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Accumulation of sludge during the treatment of wastewater from milk processing companies and its application as a soil fertilizer
2005
Steponavicius, A.(Lithuanian Univ. of Agriculture, Kaunas (Lithuania). Water Management Inst.)E-mail:AlbertasStepanavicius@one.lt
The processing of milk in dairy companies produces a certain amount of wastewater and liquid wastes. During the treatment process of such wastes sludge is accumulated in treatment facilities. The sludge is a rather valuable soil fertilizer; however, apart from plant available nutrients, it also contains large amounts of pollutants. The paper analyzes the quality of wastewater treatment process performed in treatment facilities of dairy companies, and specifies the amounts of plant available nutrients contained in sludge accumulated during the treatment process of wastewater and liquid wastes. The amounts of heavy metals contained in sludge are compared with their maximum allowable concentrations determined in the environmental requirements for soil fertilization (Aplinkosaugos reikalavimai..., 2001). On the basis of the study results and normative documents of environment protection, the article presents optimal rates and regime for sludge fertilization as well as analyzes the agro-technical and qualitative characteristics of sludge spreaders made at the Water management Institute of Lithuanian University of Agriculture and used during the technological process of fertilization.
Afficher plus [+] Moins [-]The modelling of regional economical management of land reclamation works
2005
Saulys, V.(Lithuanian Univ. of Agriculture, Kaunas (Lithuania). Water Management Inst.)E-mail:valentinas@water.omnitel.net | Bastiene, N.(Lithuanian Univ. of Agriculture, Kaunas (Lithuania). Water Management Inst.)
According to EU Water Framework Directive, anew model of land reclamation management and financing will be developed. Taking into consideration the high vale of state investment required to ensure a steady work of land reclamation systems, it is important to reject the funds allocated on an equality principles and to give preference to the regions where the maintenance, rehabilitation and repair of these structures is more effective. The discussion concerning the allocation of state funds is elaborated in this paper. On the basis of statistical analysis, natural and economical regional differences were evaluated. Four scenarios of the allocation of special subsidies from state budget are submitted for approval. When modelling the financing results based on the regional distribution methodology, the changes in base financing indices are under discussion.
Afficher plus [+] Moins [-]Investigation and evaluation of the state of protective belts and inflow of erosion products into drainage channels
2005
Ragauskas, S.(Lithuanian Univ. of Agriculture, Kaunas (Lithuania). Water Management Inst.)E-mail:valentines@water.omnitel.net
As the result of the studies on the condition of protective belts of drainage channels (PB) have shown, due to improving maintained and mechanical damaged protective belts large amounts of erosion products contained in surface water inflows the channel bed. Disorderly condition of protective belts does not correspond to the requirements of environment protection. Mechanical damages are often related to unsustainable human activity in the adjacent zone of a drainage channel. According to the principles of soil occurrence in the channel bed, four groups of damages might be distinguished: soil entrance into the channel during the tillage of a protective belt; inflow of washout products from the basin; scours of protective belts and washout of turf flumes of surface water discharge. The most frequent damages enhancing the washout of flumes and inflow of erosion products are total or partial tillage of the protective belt of a drainage channel. From the point of view of erosion process, the inflow of erosion products from the basin is considered as the most dangerous damages, which is inevitable when the width of protective belt is insufficient, particularly in places with deep turf flumes arranged.
Afficher plus [+] Moins [-]Hydraulic capacity of vegetated drainage channels
2005
Poskus, V.(Lithuanian Univ. of Agriculture, Kaunas (Lithuania). Water Management Inst.)E-mail:pvaclovas@delfi.lt
The studies were carried out in two control profiles of the Graisupis ditch excavated 40 years ago and situated at the distance of 2.4 and 4.8 km from the outlet in the land of intensive farming in Kedainiai district. The study object contained mineral loam/sandy-loam soils on the flat relief. The areas of catchments in control profiles were 12.1 and 5.9 square km, the largest discharges of spring floods were 3.4 and 1.6 m**3sE-1. Cross-sectional parameters, grass characteristics and flow parameters were measured under the conditions of different discharges (6 replications in each control profile during the vegetation period and 4 replications in spring when the channel bed is clean). As the study results show, roughness coefficient of the grass-cowered channel bed increased up to 21 times, water tables were observed to be 20-40 cm higher, the outlets of the drainage were flooded up. Considering the average grass indices determined in control profiles, grass hydraulic resistance was calculated according to 4 formulas based on the scheme when grass cover resistance is estimated as the total resistance of separate obstructions. The difference of 22.3% between calculated results and natural measurements was determined. The formula estimating grass cover parameters as well as flow regime determined to be most suitable.
Afficher plus [+] Moins [-]Beta-glucan in hydrolysed soluble and insoluble oat fractions
2005
Gramatina, I.(Latvia Univ. of Agriculture, Jelgava (Latvia))E-mail:blijaa@cs.llu.lv | Kreicbergs, V.(Latvia Univ. of Agriculture, Jelgava (Latvia))E-mail:blijaa@cs.llu.lv
Oats contain more beta-glucan (2-7%) than other croppers. Beta-glucan is the most essential water-soluble dietary fibre. It lowers cholesterine level in blood as well as stimulates elimination of carcinogens from the body. In order to enlarge possibilities of use of oats in a diet, they can be separated in water-soluble and insoluble fractions. The aim of the present study is to determine the amount of beta-glucan in hydrolysed oat soluble and insoluble fractions. Gelatinized, hydrolysed and steeped oatmeal prior to hydrolyse, which was separated in water-soluble and insoluble fractions, was used in experiments. Not more than 6% of gelatinized (non-hydrolysed) oatmeal dry matter dissolved in water. The outcome of fermentative hydrolysed dry matter of water-soluble oatmeal was 40-52%. The content of beta-glucan in soluble and insoluble oatmeal fraction was determined by using McClearly method. The content of beta-glucan fraction of gelatinized oatmeal decreased for 78% in comparison to the content of beta-glucan in oatmeal used in the experiments. The content of beta-glucan in the soluble fraction of hydrolysed oatmeal decreased for 8.1% to 9.2%, and increased for 35-42% in the insoluble fraction if compared with the content of beta-glucan in oatmeal.
Afficher plus [+] Moins [-]The comparison of chemical pollution between organic and conventional milk
2005
Zagorska, J.(Latvia Univ. of Agriculture, Jelgava (Latvia)) | Ciprovica, I.(Latvia Univ. of Agriculture, Jelgava (Latvia))E-mail:inga.ciprovica@llu.lv
In Latvia have not been carried out comparable studies regarding chemical pollution in organic and conventional milk, therefore the aim of the present study was to investigate the level of contamination in organic and conventional milk samples by heavy metals and aflatoxin M1. A total of 9 organic bulk milk and 9 conventional bulk milk samples were collected from different regions of Latvia. The content of lead, cadmium, copper, iron, and zinc were detected by flame technique, using atomic absorption spectrophotometer (AAS). The level of aflatoxin M, in organic and conventional milk samples was determined by high-performance liquid chromatography. The means of lead concentration in organic and conventional samples were 0.024 and 0.31 mg kgE-1 wet weight that exceed the permissible level for such a product. The cadmium content in organic and conventional milk samples is very low and fairly constant in all types of milk. The legally accepted upper limits of iron, copper and zinc are not exceeded by any analyzed milk sample, not even from conventional bulk milk. The study including heavy metals and aflatoxin M1 in a range of organic and conventional milk samples found no significant differences between organic and conventional milk (p=0.05) in the level of aflatoxin M1 and the heavy metals.
Afficher plus [+] Moins [-]The dynamics of vitamin C and total carotenes content in pasteurized sea-buckthorn juice
2005
Seglina, D.(Dobele Horticultural Plant Breeding Experimental Station (Latvia))E-mail:seglina@ddsis.lv | Karklina, D.(Latvia Univ. of Agriculture, Jelgava (Latvia))E-mail:kada@cs.llu.lv
To select new sea-buckthorn hybrids and forms with increased content of biologically active substances, breeding work with sea-buckthorn hybrid seedlings is carried out in Latvia. The aim of this research was to study the vitamin C and total carotenes content in sea-buckthorn juice and its stability at different pasteurization temperatures with several durations. For study 6 sea buckthorn hybrids from 3 hybrid families were used. Vitamin C and total carotenes were determined in freshly made juice and with pasteurization at 65 deg C, 75 deg C and 85 deg C for 30, 20 and 10 minutes respectively. After processing the data obtained, it was found that vitamin C and total carotene content did not alter significantly depending on pasteurization temperature and duration. For further research 3-sea-buckthorn hybrids have been selected with the highest content of vitamin C and total carotenes.
Afficher plus [+] Moins [-]Dynamics of peroxide value in flavoured rapeseed oil
2005
Kruma, Z.(Latvia Univ. of Agriculture, Jelgava (Latvia))E-mail:zanda.kruma@llu.lv | Kreicbergs, V.(Latvia Univ. of Agriculture, Jelgava (Latvia)) | Karklina, D.(Latvia Univ. of Agriculture, Jelgava (Latvia))E-mail:kada@cs.llu.lv
Spices are used to season food products. Investigations were carried out to determine dynamics of primary oxidation products in flavoured rapeseed oil depending on used spice, its concetration, storage duration, and sample preparing method. The oil was flavoured with winter savoury Satureja Montana L., hyssop Hyssopus officinalis L., and marjoram Oreganum vulgare L. Results showed that dynamics of peroxide value in flavoured oils were influenced significantly (p is less than 0.05) by all investigated factors - used spice, its concentration, storage duration, sample preparing method, and interaction of these factors, too. Heating of oil in particular cases caused unusual, hard explainable dynamics of peroxide value. It is necessary to investigate optimal conditions of flavouring of oils and components of spices which can influence oxidation of flavoured oils.
Afficher plus [+] Moins [-]Immunoglobulins and lactoferrin concentration in milk and bacteria causing subclinical mastitis in dairy cows
2005
Kocina, I.(Latvia Univ. of Agriculture, Jelgava (Latvia))E-mail:iveta.kocina@pvd.gov.lv | Antane, V.(Latvia Univ. of Agriculture, Jelgava (Latvia)) | Lusis, I.(Latvia Univ. of Agriculture, Jelgava (Latvia))
Natural defence mechanisms of the mammary gland tissues play a vital role in protecting the gland from infections. The progress of mammary infection depends on the ability of bacterial pathogens to adapt to milk and udder tissues, and on the various virulence factors they activate, as well as on the cow's response. The levels of immunoglobulins (lg) and lactoferrin (Lf) concentration in the milk from dairy cows with and without subclinical mastitis were determined. In this investigation it was stated that 82.5% of samples were negative, but 17.5% of samples were positive for pathogens. Cows had subclinical mastitis caused by Coagulase negative staphylococci observed in 48.60%, Streptococcus uberis - 32.10%, Staphylococcus aureus - 18.90% of cases in milk samples. There were no significant differences between all classes of immunoglobulins concentration in the milk without pathogens and with pathogens. The lactoferrin concentration was significantly increased for 40.33% in the milk with pathogens.
Afficher plus [+] Moins [-]System modelling of the grain drying process
2005
Arhipovs, S.(Latvia Univ. of Agriculture, Jelgava (Latvia))E-mail:sergejs.arhipovs@llu.lv
One of the prior trends of research is the problem studies of power economy of technological processes and quality automatic control. Though the theory of grain drying process has been developed profoundly, still there are problems in its implementation. The developed analytical and simulation models of grain drying are difficult to implement into practice because they do not contain all the factors, which influence the real grain drying process or they cannot be solved. The developed models enable to assess only the essentiality of factors and/or the fundamental basics of the process. In order to ensure the effective and user-friendly grain drying process, it is indispensable to develop the control methodology using system modelling approach. The present paper deals with the system approach to heat and mass transfer problem and the testing of the basic hypothesis of the diffusion theory about the normal distribution of particles in the diffusive environment.
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