All posts by simiecoind

Abstract:
The wastewater treatment plants are considered to be hotspots for antibiotic resistance
selection, transfer and dissemination. Wastewater offers favorable conditions for the
development of antibiotic resistant bacteria because it contains high amounts of organic
matter, favoring the rapid multiplication of microbial cells and the development of biofilms in
which microbial cells are in close proximity, the presence of pollutants (pesticides, heavy
metals, antibiotics) acting as selective pressure agents for resistance.
The aim of this paper is to investigate how the antibiotics susceptibility profiles of some
microbial strains isolated from wastewater are influenced by electromagnetic fields.
A number of 10 bacterial strains isolated from wastewater (E. coli, Salmonella sp.,
Enterobacter sp., Enterococcus sp., Citrobacter sp., Klebsiella sp.) were exposed to an
electromagnetic field (50Hz electric field at different voltages) for 24 hours, at 37°C. Thereafter,
the antibiotic susceptibility testing was performed for both treated and control strains, by disk
diffusion method, according to CLSI 2016.
The obtained results proved that the electromagnetic field induced in some cases a decrease
of the growth inhibition diameters such as penicillins, cephalosporins, aminoglycosides and
vancomycin, while in other cases an increase of bacterial strains susceptibility to the tested
antibiotics.
These preliminary results demonstrate that the electromagnetic filed in addition with other
selective factors which are present in the wastewaters could modulate the environmental
reservoir of antibiotic resistance and influence the frequency of the selection of resistant
bacteria and the magnitude of the potential risk of dissemination into the environment and of
contamination of animals and humans.

Abstract:
Flow cytometry represents an important tool in environmental biology, and especially in cellular
biology, through its ability to distinguish among different physiological states (viable, latent and
non-viable). Flow cytometry combined with fluorescent markers, such as propidium iodide and
ethidium bromide allows to perform rapid measurements on individual cells and also
simultaneous measurements of multiple cellular parameters, both structural and functional.
The aim of this paper was to investigate the influence of the electromagnetic field on the
morpho-physiological parameters of some bacterial strains cells isolated from wastewater,
assessed through flow cytometry. In this respect, a number of 10 bacterial strains isolated from
wastewater (E. coli, Salmonella sp., Enterobacter sp., Citrobacter sp., Klebsiella sp. and
Enterococcus sp.) were exposed to an electromagnetic field (50Hz electric field at different
voltages) for 24 hours, at 37°C. Both samples, the ones exposed to electromagnetic field and
blank samples (unexposed) were assessed by flow cytometry technique. Two possible
mechanism of action have been tracked, i.e. the efflux pumps activity (fluorescence marker Ethidium Bromide) and permeabilisation of cellular layers (fluorescence marker – Propidium
Iodide). Both mechanisms of action have been identified, from slightly to significant
modifications, as compared to untreated controls, quantified as ΔMFI (median of fluorescence
intensity). Conclusion: Our results suggest that flow cytometry could be used for the real-time
evaluation of the influence of different electromagnetic fields on the aquatic microbiota, the
obtained results being of great interest for the development of technological solution with
increased efficiency in the (waste)water treatment.

Abstract:
In this study, we followed a strategy for vegetation fly ash dumps. For this purpose Salix spp. was used.
This plant was chosen deliberately in order to form, in time, a stable and health ecosystem. The resulting
biomass can be used as a renewable energy source. The experiment was performed in situ, in a delimited
compartment, from a power plant fly ash dump. Salix spp. cultures were monitored for 18 months on soils
fertilized with 25 t/ha sewage sludge anaerobically stabilized. From experimental studies, it was found that
the species Salix. spp. developed similar to a culture performed on unpolluted land. In the Salix. spp.
burning strains ash, it was found no accumulation of Pb and Cd. Burning Salix spp. ash included Cr, Ni
and Cubetween 10 – 30 mg/kg dried matter; Mn and Fe between 178- 313 mg/kg dried matter. Thus, by
using species Salix spp. for phytostabilization, fly ash dumps can be made ecological, restoration of
ecosystems and landscape and obtaining alternative energy.

Abstract:
A wastewater treatment plant’s carbon footprint is represented by the amounts associated with collection,
treatment and final disposal of treated wastewater and sludge. The importance of evaluating the carbon
footprint in wastewater treatment facilities consists in the fact that it’s reduction is directly related to energy
efficiency measures and plant operation improvements. Considering the fact that, at a national scale,
there is a lack in methodologies and solutions for evaluating wastewater treatment plants’ carbon footprint,
the main international methodologies and tools were studied and the paper presents the main parameters
that have to be taken into account during evaluations, as well as the weak and strong points in the studied
methodologies.

Abstract:
Natural zeolites are crystalline hydrated aluminosilicates formed by the deposition of
volcanic ash in lakes with salted water. They are characterized by their ability to lose and gain
water reversibly and to exchange some of the constituents without changing their structure.
These properties recommend them as useful additives for agricultural soils as buffer matrix for
the process of nutrients translocation.
Present study aims to evaluate the ammonium exchange capacity (AEC) of treated and
untreated soils with natural zeolites as an indicator of quality soil improvement. The zeolites
used in this study (with a content of approx. 60% clinoptilolite) were purchased from Cemacom,
the exploiting company of volcanic tuff from Zalau, Salaj County. The soil samples were
collected at various time intervals during one year. Furthermore, we collecteded soil samples
from unprotected and protected (greenhouses) sources where soil had different degree of
organic fertilization in order to obtain information on the effect of zeolites addition on AEC.

Abstract:
The influence of a classic surfactant: palmitoyl-glycylglycine and bola amphiphilic: bis[2-
butyl(sodium bis-thioacetate) sodium dicarboxylate 1,10 decanediyl ester] upon the casein
membrane preparation and separation technologies for removing organic pollutants (dyes)
was studied by: UV-VIS and FT/IR-ATR spectroscopy, dynamic light scattering, optical and
scanning electron microscopy, contact angle, microbiological tests and the separation rates.
The membranes were produced by a casting-solvent evaporation technique. The casein
powder was dissolved in a water- acetic acid (75:25 v/v) solution with and without plasticizer:
glycerol and surfactant (classic or bola), constant continuous stirring for 6-8 hrs. at 40ºC, then
degassed the solution for 2 hrs. The solution was poured and afterwards maintained in the
oven at 40-50°C for 8-12 hrs. Membranes were obtained with different surfactants which
influenced the separation properties of membranes.
Ecological membranes are obtained from a biodegradable biopolymer and can be used
successfully in removing dyes from wastewaters.

Abstract:
2010 Energy Performance of Buildings Directive and 2012 Energy Efficiency Directive require
a continued reduction of energy consumption in buildings. Although consumption minimization
methods are generally available, country-specific aspects have to be analyzed for different
climates. In Romania, the climate is temperate (Köppen climate – type D) and it is characterized
by extreme temperatures with hot summers and cold winters. Although heating consumption
represents the principal component of the total energy consumption, special attention should
be paid to the cooling consumption in this kind of climate. Summer shading devices impact on
building envelope is studied in this paper. For this purpose, an office building with curtain walls,
located in Bucharest, was chosen. The curtain wall on South façade is shaded with an exterior
blades metallic system. The behavior of the glazed shaded area was analyzed in summer
time, even for a bigger period, between the spring equinox and the autumn one. Three
significant days were chosen for this purpose and the shaded area was computed hour by hour
for each day. At the end, the cooling energy load decreasing realized by the shading devices
was determined. Also, the optimal distance between two blades was calculated, in terms of
energy efficiency.