13 research outputs found
STUDY REGARDING QUALITY FOOD PRODUCTS ON THE ZLATNA MARKETPLACE (ALBA COUNTY)
The present work approaches a few problems related to the quality parameters of the food products starting from the present demands of the market economy. We have included in our study a large range of products that are permanently present market place, in a industrialized area. Some of them are vegetable products like: corn, potatoes, cabbage, carrot, spinach, together with other products. The study results highlight the degree of heavy metals contamination of these goods.vegetable products, heavy metals contaminations
Stability of tetracycline residues in honey
The problem of availability of veterinary medicines to treat honeybees is discussed extensively worldwide. An uncontrolled administration of antibiotics may lead to contamination of beehive products and contributes to the problem of food safety. In this study, the kinetics of tetracycline (TC) degradation in honey was studied for samples provided by four sideline beekeepers located in the west region of Romania. The samples of honey were stored in the dark at room temperature for 30 days and subsamples were analyzed every 3 days by Elisa method. The results of the study revealed that the level of tetracycline decreases in time for all honey samples. The tetracycline degradation follows a first-order kinetic model with reaction rate constants between 1.2•10-3 - 2•10-3 days-1. The half-life time of tetracycline in monofloral honeys: acacia and lime was 251 and 232 days respectively. Tetracycline degradation in polyfloral honey was accelerated since τ1/2 of TC was 151 days
Comparative study on factors affecting anaerobic digestion of agricultural vegetal residues
<p>Abstract</p> <p>Background</p> <p>Presently, different studies are conducted related to the topic of biomass potential to generate through anaerobic fermentation process alternative fuels supposed to support the existing fossil fuel resources, which are more and more needed, in quantity, but also in quality of so called green energy. The present study focuses on depicting an optional way of capitalizing agricultural biomass residues using anaerobic fermentation in order to obtain biogas with satisfactory characteristics.. The research is based on wheat bran and a mix of damaged ground grains substrates for biogas production.</p> <p>Results</p> <p>The information and conclusions delivered offer results covering the general characteristics of biomass used , the process parameters with direct impact over the biogas production (temperature regime, pH values) and the daily biogas production for each batch relative to the used material.</p> <p>Conclusions</p> <p>All conclusions are based on processing of monitoring process results , with accent on temperature and pH influence on the daily biogas production for the two batches. The main conclusion underlines the fact that the mixture batch produces a larger quantity of biogas, using approximately the same process conditions and input, in comparison to alone analyzed probes, indicating thus a higher potential for the biogas production than the wheat bran substrate.</p> <p>Adrian Eugen Cioabla, Ioana Ionel, Gabriela-Alina Dumitrel and Francisc Popescu contributed equally to this work</p
Mathematical Models Describing the Emission and Distribution of Heavy Metals in Surface Waters
In this paper are presented : the possibility to identify, through cause-effect diagram, the phenomena that determine the presence of heavy metals in surface water the elucidation of the structure and functional connection between the water body components, using systems theory as well as a mathematical model as a heavy metals balance equations and its validation with experimental data obtained for Arsenic. Keywords: heavy metals, mathematical model, mass balance, causes-effect diagram, Danube river Heavy metals (those metals with a density higher than 5 g/cm 3 : Zn, Hg, Fe, Cu, Cr, Pb, Cd, Os) normally present in nature, are not dangerous for the environment [1] but they may become pollutants, i.e. they may alter the balance of environmental components, when they exceed a certain threshold value set by the laws. Ppm concentrations of heavy metals in water have a toxic effect on the aquatic environment due to bioaccumulation -living organisms take them over and concentrate them The presence of heavy metals in water is due to emission processes, to direct or indirect discharges of such substances into the environment The most common sources of heavy metals which end up in rivers are: discharges of untreated or inefficient treated wastewater from various activity fields, atmospheric emissions of combustion gas generated by industrial activity or transportation and uncontrolled waste Once they get into water, heavy metals can not decompose or be destroyed [1], part of them being found dissolved in water, another part being assimilated by aquatic plants and beings, some settling on the bottom of the bed, and most of them being transported along the water course as suspensions The water body, defined as a discrete and significant element of the surface waters [9] such as a river sector, may be taken to be, from the perspective of systems theory, a complex system consisting of a multitude of entities with a certain organization and between which there occur a number of interactions. These interactions within the system and between system and environment are in fact flows of mass, energy and information In the specific case of a flowing water sector, the system is considered a real physical system, with imaginary boundaries between two villages bordering the water course and it is open, since it interacts with the environment. An imaginary interface may be taken into account, for the purpose of setting limits to the system For the purposes of a simplified approach, we may assume that the elements of the system do not depend on spatial coordinates, but only on time; thus, we obtain a ( This diagram offers the possibility to identify weaknesses, vulnerable points in a sector of activity, considered to be a potential generator of heavy metals; an intervention on them may take place, by triggering selective actions for the reduction of pollutant emissions in the investigated watercourses In this paper were studied the following objectives : identifying the causes of the presence of arsenic in the surface waters through causes-effect diagram; description of the distribution of heavy metals in the water body components by a block scheme, using systems theory; developing a balance equations to describe the process of distribution of arsenic in the aquatic environment. The case study considered was a 31 km segment from Danube river, between Bazias -km 1071 (entrance of the Danube in Romania) and Coronini -km 1040. Checking and testing the mathematical model developed (the material balance equation) was performed using experimental data obtained from monitoring the Danube River in September 2007, for the case study approach. For developing causes effect diagrams for the case study in question, and for determining a mathematical model as a material balance equation we chose Arsenic, a chemical element with a highly toxic effect on water, even at very low level
Thermal Degradation of Streptomycin Residues in Honey During Storage
In Europe there is an increasing emphasis on the quality control of honey, especially on maximum limits of veterinary drug residues (particularly antibiotics) permitted in it. Streptomycin is an aminoglycoside antibiotic used in apiculture to protect bees against a variety of brood diseases. Romanian authorities have included it in the National Monitoring Program for honey manufacturers. In this study, an enzyme-linked immunosorbent assay (ELISA) screening test was validated as a detection method of streptomycin residues in honey. The ELISA experimental results were compared to those obtained by using an HPLC method. The values generated by the two methods were very close to each other. This fact certifies that ELISA method can be successfully used for quantitative detection of the amount of streptomycin in honey samples. Following validation, three types of honey (polyfloral, lime and acacia) were analyzed for streptomycin content after exposure to 4, 22, 30, 40 or 70 °C for 20 weeks. The results show that streptomycin mass fraction decreased with time and with the increase of temperature in all honey samples. The data collected were used to fit a second-order multiple linear regression model for predicting the degradation of streptomycin in honey samples as a function of temperature and storage period. Values of the calculated statistical indicators confirm a good predictive capability of mathematical and statistical models
Toplinska razgradnja ostataka streptomicina u medu tijekom skladištenja
In Europe there is an increasing emphasis on the quality control of honey, especially on maximum limits of veterinary drug residues (particularly antibiotics) permitted in it. Streptomycin is an aminoglycoside antibiotic used in apiculture to protect bees against a variety of brood diseases. Romanian authorities have included it in the National Monitoring Program for honey manufacturers. In this study, an enzyme-linked immunosorbent assay (ELISA) screening test was validated as a detection method of streptomycin residues in honey. The ELISA experimental results were compared to those obtained by using an HPLC method. The values generated by the two methods were very close to each other. This fact certifies that ELISA method can be successfully used for quantitative detection of the amount of streptomycin in honey samples. Following validation, three types of honey (polyfloral, lime and acacia) were analyzed for streptomycin content after exposure to 4, 22, 30, 40 or 70 °C for 20 weeks. The results show that streptomycin mass fraction decreased with time and with the increase of temperature in all honey samples. The data collected were used to fit a second-order multiple linear regression model for predicting the degradation of streptomycin in honey samples as a function of temperature and storage period. Values of the calculated statistical indicators confirm a good predictive capability of mathematical and statistical models.U Europi se sve više provodi kontrola kvalitete meda, posebice maksimalno dozvoljenih količina ostataka veterinarskih lijekova (prvenstveno antibiotika). Streptomicin je aminoglikozidni antibiotik što se koristi u pčelarstvu, ponajviše za sprečavanje raznih bolesti legla. Rumunjske su vlasti nadzor tog antibiotika uvrstile u nacionalni program motrenja proizvedenog meda. U ovom je istraživanju validirana metoda detekcije ostataka streptomicina u medu pomoću ELISA testa, pri čemu su dobiveni rezultati uspoređeni s onima dobivenim HPLC metodom. Rezultati tih dviju metoda nisu se bitno razlikovali, čime je dokazano da se ELISA test može uspješno primijeniti za određivanje količine streptomicina u uzorcima meda. Nakon validacije ispitana su tri tipa meda (poliflorni, med lipe i bagremov med), te je određen maseni udjel streptomicina u uzorcima nakon 20 tjedana skladištenja pri 4, 22, 30, 40 i 70 ºC. Rezultati pokazuju da se s porastom temperature udjel streptomicina u svim uzorcima meda tijekom vremena smanjio. Pomoću dobivenih podataka napravljen je model višestruke linearne regresije drugoga reda za procjenu razgradnje streptomicina u uzorcima meda tijekom skladištenja pri različitim temperaturama. Dobivene su vrijednosti potvrdile da se primjenom matematičkih i statističkih modela može predvidjeti razgradnja streptomicina u medu
Sustainable development of Romanian cities through biogas production from municipal wastes and application in co-combustion processes
Today municipal wastes represent a general problem from multiple points of view: necessary space for depositing, odor, possible soil contamination. In the same time, a large quantity of organic residual material remains unused in terms of energy conversion by potentially producing a biofuel which, in its term, can be used for covering at least partially, the human demand for energy. In this context, the present paper underlines the possible applications of anaerobic fermentation for biogas production by using as main substrate solid municipal waste from city of Timisoara, Romania, inside a pilot installation for determining its potential for further usage at larger scale in firing or co-firing processes; in this context, conclusions will be traced, based on the resulted experiments
Qualitative Characterization and Antifungal Activity of Romanian Honey and Propolis
The purpose of this study was to review the physicochemical characterization of Romanian honey and propolis and their antifungal effect on different strains. As an indicator of environmental pollution, lead exceeded the allowed limits in two study areas. The relationship between the acidity and electrical conductivity of polyfloral honey and the antioxidant activity with the total content of phenolics and flavonoids was investigated. The antifungal activity of 13 polyfloral honey and propolis samples from North-West and Central Romania and 12 samples from Alba County was investigated against six fungal strains: Aspergillus niger, Aspergillus flavus, Candida albicans, Penicillium chrysogenum, Rhizopus stolonifer, Fusarium oxysporum. All honey and propolis samples exhibited an antifungal effect. The most sensitive strains were P. chrysogenum and R. stolonifer for honey and P. chrysogenum and F. oxisporumn for propolis. A two-way analysis of variance was used to evaluate the correlations between the diameter of the inhibition zones for the strains and the propolis extracts. Statistical analysis demonstrated that the diameter of the inhibition zone was influenced by the strain type and the geographical origin of honey and propolis. Pearson’s correlation coefficient shows a significant positive linear relationship between the diameter of the inhibition zone and the flavonoid and phenol concentration of honey and propolis, respectively