Volume 20, No. 4 (2014)
Articles
EXPERIMENTAL STUDIES ON THE POSSIBILITY OF DEPOLLUTING HYDROCARBONS-CONTAMINATED SOILS THROUGH COMBUSTION
ANDRONELA BARBULESCU(1), CRISTIAN DEAC(2), LAZAR AVRAM(3), VALENTIN PETRESCU(2), ALINA GLIGOR(2)
In the current paper the authors present some experimental researches regarding the depollution through combustion of soil samples that were contaminated with hydrocarbons. Determinations were carried out on chernozem-type soils with high germinative potential, artificially polluted with an oil-derived fraction with known characteristics and a clay-type soil accidentally polluted with an oil-derived fraction of unknown composition. Several combustion tests were carried out, varying the combustion and calcination time. The tests have shown that the calcination time should be of at least 10 minutes to eliminate the pollutant, but the actual duration does not significantly influence the result.
FITTING AN ELLIPSE TO THE SET OF INTENSITY DATA POINTS OF VRANCEA EARTHQUAKES
RASHID BURTIEV(1)
Fitting an ellipse to the set of intensity data points of earthquakes occurred on 11.10.1940, 07.04.1977, 31.08.1986, 30.05.1990 and 31.05.1990 is performed. Test criteria indicate that the ellipse smoothes the observed line of macroseismic field. For all earthquakes, focal axes of 5, 6 and 7 EMS-98 intensity zones are directed along the y-axis. For other zones are oriented along the parallels. This fact is one more acknowledgement of the anisotropy of a geophysical medium. Approximation of the set of points with an ellipse is performed using the method proposed by Fitzgibbon.
BALANCING THE DEEP LOOSENING MACHINE WITH ACTIVE FURROWS
ALEXANDRU-DORIN DAVID(1), GHEORGHE VOICU(2), MIHAI MATACHE(1), GABRIEL GHEORGHE(1)
The stability of machines for soil preparation during the work process is influenced by a number of variable sizes of which the most important are the soil strength and configuration. The stability of deep soil loosening machines with fixed furrow during the work process is studied like vertical stability for the plow. Less studied in the scientific literature, is the stability of deep soil loosening machines with active furrows powered for the tractors PTO with a quadrilateral mechanism.
INTRODUCING A METHOD OF URBAN SOIL RISK EVALUATION – A CASE STUDY ON URBAN RECREATIONAL AREAS IN CLUJ NAPOCA
ANDRA CRISTINA GAGIU(1), ELENA MARIA PICA(1), CLAUDIU TANASELIA(2), MONICA URSU(2)
Assessing risks related to urban soil contamination represents a key part of pollution management. The current research proposes a quantitative method that defines and highlights unacceptable risks. The applicability of the method is presented in a case study on several urban recreational areas from the city of Cluj-Napoca, Romania. Concentrations of As, Cu, Cd, Zn, Pb, Hg, Co, Ni and Mg were identified in a number of 48 soil samples from 12 intensively used recreational areas in Cluj-Napoca. The proposed risk assessment method is applied, and potential risks are calculated for all locations.
THE IMPACT OF MUNICIPAL SOLID WASTE STORAGE FACILITY “VIDRA” ON GROUNDWATER
AMIRA-VALENTINA GOGOANȚĂ(1), DAN NICULAE ROBESCU(1)
This case study is monitoring the impact of pH, nitrate, nitrogen in groundwater around Vidra landfill located in Ilfov; we used two monitoring wells, F19, and F10. For the obtained values, the following conclusions emerged: water from monitoring well F10 showed much higher loads compared to water from the monitoring well F19 on organic loading indicators (CCO-Cr, BOD5); although other values and indicators were higher in the monitoring well F10 to those obtained for the monitoring well F19.
MANAGING THE ENVIRONMENTAL HAZARDS OF WASTE TIRES
SANA KORDOGHLI(1,2), MARIA PARASCHIV(3,4), RADU KUNCSER(5), MOHAND TAZEROUT(1), MALINA PRISECARU(6), FETHI ZAGROUBA(7), IONUT GEORGESCU(5)
This paper presents an experimental approach on understanding and managing the environmental hazards of co-products resulted during energy recovery processes applied on scrap tires. As tire combustion faces serious problems related to harmful emissions, pyrolysis appear as a process that allow the management of toxic compounds. Thus, for the reactions that occur during pyrolysis and combustion of tires organic matters the main intensive degradation thermal ranges have been established. The work was carried out by coupling thermogravimetric analysis (TGA) of tire samples with bench scale reactor in order to identify the relationships between thermochemical behaviour and products distribution.
APPLICATION OF LOW-COST ADSORBENT IN THE TREATMENT OF SAMARU STREAM WATER
YAHAYA S. MOHAMMAD(1), EGBENYA M. SHAIBU-IMODAGBE(2), SUNDAY B. IGBORO(1), ABDUL-RAHEEM GIWA(3), CHARLES A. OKUOFU(1)
In this study, low-cost adsorbent was produced and applied in the treatment of Samaru stream water. Treatment of Samaru stream water was carried out in column mode to determine the efficiency of the low-cost adsorbent for improving the quality of Samaru stream water. To achieve this, the stream water samples were collected from three different points (point 1, 2 and 3) and the values of the following parameters were analyzed before and after treatment: pH, Electrical Conductivity (EC), Total Dissolved Solid (TDS), Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Ammonium, Nitrate, Chloride, Iron (III), Copper (II), Lead (II) and Zinc (II). Results obtained from the study show that highest removal efficiency of 96.18 % was attained for chloride and this was followed by 91.76 %, 90.91 % and 90 % for iron (III), copper (II) and ammonium respectively while the least was 6.33 % (pH). Therefore, the high removal efficiency achieved for some sample parameters in the treatment of Samaru stream water implied that the low-cost adsorbent could be employed in the simultaneous removal of contaminants from a multicomponent system.
STUDY REGARDING THE DETERMINATION OF WASTEWATER SPECIFIC FLOWS IN ROMANIA RURAL AREAS
MIRCEA-VLAD MUREȘAN(1), ELENA-MARIA PICĂ(1)
This paper intends to inform the scientific and engineering community on the importance of wastewater treatment plants of small capacity, designed for rural settlements. By analysing the evolution of Romania’s population by towns, on 1st January 2010, the weight of urban population was 55.1 %, and the weight of the rural population was 44.9 % of the total population. The rural environment representing 44.9% of the total population is grouped into 2860 villages with a degree of connection to wastewater treatment plants of only 11.21 %. At the moment the design of treatment plants, regardless of the structure and size of the settlement, is performed in a non-differentiated way, using the same technological methods for urban and rural areas. The implementation of technical solutions that are use for urban areas in case of small and very small towns’ claims high investment costs and especially operational costs, the efficiency of these solutions being unsatisfactory, because of wrong adoption of sizing parameters, for example, the influent specific flow. From this paper will result, based on case studies, that the specific flow sizing treatment plants for rural areas is overrated, much too high, resulting in oversized treatment plants.
DETERMINING DYNAMIC ACCURACY INDICATORS OF MULTICOORDINATE WORKING MACHINES IN THE FORM OF ROD STRUCTURES FOR FUZZY INERTIA AND DISSIPATION PARAMETERS
VASYL STRUTYNSKIY(1), LEONID KOZLOV(2)
The paper considers a manipulator design and its dynamic model developed by the authors. On the basis of this dynamic model a mathematical model of the manipulator has been created, which enables its spatial motion investigation. The mathematical model takes into account the manipulator inertia tensor with fuzzy components. The developed computation procedure makes it possible to determine cross-angular displacements of the manipulator for impact and sinusoidal laws of torque variation. During random variations of the moment of external forces, complex cross-angular displacements of the manipulator occur. The displacement trajectory includes an elliptical region that corresponds to the ellipse of the manipulator elastic system stiffness. The range of the manipulator upper-end displacement trajectory is maximal in the direction close to that of minimal cross-angular stiffness of the manipulator elastic system.
INFLUENCE OF THE GRANULAR MIXTURE PARTICLES SIZES AND OSCILLATION FREQUENCY ON THE SEPARATION PROCESS AT THE CONICAL SIEVES WITH OSCILLATING MOVEMENT
GHEORGHE VOICU(1), DOREL STOICA(1), GABRIEL ALEXANDRU CONSTANTIN(1), CRAITA CARP-CIOCÂRDIA(1), ELENA MĂDĂLINA ŞTEFAN(1)
The paper presents the results of experimental researches on the working process and his efficiency for a sieve with external conical surface with alternative periodic motion. The sieve is suspended at the top and bottom with three elastic threads (of silk), with thread diameter ϕ1.5 mm and is provided with circular apertures of ϕ4.2 mm. Vibratory motion was obtained with an eccentric mechanism, placed horizontally and acting on tangential direction to the sieve at adjustable distance. . Was thus obtained amplitude oscillation of 3.58, 3.74, 3.91 and 4.10 mm. The oscillation frequencies used were 250, 520 and 790 osc/min. The sieve was used for sorting of canola seeds having sizes between ϕ1.25 mm and ϕ2.5 mm, in percent of 95 %. It was found that seeds are separated closer to the feeding point of sieve the more so as the oscillation frequency is smaller. Seeds of a size less than 1.5 mm is separated close to the axis of rotation. Also, the sieve orifices can properly calibrate a seeds mix for all oscillation frequencies analyzed.