World Academy of Science, Engineering and Technology
International Journal of Environmental and Ecological Engineering
Vol:5, No:10, 2011
Solar Energy for Water Conditioning
J. Pawłat, H. Stryczewska
International Science Index, Environmental and Ecological Engineering Vol:5, No:10, 2011 waset.org/Publication/5708
Abstract—Shortening of natural resources will impose greater
Germany (12000 GWh) and Spain (6302 GWh). In Poland it
was only 1,8 GWh. [5]
limitations of electric energy consumption in various fields including
water treatment technologies. Small water treatment installations
supplied with electric energy from solar sources are perfect example of
zero-emission technology. Possibility of solar energy application, as
one of the alternative energy resources for decontamination processes
is strongly dependent on geographical location. Various examples of
solar driven water purification systems are given and design of
solar-water treatment installation based on ozone for the geographical
conditions in Poland are presented.
Keywords—solar energy, water purification, ozone water
treatment
I. INTRODUCTION
I
N spite of the fact, that near-equatorial places called “sunny
belt” are so far much more favorable and cost-effective for
solar installations, constant growth of fuel prices in the last
decade caused rapid development of solar technology across
Europe, including its northern parts. The average insolation of
Europe territory is presented in Fig. 1. [1]. The average annual
insolation on Poland’s territory amounts to about 1100 kWh/m2
(3500MJ/m2) per year on a horizontal area, which corresponds
to the calorific value of 120 kG of theoretical standard fuel
(29300 kJ/kg of hard coal, 41860 kJ/kg of petroleum). Fig. 2
depicts insolation map of Polish territory. The insolation of this
area is characterized by a big annual diversification. For
example, the annual amount for the City of Lublin is about 1107
kWh, and while over 15% of (year) annual energy reaches
Lublin in August, in December it is only 1,6% of annual
amount. [2]. The typical daily insolation in Lublin area in
Summer is depicted in Fig. 2 [3]. In Europe solar thermal
collectors are primarily used for hot water production and space
heating (use of solar energy for cooling is rather limited).
According to EUROBSERV’ER, the solar thermal panel area
installed in the EU during 2009 was 4166056 m2 giving
22786,1MWth of the accumulated installed solar thermal
capacity [4]. against each other left out in the fresh air- 148347
m2 installed in 2009 in Europe). In 2010 Europe also continued
photovoltaic plant installation reaching over 80% of global
installed capacity and generating 22,5 TWh of photovoltaic
power. The additional installed capacity in the EU over the
twelve months to the end of 2010 ranged 13023,2MWp (growth
of 120,1%).The cumulated predicted photovoltaic capacity of
EU in 2010 is presented in Fig.4 [5].Average photovoltaic
power per inhabitant in European Union in 2010 was 58,5
Wp/inhab, with leading Germany and Czech Republic with
212,3 and 185,9 Wp/inhab., recpectively. The most of
2009-2010 electricity production from this source took place in
Authors are with Lublin University of Technology, ul. Nadbystrzycka 38a,
20-618 Lublin, Poland, askmik@hotmail.com
International Scholarly and Scientific Research & Innovation 5(10) 2011
Fig. 1 Global irradiation in Europe [1]
Fig. 2 The chart (day and night) insolation in Lublin between 1-3
June 2002, [3]
II. SOLAR ENERGY IN WATER TREATMENT
Inadequate access to clean water and lack of its sanitation are
persistent world-wide problems affecting humans on each
continent (according to UN number of people who lack access
to safe drinking water will increase from over 1 bilion to over
1.8 billion in in 2025). Moreover, industry and agriculture also
require huge amounts of water of certain quality causing further
deterioration of water quality in the region, which secondary
may lead to its scarcity. There are many conventional
technologies of water decontamination, which with growing
environmental pollution are sometimes insufficient and
energy-consuming. These technologies often require addition of
suplemental chemical compounds, which lead to secondary
pollution. Ozone based technologies combined with advanced
oxidation processes (AOP), already investigated and tested for
three decades proved to be a good alternative to traditional
627
scholar.waset.org/1307-6892/5708
International Science Index, Environmental and Ecological Engineering Vol:5, No:10, 2011 waset.org/Publication/5708
World Academy of Science, Engineering and Technology
International Journal of Environmental and Ecological Engineering
Vol:5, No:10, 2011
methodes. However, AOP methodes are sometimes considered
expensive and power-consuming. Thus combining treatment
technologies with alternative enegry sources can be a perfect
solution allowing for optimum purification due to combination
of variety of decontamination techniques. In this part
applicationof solar power for water desalination, drinking water
and wastewater treatment is described.
Availability of drinking water is an ultimate condition for the
inhabitation. Extraction of water from air (EWA) [6] is the
solution in the case of lack of primary source of water. The total
quantity of water contained in 1 km2 of atmospheric air, that is,
in most regions around the globe, 10,000 to 30,000 m3 of pure
water. In the state of the art technology, the refrigerator is
operated by an electricity driven compressor. The cold fluid that
goes into the heat exchanger is produced by a reverse
compression-expansion thermodynamic cycle. (Fig. 3). It is
claimed by the manufacturers that approximately one liter of
diesel fuel operating the electrical generator can provide four
liters of water from air. In fact system integration with PV
panels could make it more reasonable from economy point of
view.
Fig. 3 Typical EWA plant for potable water production (condensation
occurs by passage of the air on the cold coils of a heat pump) [6]
In the developing countries, where sophisticated water
purification methods are not available solar water disinfection
(SODIS) reveals a great potential to reduce the global
diarrhoeal diseases burden, which affects over 1.8 million
people [7], [8]. According to extensive microbiological
investigation, 30oC water temperature, a threshold solar
radiation intensity of at least 500 W/m2 (all spectral light) is
required for 3-5 h for SODIS to be efficient for destruction of
diarrhoea-causing pathogens in contaminated drinking water.
Water can be stored in any transparent container. Since the year
2000, SODIS is being promoted in developing countries
through information and awareness campaigns and currently
used in 33 countries (Fig. 4) by more than 2 million people and
decreasing diarrhoea outbreaks by 16–57%. A large body of
microbiological research followed, that assessed and
demonstrated the effectiveness of SODIS in destroying
diarrhoea-causing bacteria, viruses as well as Giardia spp. and
Cryptosporidium spp. [9-16].
International Scholarly and Scientific Research & Innovation 5(10) 2011
Fig. 4 More than 2 million users currently practise SODIS in 33
countries [7-16]
During Haiti experiments, one-day exposure achieved
complete bacterial inactivation 52% of the time, while a 2-day
exposure period achieved complete microbial inactivation
100% of the time [17].
Single-basin, solar stills, for the removal of a selected group
of inorganic, bacteriological, and organic contaminates were
investigated [18] and turned to be efficient in removing
non-volatile contaminants from the water. Removal efficiencies
of more than 99% were noted on salinity, total hardness, nitrate,
and fluoride. The stills were also successful in removing
bacteria by more than 99.9% from the water if care was taken to
avoid cross contamination from the raw water source. Stills had
mixed success when it came to the removal of volatile organic
compounds (VOCs), such as pesticides.
Solar distiller built using local materials used for reducing the
fluoride content from underground waters was used in
Anaafobiisi, Ghana. From an initial concentration of 20.6 mg/l
of fluoride in the water from a local borehole, this was reduced
to an average of about 0.7 mg/l, which is below the WHO
acceptable limit for fluoride in drinking water when the
solar distillation unit was used to purify it [19].
Different approach for sanitation of drinking water with
chlorine was proposed by Appleyard [20]. Ferric
tannate-sensitized n-(ZnO, SnO2)/Cu photoelectrochemical
cells were constructed using recycled waste materials and
household chemicals and utilising Fe2+–Fe3+ and Cu2+–Cu redox
couples for charge transfer. The solar cells, which were
constructed in recycled clear plastic tubing and drinking straws
in a home environment, produced an open-circuit voltages of
0.4–0.6 V and a short-circuit current densities of 1–2.5 mA/cm2.
Chlorine was produced at a rate of 4 mg/h from a 1% salt
solution using an array of cells with a combined voltage of 5 V
and a current of 200 mA.
In areas where water is heavily contaminated standalone
systems, which were used for desalination might be not
sufficient. AOP methods and catalytic processes can bring rapid
improvement of the effluent water quality. Many research
groups were investigating the catalytic systems based on
titanium compounds and Fenton process.
Tests of water heavily contaminated with Escherichia coli
(K-12) were carried out in real sunlight using laboratory scale
reactors to determine the collectors’ performance of different
tubular reflector profiles [21]. The reactors were constructed
628
scholar.waset.org/1307-6892/5708
World Academy of Science, Engineering and Technology
International Journal of Environmental and Ecological Engineering
Vol:5, No:10, 2011
using Pyrex tubing and aluminium reflectors of compound
parabolic, parabolic and V-groove profiles. Compound
parabolic reflector turned out to be most efficient in inactivation
of bacteria.
International Science Index, Environmental and Ecological Engineering Vol:5, No:10, 2011 waset.org/Publication/5708
Fig. 5 General mechanism of the photocatalysis [22].
break-up of molecules yielding CO2, H2O and dilute mineral
acids.
(c) Solar Disinfection, which applies the detoxification
techniques mentioned above, using a supported photocatalyst,
to generate powerful oxidizers to control and destroy
pathogenic water organisms.
Solar-driven electrochemical and photocatalytic installation
using a boron-doped diamond electrode and TiO2 photocatalyst
for removal of volatile organic compounds and pesticides from
water was developed [26]. In a treatment test of river water
samples, large amounts of chemical and biological
contaminants were totally wet-incinerated by the system. This
system, could provide 12 L/day of drinking water from the
Tama River (Japan) using only solar energy. Authors estimated
cost of the water as 26 yen/L.
The group of Sixto Malato is investigating the solar
photocatalysis and proposing various innovations in the process
for more than decade. Mechanism of solar driven photocatalysis
is depicted in Fig. 5. [22].
TABLE I
COMPARISON OF TIO2 AND PHOTO-FENTON PROCESS ASPECTS RELEVANT TO
THE PHOTOREACTOR'S DESIGN REQUIREMENTS. [24]
Fig. 6 Integrated PV water/gas/soil conditioning system based on
ozone
Malato group is often using compound parabolic collectors
(CPC), however variety of shapes and solutions including
trough reactor (PTR), thin-film-fixed-bed reactor (TFFBR),
double skin sheet reactor (DSSR, pilot plant in Wolfsburg
factory of the Volkswagen AG), etc. are employed [23]. Solar
driven photocatalytic oxidation processes are presented in Tab
1. [24].
EU supported several different projects with the aim of
developing a cost effective technology based on solar
photocatalysis for water decontamination and disinfection in
rural areas of developing countries: SOLWATER and
AQUACAT [24].
In Europe huge solar driven photocatalytic plant was built in
Almeria, Spain under the ‘‘SOLARDETOX’’ project [25]
(Solar Detoxification Technology for the Treatment of
Industrial Non-Biodegradable Persistent Chlorinated Water
Contaminants). Nowadays facility allows to investigate
following technologies [23-25]:
(a) Solar Desalination, from two different approaches,
combined solar power and desalination plants (MW range), and
medium to small solar thermal desalination systems (kW range).
(b) Solar Detoxification, by making use of the
near-ultraviolet and visible bands of the solar spectrum
(wavelengths shorter than 390 nm for TiO2 and 580 nm for
photo-Fenton) to promote a strong oxidation reaction by
generating oxidizers, either surface-bound hydroxyl radicals
(OH-) or free holes, which attack oxidizable contaminants,
producing a progressive
International Scholarly and Scientific Research & Innovation 5(10) 2011
Advanced oxidation technologies (AOTs) using UV lamps
(UV254, UV350), UV/H2O2, UV/Fe(III) as well as photo-Fenton
and heterogeneous photo-catalysis with TiO2 were also
investigated for treating aqueous solutions of pesticides
(Vydine) [27]. Slight degradation of pesticide in aqueous
solution was observed upon using simple photolysis process.
However, the combination of H2O2 or Fe(III) with these
illumination sources were more efficient than photolysis
process alone. UV350 was less efficient than that UV254.The
degradation rate of pesticide was strongly accelerated by
photo-Fenton and TiO2 processes regardless of the illumination
source. Increase in solar radiation intensity accelerated the
degradation rate of pesticide. AOTs can be efficiently used with
solar radiation to either mineralize the organic matter or convert
hardly biodegradable organics to more biodegradable waste.
Integrated PV system based on AOP and application of
ozone (Fig. 6) for water and gas conditioning was developed by
Stryczewska group [28-31]. System was applied for
conditioning of the pool waters, soil and gas.
III. PROTOTYPE INSTALLATION OF AIR, WATER AND SOIL
TREATMENT ENERGIZED FROM PV PANELS OLAR ENERGY IN
WATER TREATMENT
Autonomous water treatment installation energized from PV
panels and installation for air, water and soil treatment were
developed in Lublin University of Technology in cooperation
with Japanese partners. Set-ups were extensively described [2,
629
scholar.waset.org/1307-6892/5708
World Academy of Science, Engineering and Technology
International Journal of Environmental and Ecological Engineering
Vol:5, No:10, 2011
International Science Index, Environmental and Ecological Engineering Vol:5, No:10, 2011 waset.org/Publication/5708
28-33].Small water treatment installations with ozone
generation using electric energy from renewable energy sources
could be the good solutions to variety of environmental
problems. Fig.7 depicts a small household water ozonation
installation. Proposed system was made of three basic
sub-systems: electric energy power system, ozone production
system and water treatment system. It was totally autonomous,
designed for a constant work in difficult climatic conditions.
The devised technological solution is excellent to be utilized in
remote terrains, which are distant from electroenergetic network
or in the places where the electroenergetic main is unstable and
fallible.
Fig. 7 Water ozonation system
Currently, the total cost of generating electrical energy from
solar batteries is one order of magnitude higher than in case of
nuclear energy. However, the application of solar batteries
becomes profitable, as far as the demand for electrical energy is
small. The correctly selected system should cover about
95÷100% of electrical energy demand during summer.
Ozone generation took place with the usage of corona
discharge. The ozonizer was powered with high frequency
supplier with pulse control and amplitude modulation. The
basic part of ozone generator were titanium electrodes (one of
the covered with ceramic dielectric material). In order to lower
the ozonier’s consumption of electric energy, the complex
system of radiators was used, electrodes were efficiently cooled
with atmospheric air. The utilized ozone generator operated
with both: pure oxygen and atmospheric air as substrate gases.
With atmospheric air and pure oxygen used as substrate gases,
1.5 g/h and 6 g/h of O3 was generated, respectively. Gas flow
ranged 3,3-4,7 l/min with 180 W of power consumption.
The appropriately made contact container has a fundamental
influence on stability and final quality of water ozonation
International Scholarly and Scientific Research & Innovation 5(10) 2011
process. In the majority of ozonation systems ozone is added to
water in the form of bubbles through diffuser. The effectiveness
of such a process is low because ozone is not evenly mixed with
water, and when in large quantities, ozone evaporates from
water into ozone destructors, from where the unused oxygen is
blown out to the atmosphere. To reduce influence of factors
mentioned above innovative WOFIL system was used. In this
solution, raw water was initially aerated and oxidized with the
oxygen mixed with ozone, which evaporated from the contact
container. This solution enabled the increase of ozonation
process’ efficiency by almost 30% (in comparison with the
competitive ideas) without the increase of electrical energy
consumption. It also resulted in reduction of amount of gas
which was blown out to ozone destructors and in lower values of
residual ozone after the contact container. In order to remove
the excess of the produced and the residual ozone the catalytic
destructors were used. System is presented in Fig. 8.
630
scholar.waset.org/1307-6892/5708
International Science Index, Environmental and Ecological Engineering Vol:5, No:10, 2011 waset.org/Publication/5708
World Academy of Science, Engineering and Technology
International Journal of Environmental and Ecological Engineering
Vol:5, No:10, 2011
Fig. 8 WOFIL water ozonation system
The main element of the circuit was bi-directional inverter,
administering loads, the flow of energy and the work of
accumulators. Inverter provided 24 V grid of DC voltage and a
typical grid of AC voltage 110 V/60 Hz or 230 V/50 Hz. Thus, it
enabled integration ranging from electric generators to energy
receivers.
Photovoltaic systems, air turbine, generators with diesel
motors, water-power plants are connected together with load on
the side of alternating voltage. The batteries of accumulators,
fuel cells and DC receivers, however, are integrated on the side
of DC voltage. The connection of solar batteries on the side of
alternating voltage required application additional DC/AC
inverter, what allowed to avoid using an expansive DC wiring
and additional adjustment.
Fig. 9 Electric energy consumption in the system
IV. CONCLUSIONS
Limited power value received from photovoltaic cells poses
the main problem in designing an efficient treatment system.
Power consumption of individual electric elements in integrated
ozonation system is shown in Fig. 9.
When the whole system is accurately aligned, usage of some
of electronic elements, utilized in pilot installation, which are
responsible for controlling functioning of the system might be
omitted. Thus, power consumption could be lowered to several
hundred Watts.
International Scholarly and Scientific Research & Innovation 5(10) 2011
Usage of solar power via thermal collectors or photovoltaic
panels to the water treatment is an environmental-friendly and
cost-effective solution.
The presented water and air/water/soil ozonation set-ups are
currently being prepared for implementation procedures. Since
being fully autonomic systems of modular construction, they
could be easily adjusted to individual needs. Power from PV
panels could cover up to 95-100% energy needs in summer
period in optimized integrated system.
631
scholar.waset.org/1307-6892/5708
World Academy of Science, Engineering and Technology
International Journal of Environmental and Ecological Engineering
Vol:5, No:10, 2011
REFERENCES
[1]
[2]
[3]
[4]
[5]
[6]
International Science Index, Environmental and Ecological Engineering Vol:5, No:10, 2011 waset.org/Publication/5708
[7]
[8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]
[16]
[17]
[18]
[19]
[20]
[21]
[22]
[23]
[24]
[25]
[26]
http://www.helpsavetheclimate.com/insoleurope.html,
Energie-Atlas
GmbH, CH-4142, Munchenstein.
J. Pawłat, J. Diatczyk, G. Komarzyniec, T. GiŜewski, H. D.
Stryczewska,K. Ebihara,F. Mitsugi, S. Aoqui, T. Nakamiya “Solar
Energy for Soil Conditioning” Proc. International Conference on
Computer as a Tool (EUROCON), Lisboa, Portugal, 2011, pp. 1-4.
K. Nalewaj T. Janowski Z. Złonkiewicz “The possibilities of using solar
energy in the conditions of the Lublin Province”, Solar Energy for a
Sustainable Future, ISES Solar World Congress, Göteborg, Sweden 2003.
Eurobserv’er, 2010, Solarthermal barometer, May 2010.
Eurobserv’er, 2011, Photovoltaics barometer, May 2011.
A. Scrivani, T. El Asmar, U. Bardi, “Solar trough concentration for fresh
water production and waste water treatment“, 2007, Desalination, Vol.
206, (No. 1-3), pp. 485-493.
R. Meierhofer, G. Landolt, “Factors supporting the sustained use of solar
water disinfection - Experiences from a global promotion and
dissemination programme”, 2009, Desalination, Vol. 248, pp. 144–151.
A. Acra, Y. Karahagopian, Z. Raffoul, R. Dajani, “Disinfection of oral
rehydration solutions by sunlight”, 1980, Lancet, Vol. 316, (No. 8206),
pp. 1257–1258
B. Sommer, A. Marino, Y. Solarte, M.L. Salas, C. Dierolf, C. Valiente,
D.Mora, R. Rechsteiner, P. Setter, W. Wirojanagud, H. Ajarmeh, A.
Al-Hassan, M.Wegelin, “SODIS – an emerging water treatment process”,
1997, J.Water SRT, Aqua, Vol. 46(No. 3), pp. 127–137.
K.G. McGuigan, T.M. Joyce, R.M. Conroy, J.B. Gillespie, M.I.
Elmore-Meegan, “Solar disinfection of drinking water contained in
transparent plastic bottles: characterizing the bacterial inactivation
process”, 1998, J. Appl. Microbiol., Vol. 84, pp. 1138–1148.
R. Reed “Sol-air water treatment” 22nd WEDC Conference, Discussion
Paper, New Delhi, India, 1996. p. 295–6.
W. Stumm, J. Morgan, “Aquatic chemistry. Chemical equilibria and rates
in natural waters” Wiley, New York 1995.
T. Brock, T. Madigan, J. Martinko,
J. Parker “Biology of
microorganisms”, Prentice Hall, Englewood Cliffs, NJ 2000.
M. Wegelin, S. Canonica, K. Mechsner, F. Pesaro, A. Metzler, “Solar
water disinfection: scope of the process and analysis of radiation
experiments”, 1994, J Water SRT-Aqua ,Vol.43 (No.3), pp. 154–169.
EAWAG/SANDEC. SODIS Conference Synthesis. 2000.
M. Hindiyeh, A. Ali, “Investigating the efficiency of solar energy system
for drinking water disinfection”, 2010, Desalination, Vol. 259, (No.1-3),
pp.208-215.
P. Oates, P. Shanahan M. Polz, “Solar disinfection (SODIS): simulation
of solar radiation for global assessment and application for point-of-use
water treatment in Haiti” 2003, Water Research, Vol. 37 (No 1), pp.
47-54.
A. Hanson, W. Zachritz, K. Stevens, L. Mimbela, R. Polka, L. Cisneros,
„Distillate water quality of a single-basin solar still: laboratory and field
studies”, 2004, Solar Energy, Vol. 76, pp. 635–645.
E. Antwi E. Bensah , J. Ahiekpor, “Use of solar water distiller for
treatment of fluoride-contaminated water: The case of Bongo district of
Ghana“, 2011, Desalination, Vol.278 (No.1-3), pp 333-336.
S. Appleyard “Developing solar cells with recycled materials and
household chemicals for drinking water chlorination by communities
with limited resources” 2008, Solar Energy Vol. 82, pp. 1037–1041.
O.A. McLoughlin, S.C. Kehoe, K.G. McGuigan, E.F. Duffy, “Solar
disinfection of contaminated water: a comparison of three small-scale
reactors”, 2004, Solar Energy Vol. 77, pp. 657–664.
D. Robert, S. Malato, “Solar photocatalysis: a clean process for water
detoxification“, 2002, The Science of the Total Environment Vol. 291, pp.
85-97.
D. Bahnemann, “Photocatalytic water treatment: solar energy
applications “ 2004, Solar Energy, Vol. 77, (No. 5), pp. 445-459.
S. Malato, P. Fernández-Ibáñez, M.I. Maldonado, J. Blanco, W. Gernjak,
“Decontamination and disinfection of water by solar photocatalysis:
Recent overview and trends”, 2009, Catalysis Today, Vol. 147 (No. 1),
pp. 1-59.
S. Malato, J. Blanco, D.Alarcon, M.Maldonado, P. Fernández-Ibáñez, W.
Gernjak, “Photocatalytic decontamination and disinfection of water with
solar collectors”, 2007, Catalysis Today, Vol. 122, pp. 137–149.
T. Ochiai, K. Nakata, T. Murakami, A. Fujishima, Y. Yao, D. Tryk, Y.
Kubota „Development of solar-driven electrochemical and photocatalytic
International Scholarly and Scientific Research & Innovation 5(10) 2011
[27]
[28]
[29]
[30]
[31]
[32]
[33]
632
water treatment system using a boron-doped diamond electrode and TiO2
photocatalyst” 2010, Water Research, Vol. 44, pp. 904-910.
A. Shawaqfeh, F. Al Momani, “Photocatalytic treatment of water soluble
pesticide by advanced oxidation technologies using UV light and solar
energy”, 2010, Solar Energy Vol. 84 pp. 1157–1165.
H. Stryczewska „Wykorzystanie energii słonecznej w procesach obróbki
wody, powietrza i gleby”, Presentation for Lublin University of
Technology, 04.2011.
G. Komarzyniec, H. D. Stryczewska, R. Muszanski “Autonomous water
treatment installation energized from PV panels”, Proc. 15th International
Conference on Advanced Oxidation Technologies for Treatment of
Water, Air and Soil (AOTs-15), New York, USA 2009.
J. Pawłat, Joanna, H. Stryczewska, K. Ebihara, “Sterilization Techniques
for Soil Remediation and Agriculture Based on Ozone and AOP” 2010,
Journal of Advanced Oxidation Technologies Vol. 13 (No. 2), pp.
138-145(8).
J. Pawłat, Joanna, H. Stryczewska, K. Ebihara, F. Mitsugi, S. Aoqui, T.
Nakamiya, “Plasma sterilization for bactericidal soil conditioning”, 2010,
Proc. HAKONE XII conference, Trenčianske Teplice, Slovakia,
pp.407-411.
K. Ebihara, H. Stryczewska, T. Ikegami, F. Mitsugi, J. Pawlat, “ On-site
ozone treatment for agricultural soil and related applications”, 2011,
Przeglad Elektrotechniczny, Vol. 7, pp. 148-152.
M. Takayama, K. Ebihara, H. Stryczewska, et al.T. Ikegami, Y.
Gyoutoku, K. Kubo, M. Tachibana, “Ozone generation by dielectric
barrier discharge for soil sterilization”, 2006, Thin Solid Films, Vol.
506-507, pp. 396-399.
scholar.waset.org/1307-6892/5708