of odour emission reduction, some economic benefitis also provided by utilizing the separation technique. The associated nitrogenconservation provided by the reduction in ammonia emission adds to the fertilizer valueof the manure. As well the manure volume can be reduced by using the spillage waterfor flushing other barn rooms. These savings have been estimated below:

Nitrogen in the manure is conserved lowering ammonia emission. The difference inannual ammonia emission between the control room (7.3 kg/sow/year) and the test room(5.5 kg/sow/year) is 1.8 kg ammonia (1.5kg nitrogen)/sow/year. To purchase the sameamount of fertilizer would cost $1.15 ($0.77/kg N).

The spillage water is calculated as 6 m3/sow/year. Assuming that 4 m3/sow/year of freshwater can be saved if the spillage is employed for other barn flushing, the total manurevolume will be reduced by 4 m3/sow/year. The saving in manure application andtransportation will be approximately $11.71/sow/year. The manure transportation costhas been estimated on the basis of a tanker hauling two miles: The unit cost was basedon the first mile $1.21/m3 ($0.0055/gallon), second mile $0.22/m3 ($0.001/gallon) (Royalservice, 2000). The cost of manure application has been estimated on $1.496/m3

($0.0068/gallon) (Manitoba Agriculture, 1998).

Currently, no gutter manufacture exists in Manitoba. The costs of importing a gutter fromthe Netherlands will be expensive (US$250/sow). However, if the separation technology

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was adopted in Manitoba, local manufacturers would fabricate these gutters and the costcould be reduced.

6.0 CONCLUSIONS

1. Odour levels detected in the two farrow rooms monitored in this study were muchhigher compared to the odour emission levels reported by Zhang et al. (2000).

2. The concrete divider provided substantial separation in TKN, NH3, TS, S and P in thetest room. The values of these parameters were approximately 8 to 15 times higherin the manure channel than in the water channel. The concentrations of Na and K inthe manure channel were 2 and 5 times higher than in the water channel.

3. The ammonia emission rate from the test room was approximately 25 percent lowerthan that from the control room. The mean emission rates were 19.8 and 26.3L/sow/day from the test room and from the control room respectively.

4. The hydrogen sulfide emission rate from the test room was 27 percent lower than thecontrol room. The mean emission rates were 0.92 and 1.26 L/sow/day from the testroom and from the control room respectively.

5. The odour emission rate from the test room was approximately 17 percent lower thanthat from the control room. The mean emission rates were 60.6 and 73.4 OUm3/sow/s from the test room and from the control room respectively.

6. The nitrogen conservation obtained was 1.5 kg N/sow/year.

7. Approximately six cubic metres of spillage water can be collected in one sow placeper year. A potential benefit of separation is to reuse this spillage water as flushwater in other rooms in the barn, which will result in a reduction in water consumptionand slurry production.

7.0 APPLICATION OF FINDINGS

Practical application of the results can be made to building design in several areas, asoutlined below.

Segregation of the manure gutter from water spillage areas can be implemented infarrowing barns immediately, as was undertaken in this study. A practice that is followedin the design of many dry sow facilities to gain some small economies in construction isthe combining of walkway and manure gutter areas, as shown in Figure 8. This practiceshould be curtailed, since the results of this study clearly confirm that increasing thesurface area of the high-strength wastes increases NH3 and odour emissions.

A large proportion of finisher facilities have been designed using totally slotted floors.Although pens are totally slotted, pigs still choose areas for dunging and do not use allareas uniformly. However, it has become common practice to open cross-over channelsbetween the various manure gutters to allow equalization of manure accumulation.

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Although this seems to simplify manure handling, the results of this study would suggestthat this practice is most likely to increase odour emissions significantly. Alternatemanure gutter strategies need to be explored.

Similarly, with weaned pig housing systems where total slats have been utilizedexclusively for several years, little regard has been given to the development of specificdunging areas. Also, a common design of manure gutters for these types of facilitieshas paid no regard to the potential to separate high strength wastes from other areas. Itmay be possible to develop pen and manure pit systems that recognize the separationbetween sleeping and dunging areas. Most certainly and immediately, subdividing pitsinto sections that can capture high strength wastes from the most common dungingareas separately will reduce NH3 and odour emissions.

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Figure 8:

Typical extended pit under alley in dry sow area

Modified pit design in dry sow area to reduce odour and gas emissions

Floor Slats

Manure Pit

ManurePit

ManurePit

Solid Alley Floor

Figure 8-A – Typical Extended pit under alley in dry sow area

Figure 8-B – Modified Pit Design in Dry Sow Area to Reduce Odour and GasEmissions

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REFERENCES

Card, Thomas R., 1998. Fundamentals: Chemistry and Characteristics of Odors andVOCs, Chapter 2 in Odor and VOC Control Handbook, McGraw-Hill, 1998.

DGH, 2001. DGH Engineering Ltd., The Effect of Earthen Manure Storage Covers onNutrient Conservation and Stabilisation of Manure, Final report submitted toMLMMI.

IC-W, 2001, IC-W Mestpan, www.intercontinental.nl.

MB, 1998. Manitoba Agriculture, The Agricultural Guidelines Development Committee,Farm Practices Guidelines for Hog Producers in Manitoba.

Miner, J. R. 1973. Odour from Livestock Production. 1973. Corvallis, Ore.: AgriculturalEngineering Dept., Oregon State University.

Overcash, M. R., F. J. Humenik, and J. R. Miner. 1983. Livestock Waste Management,Vol. II. Boca Raton, Fla.: CRP Press, Inc.

Xue, S. K., and Chen, S., 1999, Surface Oxidation for Reducing Ammonia and HydrogenSulfide Emissions from Dairy Manure Storage, Transactions of ASAE, Vol. 42,No. 5, 1401-1408.

Zhang, Q., G. Plohman, and J. Zhou. 2000. Measurement of Odour Emissions from HogOperations in Manitoba, Final Report Submitted to MLMMI.

Appendix A

Site and Operation Information

• Information about test room and control room

• Operation logs during study period

Basic Information of the Barn Rooms

Control RoomDimension: 89’ X 23’Manure collection pit: 2 X 84’ X 7’-6”Exhausts: 2 X 24” fansHolding capacity: 28 sows

Test RoomDimension: 65’ X 13’-6”Manure collection pit: 1 X 60’ X 7’-6”

Divider: 30 ft2,Water channel: 280 ft2,Manure channel: 140 ft2

Exhausts: 1 X 24” fansHolding capacity: 10 sows

Fan Fan

West Fan

East Fan

Control Room

West Pit

East Pit

Test Room

East

West

NorthSouth

Manure Channel

Water Channel

Barn: Control Room

Number of PigsDate

Sows PigletsTemperature

(ºC)Humidity

(%)Notes(Time)

13-May 28 100 23.00 40 9:0016-May 28 100 25.00 41 17:0017-May 28 180 24.00 58 8:3018-May 28 180 26.00 29 15:0019-May 28 252 24.00 36 9:0021-May 28 252 23.00 43 9:0025-May 28 252 24.00 59 9:0026-May 28 252 24.00 61 11:0029-May 28 252 23.00 47 9:0001-Jun 28 252 21.00 63 10:0002-Jun 28 23.00 53 16:0003-Jun 28 250 21.00 59 9:0005-Jun 28 250 21.00 51 9:0006-Jun 28 250 20.00 65 9:0008-Jun 28 244 21.00 70 9:00

Water Metre Waste DepthTime Date Reading M3

East WestEast Pit(inch)

West Pit(inch)

Feed

a) 13-May 20.5 25.5 6 6b) 8-Jun 28.3 34.3 11 12 22254.3 kgc) totald) water feed

29.43 per sowa) = Before fill with pigsb) = After emptyingc) = Before discharged) = After water filling

Barn: Control Room

Number of PigsDate

Sows PigletsTemperature

(ºC)Humidity

(%)Notes(Time)

26-Jun 28 254 26.7528-Jun 28 252 22.00 4030-Jun 28 252 22.50 3601-Jul 28 252 25.00 36 15:0002-Jul 28 252 23.00 57 9:0003-Jul 28 252 23.00 67 8:0004-Jul 28 252 23.00 57 9:0005-Jul 28 251 23.00 54 9:0006-Jul 28 251 25.00 70 12:0008-Jul 28 251 24.00 68 8:0009-Jul 28 251 26.00 67 9:0010-Jul 28 251 24.00 67 9:0012-Jul 28 244 23.00 67 9:00

Water Metre Waste DepthTime Date Reading M3

East WestEast Pit(inch)

West Pit(inch)

Feed

a) 26-Jun 34 93 7.75 9.5b) 8-Jul 42 57 14 16.75c)d)

a) = Before fill with pigsb) = After emptyingc) = Before discharged) = After water filling

Barn: Control Room

Number of PigsDate

Sows PigletsTemperature

(ºC)Humidity

(%)Notes(Time)

27-Jul 28 280 24.00 Zero feed 7/27 510028-Jul 28 280 24.0031-Jul 28 280 24.0001- Aug 28 280 26.0002- Aug 28 280 27.0004- Aug 28 280 28.00 10:0005- Aug 28 280 28.00 11:0007- Aug 28 280 29.00 15:0008- Aug 28 280 29.00 15:0010- Aug 28 280 22.00 9:0011- Aug 28 280 28.00 15:0015- Aug 28 250 23.00 20:00

Water Metre Waste DepthTime Date Reading M3

East WestEast Pit(inch)

West Pit(inch)

Feed

a) 27-Jul 53.8 73.7 7.75 8.75b) 16-Aug 71.6 93.0 14.75 13.5c)d)

a) = Before fill with pigsb) = After emptyingc) = Before discharged) = After water filling

Barn: Control Room

Number of PigsDate

Sows PigletsTemperature

(ºC)Humidity

(%)Notes(Time)

03-Sep 28 280 23.75 zero feed 9/3 9:0004-Sep 28 280 29.75 17:0005-Sep 28 280 24.00 9:0006-Sep 28 280 24.50 10:0010-Sep 28 270 25.50 14:0013-Sep 28 270 22.00 11:0015-Sep 28 270 22.25 10:0020-Sep 28 252 22.00 9:00

Water Metre Waste DepthTime Date Reading M3

East WestEast Pit(inch)

West Pit(inch)

Feed

a) 03-Sep 79.8 100.4 8.75 7.25 Zero feed 9/3b) 20-Sep 91.05 110.05 15 13.75c)d)

Dry M 2401.3 kga) = Before fill with pigs Total feed 29515 kgb) = After emptyingc) = Before discharged) = After water filling

Barn: Test Room

Number of PigsDate

Sows PigletsTemperature

(ºC)Humidity

(%)Notes(Time)

12-Mar 9 23.00 4716-Mar 9 24.00 3517-Mar 9 25 25.00 3318-Mar 8 77 23.50 3920-Mar 7 47 23.75 50 15:0023-Mar 10 80 23.50 42 9:3024-Mar 10 83 22.50 30 14:0025-Mar 10 83 23.00 30 14:0026-Mar 10 83 23.00 30 9:0027-Mar 10 83 22.75 36 9:0030-Mar 10 83 23.00 50 9:0002-Apr 10 83 22.00 64 13:0003Apr 10 83 22.00 40 12:0004-Apr 10 83 22.50 39 14:0006-Apr 10 83 22.75 39 9:3007-Apr 10 83 23.25 38 9:3009-Apr 10 83 23.50 40 9:3010-Apr 10 83 21.50 44 9:30

Water Metre Waste DepthTime Date Reading M3

East WestEast Pit(inch)

West Pit(inch)

Feed

a) 12-Mar 0 3.5 5b) 10-Apr 4.7 7.2 7.2c) 11-Aprd)

a) = Before fill with pigsb) = After emptyingc) = Before discharged) = After water filling

Barn: Test Room

Number of PigsDate

Sows PigletsTemperature

(ºC)Humidity

(%)Notes(Time)

08-May 10 81 21.60 54 13:0011-May 10 81 22.00 55 9:0012-May 10 80 21.70 56 10:0016-May 10 80 24.00 38 14:0018-May 10 80 20.00 49 9:0019-May 10 80 24.00 43 15:0021-May 10 80 23.00 44 9:0024-May 9 70 23.00 58 16:0025-May 9 70 22.00 50 9:3026-May 9 70 23:00 63 11:0029-May 9 70 23.00 60 9:00

Water Metre Waste DepthTime Date Reading M3

East WestEast Pit(inch)

West Pit(inch)

Feed

a) 08-May 8.9 5.25 5.25b) 29-May 13.6 7.5 9.5c)d)

a) = Before fill with pigsb) = After emptyingc) = Before discharged) = After water filling

Barn: Test Room

Number of PigsDate

Sows PigletsTemperature

(ºC)Humidity

(%)Notes(Time)

08-Jun 10 26.00 57 13:0009-Jun 10 92 22.00 62 9:0010-Jun 10 92 27.00 37 15:0011-Jun 10 92 23.00 65 9:0012-Jun 10 92 23.00 52 17:0014-Jun 10 92 22.00 66 17:0016-Jun 10 92 20.00 54 9:0018-Jun 10 92 22.00 56 9:0020-Jun 10 92 23.00 59 9:0021-Jun 10 92 23.00 61 9:0022-Jun 10 86 24.00 52 13:0022-Jun 10 86 24.00 64 9:0024-Jun 10 86 26.00 67 13:00

26-Jun 10 86 24.00 62 11:0028-Jun 10 86 24.00 75 15:00

Water Metre Waste DepthTime Date Reading M3

East WestEast Pit(inch)

West Pit(inch)

Feed

a) 08-Jun 15.5 4.5 5.25 Zero 6/8/01

b) 28-Jun 20 8.5 9.5 10.455 kg feed andwater

c) Consumed with feedingsystem

d) 115 kg dry matterconsumed

a) = Before fill with pigsb) = After emptyingc) = Before discharged) = After water filling

Barn: Test Room

Number of PigsDate

Sows PigletsTemperature

(ºC)Humidity

(%)Notes(Time)

05-Aug 10 90 24.00 8:0006-Aug 10 50 27.00 11:0008-Aug 10 90 27.00 16:0010-Aug 10 90 22.00 9:0011-Aug 10 90 26.00 15:0029-Aug 10 75 23.00 10:00

Water Metre Waste DepthTime Date Reading M3

East WestEast Pit(inch)

West Pit(inch)

Feed

a) 05-Aug 31.4 7 7 Zero Aug 5 8:00b) 29-Aug 41.6 9 15 Zero Aug 29c)d)

11820 kg feed watera) = Before fill with pigs 1038.2 kg Dry matterb) = After emptyingc) = Before discharged) = After water filling

Appendix B

Laboratory Results

• Sampling Events and Farrowing Cycles

• Results of Odour, Hydrogen Sulfide and Ammonia Test

• Results of Liquid Test

• Methodology of Odour Test

May 29 – Sampling at exhausts

(Only west fan of the control room in operation)

Room Samples Flowrate m3/h DT/OU H2S (ppm) NH3 (ppm)

5 west fan-1 2560 1172 0.625 13.2

5 west fan-2 2488 1484 0.735 14.0

5 west fan-3 2480 1641 0.625 12.1

5 west fan-4 2472 1660 0.865 12.4

5 west fan-5 2392 1484 0.665 13.4

Control –28

Sows

5 west fan-6 2208 816 0.675 10.8

6-1 1327 1035 0.315 6.2

6-2 1298 567 0.240 6.3

6-3 1345 452 0.200 7.5

6-4 1433 642 0.385 6.7

6-5 1524 567 0.265 5.9

Test –10

Sows

6-6 1572 286 0.150 5.3

August 10 – Sampling at exhausts

Room Samples Flowrate m3/h DT/OU H2S (ppm) NH3 (ppm)

5 west fan-1 1790 3875 0.41 11.2

5 west fan-2 1893 2391 0.39 10.2

5 west fan-3 2002 2113 0.56 9.7

5 west fan-4 1864 2394 0.45 10.9

5 east fan-1 1299 3458 0.46 11.5

5 east fan-2 1345 2706 0.46 10.6

5 east fan-3 1260 648 0.38 11.7

Control –28

Sows

5 east fan-4 1227 2700 0.41 10.7

6-1 1320 642 0.15 6.7

6-2 1266 2402 0.46 6.1

6-3 1207 1875 0.27 7.0

Test –10

Sows6-4 1333 2391 0.33 7.2

September 19 – Sampling at exhausts

Room Samples Flowrate m3/h DT/OU H2S (ppm) NH3 (ppm)

5 west fan-1 1344 3095 11.1

5 west fan-2 1359 2425 9.8

5 west fan-3 1230 6531 10.6

5 west fan-4 1211 4938 11.3

5 east fan-1 1342 4259 10.6

5 east fan-2 1233 5951 10.2

5 east fan-3 1370 3095 9.4

Control –28

Sows

5 east fan-4 1334 3095 10.5

6-1 1320 2711 5.8

6-2 1209 3730 5.2

6-3 1217 2711 6.2

Test –10

Sows6-4 1305 1654 5.6

September 20 – Sampling at exhausts

Room Samples Flowrate m3/h DT/OU H2S (ppm) NH3 (ppm)

5 west fan-1 1998 0.38

5 west fan-2 1903 0.39

5 west fan-3 2158 0.37

5 west fan-4 2000 0.45

5 west fan-5 2315 0.33

5 west fan-6 2219 0.31

5 east fan-1 1299 0.46

5 east fan-2 1345 0.45

5 east fan-3 1476 0.38

5 east fan-4 1321 0.41

5 east fan-5 1478 0.35

Control –28

Sows

5 east fan-6 1341 0.33

6-1 965 0.46

6-2 1477 0.30

6-3 1207 0.37

6-4 1333 0.27

6-5 1337 0.32

Test –10

Sows

6-6 1199 0.24

October 18 – Odour levels in barn rooms (DT/OU)

Control Room Test RoomID

East Pit West Pit Manure Water

Sample 1 2230 2223 1980 1986

Sample 2 2230 2819 1575 837

Sample 3 3565 3165 1397 1986

October 18 – Hydrogen sulfide concentration in barn rooms (ppm)

Control Room Test RoomTime ID

East Pit West PitHallway

Manure WaterHallway

13:00-14:45 Sample 1 2.9 2.1 2.3 1.5 1.1 1.1

13:00-14:45 Sample 2 2.8 2.8 1.8 1.7 0.99 1.3

13:00-14:45 Sample 3 2.1 2.5 2.1 1.7 1.3 1.2

16:20-17:40 Sample 4 2.5 2.6 1.04 0.52

16:20-17:40 Sample 5 2.4 2.0 1.1 0.62

16:20-17:40 Sample 6 1.9 2.2 0.91 0.71

October 18 – Ammonia Concentration in barn rooms (ppm)

Control Room Test RoomTime ID

East Pit West Pit Manure Water

Sample 1 15 10 5 4

13:00-14:45 Sample 2 6 11 3 5

13:00-14:45 Sample 3 10 10 3 2

16:20-17:40 Sample 4 10 8 2 2

16:20-17:40 Sample 5 12 16 7 2

16:20-17:40 Sample 6 11 12 3 3

Control Room Liquid Sample Analysis(Lab: Enviro-Test Laboratories)

Sample Date: June 7Sampling Point Remarkswest and east

Ammonia(mg/L)

AnalysisDate

TKN(mg/L)

AnalysisDate pH, EC, Na, K, S and total

pits, mixed 2200 June 18 3400 June 18 solids were reported.

Sampling Pointwest and east

pHEC

(mS/cm)Total Na(mg/L)

Total P(mg/L)

Total K(mg/L)

Total S(mg/L)

TotalSolids %

pits, mixed 6.7 11 273 2740 799 430 6.3

Sample Date: July 12Sampling Point Remarkswest and east

Ammonia(mg/L)

AnalysisDate

TKN(mg/L)

AnalysisDate pH, EC, Na, K, S and total

pits, mixed 1600 July 20 2500 July 20 solids were reported.

Sampling Point EC Total Na Total P Total K Total Swest and east

pH(mS/cm) (mg/L) (mg/L) (mg/L) (mg/L)

TotalSolids %

pits, mixed 7.1 8 301 1480 615 260 4.1

Sample Date: August 16Sampling Point Remarkswest and east

Ammonia(mg/L)

AnalysisDate

TKN(mg/L)

AnalysisDate pH, EC, Na, K, S and total

pits, mixed 1300 Aug 23 1900 July 20 solids were reported.

Sampling Point EC Total Na Total P Total K Total Swest and east

pH(mS/cm) (mg/L) (mg/L) (mg/L) (mg/L)

TotalSolids %

pits, mixed 7.1 7 79 1780 501 222 3.7

Sample Date: September 20

Sampling Point Ammonia(mg/L)

AnalysisDate

TKN(mg/L)

AnalysisDate Remarks

east pit 2100 Sept 27 3900 Oct 19 TKN was tested one monthlater after

west pit 1700 Sept 27 4500 Oct 19 Sampling. PH and EC werereported

Sampling Point pH AnalysisDate

EC(mS/cm)

AnalysisDate

east pit 7.3 Sept 27 8.3 Sept 27

west pit 7.5 Sept 27 8.8 Sept 27

TEST ROOM liquid sample analysis(Lab: Enviro-Test Laboratories)

Sample Date: May 29

Sampling Point Ammonia(mg/L)

AnalysisDate

TKN(mg/L)

AnalysisDate Remarks

water channel 326 June 12 426 June 16

manure channel 3390 June 5 3160 June 5 Ammonia is higher than TKN

Sample Date: June 28

Sampling Point Ammonia(mg/L)

AnalysisDate

TKN(mg/L)

AnalysisDate Remarks

water channel 300 July 5 500 July 5

manure channel 2700 July 5 4000 July 5PH, EC, Na, P, K, S, andtotal solids were reported.

Sampling Point pH EC(mS/cm)

Total Na(mg/L)

Total P(mg/L)

Total K(mg/L)

Total S(mg/L)

TotalSolids %

water channel 6.7 5 99 186 204 43 0.9

manure channel 7.3 13 298 2960 1070 497 8.6

Sample Date: July 30

Sampling Point Ammonia(mg/L)

AnalysisDate

TKN(mg/L)

AnalysisDate Remarks

water channel 192 Aug 14 411 Aug 8

manure channel 1990 Aug 14 2260 Aug 8

Sample Date: Aug 31

Sampling Point Ammonia(mg/L)

AnalysisDate

TKN(mg/L)

AnalysisDate Remarks

water channel 220 Sept 21 219 Sept 6 Ammonia is higher thanTKN.

manure channel 1650 Sept 21 1580 Sept 6 Ammonia is higher than TKN

Methodology of Odour TestIn this study, odour level test was conducted by the University of Manitoba. The followinginformation is provided by the Biosystems Engineering Department of the University ofManitoba.

Odour evaluationA dynamic-dilution olfactometer (AC’SCENT, St. Croix Sensory, Inc., Stillwater, MN) and sixscreened assessors were used to determine the odour concentration (level) of each sample.The olfactometer was capable of providing 14 dilution levels, with dilution ratios between 8 to66667. The odour concentration measured by the olfactometer was expressed as thedilution-to-detection threshold (DT), or odour unit (OU), which represented the number ofdilutions needed to bring the odour down to the level that could be detected by 50% of thepopulation. Odour evaluations were conducted in the Sensory Laboratory of the CanadianFood Inspection Agency, Winnipeg. The room that housed the olfactometer had a positiveventilation system with carbon-filtered air to eliminate background odours. For each sensorysession, flow rates of the olfactometer were calibrated before and after testing and theaverage of the two calibrations were used in calculating dilution ratios. The triangular forced-choice method was used to present samples to the assessors, with a 3-s sniff time (St. CroixSensory, 1999). Panel data were retrospectively screened to remove outliners by comparingassessors’ individual threshold estimates with the panel average. The retrospectivescreening was based on the following criterion (St. Croix Sensory, 1999):

DITE/DT DITE ≥ DT∆D= (1) - DT/DITE DITE ≤ DT

where∆D = deviation of individual threshold estimate from panel averageDITE = individual threshold estimateDT = panel average detection threshold

Any assessor with a ∆D greater than 5.0 or lower than –5.0 was eliminated from the testresults(CEN, 1999).

Selection of odour assessorsThe assessors (panelists) were selected through a two-level sequential screening procedure.At both levels, each participant was presented with three flasks of n-butanol solution orwater, one of which was different in odour intensity from the other two. Participants wereasked to choose the odd sample (triangle test). In each testing session, participants werepresented with six sets of three flasks. For each participant, the number of correct choiceswas plotted against the number of triangle tests (Meilgaard et al., 1991). This would place theparticipant in one of three regions: reject, continue testing or accept. For those who fell in thecategory of continue testing, the tests were repeated on subsequent days until they movedinto the accept or reject region. Those participants who moved into the accept region duringthe first level screening would begin the second level of screening. Participants who wereeventually moved to the accept region of the second level screening were selected asassessors.

Meilgaard, M. 1991. Sensory evaluation techniques, 2nd ed. Boca Raton: CRC Press.St. Croix Sensory, 1999. User Manual of Olfactometer. St. Croix Sensory Inc., Stillwater, MN.

Appendix C

Photographs

Examples of two segregated manure pits used in The Netherlands, similar to thoseused in this study