Raw Manure Research Articles

Can spatial reallocation of livestock reduce the impact of GHG emissions?

Historically, concentrated livestock production and, consequently, manure production and management have resulted in considerable environmental impacts in many parts of Europe. The region selected for the current case study was Belgium which is characterized by input-intensive animal production within a geographically concentrated land area. In this study, the effect of a reduction in manure pressure through spatial distribution of CO2 equivalent emissions was investigated and the impact on the carbon footprint verified through a consequential life cycle approach. This was accomplished by investigating the marginal spatial impact on CO2 emissions of a decrease in manure pressure. An economic and environmental optimization was conducted using mathematical linear programming and the main differences between both approaches determined. The results of the model simulations show that, while the economic optimum is achieved by maximizing the transport of raw manure until fertilization standards are fulfilled and subsequently processing the excess manure, the environmental optimum, from a carbon footprint point of view, is achieved by separating all manure, as this strategy causes the least CO2 emissions, mainly due to the limited manure storage time. Moreover, the analyses indicate that rearrangement of the spatial distribution of livestock production in Belgium will not substantially decrease CO2 emissions. As the study demonstrated that manure storage is the main contributor to the carbon footprint, solutions should instead be sought by changing these storage systems. This article contributes to the methodology of the consequential life cycle approach by linking carbon footprint analysis with an economic model that simulates manure disposal decisions driven by legal constraints and market forces.

Importance of Soil Amendments: Survival of Bacterial Pathogens in Manure and Compost Used as Organic Fertilizers

Biological soil amendments (BSAs) such as manure and compost are frequently used as organic fertilizers to improve the physical and chemical properties of soils. However, BSAs have been known to be a reservoir for enteric bacterial pathogens such as enterohemorrhagic Escherichia coli (EHEC), Salmonella spp., and Listeria spp. There are numerous mechanisms by which manure may transfer pathogens to growing fruits and vegetables, and several outbreaks of infections have been linked to manure-related contamination of leafy greens. In the United States several commodity-specific guidelines and current and proposed federal rules exist to provide guidance on the application of BSAs as fertilizers to soils, some of which require an interval between the application of manure to soils and the harvest of fruits and vegetables. This review examines the survival, persistence, and regrowth/resuscitation of bacterial pathogens in manure, biosolids, and composts. Moisture, along with climate and the physicochemical properties of soil, manure, or compost, plays a significant role in the ability of pathogens to persist and resuscitate in amended soils. Adaptation of enteric bacterial pathogens to the nonhost environment of soils may also extend their persistence in manure- or compost-amended soils. The presence of antibiotic-resistance genes in soils may also be increased by manure application. Overall, BSAs applied as fertilizers to soils can support the survival and regrowth of pathogens. BSAs should be handled and applied in a manner that reduces the prevalence of pathogens in soils and the likelihood of transfer of food-borne pathogens to fruits and vegetables. This review will focus on two BSAs-raw manure and composted manure (and other feedstocks)-and predominantly on the survival of enteric bacterial pathogens in BSAs as applied to soils as organic fertilizers.

Ammonia removal from raw manure digestate by means of a turbulent mixing stripping process

In this study, ammonia stripping by means of a turbulent mixing process followed by pH neutralization was investigated as a simple and cost-effective ammonia removal technique to treat raw manure digestate. Batch tests conducted using CaO, NaOH and H2O2 to control pH and temperature and combinations thereof showed that sodium hydroxide was the most suitable chemical, as it is easy to handle, minimizes treatment time and costs, does not increase the solid content of the sludge and allows to easily control the stripping process. NaOH dosage mainly depended on buffering capacity rather than on total solid content. The analysis of the ammonia stripping process indicated that ammonia removal was strongly dependent on pH, and ammonia removal rate followed the pseudo-first-order kinetics. Total solid content slightly influenced TAN removal efficiency. When NaOH was applied to treat raw digestate at pH 10 and mean temperature of 23 ± 2 °C, TAN removal efficiency reached 88.7% after 24 h of turbulent mixing stripping, without reaching inhibitory salinity levels. Moreover, pH neutralization with sulfuric acid following the stripping process improved raw digestate dewaterability.

Fate of Viable but Non-culturable Listeria monocytogenes in Pig Manure Microcosms.

The fate of two strains of Listeria monocytogenes and their ability to become viable but non-culturable (VBNC) was investigated in microcosms containing piggery effluents (two raw manures and two biologically treated manures) stored for 2 months at 8 and 20°C. Levels of L. monocytogenes were estimated using the culture method, qPCR, and propidium monoazide treatment combined with qPCR (qPCRPMA). The chemical composition and the microbial community structure of the manures were also analyzed. The strains showed similar decline rates and persisted up to 63 days. At day zero, the percentage of VBNC cells among viable cells was higher in raw manures (81.5–94.8%) than in treated manures (67.8–79.2%). The changes in their proportion over time depended on the temperature and on the type of effluent: the biggest increase was observed in treated manures at 20°C and the smallest increase in raw manures at 8°C. The chemical parameters had no influence on the behavior of the strains, but decrease of the persistence of viable cells was associated with an increase in the microbial richness of the manures. This study demonstrated that storing manure altered the culturability of L. monocytogenes, which rapidly entered the VBNC state, and underlines the importance of including VBNC cells when estimating the persistence of the pathogens in farm effluents.

Effects of using raw and composted manures on nitrous oxide emissions: a review

Effects of using raw and composted manures on nitrous oxide emissions: a review

Conversion of poultry litter into class A biosolids using autothermal thermophilic aerobic digestion

Purpose – The purpose of this paper is to minimize environmental problems related to raw poultry manure application by stabilizing its nutrient and organic matter (OM) content. This can be achieved by prior digestion before its application to agricultural soils. Design/methodology/approach – In the present study, changes in physicochemical and microbial properties of poultry litter were studied in order to evaluate the suitability of using the digested (stabilized) product for soil amendment. The poultry litter was digested in autothermal thermophilic aerobic digestor (ATAD) where organic solids were degraded and the heat released during the microbial degradation was used to maintain the thermophilic temperatures ( < 50ºC) at a hydraulic retention time of about 3 d. Findings – Results of this study showed that the poultry litter undergoes physicochemical and microbial changes similar to other digestion systems; these changes include self-heating, relative increase in Cu, Zn, Fe, Mn, P, K and NO3-N and decrease in microbial population numbers, C, OM and NH4-N contents. Originality/value – ATAD is an effective method for the conversion of poultry litter into organic fertilizer, which can be readily applied to the agriculture land. ATAD is an eco-friendly, cost effective method which also reduces the length of stabilization.

Propidium Monoazide Coupled with PCR Predicts Infectivity of Enteric Viruses in Swine Manure and Biofertilized Soil.

The use of propidium monoazide (PMA) coupled with real-time PCR (RT-qPCR or qPCR for RNA or DNA viruses, respectively) was assessed to discriminate infectious enteric viruses in swine raw manure, swine effluent from anaerobic biodigester (AB) and biofertilized soils. Those samples were spiked either with infectious and heat-inactivated human adenovirus-2 (HAdV-2) or mengovirus (vMC0), and PMA-qPCR/RT-qPCR allowed discriminating inactivated viruses from the infective particles, with significant reductions (>99.9%). Then, the procedure was further assayed to evaluate the presence and stability of two non-cultivable viruses (porcine adenovirus and rotavirus A) in natural samples (swine raw manure, swine effluent from AB and biofertilized soils); it demonstrated viral inactivation during the storage period at 23 °C. As a result, the combination of PMA coupled to real-time PCR can be a promising alternative for prediction of viral infectivity in comparison to more labour-intensive and costly techniques such as animal or tissue-culture infectivity methods, and for those viruses that do not have currently available cell culture techniques.

Influence of solid–liquid separation strategy on biogas yield from a stratified swine production system

As the fourth largest swine producer and exporter, Brazil has increased its participation in the global swine production market. Generally, these units concentrate a large number of animals and generate effluents that must be correctly managed to prevent environmental impacts, being anaerobic digestion is an interesting alternative for treating these effluents. The low-volatile solid concentration in the manure suggests the need for solid–liquid separation as a tool to improve the biogas generation capacity. This study aimed to determine the influence of simplified and inexpensive solid–liquid separation strategies (screening and settling) and the different manures produced during each swine production phase (gestating and farrowing sow houses, nursery houses and finishing houses) on biogas and methane yield. We collected samples in two gestating sow houses (GSH-a and GSH-b), two farrowing sow houses (FSH-a and FSH-b), a nursery house (NH) and a finishing house (FH). Biochemical methane potential (BMP) tests were performed according to international standard procedures. The settled sludge fraction comprised 20–30% of the raw manure volume, which comprises 40–60% of the total methane yield. The methane potential of the settled sludge fraction was approximately two times higher than the methane potential of the supernatant fraction. The biogas yield differed among the raw manures from different swine production phases (GSH-a 326.4 and GSH-b 577.1; FSH-a 860.1 and FSH-b 479.2; NH -970.2; FH 474.5 NmLbiogas.gVS−1). The differences were relative to the production phase (feed type and feeding techniques) and the management of the effluent inside the facilities (water management). Brazilian swine production has increased his participation in the global market, been the fourth producer and the fourth exporter. The segregation of swine production in multiple sites has increased its importance, due to the possibilities to have more specialized units. Generally, these units concentrate a large number of animals and generate effluents that must be correctly managed to avoid environmental impact. Due to the biodegradability of manure, anaerobic digestion is an interesting alternative to treat these effluents. The low volatile solid concentration in the swine manure suggests the need for solid–liquid separation as a tool to improve biogas generation capacity. The present study aimed to determine the influence of simplified and cheap solid–liquid separation strategies (based on screening and settling) and different manure of each swine production phases (gestating and farrowing sows houses, nursery houses and finishing houses) on biogas and methane yield. We collected samples in two gestating sows house (GSH-a and GSH-b), two farrowing sows house (FSH-a and FSH-b), a nursery house (NH) and a finishing house (FH). The Biochemical Methane Production (BMP) tests were performed according to international standard procedure (VDI 4630). The settled sludge fraction responds for 20–30% of raw manure volume, producing 40–60% of the total methane yield. The methane potential of settled sludge fraction was about 2 times higher than the supernatant fraction. There are differences on biogas yield between the raw manure of different swine production phases (GSH-a 326.4 and GSH-b 577.1; FSH-a 860.1 and FSH-b 479.2; NH 970.2; FH 474.5 NmLbiogas.gVS−1). The differences are relative to production phase (feed type, feeding techniques, etc.), but also the management of the effluent inside the facilities (water management).

Chemical, Thermal and Spectroscopic Methods to Assess Biodegradation of Winery-Distillery Wastes during Composting

The objective of this work was to study the co-composting process of wastes from the winery and distillery industry with animal manures, using the classical chemical methods traditionally used in composting studies together with advanced instrumental methods (thermal analysis, FT-IR and CPMAS 13C NMR techniques), to evaluate the development of the process and the quality of the end-products obtained. For this, three piles were elaborated by the turning composting system, using as raw materials winery-distillery wastes (grape marc and exhausted grape marc) and animal manures (cattle manure and poultry manure). The classical analytical methods showed a suitable development of the process in all the piles, but these techniques were ineffective to study the humification process during the composting of this type of materials. However, their combination with the advanced instrumental techniques clearly provided more information regarding the turnover of the organic matter pools during the composting process of these materials. Thermal analysis allowed to estimate the degradability of the remaining material and to assess qualitatively the rate of OM stabilization and recalcitrant C in the compost samples, based on the energy required to achieve the same mass losses. FT-IR spectra mainly showed variations between piles and time of sampling in the bands associated to complex organic compounds (mainly at 1420 and 1540 cm-1) and to nitrate and inorganic components (at 875 and 1384 cm-1, respectively), indicating composted material stability and maturity; while CPMAS 13C NMR provided semi-quantitatively partition of C compounds and structures during the process, being especially interesting their variation to evaluate the biotransformation of each C pool, especially in the comparison of recalcitrant C vs labile C pools, such as Alkyl /O-Alkyl ratio.

Effects of Anaerobic Digestion and Solids Separation on Ammonia Emissions from Stored and Land Applied Dairy Manure

Field and laboratory studies were conducted to evaluate the effects of anaerobic digestion (AD) and solids-liquid separation on emissions during subsequent storage and land application. The lab storage tests were conducted for 21 days with manure samples obtained at the following four points in a full-scale AD system: raw manure (RM) delivery, raw manure supplemented with other substrates (AD influent), AD effluent, and AD effluent after solids-liquid separation (AD liquid effluent). Ammonia fluxes from stored AD effluent declined from 3.95 to 2.02 g m−2 day−1. Lower NH3 fluxes, however, were observed from AD liquid effluent (1.1 g m−2 day−1) and AD influent (0.25 g m−2 day−1). Ammonia emissions from full-scale manure storages were similar to those obtained in the lab. Results also indicated significantly lower volatile fatty acid (VFA) in AD effluent and AD liquid effluent compared with that from the AD influent, indicating significant reduction in odor generation potential due to AD and solids-liquid separation processes. Two manure application methods (surface application and manure injection) for both non-AD and AD manures were simulated in the lab and studied for 9 days. Surface-applied non-AD manure exhibited the highest NH3 flux (0.78 g m−2 day−1), while injected AD manure led to the lowest NH3 flux (0.17 g m−2 day−1). Similar NH3 emissions results were observed from the field studies. Overall, while AD of dairy manure resulted in significant increases in NH3 emissions from stored effluent, the AD process significantly reduced NH3 emissions following application of AD manure on land.

Bioenergy production from algae using dairy manure as a nutrient source: Life cycle energy and greenhouse gas emission analysis

Abstract This study estimated the potential of algal bioenergy production using nitrogen and phosphorus present in the dairy manure (produced in the US). State wise dairy manure production and energy mixes were used to estimate algal bioenergy production and associated life cycle nonrenewable primary energy demand and greenhouse gas emissions for the four scenarios. These scenarios were constructed using various combination of following processes (i) anaerobic digestion, (ii) algal biodiesel production using effluent from (i), (iii) pyrolysis, and (iv) enzymatic hydrolysis. Bioenergy production, nonrenewable primary energy demand and greenhouse gas emissions of each state were aggregated to estimate the total bioenergy production, nonrenewable primary energy requirement and greenhouse gas emissions for the US. Two different cases were simulated for each scenario, one without taking into account the nutrient values (N, P) of applied sludge generated from the bioenergy production (Case B) while in the other one, nutrient values of sludge were considered (Case A). For incorporation of nutrient values of sludge, system expansion approach was used. It was estimated that by using dairy manure, 0.56 billion GJ/yr bioenergy could be produced. Minimum “nonrenewable primary energy requirement (NRPER)” (GJ/GJ) [Total primary nonrenewable energy requirement/bioenergy produced] and GHG emissions (kg CO2 eq./GJ bioenergy produced) for the four scenarios (1–4) for case B were as follows (1) 0.37, 27 (2) 0.51, −30; (3) 0.55, 47 and (4) 0.70, 15 respectively. In case A, NRPER did not change as compared to case B. GHG emissions increased in case A scenarios as compared to case B scenarios. The increase in GHG emission was mostly due to incorporation of reference scenario (raw dairy manure was applied on the ground) and N2O emission from the sludge amended soil.

Environmentally Sustainable Biogas? The Key Role of Manure Co-Digestion with Energy Crops

We analysed the environmental impacts of three biogas systems based on dairy manure, sorghum and maize. The geographical scope of the analysis is the Po valley, in Italy. The anaerobic digestion of manure guarantees high GHG (Green House Gases) savings thanks to the avoided emissions from the traditional storage and management of raw manure as organic fertiliser. GHG emissions for maize and sorghum-based systems, on the other hand, are similar to those of the Italian electricity mix. In crop-based systems, the plants with open-tank storage of digestate emit 50% more GHG than those with gas-tight tanks. In all the environmental impact categories analysed (acidification, particulate matter emissions, and eutrophication), energy crops based systems have much higher impacts than the Italian electricity mix. Maize-based systems cause higher impacts than sorghum, due to more intensive cultivation. Manure-based pathways have always lower impacts than the energy crops based pathways, however, all biogas systems cause much higher impacts than the current Italian electricity mix. We conclude that manure digestion is the most efficient way to reduce GHG emissions; although there are trade-offs with other local environmental impacts. Biogas production from crops; although not providing environmental benefits per se; may be regarded as an option to facilitate the deployment of manure digestion.

Biochar-mediated reductions in greenhouse gas emissions from soil amended with anaerobic digestates

This investigation examines nitrous oxide (N2O) fluxes from soil with simultaneous amendments of anaerobic digestates and biochar. The main source of anthropogenic emissions of N2O is agriculture and in particular, manure and slurry application to fields. Anaerobic digestates are increasingly used as a fertiliser and interest is growing in their potential as sources of N2O via nitrification and denitrification. Biochar is a stable product of pyrolysis and may affect soil properties such as cation exchange capacity and water holding capacity. Whilst work has been conducted on the effects of biochar amendment on N2O emissions in soils fertilised with mineral fertilisers and raw animal manures, little work to date has focused on the effects of biochar on nitrogen transformations within soil amended with anaerobic digestates. The aim of the current investigation was to quantify the effects of biochar application on ammonification, nitrification and N2O fluxes within soil amended with three anaerobic digestates derived from different feedstocks. A factorial experiment was undertaken in which a sandy loam soil (Dunnington Heath series) was either left untreated, or amended with three different anaerobic digestates and one of three biochar treatments; 0%, 1% or 3%. Nitrous oxide emissions were greatest from soil amended with anaerobic digestate originating from a maize feedstock. Biochar amendment reduced N2O emissions from all treatments, with the greatest effect observed in treatments with maximum emissions. The degree of N2O production and efficacy of biochar amelioration of gas emissions is discussed in context of soil microbial biomass and soil available carbon.

Thermophilic anaerobic digestion of the screened solid fraction of dairy manure in a solid-phase percolating reactor system

An increase in volatile solids (VS) content from solid fraction of dairy manure would reduce the size of biogas on-farm facilities and could be of greater interest to farmers than manure slurry biogas plants. This study examined the technical feasibility of a solid-phase batch thermophilic anaerobic digestion system for the screened solid fraction (SF) of dairy manure using the digested liquid fraction of dairy manure as inoculum. Inoculum to substrate ratio (I/S) and percolate recirculation strategy were the parameters studied. The manure slurry separation process resulted in a solid fraction that represented 16.8% of total manure mass; this aforementioned fraction showed an ultimate methane yield of 61.5 L CH4 kg−1 SF (265 L CH4 kg−1 VS) which represented 48% of methane potential from raw manure slurry. Five comparative experiments with 40 kg SF and different I/S ratios and percolate recirculation rates revealed that higher I/S ratios provide more security against inhibition states due to high VFA levels and low pH in percolate. The results of the present work have shown that increasing the percolate recirculation rate in intermittent and short recirculation operations improves the stability and speed of the process. Under this percolate recirculation strategy dry batch operation was possible with a I/S ratio of 0.6 obtaining methane yields of 145, 175, 204 and 220 L CH4 kg−1 VS after 15, 20, 30 and 60 days of operation.

Fate of faecal indicator organisms and bacterial diversity dynamics in a series of continuously fed aerated tank reactors treating dairy manure

This study aimed to investigate the fate of faecal indicator organisms and to characterize microbial diversity dynamics in dairy manure and in aerated liquid manure in different treatment reactors in a series of continuously fed aerated tank reactors using low intensity aeration and ammonia-reduced feedback. The bacterial diversity in the treatment reactors was also compared with that in the soil from which the process inoculant originated. The fate of enteric indicator organisms was studied by the enumeration of viable counts. Total bacterial community DNA was extracted, amplified using 16S rRNA primers, cloned, sequenced and identified by comparison to known sequences. At best over 90% reduction was observed in the numbers of enteric indicator organisms. However, the result obtained varied depending on treatment run and indicator organism. Firmicutes were the dominating phyla of the untreated slurry; whereas; Proteobacteria and Deinococcus-Thermus dominated in the treatment tanks. Soil had the broadest phylogenetic diversity: the major phylums were Acidobacteria, Proteobacteri and Gemmatimonadetes. At the genus level, raw manure and treatment tanks shared a number of sequences. Soil, the origin of the inoculant, and treatment tanks did not share any sequence at the genus level, although some was observed at the family level.

EFFECT OF CoCl2, NiCl2 AND FeCl3 ADDITIVES ON BIOGAS AND METHANE PRODUCTION

Anaerobic digestion is a biological process used to convert organic wastes into biogas and a stable biofertilizer for agricultural applications as environmentally friendly products. The produced biogas is used as an alternative renewable energy source. The objective of this study was to investigate the effect of the additives CoCl2, NiCl2 and FeCl3 on biogas and methane yield from fresh raw manure. A series of laboratory experiments using 2 L biodigesters were carried out in batch anaerobic mode. Each biodigester was fed with 1600 ml of slurry with individual addition of 1 mgL-1 CoCl2, 1 mgL-1 NiCl2 and 10 mgL-1 FeCl3. All of the treatments were carried out by triplication for the statistical analysis purposes, and analyzed using MStat-C software v.2.1. The results showed that the highest biogas and methane production (p CoCl2>FeCl3 in comparison with the control. These results indicated that, the addition of aforementioned salts increased biogas yield by 1.44, 1.33 and 1.17 times the biogas yielded with the control, respectively. Moreover, the methane yield was increased by 1.55, 1.43 and 1.21 times the methane yielded with the control, respectively.

Animal Manure Separation Technologies Diminish the Environmental Burden of Steroid Hormones

Newly developed treatment technologies are capable of separating livestock manure into a liquid fraction and a solid fraction using sedimentation, mechanical, and/or chemical methods. These technologies offer a potential means of distributing nutrients to agricultural lands without the unwanted environmental risks associated with the release of steroid hormones to adjacent waterways. To assess the potential benefit of these technologies in reducing the level of release of steroid hormones to adjacent waterways, distribution profiles of nine steroid hormones (pregnenolone, progesterone, dehydroepiandrosterone, androstenedione, testosterone, dihydrotestosterone, estrone, 17α-estradiol, and 17β-estradiol) were determined in raw swine manure, and in solid and liquid fractions separated from ten full-scale manure separation systems. Steroid hormone concentrations, normalized for nitrogen content, were significantly higher in separated solids than in liquids. If separated liquids are applied instead of raw manure, steroid hormone loading can be reduced by a factor of 2 at a constant nitrogen fertilization level.

Potential use of feedlot cattle manure for bioethanol production

This paper reports on processing options for the conversion of feedlot cattle manures into composite sugars for ethanol fermentation. Small-scale anaerobic digestion trials revealed that the process significantly reduces the content of glucan and xylan (ca. 70%) without effecting lignin. Moreover, anaerobic digestate (AD) fibres were poor substrates for cellulase (Cellic® CTec 2) saccharification, generating a maximum combined sugar yield of ca. 12% per original dry weight. Dilute acid pretreatment and enzyme saccharification of raw manures significantly improved total sugar recoveries, totalling 264mg/g (79% theoretical). This was attained when manures were pretreated with 2.5% H2SO4 for 90min at 121°C and saccharified with 50FPU CTec 2/g glucan. Saccharomycescerevisiae efficiently fermented crude hydrolysates within 6h, yielding 7.3g/L ethanol, representing glucose to ethanol conversion rate of 70%. With further developments (i.e., fermentation of xylose), this process could deliver greater yields, reinforcing its potential as a biofuel feedstock.

An investigation into the removal of Salmonella and enteric indicator bacteria from the separated liquid fraction of raw or anaerobically digested pig manure using novel on-farm woodchip biofilters

The objective was to investigate the removal of Salmonella and enteric indicator bacteria from the liquid fraction of raw and anaerobically digested (AD) pig manure in woodchip biofilters over a 14week (98day) period. Antibiotic susceptible Salmonella Infantis was detected in one influent material (liquid fraction of raw manure) on two occasions but was not found in the effluent at any time point. Furthermore, mean coliform reductions of 56% were observed in the biofilters treating the liquid fraction of raw manure. However, a mean increase of 228% was found in those treating the liquid from AD manure, despite the fact that the microbial challenge to these biofilters was lower. In addition, relatively high coliform counts were still present in the effluent from both biofilter treatments, especially in the systems treating the liquid fraction of AD manure. However, findings for Escherichia coli and Enterococcus were more promising, with reductions observed for both treatments (10 and 18.5% for E. coli and 71 and 87% for Enterococcus). Moreover, E. coli and Enterococcus were at, or just above, the limit of detection in the final effluents. Overall, although, there are no microbial limits for discharge or washwaters, the woodchip filter effluent would appear safe for discharge to waterways or use on-farm as regards Salmonella, E. coli and Enterococcus but not coliform. In conclusion, woodchip biofilters offer potential as a low-cost sustainable novel treatment option for the removal of pathogens from the liquid fraction of pig manure.

Possibility to eliminate emission of odor from pig manure treated using AMAK filtration method

Odor concentration in samples of gases taken from above the surface of raw pig manure and also the manure treated using a filtration method was measured. It was found out that pig manure mineralization and the filtration technology (the AMAK process) enables almost complete elimination of odor emission from post-filtration sludge and filtrate. The grade of treated manure neutralization made with the use of lime milk was found to be the most significant parameter affecting intensity of odor emission when applying a filtration method. An increase in pH value from 8.0 to 10.5 caused reduction of odor concentration by 99.1 and 99.5% in the samples taken from above the filtrate and the post-filtration sludge, respectively, comparing to the odor concentration found in the samples taken from above raw pig manure. For the tested samples, which were taken from above the fertilizer produced on the basis of post-filtration sludge coming from treated pig manure, the lowest odor concentration was 97% less than the value obtained for raw pig manure. The odor concentration in the samples taken from above the filtrate and the sediment obtained in the proposed filtration method was lower than the average value of odor concentration above pig manure lagoon by 90.5 and 94.5%, respectively.