خيارات البحث
النتائج 1 - 8 من 8
Metal uptake from contaminated soils by some plant species - radish, lettuce, dill
2013
Stapkevica, M., University of Latvia, Riga (Latvia) | Vincevica-Gaile, Z., University of Latvia, Riga (Latvia) | Klavins, M., University of Latvia, Riga (Latvia)
Plants are components of ecosystem that transfer elements from abiotic to biotic environments. Several elements, such as As, Cd, Hg, Pb, can be considered as food chain contaminants. Simultaneously, some essential micronutrients (e.g., Cu, Cr, Ni, Zn) at high concentrations may become toxic to both, plants and animals. To secure the aim to describe the uptake of metals by food crop species such vegetables, as radish Raphanus sativus L., leafy lettuce Lactuca sativa L. and dill Anethum graveolens L., were grown in soils of various grading composition and type. There were five soil types selected. A part of soils was contaminated with copper sulphate solution at different target concentrations, while another part was contaminated with mixture of metal (Pb, Cd, Cu, Zn) compounds. In half of treated soil samples the solution of humic substances was added. Harvested vegetables were dried, and after wet digestion with nitric acid quantitative analysis of metal concentrations was performed by use of atomic absorption spectrometry. The highest concentration of copper was detected in vegetable samples grown in soils with less organics, thereby indicating the importance of soil organic matter to metal transfer routes and accumulation rates in plants. Analysis of lettuce grown in soils contaminated with the mixture of metal compounds revealed that zinc was a metal absorbed more intensively, but metal uptake and accumulation was less intensive from peat if compared with other soils.
اظهر المزيد [+] اقل [-]Contamination problems in former military areas: case study in Riga [Latvia]
2012
Burlakovs, J., University of Latvia, Riga (Latvia) | Gorbunovs, E., University of Latvia, Riga (Latvia)
Contamination of urban areas is directly connected with the lack of adequate waste management planning. Problems mostly arise in former military bases, garages, warehouses and areas with other facilities. For many decades environmental problems caused by pollution in areas of military use were not managed in Latvia. The aim of this research is to assess visual environmental quality and study heavy metal contents in soil of ‘Jaunais Mežaparks’ after demolishing works in the capital of Latvia – Riga, as well as to provide comparison to the former military ‘Daugavgrīva’ site. Research was carried out from November 2011 to February 2012 by soil sampling and further analysis and comparison of the heavy metal content in soil with target and boundary levels in legislation. ‘Jaunais Mežaparks’ is a former military area which is planned to be reused in future. The former military site is planned to be used as the residential neighborhood and is situated close to important recreational object in Mežaparks area – Lake Ķīšezers. According to Riga Development Plan old military sites must be remediated in accordance with environmental legislation if the contamination exceeds critical concentration values. Thus, this case study includes assessment of visual pollution as well as soil heavy metal contamination study. Recommended actions as well as direct remediation technologies to reduce the poisonous impact of contamination to environment in this area are proposed.
اظهر المزيد [+] اقل [-]Removal of heavy metals from contaminated soils by electrokinetic remediation
2014
Burlakovs, J., University of Latvia, Riga (Latvia) | Stankevica, K., University of Latvia, Riga (Latvia) | Hassan, I., Western University, London, Ontario (Canada) | Janovskis, R., University of Latvia, Riga (Latvia) | Lacis, S., University of Latvia, Riga (Latvia)
Heavy metals as well as other pollutants are widespread and create deleterious impact to the environment and human health. There are different in situ and ex situ technologies of immobilization and removal of contaminants; electrokinetic remediation is one of such technologies. It can be applied for treatment of wide areas, e.g., former industrial and military firing-grounds. Technology is applicable to water soluble contaminants at sites with homogeneous soils that are fine-grained and exhibit both, high permeability and high moisture contents. The aim of the study was to test the efficiency of electrokinetic remediation for copper contaminated clayey soil in laboratory conditions. Pilot scale experiments were applied to test the efficiency of electrokinetic removal of contaminants from soil by application of low voltage direct current (DC). Experimental results show that the use of DC power can be selected for treatment of heavy metal contaminated soils. Batch scale experiments were done by using clayey soil with known physico-mechanical properties, spiked with copper solution of known concentrations. Electric force was changed by varying its parameters. The article gives batch experimental results for diffusion of copper ions in soil under the influence of the external electric field.
اظهر المزيد [+] اقل [-]In-situ phytoremediation: a review of natural and chemically assisted phytoextraction
2013
Kasiuliene, A., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania) | Paulauskas, V., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania)
There are about 3,000-4,000 heavy metal contaminated sites across Lithuania. According to Lithuanian legal framework, the only way to manage this pollution is ex-situ cleaning which requires excavation, transporting, storage place and later monitoring. This indicates the urgent need of innovative technologies that would be not only costeffective but also environmentally friendly and have a public acceptance. Such technologies are natural and chemically enhanced phytoextractions. Both technologies incorporate plants that can accumulate excessive amounts of heavy metals. During continuous phytoextraction plants accumulate heavy metals throughout all vegetation period and are harvested together with heavy metals when desired biomass is gained. At chemically assisted phytoextraction metal binding chelates are added to increase heavy metal uptake by plants. Since phytoextraction is considered as promising green technology, many efforts are laid to find the most suitable hyperaccumulator plants as well as ecologically safe chelating agents. This paper intends to overview latest researches done at phytoextraction field and look over this kind of remediation possibilities in Lithuania.
اظهر المزيد [+] اقل [-]Leaching of heavy metals from soils stabilized with portland cement and municipal solid waste incineration bottom ash
2013
Burlakovs, J., University of Latvia, Riga (Latvia) | Arina, D., Latvia Univ. of Agriculture, Jelgava (Latvia) | Rudovica, V., University of Latvia, Riga (Latvia) | Klavins, M., University of Latvia, Riga (Latvia)
Heavy metals are worldwide spread pollutants in soils of functioning as well as abandoned industrial territories, landfills, military areas with its historical contamination, and other sites contaminated by industrial activities. Development of soil and groundwater remediation technologies is a matter of great importance to diminish the hazardous impact of pollution to humans and environment. Sustainable solution can be found for remediation of industrial areas using the stabilization/solidification (S/S) technology, which refers to binding of waste contaminants to a more chemically stable form. Geotechnical properties of soil treated with Portland cement (PC) can be improved when municipal solid waste incineration (MSWI) ash is used as the combined additive. Ash is composed mainly of metals, so environmental impact must be evaluated if it is used as amendment in the cement industry. The use of MSWI ash in stabilization of contaminated soils would be useful for the sustainable environmental management in two ways: S/S contaminated soil gains better geotechnical stability and waste incineration industry gets rid of the ash with high metal content. The aim of research is to provide pilot batch experimental results for leaching of heavy metal compounds when S/S technology is used for contaminated soils using PC and MSWI bottom ash additives. Mineral soils were spiked with copper, PC and MSWI were added in known proportions and leaching tests applied. Main results show that PC addition allows to chemically stabilizing soil; thus, heavy metals are not leached out from combined mass of spiked soil and MSWI bottom ash.
اظهر المزيد [+] اقل [-]Impact of the fields, fertilized with manure from big livestock companies on drainage water quality
2013
Miseviciene, S., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania)
The paper presents data on the water quality in drainage from manure-fertilized areas in a large livestock company (629 conditional livestock) from 2008 to 2012. The scheme of investigation consists of two field variants: manure fertilized and non-fertilized. Researches are carried out in drained areas, where the drainage water is drained away through outlets. The nitrogen rate 170 kg haE-1 is used annually to fertilize fields in spring. The aim of the research was to ascertain the impact of large livestock company fields fertilized annually with manure on the water quality in drainage. For the purpose of chemical investigations, water samples from drainage were taken once per month. Water analyses were carried out by the accredited Chemical Analytical Laboratory of the Water Management Engineering Institute of Aleksandras Stulginskis University according to specified methods. Investigation results have demonstrated that fields fertilized annually with manure raised the contents of Nmin and P2O5 in the soil by 1.5 and 2.2 times respectively in comparison to the non-fertilized ones. The increase in these contents was conditioned by the higher air temperature and the lower rainfall. The seasonality of Ntotal concentrations in drainage water was discovered: higher concentrations were identified in autumn and winter, lower concentrations – in spring and summer. Due to low dissolubility in the soil, low Ptotal concentrations were identified in drainage water. The highest concentrations were identified with the start of drainage operation.
اظهر المزيد [+] اقل [-]The influence of different soil use practice on mineral nitrogen cycle in agroecosystem
2011
Guzys, S., Lithuanian Univ. of Agriculture, Vilainiai, Kedainiai (Lithuania). Faculty of Water and Land Management. Water Research Inst.
The investigations were carried out in the Lithuanian Agricultural University Water Research Institute land plots in the Endocalcari Endohypogleyic Cambisols (CMg-n-w-can). The basis of the investigation is 3 variants field experiment. Each variant consists of 3 in 0.54 ha drainage. The traditional arable farming is applied in variant I. In the variant II the land is not being cultivated, but in spring the perennial ryegrass (‘Lolium perenne L’) is being seeded into the spring barley and kept till spring. In the variant III the land is not being cultivated after the harvest and left for the rest till spring. The variant II is distinguished by the minimal mineral nitrogen content. Applied to cultivated and uncultivated land, the min N reserves are increased 51 - 83 and 33 - 40 and 11 - 101 and (38 - 134%) (to 9.5 - 14.3 mg kgE-1 and 152 - 68 and 154 - 61 kg haE-1). The average investigation of N concentration in the drainage water shows, that the minimum concentration of this element was in the second variant. Applied to the traditional farming and uncultivated land, the N concentration is increased by (30 - 42% to 34 and 37 mg lE-1). By average data the min N, leaching by drainage water in the variant II was minimal and about 27 kg haE-1. Applied to the arable farming and uncultivated land, the min N leching is increased (30 - 55%) (to 35 - 42 kg haE-1).
اظهر المزيد [+] اقل [-]Phytoremediation as tool for prevention of contaminant flow to hydrological systems
2018
Valujeva, K., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Burlakovs, J., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Grinfelde, I., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Pilecka, J., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Jani, Y., Linnaeus Univ. (Sweden) | Hogland, W., Linnaeus Univ. (Sweden)
This paper aims to deal with the phytoremediation approach for protection of environment and preventing the streaming of contaminant flows to hydrological systems. Phytoremediation is a cost-effective environmentally friendly clean-up technology, which uses plants and microorganisms in rhizosphere for soil and groundwater treatment. Phytoremediation is enhancing degradation of organic pollutants and improving stabilization of inorganic contaminants where plants can be used to treat soil and water polluted with hydrocarbons, chlorinated substances, pesticides, metals, explosives, radionuclides as well as to reduce the excess of nutrients. Selection of species for this type of treatment processes is based on evapotranspiration potential and ability to bioaccumulate contaminants. The project entitled “Phytoremediation Park for treatment and recreation at glassworks contaminated sites” (PHYTECO) aimed at cross-sector international partnership. The challenge of project was to develop remediation strategy where negative consequences from centuries long anthropogenic influence are turned to be something positive – development of the recreation park from the glass dump. New “Knowledge in Inter Baltic Partnership Exchange for Future Regional Circular Economy Cooperation” (PECEC) project is sequential continuation.
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