Relevant resources for renewable biomass fuel production are wood, cereal straw residues, and emergent vegetation from wetlands. Peat is an important slowly renewable biomass fuel too. Using blended peat and woody or herbaceous biomass, sulphur content of the fuels is increased and, if the mixture is burned, sulphates are formed instead of chlorides, and the risk of high temperature corrosion is avoided. The loading, storage container discharging, mixing and automatic feeding process depends on internal stresses acting in the biomass volume. To estimate vertical stress in silos, a mathematical model was built. Vertical stress in the opening of the silo hopper reaches 1.4 kPa if the diameter of a silo is 0.4 m, but for the diameter of 2 m it is possible to obtain even 7.2 kPa. Increase of the coefficients lambda and mu to the maximal values (lambda = 0.6; mu = 0.5) decreases vertical stress for more than 70%.

The paper presents the investigations performed by Water Management Institute of Lithuania University of Agriculture on the pollution and treatment efficiency of wastewater formed in an up-to-date slaughterhouse built in 2003. Wastewater is canalized from the slaughterhouse by red and green sewerage systems. Initially the wastewater is pre-treated in a fat separator, further treatment process is performed in physical-chemical treatment facilities and settling ponds. After primary treatment, the wastewater is directed into two-stage constructed wetlands of horizontal flow. The wastewater in slaughterhouse is about 4-5 times more polluted than domestic wastewater containing even 20 times higher for concentration. During the primary treatment process (fat separator + physical-chemical treatment device + settling pond), from 73.1 to 98.9% of pollutants are removed. After primary treatment, indices of wastewater are similar to those of domestic wastewater: pH - 8.5, biochemical oxygen demand (BOD5) - 98 mg lE-1 of O2, Ntotal and Ptotal - 46 and 8.9 mg lE-1 respectively. After biological treatment in two-stage constructed wetlands of horizontal flow, the wastewater satisfies the environmental protection requirements according to organic (BOD5) and biogenic (Ntotal and Ptotal) pollutants and thus may be realised into the environment. Regression dependencies of medium and strong relation (R**2=0.503-0.893) of pollutants BOd5, SS (suspended sediments), Ntotal and Ptotal in treated wastewater on the total of constructed wetlands have been determined.

In the process of biological wastewater treatment, P-removal is efficient enough when the concentration of organic pollutants according to BOD5 (biochemical oxygen demand) is no higher than 190 mg lE-1 of O2 and its relationship with phosphorus does not exceed 20. Having studied the composition of wastewater from dairy farms it was determined that wastewater pollution according to BOD5 is from 800 to 900 mg lE-1 of O2 and the ratio of BOD5/Ptotal is 30-36. The paper gives the results of the tests on P-removal from wastewater carried out in a laboratory model. During investigations wastewater was flowing via mineral filters (filtralite P (FLP), zeolite (CE), and shulgite (SG)). Total amount of Ca, Fe and Al oxides contained in those filters were 23.0, 16.1 and 7.9% respectively. The rates of P-removal from wastewater in the filters were as follows: 88.5% (FLP), 45.5% (CE), and 96.3% (SG). Considering different hydraulic load, P-mass balance was calculated. The calculation results showed the following P absorption amounts: FLP - 5.08 g dE-1, CE - 1.76 g dE-1, and SG - 3.91 g dE-1 (calculated for 1 m**3 of each filter). Wastewater filtration through mineral media resulted in the removal of other pollutants, too: organic pollutants removal (according to BOD5) was 30.8 to 72.5%, and the removal of nitrogen compounds (more than 90% of which were in the form of ammonium salts) was even 93.2% in CE filter.

In the paper there are described problems of sewerage system in Riga which essentially impede its normal functioning. There are analyzed operation regimes of two principal pumping stations which pump all wastewater of Riga to the purification plants (2001-2005). The main focus is on implementing different measures that would improve collection and pumping of wastewater. It is offered to build a third penstock from the Voleru chamber to the purification plants. It is suggested to separate the rainwater from the household wastewater. There are analyzed 11 different versions of pump operation. In the conclusions and recommendations the formation of the possible dangerous situation during heavy downpours is demonstrated. It is recommended to build a regulation reservoir near the purification plants which could essentially protect the Daugava from unpurified wastewater during the downpours.

The paper discusses the peculiarities of hydrological and hydro-chemical regime of ground water in shallow wells and boreholes in moraine soils of active karts zone. It was determined that the fluctuations in water levels in boreholes and wells have the same tendencies: water was closest to the ground surface when the air temperature was increasing in the cold period (November-March) and decreasing in the warm period (April-October) pf the year. Chemical composition of water in boreholes (sum of ions) was up to 1.2 times lower than that in well water. This was determined by higher sodium, sulphates, and chlorine and nitrates amounts. When water level is decreasing, water chemical composition is increasing in water of wells and boreholes. It was determined that water in wells was contaminated with nitrate nitrogen; water in boreholes was polluted with ammonia nitrogen.

The paper presents the analysis of legal acts and normative documents regulating the management of surface (rain) wastewater in Lithuania. On the basis of the results, the investigations on treatment efficiency of pollution of surface wastewater accumulated in the territory of the cattle and pigs slaughterhouse of Krekenavos mesa Ltd were carried out. Having applied differentiated runoff coefficients calculations of the dependence of wastewater amount territory of the company were suggested. According to the monitoring program, wastewater pollution indices and investigation frequency were determined in respect of the requirements of surface water monitoring. Wastewater pollution dynamics in treatment facilities of the company was estimated. As it was determined, the main index specifying treatment necessity of subsurface wastewater accumulated in company's territory is suspended solids. Considering this index it was determined that maximum wastewater pollution exceeded the determined rate of environmental requirements 2.13 times within the study period. After treatment in the facilities, the average wastewater pollution with suspended solids decreased from 31.44 mg lE-1 to 8.67 mg lE-1. Other pollutants concentrations contained in wastewater were insignificant and did not exceed the rate determined in the environmental requirements, thus they may be released into open water bodies. It was also determined that the average amount of suspended solids contained in the Upyte stream reached 17.55 mg lE-1. Considering this index, pollution of wastewater outlet is 50.6% lower than the background pollution of the stream.

The paper presents the test results of studies on the treatment of wastewater in experimental treatment facilities in a milk collecting station. The treatment process of wastewater was a follows: aeration-flocculation device -sedimentation pond - two-stage constructed wetlands. The laboratory investigations have shown that the primary treatment with quicklime (1 kg mE-3) reduces wastewater pollution by 54%, while the treatment with coagulant 'ZETAG 8660' (4 g mE-3) reduces it by even 68%. Such results were not obtained in the primary wastewater treatment stage under industrial conditions: biological oxygen demand (BOD5) in wastewater was reduced 27.2%, the amount of suspended sediment was reduced by 48.1%, the amounts of Ntotal and Ptotal decreased by 15.8% and 27% respectively. Such results much depended on the air temperature, inaccurate dosage of chemicals as well as on insufficient capacity of reaction and sedimentation reservoirs for 2.5 times higher amount of wastewater. However, despite such unfavourable conditions, this stage of treatment process was rather efficient: the pollution of wastewater with organic matter flowing into the stream did not exceed the maximum allowable rates. The average value according to BOD5 was 4 mg O2 lE-1, the highest BOD5 value was 9.6 mg O2 lE-1. From the environment protection point of view, it is particularly important that the removal of biogenic pollutants is quite sufficient in the wastewater treatment facilities. After the treatment process in wastewater treatment facilities, the amount of Ntotal decreased by 82.4% and the amount of Ptotal was reduced by even 97.3%.

This article analyzes the experience of economic clustering of Finnish industry. This experience is described in the report of the fundamental investigation which was carried out by the Research Institute of the Finnish Economy (ETLA) - Advantage Finland - The Future of the Finnish industries. The study deals with the competitiveness and future growth prospects of the Finnish industry on the basis of Michael E. Porter's theory of the competitive advantage of nations. The comparative advantage of Finnish industries has been moving from capital-and resource-intensive branches to those driven by know-how and technology. The author recommends to study this experience and to use it in Latvia. The finding of the real and potential business-groups in the economy of Latvia may be realized with the algorithm of clustering described by the professor of Colombian University (USA) David Stark on the base of Lursoft data of the Latvian enterprises.

The efficiency of solving of the state environmental protection policy and implementation of the environmental problems are closely related to identification of the existing problems of the environmental protection in a definite territory. In the rural territories this process depends on the process of agricultural production. In the society, alongside with the opinion about necessity of sustainable development there is also an opinion that the primary goal is to attain total economic increase even if it can damage the environment itself. Analyzing definite indices of the effect of agriculture on the environment, it is possible to evaluate changes in the development of the branch and the environmental condition as well as their mutual interrelation.

The article is meant to analyze the methodological qualitative characteristics of the creation of employees' motivation. These characteristics help to measure the reliability of research instruments. In accordance with Kendal ranking correlation (Henning, 1997) there are identified motivation indicators of managing employees and executives. The main attention is paid to the importance of motivation models' shaping and the essential principles by giving the results of model shaping and their interpretations.