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Contents
ISSN 1392-2335 Transactions of the Water Management Institute of Lithuanian University of Agriculture 2002, 21(43) DISTRIBUTION OF PHOSPHORUS AND NITROGEN COMPOUNDS IN WATERBODIES SITUATED IN THE BASIN OF THE LAKE LENAS Arvydas Povilas MALISAUSKAS Summary The paper presents the data about the distribution of nutrients in water in the hydrographic network of the basin of a flowing lake. The studies were carried out in the basin of the lake Lenas situated upstream the Nemunas. The area of the lake covers 6.4% of the basin. The investigations included the following aspects: the change of the amount of phosphorus and nitrogen compounds in the runoff from agricultural land use and woody vicinities, and the impact of the lake on the leaching of those compounds. As the study results showed, the highest phosphorus and nitrogen concentrations occurred in drainage runoff water, the lowest ones were observed in water of the effluent of the lake. The amounts of total phosphorus and nitrogen leached from agricultural land use through the drainage make up 0.12 kg/ha and 16.0 kg/ha respectively. The amounts of those compounds brought into the lake by influent make up 0.06 kg/ha and 5.0 kg/ha accordingly. The lake retains 56% of total phosphorus and 60% of total nitrogen, 84% from which falls for nitrate nitrogen. Keywods: flowing lake, basin, runoff, phosphorus, nitrogen.
Address Article received 10 2002, given to print 12 2002. ISSN 1392-2335 Transactions of the Water Management Institute of Lithuanian University of Agriculture 2002, 21(43) HYDRATION AND CARBONIZATION METHOD APPLIED FOR THE TREATMENT OF WASTEWATER FROM FOOD PROCESSING INDUSTRY Zenonas STRUSEVICIUS, Sigita Marija STRUSEVICIENE, Algirdas RADZEVICIUS Summary Wastewater from food processing industry contains as a rule several times higher organic matter concentration to compare with domestic wastewater, therefore its biological treatment must be preceded by its primary treatment. The paper presents the data about flocculation processes of pollutants when wastewater is treated with quicklime CaO. This method was first used in meat processing company "Nematekas", and the obtained results were rather satisfying, which enabled us to apply the same method for the primary treatment of heavily polluted wastewater from food industry. After laboratory flocculation tests of four different kinds of wastewater from food industry had been done, the rates of calcium oxide were determined. The rates should not exceed 1 kg CaO/m3 for wastewater from butchery, brewery and milk collecting post, and 1.5 kg CaO/m3 for wastewater from fruit and vegetable processing companies. During the flocculation process of different types of wasterwater the folowing amounts of pollutants according to BOD7 are retained: organic pollutants 60-70%, nitrogen 42.5-61%, phosphorus 35.5-62.5%. The flocculation process requires over 0.33 kg of oxygen per 1kg CaO carbonization. Keywords: wastewater, flocculation, calcium oxide, treatment efficiency.
Article received 10 2002, given to print 12 2002. ISSN 1392-2335 Transactions of the Water Management Institute of Lithuanian University of Agriculture 2002, 21(43) INVESTIGATIONS ON THE PURIFICATION OF ORGANIC POLLUTANTS IN BIOLOGICAL PONDS Simanas ASKINIS Summary The article presents study results dealing with organic pollutants destruction in biological retention ponds. The study was carried out in domestic wastewater treatment facilities of Tiskunai village, in 1999-2002. The treatment facilities include a septic-tank and three retention ponds. It was determined that the discharge and pollution degree of wastewater from the settlement are strongly influenced by meteorological factors. Wastewater discharge fluctuated from 400 m3 /d during the snow thaw period up to 2.7 m3 /d during dry periods, and the pollution index was 14.6-203 mgO2/l according to BOD7. At the first stage of wastewater treatment process in a septic-tank the amount of organic pollutants is reduced on the average by 30.4%. The highest pollution coefficient of wastewater entering the first pond was 93.5 mgO2/l, the average one was 59.0 mgO2/l. During the last three years the biocenosis was finally formed in the ponds, therefore the amount of organic pollutants was reduced by 49.5% after wastewater had flown through the pond system. Wastewater that outflew the first, the second and the third ponds contained 44.8, 42.8 and 29.8 mgO2/l of BOD7 respectively. The warm period creates favourable conditions for a rapid reproduction of autotrophic microorganisms that uptake all oxygen contained in ponds, therefore domestic wastewater treatment efficiency decreases at that period. When the amount of total nitrogen increases in wastewater the treatment efficiency is reduced. The biggest amount of total nitrogen contained in wastewater from the settlement reached even 113 mg/l. In such cases much oxygen is uptaken during the nitrification process, while the oxidation process of organic pollutants does not experience the deficiency of this element. In spring 2002, a float was introduced into the ponds and wastewater surface was covered with leaves to slacken the reproduction of microorganisms by light deficiency. No positive effect was observed as the float covered the whole surface of ponds only in September. After the effectiveness of domestic wastewater treatment in all retention ponds had been compared, it was determined that each successive pond reduced the amount of pollutants. Obviously, it is possible to improve wastewater treatment efficiency by arranging another one shallow pond overgrown with macrophytes. Keywords: retention ponds, domestic wastewater, organic pollutants, dissolved oxygen.
Address: Article received 10 2002, given to print 12 2002. ISSN 1392-2335 Transactions of the Water Management Institute of Lithuanian University of Agriculture 2002, 21(43) INVESTIGATIONS ON LANDFILL LEACHATE AND ITS IMPACT ON THE ENVIRONMENT Valerijus GASIUNAS, Zenonas STRUSEVICIUS, Albertas STEPONAVICIUS Summary At present each district contains a number of legal and illegal landfills. A leachate is formed nearby the landfills, which later gets into ditches and streams and pollutes them. The leachate, comparing to domestic wastewater, contains a much higher pollutants concentrations that are predetermined by the age and arrangement technology of a landfill itself, the composition of wastes that it contains and climatic conditions. Three principal stages of landfill development are distinguished: acid-forming, transitional and methane-forming stage. Each stage is determined considering BOD5 and COD relationship. When the relationship is 0.4, there is an acid-forming stage, when it is 0.2, the stage is determined as methane-forming one. At the acid-forming stage the leachate contains the highest pollutants concentration. It was determined that Zabieliskis landfill leachate indices correspond to those indicating the acidic stage, as BOD5 and COD relationship here is 0.9. Organic pollutants concentration here is 5000-10000 mgO2/l by BOD7 and 6000-15000 mgO2/l by COD, the amounts of total N and total P are 430 and 11 mg/l respectively. Long-functioning landfills are usually attributed to methane-forming stage. This type of landfills include those in Babenai and Kairiai. Organic pollutants concentration of their leachate is on the average 120 mgO2/l by BOD7 and 500-1500 mgO2/l by COD. Total N amount is 57.1 mg/l in Babenai and 466.2 mg/l in Kairiai, total P concentration is 1.5-3.5 mg/l in both landfills. Leachate of the landfill situated in rural area contained rather small pollutants concentrations due to small amount of wastes and large territory for their distribution, which resulted in a quite satisfying dilution of wastewater. Average organic pollutants concentration of a leachate in Josvainiai landfill reached 25 mgO2/l by BOD7 and 108 mgO2/l by COD. Total N and P amounts were on the average 15.3 and 6.5 mg/l respectively. The change of leachate qualitative indices within a certain period of time is to be considered and evaluated before wastewater treatment technologies had been designed. Keyword: landfill, leachate, impact on the environment.
Address Dr. Zenonas Strusevicius,
Address Dr. Albertas Steponavicius,
Address Article received 10 2002, given to print 12 2002. ISSN 1392-2335 Transactions of the Water Management Institute of Lithuanian University of Agriculture 2002, 21(43) DEPENDENCE OF DRAINAGE RUNOFF ON THE THICKNESS OF HUMOUS SOIL LAYER Aloyzas DIRSE, Zigmas GALMINAS, Gintaras JUODINIS Summary The dynamics of drainage runoff for the period 1990-2000 under two top soil layer treatments with a thicker homous layer (up to 40-50 cm) and with a conventional one (20-30 cm) has been presented in the article. The investigations have been carried out in a small experimental field, occupied by derno podzolic soils, which covers an area of 3.4 ha. There has been determined that the thickness of humous soil layer influences the draining. Keywords: drainage, runoff, humus, yield.
Article received 10 2002, given to print 12 2002. ISSN 1392-2335 Transactions of the Water Management Institute of Lithuanian University of Agriculture 2002, 21(43) ANALYSIS OF FIELD INVESTIGATIONS CARRIED OUT ON DAM GEOHYDRODYNAMICS AT KAUNAS HYDROELECTRIC POWER STATION Vitas DAMULEVICIUS, Zenonas RIMKUS, Bronislovas RUPLYS Summary Kaunas hydroelectric power station (HEPS) is the only HEPS on the main Lithuanias river the Nemunas. It is the most powerful HEPS in Lithuania with the capacity of P = 100.8MW. In the paper the particularities of two different dams and field investigations of their geohydrodynamics are described. Data about piezometers installed in two dams on the left bank of the Nemunas river, their allocation and functionality are generalized. Measurement data of piezometric heads and seepage discharges are collected into electronic files in the form handy for statistical analysis. Data analysis is carried out and the files are presented to Kaunas HEPS administration for the collection of further electronic measurement data. In addition, measurement and research data were presented for another research phase the numerical simulation of the most actual fragments of Kaunas HEPS geohydrodynamics. Results of our research show that geohydrodynamics intensity is within a clear stabilization phase in the dams, their foundations and neighbouring territories. Attention is paid to the imperfection of currently applied method for piezometric head measurement, as the influence of HEPS upstream and downstream water level differences on piezometric head readings is not encountered at the measurement moment. To improve this method it is advisable to carry out a special study. Keywords: hydroelectric power station, geohydrodynamics, dam, drainage.
Address: Dr. Zenonas Rimkus
Address: Dr. Bronislovas Ruplys,
Article received 10 2002, given to print 12 2002. ISSN 1392-2335 Transactions of the Water Management Institute of Lithuanian University of Agriculture 2002, 21(43) ENVIRONMENTAL POLLUTION WITH STAINLESS STEEL CORROSION PRODUCTS Violeta GRAZULEVICIENE, Juozas MIKELAITIS, Jurate VEDEGYTE Summary The resistance investigation on various sorts on stainless steel, used in the manufacturing of chimney inserts, and solutions of sulphuric acid were carried out in this work. Corrosion intensity was rated by the decrease of mass in a steel sample and the loss of iron, chromium and nickel mass in samples processed by the solution of sulphuric acid. The corrosion intensity and the dependence of corrosion product composition on steel chemical composition and acid concentration in the solution were analyzed as well. It was determined that there were environmentally harmful metals such as chromium and nickel in the composition of stainless chromium-nickel steels and products of fuel burning gas reaction. Their amount in corrosion products depended on the type of steel and acid concentration in the solution. Those metals were found in the products that had formed on walls of steel inserts when burning wood and gas fuel. Keywords: stainless steels, chrome, nickel, corrosion products, environmental pollution.
Address Dr. Juozas Mikelaitis
Address Dr. Jurate Vedegyte
Address Article received 2002 10, given to print 2002 12. ISSN 1392-2335 Transactions of the Water Management Institute of Lithuanian University of Agriculture 2002, 21(43) Zoning of Lithuania according to real estate prices Audrius ALEKNAVICIUS, Marius ALEKNAVICIUS Summary Information of real estate market and prices is important privatising state land during the land reform, selling real estate, calculating real estate taxes, etc. This paper analyzes the main factors of real estate value. The real estate markets are very specific, so the analysis should be expressed graphically in maps. The data of transactions was taken from the Real Estate Register and was analysed in order to establish the connection between price and size of towns. The distance from district centre was also taken into account. The analysis shows the correlation among real estate price, size of towns and distance from district centres. The seasonal fluctuation of market activity is also observed. Zoning of Lithuania for preliminary appraisal of real estate is made taken into account the main value factors. The map shows towns classified according to size and value zones, where prices are high, medium and low. Keywords: real estate, research on real estate market, value map.
Address Marius Aleknavicius,
Address Article received 10 2002, given to print 12 2002. ISSN 1392-2335 Transactions of the Water Management Institute of Lithuanian University of Agriculture 2002, 21(43) THE ANALYSIS OF MODELLING RESULTS OF PANEMUNE ROAD INFLUENCE ON THE HYDRAULIC CONDUCTIVITY OF FLOODPLAIN Saulius VAIKASAS, Alfonsas RIMKUS Summary To improve road communication Pagegiai-Sovetskas between Lithuania and Kaliningrad district a new international detour road in the Nemunas delta is designed. Existence of this main road can adversely affect the hydraulic conductivity of the floodplain as well as the distribution and sedimentation of steady flood currents. The numerical hydraulic model "Delta" was used to select optimal variants for roadbed and hydraulic conductivity of new bridge openings. The results of modelling are analyzed in the article. It was determined that a new roadbed and bridge were necessary to be built as close to the junction canal "Uzlenke" as possible, which would reduce the area occupied by floodplain streams. Variant IVa was found to be an optimal one. The study results showed that inflow and outflow canals were necessary in order to increase hydraulic conductivity of bridge openings. Optimal parameters of these hydraulic structures were calculated and a possibility to use the excavated ground for the construction of road bed structures was discussed. Keywords: hydraulic conductivity of floodplain, bridges, hydraulic-mathematical modelling.
Address: Dr. habil. Alfonsas Rimkus,
Address: Article received 10 2002, given to print 12 2002. ISSN 1392-2335 Transactions of the Water Management Institute of Lithuanian University of Agriculture 2002, 21(43) CHEMICAL DECOMPOSITION OF SOME HEAVY METALS (Cu, Zn, Mn, Pb) IN SOIL AND SEWAGE SLUDGE COMPOST Nomeda SABIENE, Dalia Marija BRAZAUSKIENE, Valdas PAULAUSKAS Summary Certain concentrations of heavy metals are threatful for soil fauna and flora, soil fertility, crops, animals and human beings. Although the organic wastes, such as sewage sludge, applied on agricultural land might be useful for soil, possible environmental pollution hazard (e.g. odour, water pollution, veterinary hazard, contamination with heavy metals) has to be considered. After sewage sludge compost had been applied on the land, heavy metals might be taken up from soil by plants, ingested by grazing animals or leached into groundwater and surface water bodies. Mobility of heavy metals as well as their bioavailability in soil depend on soil texture, clay and organic matter content, acidity, their decomposing ability, also on the nature and specific properties of heavy metals ions. Apart from total values, specific chemical forms of heavy metals in which they occur in soil can be investigated by using different extractants and special extraction techniques. The aim of this research was to study decomposition process of selected heavy metals (Zn, Cu, Pb and Mn) according to sequential extraction procedure in sandy and clay soils as well as in sewage sludge compost. The obtained results showed that the amount of extracted heavy metals in various forms depended on matrix composition, pH, soil texture and metal chemical nature. Mobility of metals in soil was much lower than in sewage sludge compost. A greater amount of heavy metals in potentially mobile forms occurred in sandy soil to compare with clay soil. Cu and Pb, that are usually described as soil-related organic matter, mainly were observed in organically bound form in compost. Cu and Pb potential bioavailability, which can be calculated as the ratio of relatively mobile and extremely immobile forms, was low in both compost and soil, while the risk coefficients of Zn and Mn mobility were higher in compost as well as in soil. Keywords: environmental pollution, heavy metals, soil, sewage sludge compost, sequential extraction.
Address Dr. Dalia Marija Brazauskiene,
Address Dr. Valdas Paulauskas
Address Article received 10 2002, given to print 12 2002. ISSN 1392-2335 Transactions of the Water Management Institute of Lithuanian University of Agriculture 2002, 21(43) INFLUENCE OF MAGNETIC FIELD ON THE ACCURACY OF READINGS OF HOUSEHOLD WATER METERS Vladas VEKTERIS, Mindaugas JUREVICIUS, Juozas LAUCIUS Summary Research results on the accuracy of readings of household water meters with magnetic couplings affected by magnetic field are discussed in the paper. Water meters produced by different firms and imported into Lithuania during the last years were investigated. Selection peculiarities of magnetic field intensify for permanent magnets is described, methodology of experimental research is presented, varying factors are determined. Apart of that the scheme of experimental research stand and its characteristics are presented and its functioning is described. Research results and analysis show that water meters affected by magnetic field with the intensity of 70χ115 kA/m at minimal flow rates show no readings. At the rates up to 0.3 m3/h only the readings of two water meters exceed permissible errors. The readings of the rest five water meters do not exceed them. At flow rates up to 0.7 m3/h the readings of all water meters significantly exceed permissible errors. Conclusions are presented at the end of the paper. Keywords: measuring device, influence, intensity of magnetic field, error.
Article received 10 2002, given to print 12 2002. ISSN 1392-2335 Transactions of the Water Management Institute of Lithuanian University of Agriculture 2002, 21(43) CHANGES OF THE USE OF ARABLE LAND IN MIDDLE LITHUANIAN REGIONS Vaiva BRUSOKAITE-STRAVINSKIENE Summary During the last decade crop areas in Lithuania noticeably decrease. The greatest part of arable lands lies wasted, however, that is not reflected in statistics. Trying to determine factors evaluating the land use in Lithuania, the investigation on the real estate has been carried out in four regions of Middle Lithuania. A more thourough investigation on land use have been carried out in 6 cadastre vicinities of 5 local authorities. Having cartographed the limits of derelict (without crops) arable land areas in cadastre maps, the areas of this land have been calculated. The reasons of the unused arable land have been determined after having questioned people in local authorities, land management departments of the regions as well as the specialists preparing the land management projects at the land reform. The main reasons include the defects of reclamation systems, lands of little economical value, unfavourable farm structure. Keywords: agricultural land use, arable land, crops.
Article received 10 2002, given to print 12 2002. ISSN 1392-2335 Transactions of the Water Management Institute of Lithuanian University of Agriculture 2002, 21(43) HYDRAULIC MODELING OF ANAEROBIC WASTEWATER PLANT Midona DAPKIENE, Albinas KUSTA Summary Analysis of the state of anaerobic treatment plants in small settlements in Lithuania shows their operation efficiency to be insufficient. Results of anaerobic plant investigation indicate that a very small part of the plant volume is used, which influences the operation efficiency. As the results of the investigations in industrial areas were not precise enough the hydraulic modeling of anaerobic plant was carried out. In the course of investigations the distribution of flows in laboratory and semi-industrial models was revealed and coefficients of the usage of their volume were calculated. The investigation results presented in this article confirm bad distribution of wastewater in a reservoir due to inefficient operation of anaerobic plant. On the average only 25 % of semi-industrial anaerobic plant volume is used. The dependence of volume usage coefficient on discharge has been obtained. The arrangement of a hydraulic mixer in the conoidal part of the plant improves the distribution of wastewater in the reservoir. Keywords: anaerobic plant, wastewater retention time, volume usage coefficient.
Address Dr. habil. prof. Albinas Kusta,
Address Article received 10 2002, given to print 12 2002. ISSN 1392-2335 Transactions of the Water Management Institute of Lithuanian University of Agriculture 2002, 21(43) REGIME OF GROUND WATER AND CHARACTERISTICS OF POLLUTION IN KARST ZONE Aurelija RUDZIANSKAITE, Povilas SUKYS Summary The paper discusses the chemical composition of ground water in drained moraine sandy loam and peatbog of active karst zone. The dependence of the main plant nutrient concentrations on water level surface and its fluctuations, also on land use is presented in the paper. It was determined that, according to ion sum, ground water mineralization process in peatbog was 1.1-1.2 times more intense than that in ground water of loam soil. The highest, sometimes non-permissible for drinking water, nitrate nitrogen concentrations (>10 mg/l) were observed in ground water of arable land. 2-3 times lower nitrate nitrogen concentrations occurred in a pasture, the lowest ones (0.05-0.06 mg/l) were observed on the common edge of a wood and perennial grass field. Potassium and nitrate nitrogen concentrations depended on the fluctuation of ground water levels in mineral ground. The lower ground water level is, the higher potassium concentration is observed. Nitrate nitrogen concentration decreases during ground water subsidence phase, particularly in winter-spring period. However, such regularity is not characteristic to water concentrations in a borehole arranged near the karst sinkhole. Keywords: ground water, water level, concentration of chemical elements, characteristics of pollution.
Dr. assoc. prof. Povilas Sukys
Address: Article received 10 2002, given to print 12 2002. ISSN 1392-2335 Transactions of the Water Management Institute of Lithuanian University of Agriculture 2002, 21(43) ANALYSIS OF LOADS INFLUENCING REINFORCED CONCRETE SLABS STRENGTHENING SLOPES OF PONDS Raimondas SADZEVICIUS Summary Reinforced concrete strengthening slabs are the most popular coverage of slopes. In order to describe the type of the environmental impact on strengthening slabs, a number of initial data must be collected. Calculation techniques of reinforced concrete strengthening slabs in accordance with building standards and regulations of various countries were investigated. The advantages and disadvantages of each technique were discussed. The main conclusions were made:
Keywords: reinforced concrete slabs, wave and ice loads, analysis.
Address Article received 10 2002, given to print 12 2002. |
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