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HEAVY METAL ACCUMULATION IN DIFFERENT PARTS OF TREES GROWN ON SEWAGE SLUDGE Full text
2024
Paulauskas, Valdas | Kasiulienė, Alfreda
Sewage sludge is a rest product deriving from the wastewater treatment plants. It is rich in nutrients and essential elements. Therefore sludge on-land utilisation can create an added value by recovering energy from biomass produced on marginal lands. However, widespread on-land recycling of sewage sludge might be limited due to high heavy metal content. Health organisations show an increasing concern about the risks posed to the environment and human health as many countries worldwide already are facing the heavy metal contamination problem. In the scientific literature it can be found, that high total heavy metal content is not directly related to an intensive metal uptake by plants. In this study samples were collected from three woody plant species (black locust, silver birch and aspen) growing directly on the sewage sludge in a storage site near Kaunas, Lithuania. Heavy metal content was detected separately in the leaves, stems and roots. It was determined that nearly all analysed heavy metals (lead, chromium, nickel, copper and zinc) were accumulated within normal range despite high total concentrations in the growing media, and only cadmium was accumulated at elevated concentration. Based on bioaccumulation factor, aspen could be considered as a Cd-accumulator and used for phytoremediation purposes.
Show more [+] Less [-]IMPACT OF ICT USE ON TIME STRUCTURE OF ADVISORS WORK AT THE LITHUANIAN AGRICULTURAL ADVISORY SERVICE Full text
2024
Stabingis, Linas
Information and communication technologies (ICT) already several decades is an integral part of business management and accounting data processing. Scientific publications most cases deal with increase the efficiency of calculations and information processing, improvement the quality of accounting information systems, but very little attention is paid to changes in the behaviour of accounting staff resulted by the implementation of modern information processing technologies. Scientific problem is the measuring of impact of the modern information and communication technologies on behaviour of advisors in accounting. Paper provides the results of theoretical analysis of impact, made by ICT on changes in registration and processing of accounting transactions and competences are necessary for accounting specialist. Empirical investigation bases on analysis of the data received during questioning consultants in accounting and economics, working at the Lithuanian Agricultural Advisory Service about the structure of working time allocated for various tasks and on changes in the structure of working time due to the use of ICT.
Show more [+] Less [-]COMPARISON OF COSTS IN PRE-COMMERCIAL THINNING USING MEDIUM-SIZED AND SMALL-SIZED HARVESTERS Full text
2024
Kalēja, Santa | Zimelis, Agris
The aim of this study is to compare productivity and costs of medium-sized and small-sized harvesters in pre-commercial thinning. In this study the data on harvesting productivity were obtained in stands, where biofuel was prepared using two medium-sized and two small-sized harvesters equipped with different harvester heads. In total 677 m3 of wood was prepared with medium-sized harvester, but with small-sized harvesters 1 164 m3 of wood was prepared. Although the total annual costs of small-class harvesters are lower by 16 %, comparing with middle-class harvesters, the productivity rates shown by the middle-class harvester John Deere 1070 E (equipped with H 754 harvester head) are significantly higher and the average wood preparation costs are lower, comparing with the other harvesters employed.
Show more [+] Less [-]CUT-AWAY PEATLAND RE-CULTIVATION WITH FAST GROWING WOODY PLANTATIONS: COST-BENEFIT ANALYSIS. Full text
2024
Makovskis, Kristaps | Lazdina, Dagnija | Popluga, Dina
In Latvia peat production is historically important economic sector, giving significant contribution to rural economic development and providing work places in rural areas, where other job opportunities are limited. Every peat extraction field has certain lifespan, based on economic, social or ecological assumptions. Every peat field could be extracted for set period of time, after which peat extraction is not feasible any more. Current legislation in Latvia requires re-cultivating of places, where mineral resources, including peat, were extracted. Aim of the study is to evaluate afforestation as one of the cut-away peatland re-cultivation possibility. Economic analysis were done for extracted peat field afforestation with birch, black alder, grey alder, pine, spruce, hybrid aspen, poplar and willow. The economic calculations were done comparing different timber products from plantations, different planting materials and plantation lifespans. Lowest investment costs for plantation establishment on cut-away peatlands are for pine and spruce plantations and highest for willow plantations. Highest revenues in plantations with 20 years rotation cycle are in poplar plantations with 0.2 m cuttings and lowest in grey alder plantations. In plantations with rotation cycle 40 years highest revenues are in hybrid aspen plantations and lowest in pine plantations.
Show more [+] Less [-]MANAGEMENT OF SEPARATED MUNICIPAL WASTE FLOW IN KAUNAS CITY Full text
2024
Šileikienė, Daiva | Česonienė, Laima | Mažuolytė-Miškinė, Edita
Individual municipal waste streams of Kaunas (Lithuania) in the period 2012-2015 period was found that mixed municipal waste collected in the city of Kaunas municipality, prefabricated containers, compared to the 2012 decreases. 2015. Collect points mixed municipal waste are reduced from 118,065.56 tons to 100,470.6 tons, accounting for 15%. Biodegradable (green waste) quantities of green waste collection a site does not increase compared in 2012 and 2015. (in 2014 these waste was not collected). The decrease may be affected by that green waste is used boiler house that green waste for energy recovery. The recyclable waste separate secondary maximum (4.5 times) Increased quantities of collected waste paper, plastic positive capture an increase of 1.5 times. Glass collection containers steadily decreasing (from 2.46 tons 2012 to 1094 tons 2015). The trend to rise only noticeable only after complementary systems and DGASA (deposit system). In particular increased textile waste collection (up to 10 times). Toxic waste collection Kaunas City Municipality is constantly increasing tire (up to 2 times); waste containing mercury and packages containing hazardous substances (up to 3 times.). Electrical and electronic waste collection throughout the 2012 -2015 year. Period effective complementary systems (collected 99 % of such waste), but the amounts vary from year to year, and substantial growth was observed. Population change shows that especially affect the population of secondary separate paper (r= 0.994, p = 0.04), plastic (r=0.923, p =0, 0.047), tires (r=0.960, p =0, 0.040), and toxic waste (lamps, and hazardous materials) collection. According to the results it can be said that some of the waste (green, glass, electrical equipment) gathers a group of people decided to lead.
Show more [+] Less [-]MASTERING AGTECH AGAIN: EMERGING OF NEW TRAINING OFFERS AND INTERMEDIATE PLAYERS Full text
2024
Rizzo, Davide | Ritz, Simon | Combaud, Anne
Agricultural machinery manufacturers historically referred to the intermediate players for selling, maintenance, customer service and/or training of equipment appear to interact with farmers and end-users. Intermediate players have therefore faced the burden to master the technology, in constant evolution, and the associated training needs at the interface between a sophisticated equipment and the end-user and its sociological characteristics (age, education, background, etc.). However, the effective deployment of agricultural technologies data augmented equipment demands well trained players. How to ensure that the intermediate players have the required skills to integrate the use of agtech in the farm? This paper will discuss the role of educational and ongoing vocational training for the mastery of agtech. We will start from a comparative review of some key national and European technical reports in the agricultural equipment and innovation domains. On these bases, we will focus on France to describe the role of intermediate players of the agricultural equipment sector to realize their agricultural and digital transitions.
Show more [+] Less [-]CHEMICAL IMMOBILISATION OF TRACE ELEMENTS USING INDUSTRIAL BY-PRODUCTS Full text
2024
Kasiulienė, Alfreda | Paulauskas, Valdas | Zaleckas, Ernestas
. Alkaline soil additives used in this study, as cement kiln dust and lime mud, resulted in significant rise of the pH in contaminated soil and sludge mixtures, while buffering capacity of the sludge appeared to be much stronger than that of the soil. Total concentrations of the investigated trace elements in the tested samples in most cases were above limit values given in Lithuanian environmental normative documents HN 60:2015 and LAND 20:2005; Cd, Zn and Pb concentrations exceeding MPCs by 2-10 times. Nickel, cadmium and copper in the sludge appeared to be the most mobile elements, their EDTA-extractable fraction reaching 30-50% from the total. The tested industrial by-products in most cases significantly reduced trace element mobility. Immobilizing effect in the contaminated soil was from low to moderate, while impact on the reduction of Cd, Pb, Zn, Cr, Ni, As, Se, Hg mobility in the sludge was much stronger. Alkaline treatment was not so effective to reduce mobility of Cu and As in the soil, but immobilising effect of lime mud on these elements in the sludge was significant. A multivariate data analysis model with two principle components explained 94% of the data variation. The most distinctive factor, separating samples, was the origin of the two tested metal-rich substrates: contaminated soil and sewage sludge. Contaminated soil could be distinguished by high concentrations of As, Tl, Hg and Pb. Both alkaline treatments on sewage sludge were more effective, thus scores are further from the origin, although, difference between kiln dust and lime mud immobilising effectiveness was not so significant. Application of alkaline amendments: cement kiln dust and lime mud, proved to have strong immobilizing effect on the most of the investigated trace elements, and usage of local by-products for contaminated soil (sludge) remediation purposes could be seen as an environmentally friendly, cost-effective and safe disposal alternative.
Show more [+] Less [-]BIODEGRADABLE CHELANTS FOR HEAVY METAL REMOVAL FROM SLUDGE AND SOIL-SLUDGE MIXTURES Full text
2024
Paulauskas, Valdas | Zaleckas, Ernestas | Karnaukh, Oleksandr
Heavy metal extraction study was performed using five chelating agents with different biodegradability: EDTA, EDDS, MGDA, SCLC and citric acid. Aminopolycarboxylic acids EDDS and MGDA showed high heavy metal extraction capability from sewage sludge and sludge-soil mixtures. According to heavy metal removal efficiency investigated chelants can be ranked in the following order: EDTA≈ EDDS≈ MGDA> CA> SCLC. Extraction efficiency from sludge mixtures with clay soil was markedly lower than from the mixtures with sandy soil. Biodegradability of EDTA, MGDA, EDDS and CA was evaluated measuring BOD in water environment over 28 day period. According to the results of biodegradability test after 28 days the ranking order of the chelants was following: EDDS (99%)> CA (32.4%)> MGDA (29.2%)> EDTA (14.9%). Results showed that significantly easier than EDTA biodegradable chelating agents, such as EDDS and MGDA, can be successfully used for heavy metal removal from sewage sludge as well as metal-contaminated soil.
Show more [+] Less [-]Greenhouse gas emissions from livestock production in rural area of Algeria, the case of Chemini (Kabylie) Full text
2015
Moula, Nassim | Salhi, A. | Touazi, L. | Philippe, François-Xavier
peer reviewed | The Algerian agricultural sector faces the challenge to meet the food needs of its population despite low agricultural capacity, resulting in increasing pressure on natural resources. This paper aims to inventory the greenhouse gas (GHG) emissions related to livestock sector in the rural area of Chemini (province of Bejaia), taking into account the emissions due to enteric fermentation, in the form of methane, and manure management, in the form of methane and nitrous oxide. Emissions intensity, expressed in CO2- equivalents (CO2-eq) per kg of edible protein, was included in the study. Ruminants contribute to 94% of livestock GHG emissions and to 53% of protein production, with a large share due to cattle. The main part of emissions is related to enteric fermentation. High-producing cattle present the lowest emission intensity of the ruminant category with 24 kg CO2-eq per kg protein. Chickens produce 2.7% of livestock related emissions but provide 47% of animal protein. It results in low emission intensities whereas important difference is noticed between backyard and industrialized systems (around 21 versus 1 kg CO2-eq per kg protein, respectively). Improvement of animal performance should contribute to mitigate the environmental impact of livestock production in Algeria.
Show more [+] Less [-]Factors influencing the trade of local chickens in Kampala city markets Full text
2010
Emuron, Nathan | Magala, Henry | Kyazze, Florence B.||Kugonza, Donald R.||Kyarisiima, Connie C. | Kyazze, Florence B. | Kugonza, Donald R. | Kyarisiima, Connie C.
A study was conducted to determine the factors influencing the supply of live indigenous (local) chickens in Kampala city markets in December 2008. A total of fifty local chicken traders were randomly selected from five markets to respond to a structured questionnaire. Chicken trade was generally informal. Local chickens were mainly marketed alive in Kampala markets and the main customers were piecemeal consumers. The majority of the traders (52.9%) obtained local chickens from Eastern Uganda. Chickens were transported to markets in passenger vehicles, on motorcycles and on lorry trucks that were carrying cattle and other agricultural produce. This mode of transport sometimes caused injuries and bird mortality. Fifty percent of the traders obtained the chickens from middlemen while 46% of the traders personally bought the birds from rural farm households. Chicken trade was the major source of household income to 72.7% of the chicken traders and many of the traders had secondary sources of income. During peak seasons, the traders could sell an average of 120 birds per week per person. Local chicken marketing involved traders of varying levels of education (with a mean of 9.5 years of formal education). The number of local chickens traded per week was positively correlated (P<0.01) with the level of education of the traders. The demand for these chickens was highest in the festive months of December and April; and lowest in February and March. The cost of local chickens was more than twice as much as that of exotic chickens. Most traders (56.7%) perceived taste to be the basis for consumers’ preferential demand for local chickens in preference to exotic chickens. The major constraints in the marketing of local chickens in Kampala city markets were identified as high mortality rates/chicken diseases (43.5%), costly transport (22.4%), and irregular demand (15.3%). The study revealed that there was a high potential for the development of local chicken trade in Uganda. Designing solutions for the constraints of local chicken marketing would act as a tool for poverty alleviation not only to the rural chicken farmers but also the traders.
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