Volume 13 - 2011

https://doi.org/10.30955/gnj.000760

Abstract

The use of phosphate slime or phosphate water in a Mediterranean region (Gafsa, Tunisia) was
investigated through hydrologic modeling. The simulations were made using the Hydrus 1D
software package for a typical soil in the area of Gafsa (Tunisia). Two main applications were
examined: mixing the surface soil with the phosphate slime and irrigating with polluted (phosphate)
water or irrigating only with phosphate water. The elements under study were Cd, Cr, Ni, and Sr.
The results show that there is no significant risk of groundwater pollution with these elements if the
phosphate slime or the phosphate water is used for agricultural purposes. The addition of slime in
the upper soil layer retards the mobility of the pollutants. The results also show that the mobility of
these elements is highly dependent on the applied irrigation dose. These pollutants need high
amounts of water in order to reach great depths. This research was carried out in the framework of
the EU project “Integrated water management of Mediterranean phosphate mining and local
agricultural systems” (ELMAA).

Municipal solid waste management and landfill site selection in Greece: irrationality versus efficiency

Hadjibiros K. , Dermatas D. and Laspidou C.S., Pages:150-161

DOI:

Paper Topic:

General

Issue:

https://doi.org/10.30955/gnj.000739

Abstract

Municipal solid waste (MSW) collection and disposal is a major problem of urban environment in
the world today. MSW management solutions have to be technologically feasible, legally and
socially acceptable and environmentally and financially sustainable. European policy is pushing to
a rational management of natural resources; a promising technological perspective today is waste
valorization, a process that becomes possible through sorting at the source, combined with material
recycling and waste-to-energy methods. On the other hand, technologies like mechanical sorting,
or disposal of MSW in landfills do not really improve MSW management efficiency. Landfills should
become the ultimate disposal site of a few inert residuals from MSW valorization. Despite all this,
conventional landfills for disposal of mixed MSW are still being constructed, with landfill site
selection being a major social problem due to the lack of public acceptance; objectivity in landfill
site selection is therefore extremely important. In Greece, we find several examples of inefficient
MSW management and curious landfill site selection. In this paper, we criticize environmental
policy issues for MSW management in Greece and identify weak points in the criteria used for the
selection of landfill sites. We conclude that there is a real need for rational MSW management
based on high quality scientific input.

Route time estimation of solid waste collection vehicles based on population density

Apaydin O. and Gunullu M.T., Pages:162-169

DOI:

Paper Topic:

General

Issue:

https://doi.org/10.30955/gnj.000782

Abstract

In this study, a model for stationary container system is presented to estimate collection time based
on population density per 100 m road distance (LPD100). The model also estimates travel and
collection times, and time spent on waiting at stop signs and traffic lights separately for stationary
collection. The main scope of the model is to determine required container number (NC), the number
of container locations (NCL) and collection time with stationary solid waste collection (PTC) based
on LPD100. Model parameters are based on route observation using a video camera of solid waste
collection in 39 districts (having 38.6 sq m area) in Trabzon City in Turkiye. Moreover, a digitized
route map of Trabzon City including many layers such as road distance, container location, road
direction, traffic lights was used to simulate the model. The model was tested using data obtained
from collection route in Erdogdu district in Trabzon, located in Eastern Black Sea of Turkiye.
Compared to observed values form a collection route in Trabzon, the model estimated route time
(RTC) within % 2.9-4.9 of error margin.

Statistical predictors of hazardous medical waste generation rates in a 40-bed general hospital

Komilis D. and Katsafaros N., Pages:170-175

DOI:

Paper Topic:

General

Issue:

https://doi.org/10.30955/gnj.000673

Abstract

Objective of the work was to investigate correlations among hazardous medical waste generation
rates and various hospital parameters in 2 departments and a clinic of a 40-bed Hellenic general
hospital (Hospital of Ikaria). Medical waste was recorded at the bio-pathology lab, the pathology
clinic and the emergency department 4 times daily during a 42 sampling day period (from December
2008 to May 2009). The hospital parameters recorded on a daily basis were the number of
examinees, the number of patients that occupied beds and the number of tests performed daily at
the clinical bio-pathology laboratory. The dependent variable was the medical waste generation rate
(kg day-1) in all cases. Statistically significant linear correlations were established in all departments;
the strongest correlation (R2≈0.75) was calculated at the clinical bio-pathology laboratory and the
weakest (R2=0.30) at the emergency department. An analysis of variance (Tukey’s t-test) and a nonparametric
statistical test revealed that medical waste generation rates from the clinical biopathology
laboratory were statistically lower in the weekends compared to weekdays. In addition,
medical waste amounts generated by the pathology clinic were statistically lower during December
and January compared to February and April.

Utilization of textile fibres from worn automobile tires in cement based mortars

Mavridou S. and Oikonomou N., Pages:176-181

DOI:

Paper Topic:

General

Issue:

https://doi.org/10.30955/gnj.000768

Abstract

This research paper focuses on the properties of laboratory made cement mortars modified with
textile from worn automobile tires. Textile, in the form of fibres, has been added to cement mortars at
various percentages of total cement mortar volume, which ranged from 0-2.0%. Properties of mortartextile-
aggregates mixtures such as consistency-workability-, bulk density as well as mechanical
ones such as dynamic modulus of elasticity, compressive and flexural strengths have been studied.
Moreover, water absorption under vacuum and capillarity by suction of such mixtures have been
measured, as a preliminary examination of cement mortars’ durability. The study of the mixtures has
been completed by the observation of their microstructure. All properties have been tested according
to European Specifications.
Laboratory results showed that properties of cement mortars, modified with textile from worn
automobile tires, were found to be familiar to the ones of the control mixture (with no additive).
Incidentally, a solid waste material such as textile fibers from worn automobile tires can be utilized
properly in cement products providing an opportunity to recycle non-reusable end of life tires and as
a result contributing to the protection of the environment.

Feasibility study of cement composites with para wood particle wastes: strength and durability

Woraphot P., Abideng H. and Thaniya K., Pages:182-191

DOI:

Paper Topic:

General

Issue:

https://doi.org/10.30955/gnj.000778

Abstract

The purpose of this study was to investigate the potential use of Para wood particle wastes and
cement for producing the cement composite as a new environmental friendly construction material.
Strength and durability of cement composites mixed with different mix proportions of Para wood
particles (PWP) were evaluated and compared with those of control samples (ordinary Portland
cement). To study property degradation, the cement composite test samples were determined under
different aging conditions. Three different conditioning schemes including: 1) seawater immersion at
room temperature, 2) alkaline solution immersion at room temperature and 3) elevated temperatures
were considered in this study. The experimental results show that the average compressive strength
and elastic modulus of the cement composites mixed with PWP decreased with the increasing of
PWP content. In addition, the average compressive strength of cement composites mixed with PWP
aged in alkaline and salt solutions had a similar trend as cement composites with mixed PWP
(normal curing). For temperature effect, the average compressive strength significantly dropped
between 100°C and 150°C. The experimental results present a potential use of Para wood particle
waste in cement composites. Productions manufactured from these materials with the optimum
content (2% to 10%) of MPWP are acceptable for non- and structural (with low load carrying
capacity) members.

Catchment scale hydrological modelling: A review of model types, calibration approaches and uncertainty analysis methods in the context of recent developments in technology and applications

Pechlivanidis I.G., Jackson B.M., McIntyre N.R. and Wheater H.S., Pages:193-214

DOI:

Paper Topic:

General

Issue:

https://doi.org/10.30955/gnj.000803

Abstract

In catchment hydrology, it is in practice impossible to measure everything we would like to know
about the hydrological system, mainly due to high catchment heterogeneity and the limitations of
measurement techniques. These limitations and the need to extrapolate information from the
available measurements in both space and time initiated the application of hydrological models.
However, hydrological models suffer from uncertainty in their predictions, which reduces applicability
of and confidence in such models. In this review, we summarise the different classifications of
hydrological model types, and discuss relative advantages and disadvantages of each type of
model. In addition, we summarise established model calibration processes and discuss the sources
of uncertainty that affect model predictions. We summarise different methods to quantify uncertainty
in the model predictions that could sit well within a model evaluation framework. And, finally, some
recent developments in hydrological modelling are reviewed.
KEYWORDS:

Statistical analysis of temperature changes in israel: an application of change point detection and estimation techniques

Gurevich G., Hadad Y,. Ofir A and Ohayon B., Pages:215-228

DOI:

Paper Topic:

General

Issue:

https://doi.org/10.30955/gnj.000653

Abstract

The main goal of this study is to present and apply recently developed nonparametric change point
detection and estimation techniques for confirming patterns of regional changes in temperature.
Utilizing these methods, monthly temperatures (mean, mean maximum, mean minimum) and diurnal
temperature ranges in different regions of Israel have been investigated over a period of 37-years,
(1967-2003). The results were supported also by traditional statistical methods. The temperature
and the diurnal temperature range analyses reveal a complex pattern of change. In particular, we
found an increase in the monthly mean temperatures in the warm season in all areas of Israel
approximately from the mid-1980s to the mid-1990s, namely, the summers have become warmer.
Also detected was a significant increase in the monthly mean minimum temperature in Israel's
coastal plain area for all months of the year. Whereas, in mountainous and desert areas a significant
increase in the monthly mean minimum temperature was detected only in months of the warm
season. The winters have become warmer in the Israeli coastal plain and have not significantly
changed in its mountainous and desert areas. In addition, in Israel's coastal plain the monthly mean
DTRs are decreasing, while in mountainous and desert areas the situation is reversed, that is,
monthly mean DTRs are increasing.

Multivariate analysis of hydrochemical data of the groundwater in parts of Karwan – Sengar sub - basin, Central Ganga basin, India

Khan T.A., Pages:229-236

DOI:

Paper Topic:

General

Issue:

https://doi.org/10.30955/gnj.000751

Abstract

Ganga basin is one of the world’s biggest aquifer repositories. The thick alluvium of the basin hosts
its three tier aquifer system. The aquifer of the basin is under high stress due to unethical human
intervention in the natural system. This warrants the need to evolve the basic hydrochemistry of
every bit of the basin to make a scientific planning followed by a pragmatic execution. A multivariate
statistical analysis was carried in order to give the hydrochemistry of the shallow aquifer a new
dimension which is easily understood at a glance. In the present paper an attempt has been made
to study the hydro chemical analysis data of shallow groundwater in parts of Karwan – Sengar sub
basin, Central Ganga basin. The study is made of shallow aquifer of the region in which the
movement of groundwater is from northwest to southeast. The descriptive statistical analysis was
done beside Pearson correlation, principle component and regression analysis. All these are
synthesized here to decipher the dynamics involved in the hydrochemistry of the area. The principle
component analysis identified five factors that are responsible for the data structure explaining
83.49 % of the total variance of the data set. Factor 1 to 5 explains variance of 31.23, 19.445,
13.131, 12.105 and 8.647% respectively. Regression analysis show that Electric Conductivity (EC)
as an independent variable which can be used to measure Carbonate (CO3
2-), Chloride(Cl-),
Sodium (Na+), and Total Dissolve Solids (TDS). Further Magnesium (Mg2+) can be used to calculate
the Total Hardness (TH) directly in the area.

Foaming control in activated sludge treatment plants by coagulants addition

Mamais D., Kalaitzi E. and Andreadakis A., Pages:237-245

DOI:

Paper Topic:

General

Issue: