All posts by simiecoind

Abstract:

The aim of the research was to evaluate the quality of drinking water from five
private wells (W1 -W5) located in Negresti-Cobadin, Constanta County, Romania.
The evaluation consisted in determination of some specific parameters as pH,
electrical conductivity (EC), total hardness (TH), ammonium, nitrate and nitrite
concentrations and oxidisability index. The results were compared with quality
standards for drinking water imposed by Council Directive 98/83/EC and also with
Romanian legislation. The pH, EC, nitrite and ammonium levels for all water
samples are within recommended ranges. The TH values are higher and range
between 27.41 and 47.14 mg CaO/L. Concerning nitrate levels, it is noteworthy to
mention that excepting W4 sampling point, all water samples exceeded (as average)
maximum admitted level. Oxidisability parameter indicates for wells W1 -W4 values
were below 5 mg O2/L, meanwhile in the case of W5 found value exceeded slightly
limit value.

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Abstract:

The present study investigated the quality of potable water that was taken from the
treatment plants in three counties from Romania (Ialomița, Gorj and Tulcea) for a
two-year period (2016 and 2017). A series of organic and inorganic indicators have
been analyzed in the drinking water from the respective locations.
Out of the 37 samples collected in Ialomița county in 2016, the following indicators
have exceeded the maximum admissible concentrations (MAC): sodium in 8% of
the total samples, nitrogen in 38%, copper in 27%, manganese in 5%, iron, nickel
and chromium in 3% of the samples. In Gorj County, samples from 25 locations
were analyzed during 2017. Exceedings of MAC were recorded for hardness in 36%
of the samples, for boron in 16%, for ammonium, iron and manganese in 12%, for
sodium and for chloride in 4% of samples. In 2017 a total of 33 samples were
analyzed in Tulcea County; the following indicators have exceeded MAC
trihalomethanes and iron in 3% of samples and manganese and fluorides in 9% of
samples.
For the analyzed indicators that exceeded the maximum admissible concentrations a
database including the physical-chemical characteristics of drinking water at the exit
from the treatment plants was created.

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Abstract:

The paper presents the characterization of the content of metals from three different waste biomass using ICP-MS and AAS techniques. The purpose of the study was to finding an appropriate method of analysis for the complex matrix of waste biomass by comparing two methods of digestion using a closed system (microwave) and an open system (sand bath). For this study were analyzed six metals (Al, Mg, K, Ca, Na, Fe) in three different waste samples from agriculture, forestry and related industries (horticultural and wine waste).
It was observed that the highest concentrations of metals were recorded for the sample P3 horticultural and wine waste through both analysis techniques. The results obtained were compared with a certified reference material (CRM) and value to demonstrate the precision of the method and the quality of the results.
The concentration obtained for Al, Mg, K, Ca, Na and Fe by microwave digestion in a closed system analyzed using ICP-MS technique were better than the AAS technique. The method of analysis chosen in this study was emphasized as being optimal for the analysis of biomass waste using performance parameters: precision, accuracy, detection limit, quantification limit and extended uncertainty.
From the obtained results it can be said that the method of digestion by using microwave systems of the metals` analysis from biomass waste is within the desired purpose.

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Abstract:

Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) are the
most commonly used parameters for the characterization of the organic pollution of wastewaters. Both of these parameters have advantages and disadvantages and the choice usually depends on many factors such as the time period required to
determine each one of them. It is essential to obtain a control between BOD and
COD for various wastewater treatment plants, to help in the design and operation of
these plants. In this paper the modelling results of BOD and COD for an aeration
tank from Dej wastewater treatment plant by Matlab/Simulink software program has no significant difference, because the results are close enough to the real ones that allow the user to make a good prediction regarding this parameters. A true validation of these results, including experimental validation of simulations of the entire collecting data was realistic.

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Abstract:

Cavitation influence has different destruction action on the microbial cells that
depends on their size, shape, type of bacteria, etc, i.e. it depends on the
morphological features of the cells. The effectiveness of this process also depends
on the nature of bubbled gas into reactive cavitation zone. Ar/US has shown the
highest effectivity of cells destruction conditions regardless of the size of their cells
compared with Не/US, О2/US and СО2/US. Concerning of gas/US-action on the
type of microorganisms it was found that yeast cells were destroyed most rapidly,
because their sizes are several times larger than bacterial cells.

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Abstract:

A rapid, sensitive and accuracy method was developed for detection of rhodium in wastewater samples. The recovery test indicate that 343.489 nm is the proper wavelenghts for Rh determination.

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Abstract:

The aim of this study was to develop an analytical method capable to determine mercaptans in air at low concentrations, lower than the ones that produce an
olfactory discomfort. A reliable, rapid, and simple high performance liquid chromatography (HPLC) method was developed for the determination of mercaptans, a sulphur compounds class. The developed method can be successfully
applied to the quantitative determination of four compounds (Methyl mercaptan, Butyl mercaptan, Ethyl mercaptan and Propyl mercaptan).

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Abstract:

In the European Union, the regulation in the sector of emissions into the atmosphere from industrial plants did not evolve homogeneously. As demonstrated in this article, the sector of waste to energy plants has shown important improvements in the latest 20 years, whilst other industrial plants were subject to less stringent regulations. As consequence, the human exposure resulting from industrial plant authorisations depend on the plant to be authorised. Examples of consequent inequalities and related criticalities concern both macro and micro-pollutants. The present article concerns a category of micro-pollutants: heavy metals emissions into the atmosphere. The sector of thermo-chemical treatment of waste is presently analysed in details in the University of Insubria in the frame of a research in progress. The present article refers to some aspects emerged in that research and integrates them by a preliminary analysis of the underestimated criticalities of other industrial sectors. In both cases, the core of the problem is the demonstrable excessive simplification of the control of heavy metals emissions. Large industrial plants are controlled through an approach that does not exploit in details the available information of toxic effects of each heavy metal. Small industrial plants can be subject to simple authorisations with no analysis of the local impact of their emissions. In both cases, secondary and diffused emissions can have an impact higher than the conveyed ones, as discussed in this article. A methodology of control that integrates the present regulation, avoiding under-estimated human exposures to heavy metals is mandatory.

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Abstract:

In the 21 st century the world faces ecological problems due to the industrialization. One of these issues may be intensive agriculture. The next study reflects the attempt
to use a natural means compounds in organic farming. Considering the antibacterial capacity of the coloidal silver solutions was born the idea of using it in organic
farming for medical plants development.
Over the course of several years, the observations made have favored the balance to lower concentrations of colloidal silver water solutions.
During this study was observed that the plants were more healthy and the production and the quality of the fruits was also modiffyed. The plant specie of Momordica charantia L. was chosen for its high interest in its
effects. The fruit being used in alternative medicine, also being called „natural insulin”. The seeds used in the experiment were organic certified and were obtained
from already acclimatized plants. The experiment unfolding in partially protected environment on an area of about 400 square meters. This paper highlights the effects of seeds treatament and watering treatment with 3
different concentations (5 ppm, 15 ppm and 30 ppm) of colloidal silver watter solutions on the development of Momordica charantia L. plants. It is worth mentioning that in previous studies these concentrations attracted the most attention. The most favorable results could be seen in plants treated with colloidal silver solution at the higher concentrations.The Momordica charantia L. plants being obtained by using organic farming method, this study can reflect an inovative method of organic fertilization.

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Abstract:

The filtration efficiency of organic contaminants like triazine herbicides class (simazine, atrazine and propazine) has been tested using more types of filter
membranes (PTFE, glass, cellulose acetate, regenerated cellulose) from synthetic solutions with variable content of organic modifiers (acetonitrile and methanol).
Thus, 2 mL of synthetic solutions (10%, 25%, 50%, 75% and 100% methanol and respectively acetonitrile) were filtered on each of the membrane filters. Simazine pesticide responds very well on PTFE, glass and regenerated cellulose filter membrane when the organic modifiers was acetonitrile. An excellent recovery was obtained when filtering simazine with 25% ACN on PTFE, glass and regenerated cellulose. In case of atrazine was observed a good recovery on the four filters when the solution contained 100% acetonitrile and 75% methanol. The propazine has an efficient filtration on all four membranes, on hydrophobic and hydrophilic
membranes, contrary to theoretical prediction. For the samples prepared in 100% organic solvent (methanol), PTFE filters provided excellent recovery (>95%) for all
three pesticides (simazine, atrazine and propazine). The study is useful in the filtration stage of organic extracts resulting from processing of environmental
samples (water / soil).

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Abstract:

Composite materials obtaining, based on wastes mixing, can have both, economical and social positive impact, and also the use of such composites materials leads to a level of environmental pollution reduction, generally, and in the level of noise pollution, particulary. This aim of this study is essential for the future development of such materials because, the results will give us informations regarding the formulation of oxide and polymeric composite materials, by associating the components and leads us to superior properties products, having the property to
absorb sound waves. In this paper we characterize a number of wastes that are resulting from industrial technological processes. The wastes are characterized by granulometry, oxide composition and apparent porosity that are specific properties for obtaining composite materials with sound-absorbing properties.

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Abstract:

Composite materials obtaining, based on wastes mixing, can have both, economical and social positive impact, and also the use of such composites materials leads to a level of environmental pollution reduction, generally, and in the level of noise pollution, particulary. This aim of this study is essential for the future development of such materials because, the results will give us informations regarding the formulation of oxide and polymeric composite materials, by associating the components and leads us to superior properties products, having the property to
absorb sound waves. In this paper we characterize a number of wastes that are resulting from industrial technological processes. The wastes are characterized by granulometry, oxide composition and apparent porosity that are specific properties for obtaining composite materials with sound-absorbing properties.

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Abstract:

As is known all forms of life depend on water. Water is a vital part of many metabolic processes inside the body. By increasing the world population, increasing global pollution and global warming, fewer people benefit from water. This problem can be solved by increasing water production, better distribution and disruption
existing resources. For this reason, water is a strategic resource for many countries.
Regarding to this, is important to protect the water resources from the action of pollutants and to monitor the quality of the water already existing. Wastewater is composed of different proportions of residual water from domestic or industrial
origin and rainwater. To evaluate the quality of wastewater various parameters are available but for common people it is difficult to understand the meaning of this values. The concept of Water Quality Index (WQI) has been developed by
representing it as numeric value for easy and quick understanding of quality of the water. This study aimed to assess the wastewater quality of 8 sampling stations in Valcea County. The data were collected over a five years’ period (2013-2017) from each sampling point and the physical-chemical parameters were analysed to evaluate
the variations registered in the study period.

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