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A pioneer effort is made in this study to carry out an experimental determination of shrinkage
characteristics of neem (Azadirachta indica A. Juss) wood on its linear, volumetric, and
coefficient values with the hope of ascertaining its utilization potential as timber. Three study
locations were randomly selected from defined vegetation zones of north eastern Nigeria for
the study. These are Maiduguri (Sahel savanna) Yola (Sudan savanna), and Bauchi (Guinea
savanna). Forty five (45) tree samples of neem trees were randomly selected and felled, from
which 135 wood specimens were extracted and prepared using Romanian Standard for the
research. The analysis of variance (ANOVA) was used to analyze the obtained data. Results
showed that the tree species has an average tangential linear shrinkage of 12.74%, radial
linear shrinkage of 6.26%, longitudinal linear shrinkage of 1.15%, and volumetric shrinkage of
19.12%. The coefficients of tangential, radial, and longitudinal shrinkage were 0.00674,
0.00339, and 0.00061 respectively. The analysis of variance revealed insignificant differences
of shrinkage between the three vegetation zones, the sampled trees, as well as between the
tree trunk sections. Since the shrinkage value of neem wood compares favorably with some
local wood species used for timber, neem wood could be considered suitable for timber
production.

The present study investigated tertiary physico-chemical treatment of the secondary effluent
from the Chania municipal Wastewater Treatment Plant (WTP). Laboratory experiments were
carried out with the aim of studying coagulation efficiency regarding reduction of turbidity,
soluble COD and phosphorus both in a conventional Coagulation-Settling treatment scheme,
as well as by means of Contact Filtration. The results showed that high doses of coagulants
(0,5 mmol Me+3 l-1 or higher) are required to achieve significant removals of turbidity after
settling. At these high doses, soluble COD can be removed by about 50%, while soluble
Phosphorus by 80-95%. Ferric Chloride demonstrated slightly better removal ability as
compared to Alum. The Chania WTP effluent was also treated by Contact Filtration, using a
very low dose of coagulants, 0,1 mmol Me+3 l-1. Turbidity was removed by around 50%, while
at this low coagulant dose removals of COD and Phosphorus were insignificant. Filtration was
effective in the first 35cm of the filter bed. No significant differences were observed between
the coagulants Alum and FeCl3 in the elimination of turbidity. Nevertheless, with the use of
Alum a smaller filter headloss was observed, during the first two hours of continuous filtration,
in comparison with the use of FeCl3 (nearly double). No difference was observed between the
headloss developed at a filter depth of 5cm as compared to that developed at a depth of
70cm. This indicates that the headloss increase was due to the accumulation of suspended
and colloidal solids within the first layers of the sand filter.

Slurry seal is applied for low-cost paving and surface maintenance. The principal materials
used to create slurry seal are aggregates, asphalt emulsion, water and fillers like Portland
cement (mainly), lime and other materials.
This paper presents the use of alternative fillers instead of expensive and high consumed
energy cement. These fillers are by-products and their increased deposits create a serious
environmental problem. Fly ash, ladle furnace slag, cement kiln dust, marble dust were tested
as fillers in slurry seal and results showed that they can be used producing slurry seal
according to specifications. Mixing time, consistency, set time, cohesion, wet stripping, wet
track abrasion and loaded wheel were the tests for checking of the characteristics of designed
slurry seals.
The use of these by-products will minimize their deposits and in a parallel manner will
decrease the use of corresponding amount of cement saving raw materials and energy
consumed for its production.

A survey was conducted in order to evaluate the levels of available (DTPA extractable) Cd in
salt affected and normal soils of Halastra−Kalohori area, located in N. Greece. In this area,
phosphogypsum (PG) (a byproduct of P fertilizer industry, occasionally enriched with Cd) has
been used as amendment for the salt affected soils, for at least 20 years until 2000. The area
is about 6300 ha, and 4500 ha were cultivated with rice. Soil samples were collected from 632
points and four depths (0−25, 25−50, 50−75, 75−100 cm), during 2003 and 2004. All soil
samples were analyzed for particle size distribution, pH in the paste, electrical conductivity of
the saturation extract (ECe), water soluble Na, Ca and Mg, cation exchange capacity (CEC)
and exchangeable Na. The sodium absorption ratio (SAR) and exchangeable sodium
percentage (ESP) were calculated. The 632 soils were characterized as salt affected (saline,
saline−sodic, sodic) or normal, using the values of EC, SAR and ESP, and pH. In addition, the
soil samples collected from the 0−25 and 25−50 cm depths were analyzed for DTPA
extractable Cd and Olsen P. All soils were alkaline in reaction. In most of the cases,
concentrations of DTPA extractable Cd in the 0−25 cm depth were higher than in the 25−50
cm depth and the mean values differed significantly (p < 0.001). For both depths,
concentrations of DTPA extractable Cd were higher for salt affected than normal soils and the
mean values within each depth differed significantly (p < 0.001). This could be attributed to
the use of PG as soil amendment. In addition, a significant and positive relationship was
obtained for DTPA extractable Cd and ECe (r = 0.31, p < 0.001). However, DTPA extractable
Cd ranged at levels similar or lower to those reported in the literature for cultivated soils with
high P fertilization, in almost all cases. This is something to be expected since 80 % of all
soils were sufficient or over−fertilized with P (Olsen P > 15 mg kg−1). A significant and positive
relationship, obtained for DTPA extractable Cd and Olsen P (r = 0.47, p < 0.001), supported
the conclusion that the source of DTPA extractable Cd could also be traced to the long−term
P fertilization. Concentrations of DTPA extractable Cd were significantly (p < 0.001) correlated
with certain soil properties that affect Cd availability to plants, such as pH (r = −0.26), clay
content (r = 0.22) and CEC (r = 0.26).