The Municipality of Athens (M.A.) currently comprises 7 municipal districts, 7 waste collection
districts (WCD) and approximately 5800 residential blocks. Solid waste is collected daily on a
7 days per week basis. The M.A. comprises approximately 119 waste collection sub-districts
(herein referred to as ‘collection programs’ or simply ‘programs’). Each ‘program’ consists of a
number of adjacent residential blocks, whilst certain special programs include only central
streets in Athens (e.g. Aharnon, Patision) or the commercial center of Athens. During the past
years, each waste collection vehicle has been making 2 daily trips to the final disposal site in
the Attica region, in Liosia. The above scheme is the basis on which daily collection of
municipal solid waste (MSW) in the M.A. takes place. The actual residents at each residential
block in Athens were based on the 2001 census. The coding of the National Statistical
Agency was initially used and adjusted to the residential blocks’ coding used by the M.A. The
residential blocks included in each collection program were precisely identified. Average unit
waste production rates (UPRs) were estimated for each collection program using:
• vehicle net weights data for February and July 2002 at the central Liosia landfill
• actual population for each residential block in Athens (2001 census) and
• number of residential blocks at each collection program
The number of waste storage containers (WSC) at each residential block was estimated by
accounting for a 1,1 m3 container volume, a 80% fill ratio and a 95 kg m-3 uncompacted waste
density. As a result of the above, UPRs and the required number of WSC were estimated for
each residential block, each collection program, each WCD and for the M.A. as a whole.
Sunday has the smallest production of MSW during a week, whilst Tuesday is the day with
the largest amount of MSW produced within a week. The average production rate for the M.A.
was estimated to be 3,8 kg cap-1 d-1, ranging from 1,3 kg cap-1 d-1 (for district 6) to 8,9 kg cap-1 d-1
(for district 1). The relatively large UPR recorded for district 1 is attributed to the increased
number of commercial stores (center of Athens) and due to the relatively small recorded
actual population, since few apartment buildings exist in the center of Athens. The total
number of waste storage containers required in the M.A. is approximately 16660, whilst the
existing number is approximately 14580.
In a municipal solid waste management system, decreasing collection/hauling costs, which
consist of 85 % of total disposal expenditure, can be carried out by a route optimization. Thus,
a huge amount of economical benefits is getting furnished. If route optimization is performed
in solid waste collection/hauling process, due to reductions in “empty miles” negativity, total
expenditures will be decreased.
Trabzon City located in the northeast side of Turkey has about 185 thousand inhabitants
according to Census 2000. The city shares just about 1% of the Gross Domestic Income in
Turkey. In other words, that means that Trabzon City livings have moderate revenue.
The objectives of this study are to optimize for the route of collection/hauling in Trabzon City
by taking consideration of data about road net, demographics and solid waste production.
In order to analyse the solid waste collection/hauling process in the city, the processes were
recorded by a Sony DCR-TRV145E brand video camera. To use route optimization process,
data related in present spending, truck type and capacity, solid waste production, number of
inhabitants and Global Positioning System (GPS) receiver data for each route were collected
and all the data were analyzed with each other.
For 39 districts in the city, a shortest path model was used in order to optimize solid waste
collection/hauling processes, as minimum cost was aimed. The Route View ProTM software as
an optimization tool was used for that purpose. Geographic Information System (GIS)
elements such as numerical pathways, demographic distribution, container distribution and
solid waste production amount were integrated to the software. To give an idea, thematic
container layer has 777 container location points for the entire city.
After performing routes by the software, the optimized routes were compared with the present
routes. Success by the optimization process was around 4-59 % for distance and 14-65 % for
time. Consequently, a route optimization process on the street stationary container collection
system will contribute a benefit by 24 % in total cost.
Consumption of plastic products has increased dramatically over the past few decades. This
trend results in the generation of a vast waste stream that needs to be properly managed to
avoid environmental damage. Increasingly stringent European legislation is setting new
standards that promote the application of novel recycling technologies capable of absorbing
large amounts of plastic wastes. An option with great potential is feedstock recycling, which
includes a variety of processes like pyrolysis, catalytic conversion, depolymerisation and
gasification, designed to transform plastic waste into hydrocarbon products for use in the
preparation of recycled polymers, refined chemicals or fuels. This paper summarises the
current situation regarding the generation of plastic residues in Europe and provides a
general view of alternative recycling methods. Up-to-date information is also included on
commercial or demonstration recycling activities currently in operation, paying special
attention to the development and application of novel catalytic feedstock recycling processes.
The restrictions in availability of forest-based raw materials along with favourable
environmental policies towards alternative sources of raw materials have forced corrugated
packaging industry to shift towards recycled paper and other fibre sources such as non-wood
and agro-residues. The variability in raw pulp materials with increasing percentages of
recycled fibres is a very common technical problem for the corrugated packaging industry
worldwide. Corrugating packaging production is facing the challenge to ensure a satisfactory
strength of packages despite the increase of recycled paper as the main fibrous component.
Sustainable manufacturing of papers of consistent and acceptable quality requests
comprehensive characterization of the fibrous components, which are becoming more
heterogeneous. Understanding the influence that heterogeneous recycled raw materials have
on packaging grade paper properties offers great potential value to the corrugated board and
57 linerboards and corrugating medium were selected to represent all the variety of paper
grades available on the market at the moment for the production of corrugated board in
Spain. The papers were analyzed for their fibre morphology (fibre length, fibre width, lumen
diameter, cell wall width and flexibility) and fibre composition (softwood to hardwood and nonwood
fibre count and weight) and their strength (compression, bursting and crushing
resistance) was evaluated. All the determinations were in accordance with the relevant TAPPI
Test Methods. The significant differences found in most of the anatomical characteristics,
fibre composition and strength properties among the paper grades reflected the diverse raw
materials used for their production as well as their qualitative differences. By means of simple
correlation the influence of fibre characteristics and composition on the strength of the papers
was determined under two different conditions, at 23 oC and 50% RH and at 20 oC and 90%
The results demonstrate that besides the physical-mechanical characterization of packaging
grade papers, fibre anatomy and composition can be used successfully as a complementary
practical test to predict the performance of papers. The application of the predicting
correlations is proposed for the evaluation of the fibre supplies for the packaging industry. An
enormous potential for cost reduction can be created by the selection of the most appropriate
and inexpensive combination of grade papers for a specific packaging use.
The use of Geographical Information Systems (GIS) for Landfill Sitting is studied. The
necessary spatial information required to determine the candidate sites for any type of
terrestrial area (Community/Prefecture/Region/Country) is examined. This spatial information
is then used for site selection via successive spatial operations: Buffering, overlaying and
attribute calculations. The method is tested for the whole region of the island of Crete,
producing spatial numerical results, which can be used as points of reference for any future
Landfill Sitting study for this area.
In our study, the main spatial information required for Landfill Sitting is determined in such a
manner, so that the spatial development of the region is assured to be sustainable for the
future generations. This means that we try to include as much as possible Environmental /
Ecological / Economic factors characterizing the region under consideration. These factors
take the form of spatial information, organized in spatial layers. The layers are then inserted
into the GIS model for (a) Landfill site exclusion, and (b) Landfill site evaluation. All spatial
layers correspond to subcategories of the main categories, defined as follows (GIS model
setup): A. NATURE / ECOSYSTEM, B. HUMAN ACTIVITIES, C. WATER RESOURCES /
HYDROLOGY, and D. ANTIQUITIES.
The exclusion “rules” are then defined by varying buffer distances surrounding each of the
above layers separately (distance maps). The total areas to be excluded for each Category
are defined by overlaying (union) the various distance maps in a sequential order, with the
final “exclusion” map to be the union of all the above sub/distance maps. The remaining areas
are then to be evaluated individually.
The GIS model results showed that, for the island of Crete, and a moderate buffer distances
(“restrictions”) scenario, a total of 47.73% of the whole area is excluded when we consider
restrictions residing from Category A. NATURE/ECOSYSTEM, 61.40% is excluded due to
the HUMAN ACTIVITIES (Category B), 16.03% is rejected due to WATER
RESOURCES/HYDROLOGY protection considerations (Category C), and only 1,04% of the
total island area is excluded due to existence of ANTIQUITIES (Category D). If we are to
combine the above Categories (A-D), a total of 82.65% of the total area is to be excluded, or
a total of 17.35% of the island area only is suitable for Landfill Sitting. The GIS model results
defines precisely which these areas are, so small-scale research, based on these results, is
required for the final site ranking and selection.
Green waste (leaves, grass and shredded twigs) was composted for 5.5 months in a wooden
composting bioreactor, of 1 m3 capacity, using both passive convective aeration, facilitated by
the design of the bioreactor, and manual turning. Temperature was measured daily, while
samples were analysed for moisture content, volatile solids, pH value and electrical
conductivity, all of which showed a typical variation for the type of composted material and
For the assessment of compost stability, a simple automated respirometric technique was
applied (SOUR test), which utilised a dissolved oxygen probe to measure changes in the
oxygen concentration in an aqueous compost suspension, under conditions ensuring
optimum microbial activity and maximum reaction rates. Results were compared with other
stability tests, such as the dehydrogenase activity and the germination index (GI) of cress
seeds and correlated with the changes in population size of different microbial groups (total
aerobic and spore forming heterotrophs, ammonium- and nitrite- oxidising bacteria,
actinomycetes, filamentous fungi, yeasts and cellulolytic bacteria).
Both the SOUR test and the GI indicated increasing compost stability with processing time
and gave significant correlation with compost age and with each other. SOUR reached a
value of 4 mg O2 g-1VS hr-1 at the end of the active composting phase (after 3 weeks) and
declined gradually to below 1 mg O2 g-1VS hr-1, a value indicative of stable composts, after
about 3 months of processing. GI increased from 30% for the raw material, a value indicating
high phytotoxicity, to about 80% at the end of the active phase and fluctuated around this
value thereafter. Dehydrogenase activity fluctuated during the process, with the highest
values being measured during the active composting phase. However, high values were also
recorded towards the end of the maturation phase, following a long period of stabilisation at
low values. The parameter did not correlate with compost age or SOUR and GI and thus did
not seem suitable for monitoring green waste compost stability.
Although at lower levels compared to other substrates, such as manures and biowaste, the
population size of different microbial groups did not seem to be a limiting factor in green
waste composting. The numbers of most microbial groups increased after the end of the
active composting phase, indicating that microorganisms multiplied rapidly as temperatures
felled, although for some groups population counts declined again towards the end of the
maturation period, possibly indicating the exhaustion of specific substrates.
Poor landfill gases cannot be used to drive gas engines or be burnt in gas flares. This follows
why the combustion flame front velocity for poor gases becomes very low. From this moment
the non-flammable poor landfill gases are polluting the environment. An energetical utilisation
of very poor landfill gases is of ecological interest and is also an important contribution for
climate protection. A feasible solution must be found.
In our University lab we are using a Fluidised Bubbling Bed Combustion (SFBC) plant with
200 kW completed by heat exchangers for pre-heating the combustion air as well the
combustion gas. In the past this SFBC-principle had successfully been applied to a thermal
utilization of very different wastes. Using this principle we are able to recover the energy
content of very poor landfill gases down to a concentration below the lower explosion limit.
The fluidised red hot inertia bed material at a temperature of 850°C is an excellent ignition
source to run the process at constant parameters within legal limits. Therefore we have very
low pollutant emission levels.
Using a developed mathematical SFBC-model we theoretically investigated the lowest
possibly methane concentration limits under given pre-conditions as well as fluidised bed
temperature level, fluidisation air and fuel gas temperatures, necessary oxygen concentration
level. Following to these model investigations we realized their experi-mental verification in
our 200 kW lab SFBC testing plant in a wide-spread plant load range. These lab tests had
very successful results. The possible SFBC operation conditions have been estimated.
Based on these results we engineered by the help of industrial partners a real SFBC plant
installed on a closed landfill in Mecklenburg – Western Pomerania, 65 km far from our
University lab. Using these plant we dispose there real very poor landfill gas. The landfill gas
is poor enough to avoid a further operation of a common gas flare. The automatically
operated SFBC process is running at 850 °C without any technical interruptions since one
year. At the moment the maintenance rate is 3 weeks. The plant is supervised by data remote
control. The contribution will compare the lab test results with the results of the real existing
If the poor landfill gas flow is strong enough the SFBC produces enough energy e.g. to drive a
steam cycle or a gas turbine externally fired by the SFBC that generates electrical power. In
this case the necessary power equipment has to be added to the SFBC plant.
Biological treatment (aerobic and anaerobic) of industrial landfill leachate is limited by the
presence of toxic contaminants (e.g., heavy metals) and recalcitrant (biopersistent) organics
(e.g., polyphenols, pharmaceuticals, cosmetics, etc.,), hindering viable conditions for biomass
proliferation in biological reactors, with difficulties in meeting concentration limits imposed by
Fenton’s oxidation by the use of Fe2+-H2O2-H+ mixture may be used as a pre-treatment of
industrial landfill leachate for preliminary abatement of the organic load and to improve
biodegradability (BOD/COD>0.4) to favour biological oxidation in conventional wastewater
Leachate from Grottaglie (S.E. Italy) non-hazardous landfill (pH 8.6; COD=11.000 mg l-1;
BOD5=2.400 mg l-1; NH4-N=2.900 mg l-1; conductivity=60.000 μS cm-1) was laboratory tested in
different operative conditions, i.e., initial pH, Fe2+/H2O2 ratio, concentrations and reaction time.
The oxidation reaction was monitored by equilibrium pH and residual COD and BOD5
Best operative conditions were obtained at pH 3, Fe2+=700 mg l-1, H2O2=9,900 mg l-1
(H2O2/Fe2+ratio~13w/w), reaction time=2h. Following the oxidation reaction, solution pH was
neutralized by the addition of Ca(OH)2 or NaOH (120 meq l-1) for further abatement of target
parameters by precipitation/sorption.
Preliminary technical/economical evaluation of possible process schemes is also given in the
The waste to renewable energy source has become a priority in the wastes treatment field.
The research goal is not only the wastes destruction but also a better thermal energy
recovery from the processes. The municipal solid waste presents a high heterogeneity degree
from the dimensional point of view, form and its components specific weight of as well as
thermal-chemical characteristics. That’s why there are many treatment methods, each one
with its own particularities.
For a better understanding of the phenomenon during thermal degradation processes both
under pyrolysis or atmospheric pressure gasification stages we first accomplished a
laboratory scale series of experiments in a tubular reactor, on small quantities (5 – 10 grams)
of reconstituted urban wastes. For the validation of the obtained data on more representative
samples we extended the experiment to an original industrial scale pilot installation that
enables the continuous thermal treatment of 10 – 50 waste kilograms per hour under oxidant
or non-oxidant atmosphere (on choice) and at variable temperature between 400 °C – 1100 ºC.
The residential time of the treated sample in the installation and the flow conditions can be set
independently. The installation reproduces the incinerators or the pyrolysis / gasification
reactor process conditions and provides complete information on the wastes thermal
degradation kinetics and on the pollutant emissions. The particularity of the device consists in
the product advancing piston – like flow system based on the bed vibration. The product
particles in the bed have a translation movement without any layer shift. Therefore the
particles distribution in a given product bed section is the same all along the installation from
the feeding inlet to the extraction. That characteristic enables us to extrapolate and compare
the laboratory results of the fixed bed treatment to the industrial pilot continuously treatment
applied on the same product: reconstituted municipal solid waste, one of the most
heterogynous solid wastes in mixture.
The main targets were the sample mass reduction rate, the resulting gases composition, the
samples mechanical behavior for different temperature levels, residential time, treatment
atmosphere conditions and different steam flow rates (in the gasification process). The results
were compared to an established reference – the incineration.
The paper presents the research and results on the degradation mechanisms of MSW treated
samples in those two equipments from the Science Division CNRS, Department of Industrial
Methods, University of Technology Compiègne, France.
Maisiagala RADON type radioactive waste storage facility was commissioned in 1963 in a
marshy, ecologically sensitive locality, where soluble radionuclides easily can penetrate and
migrate with groundwater. To assure the requirements of radiation safety, the analysis of
radionuclide leakage from the radioactive waste storage facility is performed continuously. 3H
(tritium, T1/2=12.33 years) is of greatest interest in the storage facility reservoir or its
surroundings. Liquid scintillation counting (LSC) involving ultra-low level device Quantulus
(Wallac) was utilized for quantitative determination of tritium. Elevated 3H concentration
(reached 23900 Bq l-1) is observed continuously in the borehole, which is nearest to the
radioactive waste reservoir. The average prevailing groundwater flow direction is close to the
northern direction. This is the direction of waterlogged lowland, the head of the river, where
radionuclides can penetrate. 3H concentration in the borehole located 12 m further in the
prevailing groundwater flow direction, varies from minimum detectable values to 7500 Bq l-1.
MOC3D software was used for modelling 3H transport in groundwater.
For field measurements a portable gamma-spectrometer Inspector-2000 (Canberra) with 20%
relative efficiency HPGe detector (GC2018) was used. The measurements in-situ revealed
both qualitative and quantitative variation of gamma-ray intensity at the facility’s territory and
outside.The remaining contamination by 226Ra was confirmed at the spot at the distance of
~20 m from the radioactive waste reservoir, 226Ra concentration at the spot reached 106
Bq kg-1 in 2004. 137Cs concentration in soil does not exceed that in Lithuanian soils after
Chernobyl NPP accident.
3H concentration in soil moisture, both on the territory of facility and outside, increases with
depth and reached 187±10 Bq l-1. 3H concentration in lupine (Lupinus polyphyllus) reached
150±9 Bq l-1. It exceeds 3H concentration in grass outside the facility territory by 20-30 times.
The fact that elevated 3H concentration was found not only in groundwater of boreholes on
the territory of the storage facility, but in soil moisture and vegetation samples shows that
radionuclide leakage from the reservoir occurs and the possibility of leakage can increase
over time. The storage facility requires continuous monitoring and management strategy in
the nearest future.