Herman Van den Weghe

Upflow anaerobic solid-state (UASS) digestion of horse manure: Thermophilic vs. mesophilic performance

Energetic use of complex lignocellulosic wastes has gained global interest. Thermophilic digestion of horse manure based on straw was investigated using the upflow anaerobic solid-state (UASS) process. Increasing the organic loading rate from 2.5 to 5.5gvsL(-)(1)d(-)(1) enhanced the average methane production rate from 0.387 to 0.687LCH4L(-)(1)d(-)(1), whereas the yield decreased from 154.8 to 124.8LCH4kgvs(-)(1). A single-stage and two-stage process design showed almost the same performance. Compared to prior experiments at mesophilic conditions, thermophilic conditions showed a significantly higher efficiency with an increase of 59.8% in methane yield and 58.1% in methane production rate. Additional biochemical methane potential (BMP) tests with two types of horse manure and four different bedding materials showed that wheat straw obtained the highest BMP. The results show that the thermophilic UASS process can be the key to an efficient energy recovery from straw-based manures.

Anaerobic digestion of horse dung mixed with different bedding materials in an upflow solid-state (UASS) reactor at mesophilic conditions.

Aim of this study was to investigate the use of upflow anaerobic solid-state (UASS) digestion for treating horse manure. Biochemical methane potential (BMP) tests conducted for varying mixtures of dung (hay and silage feed) and bedding material (wheat straw, flax, hemp, wood chips) showed that straw mixed with hay horse dung has the highest potential of [Formula: see text] . Continuous mesophilic digestion was conducted for 238 days using a single-stage UASS reactor (27 L) and a two-stage UASS system with an anaerobic filter (AF, 21 L). Increasing the organic loading rate (OLR) from 2.5 to 4.5 g vs L(-1)d(-1) enhanced the methane rate of the single-stage reactor from 0.262 to 0.391 LL(-1)d(-1) while the methane yield declined from 104.8 to 86.9 L kg vs(-1). The two-stage system showed similar yields. Thus, for solid-state digestion of horse manure a single-stage UASS reactor appears sufficient.

Greenhouse gas emissions after application of digestate: short-term effects of nitrification inhibitor and application technique effects

ABSTRACT Nitrogen-use efficiency in arable agriculture after organic fertilization can be improved by the incorporation of digestate into soil and through the use of nitrification inhibitors. To test the efficiency and the interaction of these measures, a laboratory microcosm study was conducted with undisturbed samples from two arable soils – a Gleysol and a Plaggic Anthrosol. Treatments were digestate application by injection to 15 or 20 cm depths or by trailing hose with subsequent incorporation. Half of the replicates of each application treatment were treated with the nitrification inhibitor 3,4-dimethyl pyrazole phosphate (DMPP). Emissions of the greenhouse gases (GHGs) CO2, N2O and CH4 were monitored during 51 days of incubation. Deeper injection (20 cm) did not lead to different GHG emissions compared with a shallow injection (15 cm). Application of DMPP decreased cumulative N2O emissions significantly by 17–70%. DMPP inhibited N2O fluxes and NO3- production, suggesting a positive effect of DMPP on the mitigation of direct GHG emission and nitrate leaching at least during several weeks after digestate fertilization. The effect of DMPP is independent of the application technique.

Ammoniakemissionen: Eignen sich plasmaphysikalische Verfahren zur Behandlung von Stallabluft?

Exhaust air treatment with the aid of non-thermal plasma techniques (NTP) makes it possible to reduce ammonia and odour emissions, as well as the number of germs. In initial tests on a NTP exhaust air cleaning system installed in a pig fattening stall, ammonia concentration was reduced by 18%, however, the energy requirements are significantly higher than for other exhaust air treating systems. Furthermore, the process creates ammonium nitrate, causing further disposal problems.

Drehmoment-geregelte Kratzbodengeschwindigkeit bei Festmiststreuern

Zur Verbesserung der Verteilgenauigkeit von Festmiststreuern in Langsrichtung wurde eine DLC-Steuerung (Drive-Line-Control-Steuerung) entwickelt, bei der der Massenstrom an den Streuorganen durch einen Regelkreis konstant gehalten wird. Die Variationskoeffizienten der Querverteilung (VKQ) lagen zwischen 11,7 % und 16,5 %. Die Variationskoeffizienten der Langsverteilung (VKL) waren sowohl mit als auch ohne DLC-Steuerung mit Werten zwischen 15,6 % und 35,7 % deutlich hoher. Die DLC-Steuerung hatte in dem Prufverfahren keinen Einfluss auf die VKL.

Füllstandsgesteuertes Anfütterungssystem oder konventioneller Rohrbreiautomat

Es wurde der Einfluss eines sensorgesteuerten Futterautomaten im Vergleich zum Rohrbreiautomaten auf die Aufzuchtsleistung untersucht. In einer Gruppe wurde in den ersten 14 Tagen das sensorgesteuerte Anfutterungssystem eingesetzt, ab dem 15. Tag wurde mit einem Rohrbreiautomaten gefuttert. In Gruppe 2 wurde nur der Rohrbreiautomat eingesetzt. Ferkel der Gruppe 1 konnten in den ersten 14 Tagen signifikant hohere Zunahmen aufweisen. Dies war auch nach funfwochiger Aufzucht noch statistisch nachzuweisen. Mehrzunahmen von 660 g der ersten zwei Versuchswochen stand ein Mehrverbrauch an Futter von 815 g gegenuber.

Ferkelaufzucht in Großgruppen

In large group keeping with sensor controlled liquid feeding, the behaviour and the fattening performance of rearing piglets were examined. Special attention was given to the animal-feeding place-ratio. The results prove that the methods investigated give a high performance with very low animal loss. Furthermore, it shows that modern feeding technology alone is no guarantee that with higher housing density consistent piglet development will result.

Emissionen frei gelüfteter Ställe

Emission characteristics of naturally ventilated housing systems have hardly been investigated till now and are therefore the subject of current research activities. The dynamic ascertainment of air flow at any time in naturally ventilated houses causes considerable difficulties. The focal point of the investigation presented was the development of a tracer gas measuring configuration for continuous air volume flow calculation in two selected outside climate houses for fattening pigs with cross ventilation.

Trends bei der Technik für die Zuchtschweine- und Ferkelhaltung

The recent development in sow keeping and piglet rearing is shaped by three tendencies, which are equally important and should simultaneously be achieved methodically: ·increasing physiological and monetary rearing efficiency per sow and year, simultaneously reducing production costs ·animal-friendly keeping ·eco-friendly production processes, i.e. increasing substance and energy efficiency, lowering emissions

Außenklimaställe für Schweine – Worauf in Norddeutschland Wert gelegt wird

Natural ventilation in pig housing meets future requirements for sustainable livestock production in two important respects. In comparison with conventional closed housing, the former can require substantially lower investment and running costs and, with regard to production methods and housing climate, can be organised to be more in-line with welfare demands. The common aspect of all variations is the foregoing of full insulation and of forced ventilation as well as the structuring of the house compartments into separate climate areas. Natural ventilation houses are used for pregnant sows, pig rearing and for feeding pigs.