Pranas Baltrenas

Mathematical simulation of solid particle dispersion in the air of Vilnius city

Abstract One of the main methods for the air quality assessment and forecast is mathematical simulation of pollutants. In order to simulate the dispersion of solid particles (SP) in the air, there may be applied the package of “Phoenics” software in which the proximity methods of equation solution are used, because an accurate analytic solution of movement equations is not possible to be applied. The software was used in Žverynas district of Vilnius city in which the exact values of SP were selected. The paper presents the technique of mathematical simulation of SP dispersion in the air, the Algebraic Slip Model is described which is used for the solution of the problem; the model uses calculation‐based formulas. Based on the results of the experiment (the values of SP concentration) and the obtained results by applying “Phoenics” mathematical simulation program, the feasibility of the simulation program for modeling the SP concentration dispersion is determined. The results of simulation are submitted in...

Sustainable ecological development reducing negative effects of road maintenance salts

Abstract To ensure traffic safety in winter, large amounts of technical salts (chlorides) are applied on roads. De‐icing salts directly or indirectly contaminate the road environment and have a negative effect on the components of road environment. The analysis of the situation raises a question: how to ensure traffic safety in wintertime applying salts and achieve sustainable development. The article presents the investigations of chloride concentrations on the roadsides of a highway. In 5 recent years, complex environmental laboratory investigations and investigations under natural conditions of the effect of salts on the components of the road environment have been carried out proving their toxic effect. Consequently, to reduce a negative effect of salts on the road environment, measures of sustainable ecological development have to be taken. To achieve a balanced use of salts, the proposal is to apply alternative materials (formiates, molasses‐based material). The introduction of biotechnical measures...

Modelling of motor transport exhaust gas influence on the atmosphere

Santrauka Pagrindiniai atmosferos tarsos saltiniai miestuose yra mobilūs (automobiliu transportas), taip pat ir pramones bei energetikos tarsos saltiniai. Automobiliu transporto ismetami tersalai duoda didžiausia emisija i aplinka. Tyrimais nustatyta, kad daugiausia tersalu yra ismetama rytinio ir vakarinio piko valandomis, kai automobiliu transporto eismo intensyvumas mieste yra pats didžiausias. Automobiliu transporto ismetalai yra ypac dideli intensyvaus eismo miesto gatvese ir 2–5 m atstumu nuo važiuojamosios kelio dangos, o esant 6–10 m atstumui ju kiekiai staigiai sumažeja. Nustatyta, kad CO, NOx, CHx, SO2 koncentracijos tiesiogiai priklauso nuo automobiliu transporto eismo intensyvumo. Koncentracija tolygiai mažeja didejant atstumui nuo gatves važiuojamosios dalies. Tyrimai atlikti Vilniaus mieste 14 Žirmūnu gatviu vietu, kur skaiciuotas važiuojancio automobiliu transporto (lengvuju, vidutinio lengvumo, sunkiuju automobiliu) skaicius, pagal tai su COPERT programa nustatytos rytinio ir vakarinio pik...

Triukšmo slopinimo sieneles efektyvumo ivertinimas

Santrauka Mechanizavus pramones ir žemes ūkio gamyba, didejant transporto srautams miestuose ir gyvenvietese, modernejant buitinei technikai, sparciai dideja akustinio diskomforto zonos. Triuksmo lygis darbo vietoje ar namu aplinkoje yra vienas pagrindiniu veiksniu, lemianciu komforto rodikli, todel vis daugiau demesio skiriama triuksmo procesu nagrinejimui. Triuksma kelia ir jūru uostu kroviniu stotys. Klaipedos uosto siaurineje dalyje vykdomi krovos darbai kelia dideli uostamiescio gyventoju susirūpinima. Viena is opesniu problemu yra is AB KLASCO biriuju trasu terminalo sklindantis triuksmas. Salia terminalo irengta triuksmo slopinimo sienele. Straipsnyje pateiktas sieneles efektyvumo ivertinimas, atlikus tyrimus taikant skaiciavimo, matavimo bei modeliavimo metodus. Triuksmo matavimo tyrimai atlikti naudojant triuksmamati Bruel&Kjaer mediator 2260. Is gautu rezultatu matyti, kad triuksmo lygis gyvenamojoje teritorijoje 3–6 dB virsija leistinasias higienos normos HN 33–1:2003 vertes dienos metu, taip p...

Investigation of cleaning efficiency of a biofilter with an aeration chamber

Abstract The investigation was carried out using a biological air‐treatment device, i.e. a biofilter with an aeration chamber filled with water saturated with biogenic elements. To accelerate the absorption of organic compounds, air polluted with volatile organic compounds is directed to a water reservoir installed in the lower part of the filter where organic compounds are destructed. In the process of aeration, microorganisms propagate in the chamber, degrading part of pollutants to harmless products, carbon dioxide and water. Since all hydrocarbons are water‐soluble, the aeration chamber is the first phase in a hydrocarbon degradation process. Application of such a polluted air‐feeding model improves the sorption qualities of a charge. When relative air humidity reaches 100%, water‐drops evenly distribute over the entire surface area of the charge and improve the activity of microorganisms. Having passed through the aeration chamber, polluted air is filtered via charges of a different origin, composed ...

Research on anaerobically treated organic waste suitability for soil fertilisation

Abstract One of the most promising methods to convert organic waste into alternative energy and still obtain fertiliser is anaerobic digestion of waste in bioreactors. To evaluate the suitability of biodegraded organic waste for soil fertilisation, an experiment aimed at determining the amount of total nitrogen, total phosphorus and heavy metals contained in this waste and testing of its pH was carried out. The following organic waste was used for the research: sewage sludge from wastewater treatment plants, fruit and vegetable waste, hen manure, piggery slurry and grain. The biggest contents of nitrogen and phosphorus were determined in anaerobically treated swine manure and therefore, it was found the most suitable organic fertiliser to remediate exhausted soils and used‐up areas. Treated swine manure contains 8.27 mg/l of nitrogen and 293.1 mg/l of phosphorus. The biggest contents of heavy metals were determined in anaerobically treated sewage sludge from wastewater plants. The concentration of chromiu...

Investigation of particulate matter concentration in the air of Žvërynas district in Vilnius

Abstract Reduction of pollution is among priority environmental problems in our country. Real‐time information about the air pollution in the biggest Lithuanian cities and industrical centers is received from the air quality stations every day. It is the main method for the air quality assessment. On the basis of this information it is possible to conclude that concentration of particles in some areas exceeds allowable limits. The concentration of particles in Žirmunai and Žverynas districts of Vilnius exceeds the limits too. Assessment of changes in this air quality indicator and forecasting their development is rather complicated as regular measurement of particulate matter concentration (with the particle diameter up to 10 μm) was started at Lithuanian air quality stations only in 2003. The paper describes the methodology of recording particle concentrations in Žverynas district of Vilnius. The results of particle measurements are compared with a maximum allowable concentration (MAC) of the analyzed po...

Experimental investigation of particle concentration using mass and optical methods

Abstract Devices of various design and measuring methods are applied for determining particle matter (PM) concentration. Therefore, it is important to know measuring precision of different measuring devices. Measurements were carried out by a recognized and widely used mass as well as the optical method. Materials commonly occurring in technological processes were used for investigation: particles of wood, cement, quartz sand and metal from polishing processes, clay and charcoal particles. Besides, the concentration of PM at one of the most bustling crossroads of Vilnius city was measured to estimate and compare the results of the mentioned methods and evaluate their suitability for measuring very low concentrations of PM. Measuring results of PM concentration are compared and estimated in this work, and coefficients, showing measuring differences among different devices and methods, are given and measuring errors are rated.

Investigation of noise dispersion from seaport equipment on the enterprise territory and residential environment

Santrauka Ivertinamas triuksmo lygis ir jo sklaida Klaipedos valstybinio jūru uosto kompanijoje AB KLASCO. Tyrimai atlikti 24 matavimo vietu, isdestytu zonomis, imones teritorijoje ir 6 matavimo vietose gyvenamojoje aplinkoje, atlikti ekvivalentinio triuksmo tyrimai. Siekta ivertinti triuksmo saltinius, higienos normu virsijimus ir ju galimas priežastis imones gamybineje teritorijoje ir salia jos gyvenamojoje teritorijoje, nustatyti imones skleidžiama triuksma ir parengti priemones jam mažinti. Rezultatai pateikiami triuksmo sklaidos pasiskirstymo izolinijomis.

Biological purification of air polluted with volatile organic compounds by using active sludge recirculation

Abstract Various methods for removal of volatile organic compounds (VOC) from the air are applied in the world. Their selection is determined by the efficiency and costs of the method. Biofiltration is a new technology to control environmental pollutants helping to regulate emissions of VOC with unpleasant odours in to the air and working environment. When VOC are to be removed from large volumes of air, equipment of biological purification charged with active sludge is used. Such an equipment has a rather simple structure and efficiency of to 98–99 %. Active sludge as a biocharge has both a high concentration of microorganisms compared to stationary charges and good sorption features. Sorptive capacity changes when a load to active sludge is changed, and this has a negative impact on biochemical decomposition of organic substances and, at the same time, on purification efficiency. Calculation and evaluation of an optimal working mode of the equipment enable to avoid desorption of VOC in the system or to ...