Oxidant treatment of ballast water (BW) is commonly used in BW systems in order to minimize the transport of alien species. The release of disinfection by-products (DBPs) associated to the treatment ...of BW and cross-contamination of butyltin (BT) compounds through BW discharge is a topic of environmental concern. A chemical port baseline survey has been conducted in seven ports of the Adriatic Sea. Analysis have been performed on transplanted mussels, surface sediment, seawater, BW. Results showed an evidence of BT contamination, particularly in sediments, probably related to their illegal usage or to intensive shipping activities. Therefore, BW may act as a vector and contribute to re-buildup of BT contamination in the coastal regions.
A baseline set of data concerning DBPs is provided, showing the preferential distribution of these compounds in the marine environment that will be useful for future considerations on monitoring and assessment of chemical contamination associated with BW.
•Chemical port baseline survey in seven Adriatic ports was carried out.•Butyltin compounds associated with transport of ballast water was studied.•Disinfection by-products associated with ballast waters treatment were evaluated.
Reconstruction of charged particles' trajectories is a crucial task for most particle physics experiments. The high instantaneous luminosity achieved at the LHC leads to a high number of ...proton-proton collisions per bunch crossing, which has put the track reconstruction software of the LHC experiments through a thorough test. Preserving track reconstruction performance under increasingly difficult experimental conditions, while keeping the usage of computational resources at a reasonable level, is an inherent problem for many HEP experiments. Exploiting concurrent algorithms and using multivariate techniques for track identification are the primary strategies to achieve that goal. Starting from current ATLAS software, the ACTS project aims to encapsulate track reconstruction software into a generic, framework- and experiment-independent software package. It provides a set of high-level algorithms and data structures for performing track reconstruction tasks as well as fast track simulation. The software is developed with special emphasis on thread-safety to support parallel execution of the code and data structures are optimised for vectorisation to speed up linear algebra operations. The implementation is agnostic to the details of the detection technologies and magnetic field configuration which makes it applicable to many different experiments.
Phenol and substituted-phenols varied in their equilibrium sorption rates with paper mill sludge.
In this paper we studied the sorption capacity of paper mill sludges for phenols. Phenol, ...2-chlorophenol (2-CP), 3-chlorophenol (3-CP), 4-chlorophenol (4-CP), 2-nitrophenol (2-NP), 4-nitrophenol (4-NP), 2,4-dichlorophenol (2,4-DCP), 3,4-dichlorophenol (3,4-DCP) 3,5-dichlorophenol (3,5-DCP) and 2,4,5-trichlorophenol (2,4,5-TCP) were chosen for the sorption tests. Kinetic experiments showed that substituted-phenol sorption on papermill sludge was rapid (equilibrium was reached after 3 h); conversely, the time taken by the phenol to reach equilibrium conditions was 260 h. Experimental data showed that particle diffusion was involved in the sorption process but was not the only rate-limiting mechanism; several other mechanisms were involved. The adsorption isotherms showed the following order of retention capacity of papermill sludge: 2-NP=4-NP<<2-CP<phenol<4-CP⩽3-CP<2,4 DCP<3,4 DCP=2,4,5 TCP<3,5 DCP. In all cases the experimental data showed a good fit with the Hill equation, which is mathematically equivalent to the Langmuir–Freundlich model obtained by assuming that the surface is homogeneous, and that the adsorption is a cooperative process influenced by adsorbate–adsorbate interactions.
In the last few years solidification/stabilisation of acidic soils polluted by heavy metals with low-cost sorbents has been investigated. Paper mill sludges are produced in large amounts and their ...disposal is a serious environmental problem. The possibility was therefore studied of using paper mill sludge as a stabilizer to reduce the bioavailable metal forms in polluted soils and thus the transferability of metals to plants (barley). We first investigated the sorbing properties of paper mill sludge for Zn(II) and Pb(II) and then their fractionation both in a polluted soil and in the same soil amended with paper mill sludge in order to check the decrease in mobile forms. Finally in both soils we tested the uptake of two metals by common barley in order to assess the performance of soil remediation from an ecological point of view. The addition of paper mill sludge to a soil contaminated by lead and zinc induces a decrease in the mobile forms of both metals, probably due to the presence in sludge of organic matter and kaolinite, which are able to bind the metals very strongly. The decrease in the mobile forms, which are the most readily available for uptake by plants, corresponds to a decrease in plant uptake.
Metal pollution of soils is a great environmental problem. The major risks due to metal pollution of soil consist of leaching to groundwater and potential toxicity to plants and/or animals. The ...objective of this study is to evaluate by means of chemical and ecotoxicological approach the effects of paper mill sludge addition on the mobile metal fraction of polluted metal soils. The study was carried out on acidic soil derived from mining activities and thus polluted with heavy metals, and on two paper mill sludges having different chemical features. The results obtained by leaching experiments showed that the addition of a paper mill sludge, consisting mainly of carbonates, silicates and organic matter, to a heavy-metal polluted soil produces a decrease of available metal forms. The carbonate content seems to play a key role in the chemical stabilisation of metals and consequently in a decrease of toxicity of soil. The leached solutions have a non-toxic effect. The mild remediation by addition of sludge has moreover a lasting effect.
Paper mill sludge decreased available metals.
In the present work we studied the role of humic acids in the heavy metal-soil interaction after the addition of different amounts of humic acids to a soil poor in organic matter. Both adsorption ...isotherms and breakthrough curves of cadmium(II) and nickel(II) were examined. Using the multi-method approach it is possible to obtain a greater amount of information than that obtained by employing only adsorption isotherms or breakthrough curves. Both methods show that the amount of cadmium retained by the soil is greater than that of nickel and that the two metals are characterised by different sorption mechanisms. Moreover, adsorption isotherms evidence the humic acids-soil interaction whereas breakthrough curves indicate that two different types of sites or two different mechanisms are involved in the sorption process. For nickel humic acid addition increases only the metal fraction strongly bound to the soil, whereas for cadmium both fractions (strongly bound and weakly bound) increase.
A landfill leachate characterisation, based on the distribution of different molecular weights of constituents is proposed.
We have characterised two kinds of municipal landfill leachates derived ...from ‘old’ and ‘young’ municipal waste landfills on the basis of the molecular weight distribution of the constituents, taking into account that the great variety of leachate constituents prevents any evaluation of the fate and of the role played by each component in the environmental impact. In the sample S1 (old leachate), the constituents were distributed over a wider range of molecular weights; high molecular weight fractions were present. In sample S2 (young leachate), the fractions are actually narrower at the lower molecular weights. The high molecular weight fractions of old leachates are found to be complex structures formed by condensed nuclei of carbons substituted by functional groups containing nitrogen, sulphur and oxygen atoms; the low molecular weight fractions of leachates are, instead, characterised by linear chains substituted by oxygenated functional groups such as carboxyl and/or alcoholic groups. After characterising each fraction we studied the role played by these fractions in the soil's capability for retaining heavy metals copper (Cu) and cadmium(Cd). The Cd uptake increases only on the soil treated with sample S1 characterised by a higher pH value and by the presence of high molecular weight fractions. The Cu uptake also increases on the soil treated with sample S2, characterised by the sole presence of low molecular weight fractions. On the other hand, the metal adsorption tests performed on soil treated with the single fractions show that the amount of Cu and Cd retained by soil treated with the high molecular weight fractions of sample does not increase after 72 h of treatment and that the amount of Cu retained by the low molecular weight fractions of sample S1 and by the fractions of sample S2 increases, but does not justify the amount retained by soil treated with the total leachates.
The performance of the missing transverse momentum (
E
T
miss
) reconstruction with the ATLAS detector is evaluated using data collected in proton–proton collisions at the LHC at a centre-of-mass ...energy of 13 TeV in 2015. To reconstruct
E
T
miss
, fully calibrated electrons, muons, photons, hadronically decaying
τ
-leptons
, and jets reconstructed from calorimeter energy deposits and charged-particle tracks are used. These are combined with the soft hadronic activity measured by reconstructed charged-particle tracks not associated with the hard objects. Possible double counting of contributions from reconstructed charged-particle tracks from the inner detector, energy deposits in the calorimeter, and reconstructed muons from the muon spectrometer is avoided by applying a signal ambiguity resolution procedure which rejects already used signals when combining the various
E
T
miss
contributions. The individual terms as well as the overall reconstructed
E
T
miss
are evaluated with various performance metrics for scale (linearity), resolution, and sensitivity to the data-taking conditions. The method developed to determine the systematic uncertainties of the
E
T
miss
scale and resolution is discussed. Results are shown based on the full 2015 data sample corresponding to an integrated luminosity of
3.2
fb
-
1
.
A measurement of the mass of the
W
boson is presented based on proton–proton collision data recorded in 2011 at a centre-of-mass energy of 7 TeV with the ATLAS detector at the LHC, and corresponding ...to
4.6
fb
-
1
of integrated luminosity. The selected data sample consists of
7.8
×
10
6
candidates in the
W
→
μ
ν
channel and
5.9
×
10
6
candidates in the
W
→
e
ν
channel. The
W
-boson mass is obtained from template fits to the reconstructed distributions of the charged lepton transverse momentum and of the
W
boson transverse mass in the electron and muon decay channels, yielding
m
W
=
80370
±
7
(
stat.
)
±
11
(
exp. syst.
)
±
14
(
mod. syst.
)
MeV
=
80370
±
19
MeV
,
where the first uncertainty is statistical, the second corresponds to the experimental systematic uncertainty, and the third to the physics-modelling systematic uncertainty. A measurement of the mass difference between the
W
+
and
W
-
bosons yields
m
W
+
-
m
W
-
=
-
29
±
28
MeV.
The luminosity determination for the ATLAS detector at the LHC during
pp
collisions at
s
=
8 TeV in 2012 is presented. The evaluation of the luminosity scale is performed using several luminometers, ...and comparisons between these luminosity detectors are made to assess the accuracy, consistency and long-term stability of the results. A luminosity uncertainty of
δ
L
/
L
=
±
1.9
%
is obtained for the
22.7
fb
-
1
of
pp
collision data delivered to ATLAS at
s
=
8 TeV in 2012.
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