S.G. Sommer

• University of Southern Denmark

Ammonia (NH3) emission from animal manure contributes to air pollution and ecosystem degradation, and the loss of reactive nitrogen (N) from agricultural systems. Estimates of NH3 emission are necessary for national inventories and nutrient management, and NH3 emission from field-applied manure has been measured in many studies over the past few de...

Anaerobic digestion is one of the most effective methods for treating swine manure by converting it into green energy, and efficiently reducing methane (CH4) emission to the atmosphere. Low C/N ratio of swine manure and the production of high levels of total ammoniacal nitrogen (TAN) during acidogenesis due to the high N contents of swine manure co...

Maintenance of the ideal carbon: nitrogen (C:N) ratio with a minimum level of TAN is a key challenge for achieving maximum potential CH4 production through the anaerobic digestion process of agricultural waste such as swine manure. Biogas production can be enhanced by adding zeolite into the anaerobic digestion medium. However, the effects of zeoli...

The objective of this study was to investigate the feasibility of using natural and NaCl-treated Australian zeolites to simultaneously remove excess nutrients from anaerobically digested swine manure. Ion adsorption and desorption properties of Australian zeolite during the anaerobic digestion of swine manure were investigated. Two experiments were...

In developing countries, the simple biogas digesters installed underground without heating or stirring are seen as a ‘green’ technology to convert animal waste into biogas, a source of bio-energy. However, quantitative estimates of biogas production of manures from steers fed local feed diets at actual incubation temperatures have yet to be carried...

Acidification of livestock manure can reduce emission of the greenhouse gases methane (CH4) and nitrous oxide (N2O), as well as ammonia (NH3). We examined the relation between emission of these gases and transformation of organic matter as affected by acidification. Liquid cattle manure was acidified with sulfuric acid to pH 5.5 at a pilot scale (1...

Organic wastes are composted to stabilize organic matter, reduce the moisture content, increase the concentrations of plant nutrients, eliminate pathogens and weed seeds, develop disease suppressiveness, and reduce greenhouse gas emissions. The requirements for compost quality depend on its final destination, which includes agriculture, horticultur...

Interfacial mass transfer of \(\hbox {NH}_3\) and \(\hbox {CO}_2\) are important in processes as diverse as \(\hbox {NH}_3\) emission from animal manure and gas scrubbing for removal of carbon dioxide. Predicting transfer rates is complicated by bidirectional interactions between solution pH and emission rates, which may be affected by physical, ch...

Quantifying in-house emissions of methane (CH 4) from liquid manure (slurry) is difficult due to high background emissions from enteric processes, yet of great importance for correct estimation of CH 4 emissions from manure management and effects of treatment technologies such as anaerobic digestion. In this study CH 4 production rates were determi...

Relationship between volatile solids in cattle (circles) and pig (triangles) slurry materials and TOC. (PDF)

Amounts of residual volatile solids (VS) in two pools (VSd = easily degradableThe 95% confidence intervals represent the confidence limits of observed storage temperatures for pig and cattle slurry. Given that excretal returns VS; VSnd = "non-degradable" VS), with daily time steps. The proportions of CH4 and CO2 emitted are unknown. Here residual V...

Evolution of CO2-C from cattle slurry samples during aerobic decomposition. The blue lines represent observations, corrected for background emissions from the soil, while the red lines represent 95% confidence limits of model fits. (PDF)

Dry matter (%) in slurry delivered to Thorsø Biogas plant during 2014. For information about farms, please refer to S1 Table. Data were obtained from the biogas plant manager, Anders Nedergaard. (PDF)

Evolution of CO2-C from pig slurry samples during aerobic decomposition. The blue lines represent observations, corrected for background emissions from the soil, while the red lines represent 95% confidence limits of model fits. (PDF)

Summary of in-house storage conditions at the time of sampling. Where possible, information about time of last emptying was recorded for calculation of collection period (continued on next page). (PDF)

Selected properties of the slurry materials collected for this study. (PDF)

In studies of biochemical methane production (BMP) researchers often collate a large number of samples at the same time for a sample archive. The samples are often frozen to avoid microbial transformation, further homogenized by grinding. We studied the influence of subfreezing/thawing and drying/milling of energy crop on BMP and anaerobic biodegra...

The biochemical methane potential and composition of sugar beet pulp silage were investigated using samples taken from six different depths in both open and closed silos (height 3.6 m). The biochemical methane potential (BMP) of pulp silage in open silos ranged from 337 to 420 normal litre (NL) CH4/kg volatile solids (VS), while the BMP of pulp sil...

Removal of ammonium nitrogen (NH4(+)-N) particularly from sources which are highly rich in nitrogen is important for addressing environmental pollution. Zeolites, aluminosilicate minerals, are commonly used as commercial adsorbents and ion-exchange medium in number of commercial applications due to its high adsorption capacity of ammonium (NH4(+))....

Globally, large amounts of agricultural waste biomasses are produced and used. Organic agricultural waste is also a potential source of energy and using, for example, animal manure for biogas is recognized as a cost-effective mitigation technology for greenhouse gas (GHG) emissions in agriculture. This chapter presents an overview of the magnitude...

Concerns over the negative environmental impact from livestock farming across Europe continue to make their mark resulting in new legislation and large research programs. However, despite a huge amount of published material and many available techniques, doubts over the success of national and European initiatives remain. Uptake of the more cost-ef...

Ammonia (NH3) emission from livestock manure constitutes a loss of crop-available nitrogen (N) and poses a threat to the environment. Therefore, low NH3 emission slurry application technologies have been developed, the reduction efficiency of which has typically been estimated through measurements using wind tunnels or integrated horizontal flux (I...

A combined mesophilic anaerobic-thermophilic aerobic process was used to treat high-strength food wastewater in this study. During the experimental period, most of solid residue from the mesophilic anaerobic reactor (R1) was separated by centrifugation and introduced into the thermophilic aerobic reactor (R2) for further digestion. Then, thermophil...

The emerging slurry acidification technology affects gaseous emissions, fertiliser value, biogas production and solid-liquid separation; however, maximising the advantages is difficult, as the effect of acidification on the slurry characteristics resulting in those observations remains unclarified. A full-scale study was therefore performed, compar...

Small-scale household digesters have been promoted across Asia as a sustainable way of handling manure. The major advantages are that they produce biogas and reduce odor. However their disadvantages include the low recycling of nutrients, because digestate is dilute and therefore difficult to transport, and the loss of biogas as a result of cracks...

Anaerobic digestion is an efficient and renewable energy technology that can produce biogas from a variety of biomasses such as animal manure, food waste and plant residues. In developing countries this technology is widely used for the production of biogas using local biomasses, but there is little information about the value of these biomasses fo...

Animal slurry is separated in order to avoid excessive nitrogen, phosphorus and potassium (NPK) fertilization of crops in the field. To enhance fertilizer efficiency further, slurry and its separation products may be acidified, for instance in animal houses. The current study quantified the effects of these treatments, both individually and in comb...

Millions of unheated and simple biogas digesters are currently used on small-scale livestock farms in developing countries. These digesters are not equipped to measure methane production and methane production is low during cold periods. The aim of this study was to develop kinetic models for predicting methane production in such conditions by dete...

Ammonia (NH3) emissions from manure constitute a significant loss of fixed nitrogen (N) from agricultural systems and contribute to air pollution and ecosystem degradation. Accurate models of such NH3 emissions will improve our understanding of the factors that control the emissions and allow appropriate mitigation actions to be identified and quan...

Biogas production from animal slurry can provide substantial contributions to reach renewable energy targets, yet due to the low methane potential of slurry, biogas plants depend on the addition of co-substrates to make operations profitable. The environmental performance of three underexploited co-substrates, straw, organic household waste and the...

The composition of manure fibres (MF) from 17 commercially separated pig slurries and seven raw pig slurries were characterised in terms of dry matter (DM), volatile solids (VS), protein, hemicellulose, cellulose and lignin. The average lignocellulose concentration in manure fibres and pig slurries was 790 and 370 g kg−1 [VS] respectively. Biochemi...

This study investigated the main factors influencing digester temperature and methods to reduce heat losses during the cold season in the subtropics. Four composite digesters (two insulated and two uninsulated) were buried underground to measure their internal temperature (°C) at a depth of 140 cm and 180 cm, biogas production and methane (CH4) con...

Determination of biochemical methane potential (BMP) by fermentation tests is time-consuming and costly, and therefore not useful for operators of full-scale biogas digesters. A great advantage of NIRS in determining BMP is the reduction in measurement time from at least one month for chemical determination to a couple of minutes for production of...

In many developing countries simple biogas digesters are used to produce energy for domestic purposes from anaerobic digestion of animal manure. We developed a simple, one-dimensional (1-D), thermal model with easily-available input data for unheated, unstirred, uninsulated, fixed-dome digesters buried in the soil to study heat transfer between bio...

In the project “ICT-AGRI: Development of harmonized sampling and measurement methods for odour, ammonia and dust emissions” different subgroups have been formed focusing on either ammonia, odour or dust. In this report, the conclusions of the ammonia subgroup regarding harmonization of measurement methods for the estimation of the ammonia removal f...

A rapidly changing and expanding livestock and poultry production sector is causing a range of environmental problems on local, regional and global scales. Animal Manure Recycling: Treatment and Management presents an accessible overview of environmentally friendly technologies for managing animal manure more efficiently and in a sustainable mann...

Biogas production is a clean renewable energy source that can improve lives in developing countries. However, winter temperatures in some areas are too low to enable enough biogas production in small unheated digesters to meet the energy requirements of households. Low-cost, high yield reactors adapted to the local climate are needed in those situa...

The intensification of livestock production has led to increasing volumes of manure to be managed on the farm. Livestock manure is rich in carbon, nitrogen and water, and manure environments therefore have the potential for emission of the greenhouse gases (GHG) methane (CH4) and nitrous oxide (N2O). Methane is produced in strictly anaerobic enviro...

Emissions of ammonia (NH3) from livestock manure pose a risk to the health of animals and humans and cause pollution of the environment, while emissions of odorous compounds from animal manure are a large and increasing nuisance due to intensified livestock production in many parts of the world. The standardized method to estimate odour strength fr...

Animal manure is the major source of atmospheric ammonia (NH3) and the most important source of malodorous gases in the countryside. Emissions of these gases from the manure are described by a two-film model, which includes diffusion and convective mass transport of the gases from liquid manure to the atmosphere. For NH3 as well as many odorous com...

Large quantities of animal manure are collected worldwide and used for energy production. Owing to the high water content of manure, energy production by incineration may demand much pre-treatment in terms of separating water from the biomass, drying or torrefaction and thus the energy surplus of the process may be low. Anaerobic fermentation of bi...

Livestock or animal production systems differ between countries, as does animal manure management. This chapter presents the most common terms used to define animal production and manure management, and introduces systems and mass balances of carbon and plant nutrient flows in an aerobic and anaerobic manure management system. An engineering system...

The agglomeration of intensive and large animal production systems in various regions of the world has resulted in regional surpluses of animal manure. As a consequence, manures are not considered a valuable nutrient and organic matter resource, but a waste product. Inappropriate manure management causes significant pollution of the local environme...

Intensive and large-scale livestock production units produce considerable amounts of manure containing plant nutrients and organic matter. Due to intensification of production, a surplus of plant nutrients may accumulate on these farms and risks being discharged or emitted to the environment. Much manure is managed on farms as slurry with a high wa...

Intensification may increases the environmental impact of livestock production systems. Efforts to recycle nutrients in livestock manure for crop production will effectively reduce several pollution problems. A variety of environmental technologies are being developed for treatment of manure, many of which have a significant potential for reducing...

During storage of biomass, the components are transformed between pools of organic matter and pools of inorganic components. This chapter describes these transformation processes, which are the result of microbial activity and occur at fast rates under aerobic conditions, producing oxidised products, and at slower rates in anaerobic manure. The foc...

A rapidly changing and expanding livestock and poultry production sector is causing a range of environmental problems on local, regional and global scales. Animal Manure Recycling: Treatment and Management presents an accessible overview of environmentally friendly technologies for managing animal manure more efficiently and in a sustainable manner...

Livestock production is experiencing dynamic growth and specialisation, and is facing the challenge of ensuring that changes in production systems include the development of environmentally friendly manure management systems. This chapter provides an overview of manure management systems and technologies for removing solid and liquid manure from an...

Manure has for centuries been used as a fertilizer to grasslands and for crop production in most farming systems. Unfortunately, poorly managed recycling of manure to land poses an environmental risk especially due to the content of nitrogen (N), organic carbon (C) and water-components that are substrates for the microbial production of the two gre...

In developing countries, biogas energy production is seen as a technology that can provide clean energy in poor regions and reduce pollution caused by animal manure. Laboratories in these countries have little access to advanced gas measuring equipment, which may limit research aimed at improving local adapted biogas production. They may also be un...

Ongoing intensification and specialisation of livestock production lead to increasing volumes of manure to be managed, which are a source of the greenhouse gases (GHGs) methane (CH4) and nitrous oxide (N2O). Net emissions of CH4 and N2O result from a multitude of microbial activities in the manure environment. Their relative importance depends not...

This survey was carried out to study animal manure management on livestock farms with biogas technology (biogas farms) and without (non-biogas farms) in the areas surrounding the Vietnamese cities Hanoi and Hue. The objective of the study was to assess the contribution of biogas production to a better environment as well as to recognize the problem...

Nitrogen (N) losses from pig production and the recycling of N from manure to crops can harm the atmosphere, soil and ground water quality. This study intended to build a dynamic management model, adapted to the Vietnamese context, that links the N flow at all stages along the manure management chain from the N in the diets fed to grower-finisher p...

The efficient use of animal slurries, including separated animal slurries, in farming requires knowledge of the concentrations of plant nutrients in the slurry. This study shows that concentrations of total ammoniacal nitrogen (TAN), total Kjeldahl nitrogen (TKN) and, to some extent, potassium (K) in slurry can be assessed by measuring either the d...

Models are widely used to simulate the emission of greenhouse gases (GHG). They help to identify knowledge gaps, estimate total emissions for inventories, develop mitigation options and policies, raise awareness and encourage adoption. These models vary in scale, scope and methodological approach. The scale increases from field, manure storage or r...

Models are widely used to simulate the emission of greenhouse gases (GHG). They help to identify knowledge gaps, estimate total emissions for inventories, develop mitigation options and policies, raise awareness and encourage adoption. These models vary in scale, scope and methodological approach. The scale increases from field, manure storage or r...

This article presents an overview of the development and future perspectives of the Chinese biogas industry. The development of the industry has the potential to improve the rural environment and produce significant amounts of sustainable energy for China. Barriers to the development are the relatively weak environmental policies, imperfect financi...

Organic manures arising from livestock production provide a source of plant nutrients when applied to agricultural land. However, only about 52% of the N excreted by livestock is estimated to be recycled as a plant nutrient. The ­greatest losses of N from livestock excreta and manures are as gaseous emissions. These emissions are in the form of amm...

We examined the influence of fibrous fractions of biomass on biochemical methane potential (BMP) with the objective of developing an economical and easy-to-use statistical model to predict BMP, and hence the biodegradability of organic material (BD) for biogas production. The model was developed either for energy crops (grass, maize, and straw) or...

A high proportion of plant nutrients present in animal feed are excreted and therefore animal manure can be an important source of nitrogen (N) for crop production if losses of plant nutrients to the environment during storage and processing are minimized. The present study examines gaseous N losses from stored pig slurry and during composting of s...

Slurry, farmyard manure and poultry manure are an inevitable consequence of livestock products generated from housed animals. These manures are recycled back to land for plants to use the nutrients they contain. However, since they contain inorganic N, microbially available sources of C and water, they provide the essential substrates required for...

Intensification of livestock production in many parts of the world has led to increasing atmospheric losses of N in connection with storage and field application of manure. Both types of emissions are influenced by manure organic matter content via mechanisms such as composting, crust formation, mineralization–immobilization turnover, and water ret...

In the near future phosphorus (P) will be a limited resource in high demand. This will increase the incentives for recycling P in animal manure. In this study the dry-matter-rich fraction from slurry separation was incinerated and the P availability of the ash fraction examined. The aim was to adjust incineration temperature to support a high plant...

Animal slurry contains plant nutrients that are essential for crop production. However, intensive livestock production may lead to a surplus of plant nutrients on farms and, as a consequence, discharge or emission to the environment. In order to ensure that the slurry applied to fields matches the nutrient requirements of the crops, techniques have...

Swine slurry is a source of atmospheric pollutants. Emissions of basic and acidic compounds from slurry are largely dependent on the surface pH. In a storage system, the pH at the surface layers changes over time due to the volatilisation of ammonia (NH3), carbon dioxide (CO2) and acetic acid (HAc). In this article, a comprehensive gas emission–pH...

Animal slurry contains plant nutrients that are essential for crop production. However, intensive livestock production may lead to a surplus of plant nutrients on farms and, as a consequence, discharge or emission to the environment. In order to ensure that the slurry applied to fields matches the nutrient requirements of the crops, techniques have...

Pig slurry is a source of atmospheric pollutants. Emissions of basic and acidic compounds, such as hydrogen sulphide (H2S) from slurry are largely dependent on surface pH. In a storage system, the pH at the surface changes over time due to volatilisation of ammonia (NH3), carbon dioxide (CO2) and acetic acid (HAc). In this article, a gas emission–p...

Crop fields can be fertilised by application of manure because manure contains fertilising elements such as N and P, and organic matter that enhances soil physical properties. However, application of manure may also cause P and N pollution of surroundings, odour emission and waste of energy. A solution may be to apply an improved liquid manure frac...

Livestock farming systems are major sources of trace gases contributing to emissions of the greenhouse gases (GHG) nitrous oxide (N2O) and methane (CH4), i.e. N2O accounts for 10% and CH4 for 30% of the anthropogenic contributions to net global warming. This paper presents scenario assessments of whole-system effects of technologies for reducing GH...

Substantial emission of ammonia (NH3) from animal houses and the related high local deposition of NH3-N are a threat to semi-natural nitrogen-deficient ecosystems situated near the NH3 source. In Denmark, there are regulations limiting the level of NH3 emission from livestock houses near N-deficient ecosystems that are likely to change due to nitro...

Swine slurry is a source of atmospheric pollutants. Emissions of basic and acidic compounds (such as hydrogen sulphide, H2S) from slurry are largely dependent on surface pH. In a storage system, the pH at the surface layers changes over time due to volatilization of ammonia (NH3), carbon dioxide (CO2) and acetic acid (HAc). In this article, a gas e...

This chapter discusses discuss the origin, importance and controls of gaseous nitrogen (N) emissions from livestock farming systems. It discusses the N transformation during feed digestion and of the relationship between feed composition and the composition of feces and urine. The chapter also describes the emissions from feces and urine deposited...

Ammonia (NH3) emission following the application of livestock slurry to agricultural land is a significant source of atmospheric NH3, and not only poses a risk to the environment through eutrophication and acidification of sensitive ecosystems, but may also result in a loss of plant-available nitrogen (N). The band-spread slurry application technol...

Ammonia (NH3) volatilisation following the application of ammoniacal fertilisers and liquid manure to agricultural land is a significant source of atmospheric NH3, which not only poses a risk to the environment, but may also result in a loss of plant available nitrogen (N). This study examined the potential for reducing NH3 emission through acidify...

Livestock slurry in animal houses, in manure stores and applied on fields is in Denmark the most important source of ammonia (NH3) in the atmosphere. The emitted NH3 is a source of NH3 and ammonium (NH4+) deposition, which causes eutrophication of N-deficient ecosystems and may form NH4+-based particles in the air, which are a risk to health. This...

Phosphorus (P) in manure is a nutrient source for plants, but surplus P amended to fields represents a risk to the environment. This study examines the interactions between low-P diets for pigs and dairy cows and the separation of animal slurry into a solid P fraction and a liquid fraction. Replacing inorganic phosphates with phytase in pig feed re...

Intensification increases the environmental impact of livestock production systems. Efforts to recycle nutrients in livestock manure for crop production will effectively reduce several pollution problems, although general solutions are difficult to devise in view of the diversity in production systems, management strategies and legislation between...

Ammonia (NH3) is emitted in vast quantities from exposed livestock manure. The volatilisation of NH3 from livestock manure is a loss in valuable nitrogen in land-applied manure that could otherwise be used for crop production. Ammonia loss to air is also affiliated with environmental problems when it is deposited to the surrounding landscape. The g...

Animal slurry stored in-house and outside is a significant source of atmospheric methane (CH4). The CH4 source strength of stored slurry is greatly affected by temperature. To improve emission calculations on a global scale there is a need for knowledge about the relationship between production of CH4 in slurry and temperature. In this study, the f...