=Paper=
{{Paper
|id=Vol-1152/paper63
|storemode=property
|title=Data Acquisition During Composting Experiments with Usage of 4-chamber Bioreactor for Modeling of Biological Processes
|pdfUrl=https://ceur-ws.org/Vol-1152/paper63.pdf
|volume=Vol-1152
|dblpUrl=https://dblp.org/rec/conf/haicta/DachBPK11
}}
==Data Acquisition During Composting Experiments with Usage of 4-chamber Bioreactor for Modeling of Biological Processes==
https://ceur-ws.org/Vol-1152/paper63.pdf
Data acquisition during composting experiments with
usage of 4-chamber bioreactor for modeling of biological
processes
Jacek Dach, Piotr Boniecki, Krzysztof Pilarski, Adam Krysztofiak
Institute of Agricultural Engineering, Poznan University of Life Sciences, Poznań, Poland,
e-mail: jacek.dach@up.poznan.pl
Abstract. The paper presents the system for data acquisition from composting
process in 4-chamber bioreactor. This system lets to create the model for
decomposition process for different biowaste, especially including ammonia
and GHG emissions.
Keywords: bioreactor, composting process, data acquisition, modeling.
1 Introduction
The problem of environmental friendly biowaste management has become one
of the most important areas of scientific activities within last 20 years in Europe. The
strong increase of research concerned on recycling and re-utilization of organic
wastes from agricultural, municipal and industrial origin has been observed (Gomez,
1998; Raghavarao et al, 2003). This fact was related with the tendencies in suitable
law regulations according to the strict ecological norms implemented after 1992 in
EU. One of the most environmental promising technologies is composting of
biowaste.
Composting is a process creating a closed ring of circulation of organic
substances in the environment. It consists of the microbiological decomposition of
organic substances in oxygenic conditions under the influence of thermophilic
microorganisms and moulds. The composting process can run in the piles or open
containers on a free air, in closed chambers or barrels with controlled oxygen supply
(Dach et al., 2003; Raghavarao et al., 2003). The very important condition for the
correct execution of this process is a suitable oxygen content in the delivered air
(above 8-10%) as well as the proper moisture degree (remaining on a level of 55-
75%) for the whole duration period.
However, in some cases, the composting process can be a source of
ammonia and GHG (greenhouse gases) emissions. It happens while bad, insufficient
porosity of composted material (emission of CH4 and H2S) or high nitrogen content
________________________________
Copyright ©by the paper’s authors. Copying permitted only for private and academic purposes.
In: M. Salampasis, A. Matopoulos (eds.): Proceedings of the International Conference on Information
and Communication Technologies
for Sustainable Agri-production and Environment (HAICTA 2011), Skiathos, 8-11 September, 2011.
737
(emission of NH3). That is why during the last years different scientific teams carried
on the research concerning an estimation of ammonia and greenhouse gases
emissions from composting of different biowaste and the factors influencing on this
emission. These activities are focused around national projects and international
concerted actions where the different models of gaseous emissions are developed for
many countries under different conditions.
However, the fieldworks related with composting process of organic materials
require an extreme labor and financial input. The weather conditions variability does
not ensure the guarantee of repeatability. Moreover during the fieldworks it is
difficult or sometimes completely impossible to use so complex measuring apparatus
as it is in case of laboratory experiments. Usage of bioreactor eliminates some part of
fieldwork, considerably decreases the costs and accelerates the final results.
In 2002 scientific team from Institute of Agricultural Engineering (Poznań
University of Life Sciences) worked out the idea and built isolated 2-chamber
bioreactor for model research on the processes of organic matter decay (in the frame
of Ministry of Science and Higher Education grant concerning the study of gaseous
emissions from different technologies of manure management (Dach et al, 2003). On
the basis of many investigations it has been stated that during the experiments
bioreactor ensures the run of decomposition similar like in real conditions during
heap composting with usage of tractor aerator. Simultaneously allows to control very
precisely changes running during the process (Czekała et al, 2006; Dach et al, 2004).
Numerous experiments explored with usage of bioreactor resulted in new
conceptions of solutions. In 2006 (under the CleanCompost 6 FP UE project) 4-
chamber bioreactor was designed. Completely new idea of gaseous measurement was
introduced, the tightness level and thermal isolation were raised, control and
measurement of aeration level were improved.
The aim of this study is to check the possibility of data collecting from aerobic
and/or anaerobic decomposition of organic wastes in order to create the ammonia and
greenhouse gases emissions prognostic model. Technologies of reduction of methane
emission from animal production and manure management in the context of GHG
taxation” (research project financed by the Polish Ministry of Science and Higher
Education, Contract number: N N313 271338).
2 Material and methods
4-chambers bioreactor set-up
Scheme of bioreactor construction and working is presented on Fig.1. The
capacity of one bioreactor chamber amounts 165 dm3. Thermal isolation consists of
hermetic 10 cm tight polystyrene layer. It ensures the run of composting process
under exact control without any disturbances from the outside.
The air pressed by the air pomp flows through the biomass placed in bioreactor
chamber. Chambers are made of metal sheet and components from stainless steel. It
is conditioned with highly aggressive environment occurring during composting, in
particular sewage sludge composting process (Harrison et al, 2006). Chambers have
second bottom with openings of ø 2,5 mm placed every 50 mm on the whole surface.
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It allows to distribute evenly the delivered air in the entire mass volume, as well as to
obtain wholeness of drains leaking out from the biomass while composting.
Fig. 1. Schematic diagram of the bioreactor: 1. pump, 2. flow regulator, 3. flow meter
4. isolated chamber, 5. drained liquids container, 6. composted mass, 7. sensors set, 8. air
cooling system, 9. condensates container, 10. column of gases content analysis (NH 3, O2/CO2,
CH4), 11. 16-channel recorder, 12. air pomp steering system
Between the chamber and the cover specialistic seals were used. In connection
with 60 kg charge it is a hermetic set-up empowering the chemical analysis of the air
leaving the chamber. Between the air pomp and chamber inlet there is an air flow
regulator integrated with a flow sensor (produced in IAE by own idea of dr. A
Jędruś), processed according to the individual solution. This system allows to precise
control and constant registry of the air amount delivered into the chamber (in the
range 0,5-6 l/min).In every bioreactor chamber there are at least 2 temperature
sensors in special acid-resistant covers. The air leaving the chamber at first gets to
the cooler cooperating with condensers system. The cooler target is to chill the air to
the temperature below 40oC (maximal working temperature for gases sensors).
Integrated sensors and systems for signals measuring and recording
Selected parameters of bioreactor measuring system are shown in Tab. 1. Parent
part of this measuring system are simultaneously working two microprocessor
recorders of measuring signals. Main parameters are presented in Tab. 2. In case of a
breakdown of one of the recorders the data continuity is ensured by working of the
second one. In case of voltage fading of feed net system automatically passes on a
battery power supply. It allows to save the data already recorded in the memory and
to register further measurements. The system is constantly connected with a
computer. In any moment the measurements results can be forward to the computer
with usage of standard output RS 232C.
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Table 1. Selected parameters of bioreactor measuring system.
Measured parameter Sensor type Measuring range Output signal
Temperature LM35DZ 0-100oC 0-1 V
Air flow Electronic flowmeter 0.5-6 l/min 0-5 V
NH3 MG-724AM 0-100 ppm 4-20 mA
NH3 MG-724AM 0-1000 ppm 4-20 mA
O2 MG-724OX 0-25 % 20-4 mA
CH4 MG-724P-90 0-5 % 4-20 mA
CO2 MG-724CF 0-100 % 4-20 mA
Table 2. Selected parameters of bioreactor measuring system.
Parameter Type 1 Type 2
Maximum amount of measurement 168 2011
Measurement frequency 1 measurement/h £ 4 measurements/s
Supply voltage 12 V DC 12 V DC
Amount of measuring channels 16 32
Applied measurement heads MG-72 of Alter S.A. firm are designed to measure
the gasses concentration and to forward this information to the central measuring
unit. Tab.3 shows the basic technical parameters of gaseous heads.
Table 3. Basic technical parameters of gaseous heads MG-72.
Delivery time of metrologic ability £ 20 sec.
Nominal supply parameters 5,6V DC/30 mA
Maximum termination resistance of current loop 50W
Temperature working range -20 - +40oC
10 – 90%Rh
Humidity working range
(without condensation)
Electro-chemical sensor is the main part of this head. It turns the changes of
concentration magnitude of measured gas onto adequate changes of electric
parameters. Output signal is the most essential information from the recorder point of
view. Gasses measuring system consists of the following heads: NH3 (0-1000 ppm),
CH4 (0-5%), O2 (0-25%), CO2 (0-25%). It cooperates with an original system of
electro valves which empower to use one set of heads for 4-chamber bioreactor.
3 Results
Within last 5 years, described bioreactor set-up was used in many projects. The
integrated sensors and systems for signals measuring and recording let to collect
during all experiments many valuable data separately for each bioreactor’s chamber.
This let to compare the process parameters in each moment of the experiments and
help to create the database for gases emission model (Fig. 2).
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Fig. 2. Measurements
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reme
rement
ntss of ssel
selected
elec
ecte
tedd pa
para
parameters
rame
mete
ters
rs w
whi
while
hile
hile ssew
sewage
ewag
ewagee sl
slud
sludge
udge
ge ccom
composting
ompo
post
stin
ingg a) T
Tem
Temperature
changes b) Changes of ammonia nitrogen c) Carbon dioxide concentration d) Ammonia
concentration; Three vertical lines are the examples of learning data vectors.
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4 Conclusions
Measuring systems and measuring signal recorders used in bioreactor are the source
of wide amount of data. Large measuring frequency reflects the real dynamics of
physical and chemical changes of composted mass. Moreover, it is very helpful in
gaining the representative data indispensable in modeling of occurring processes.
This is an essential for usage of bioreactor as a tool for prediction of aerobic and
anaerobic decomposition process with usage of artificial neural network.
Usage of bioreactor eliminates some part of fieldworks, considerably decreasing
costs and accelerates the obtainment of final results. Laboratory conditions give an
opportunity of usage of more developed measuring apparatus in comparison with
fieldworks ones.
Constant control of oxygen content allows to avoid the presence of anaerobic
conditions, unfavorably influencing on the quality of compost.
Acknowledgments. The authors thank to dr. A. Jędruś and dr. P. Niżewski from
PULS for their contribution in the bioreactor building.
References
1. Czekała, J., Dach, J., Wolna-Maruwka, A. 2006 Use of a Bioreactor For Model
Studies of a Sewage Sludge Composting. (In Polish). Woda-Środowisko-Obszary
Wiejskie T. 6 Zeszyt 2 (18), 29-40.
2. Dach, J., Jędruś, A., Kin, K., Zbytek, Z. 2004 The Influence of the Aeration
Intensity on The Run of The Manure Composting Process in Bioreactor. Journal
of Research and Applications in Agricultural Eng. 49 (1), 40-43.
3. Dach J., Jędruś A., Adamski M., Kowalik I., Zbytek Z. 2003 Bioreactor to
Research the Organic Materials Decomposition Processes. Journal of Research
and Applications in Agricultural Engineering, vol. 48/4.
4. Gomez, A. 1998 The evaluation of compost quality. Trends in Analytical
Chemistry 17, 310-314.
5. Harrison, E. Z., Oakes, S.R., Hysell, M., Hay, A. 2006 Organic chemicals in
sewage sludges. Science of the Total Environment 367, 481–497.
6. Raghavarao K.S.M.S., Ranganathan T.V., Karanth N.G. 2003 Some engineering
aspects of solid-state fermentation. Biochemical Engineering Journal 13, 127–
135.
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