| 1. |
- Danila, Vaidotas, et al.
(author)
-
Immobilisation of metal(loid)s in two contaminated soils using micro and nano zerovalent iron particles : Evaluating the long-term stability
- 2020
-
In: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 248
-
Journal article (peer-reviewed)abstract
- The aim of this study was to compare the immobilisation of metal(loid)s in two differently contaminated soils using micro zerovalent iron (ZVI) and nano zerovalent iron (nZVI) particles. Chromated copper arsenate-contaminated soil contained high amounts of As, Cu, Cr, and Zn, whereas mining-contaminated soil contained high amounts of As, Cu, and Pb. Contaminated soils were amended using 2% ZVI and nZVI. As determined by the leaching procedures, nZVI was more efficient in immobilising all the studied metal(loid)s in the soils compared to ZVI. The greatest immobilisation was achieved for As in both soils. The long-term stability of immobilised metal(loid)s was studied in mining-contaminated soil by performing thermal oxidation (ageing). In the ZVI and nZVI-treated soils, high retention results were achieved for As and Cu, whereas in the ZVI and nZVI-treated soils, significant desorption of Pb was observed. The results also showed that retention of metal(loid)s over a long period of time could be more effective in soils treated with ZVI, as the crystallisation of Fe in ZVI-treated soil was to a lesser extent compared to the crystallisation of Fe in nZVI-treated soil.
|
|
| 2. |
- Kasiuliene, Alfreda, et al.
(author)
-
Accumulation of heavy metals in forest dwarf shrubs and dominant mosses as bioindicators of atmospheric pollution
- 2019
-
In: Journal of Elementology. - Olsztyn : Polish Society for Magnesium Research. - 1644-2296. ; 24:3, s. 1079-1090
-
Journal article (peer-reviewed)abstract
- This article discusses the environmental concerns about heavy metal accumulation in dominant forest mosses and dwarf shrubs. Samples of two different species of mosses, such as glittering wood moss (Hylocomium splendens) and feathermoss (Pleurozium schreberi), and two species of dwarf shrubs, that is European blueberry (Vaccinium myrtillus) and lingonberry (Vaccinium vitis-idaea), were collected from specifically chosen areas with evident anthropogenic pollution (vicinity of an airport and close to heavy road traffic) and from contamination-free, secluded forest areas in Lithuania and Sweden. Instrumental analysis of heavy metals, including cadmium, chromium, copper, lead and zinc, revealed that the selected plant species tend to accumulate zinc and copper the most and chromium the least. Forest mosses, used as indicators of airborne pollution, accumulated less heavy metals than dwarf shrubs, indicating more metal accumulation from the soil. The results also revealed that forest, dwarf shrub leaves even picked from areas with known anthropogenic pollution sources were safe to use. since concentrations of cadmium and lead remained below the maximum permissible level. A multivariate data analysis model with two principle components explained more than 70% of the data variation. The heavy metal content in soil was the most distinctive factor separating the Lithuanian and Swedish sites. Cadmium and chromium soil contents were more significant in the Lithuanian soils, whereas copper, lead, and zinc were more significant in the Swedish soils.
|
|
| 3. |
- Kasiuliene, Alfreda, et al.
(author)
-
Chelant-Assisted Accumulation of Cd, Cu, and Zn in Rapeseed (Brassica napus L.) Biomass as a Renewable Energy Feedstock
- 2016
-
In: Polish Journal of Environmental Studies. - : HARD Publishing Company. - 1230-1485 .- 2083-5906. ; 25:5, s. 1985-1993
-
Journal article (peer-reviewed)abstract
- This article discusses the environmental concerns regarding soil contamination by heavy metals and the possibility of growing a high biomass-yielding crop (i.e., rapeseed) as a tool of phytoremediation. The aim of our research was to investigate the growth parameters and the capacity of rapeseed to accumulate Cd, Cu, and Zn from the contaminated soil and to investigate the effects of the chelants (EDTA, EDDS) as potential heavy metal mobility-enhancing agents. A pot experiment was performed under greenhouse conditions where rapeseed was grown on heavy metal-contaminated soil taken from former septic drain fields. Chelants were applied twice using doses of 3 mmol kg(-1) of wet soil weight. Plants from contaminated soil produced more biomass and heavier seeds. The highest Cd concentrations were detected in rapeseed stems and leaves: Cu in roots and Zn in seeds and stems with leaves. Rapeseed in some cases exhibited translocation factor values for single plant parts greater than unity, whereas the bioconcentration factor was always below unity. Detected concentrations of Cd, Cu, and Zn in the biomass indicate that rapeseed may be considered an excluder rather than accumulator. Chelant application did not provide the expected enhancing effect on heavy metal uptake by rapeseed.
|
|
| 4. |
- Kasiuliene, Alfreda, et al.
(author)
-
Hydrothermal carbonisation of peat-based spent sorbents loaded with metal(loid)s
- 2019
-
In: Environmental Science and Pollution Research. - : Springer. - 0944-1344 .- 1614-7499. ; 26:23, s. 23730-23738
-
Journal article (peer-reviewed)abstract
- Hydrothermal carbonisation (HTC) is a wet and relatively low-temperature process where, under autogenous pressures, biomass undergoes a chain of reactions leading to the defragmentation of organic matter. As well as its other uses (e.g. for producing low-cost carbon-based nano-compounds), HTC is utilised for the treatment of wet wastes, such as manure and biosludge. This study aimed to determine if hydrothermal carbonisation is a feasible treatment method for spent sorbents that are highly enriched with arsenic, chromium, copper, and zinc. The chemical properties of hydrochar and process liquid were evaluated after HTC treatment, where peat-based spent sorbents were carbonised at 230 °C for 3 h. Analysis of Fourier transform-infrared spectra revealed that during HTC, the oxygenated bonds of ethers, esters, and carboxylic groups were cleaved, and low-molecular-weight organic fragments were dissolved in the process liquid. A large fraction of arsenic (up to 62%), copper (up to 25%), and zinc (up to 36%) were transferred from the solids into the process water. Leaching of these elements from the hydrochars increased significantly in comparison with the spent sorbents.
|
|
| 5. |
- Kasiuliene, Alfreda, et al.
(author)
-
Influence of nitrogen fertilizer on Cd and Zn accumulation in rapeseed (Brassica napus L.) biomass
- 2016
-
In: Agronomy Research. - 1406-894X .- 2228-4907. ; 14:2, s. 418-427
-
Journal article (peer-reviewed)abstract
- Diffuse soil contamination with heavy metals and Cd in particular is a matter of serious concern. Application of conventional remediation methods usually is not feasible due to the large territories and relatively low heavy metal content. Thus, phytoremediation is seen as an alternative. Rapeseed was grown on Cd and Zn contaminated as well as clean soil under the greenhouse conditions. Solid and liquid nitrogen fertilizers were applied during the pot experiment in order to test their influence on heavy metal accumulation in plant tissues. Vegetative parameters were measured four times during the pot experiment and it was concluded, that the elevated concentrations of Cd and Zn in the soil did not disrupt the development of rapeseed plants. Furthermore, plants from contaminated soil produced significantly bigger seeds in comparison to plants from uncontaminated soil. Calculated Bioconcentration factors for rapeseed grown on Cd and Zn contaminated soil in all cases were below unity, thus possibility to use this plant species for phytoextraction purposes is limited, but it can be successfully grown on contaminated land as an energy crop. Application of nitrogen fertilizers had a significant effect on heavy metal accumulation and decreased Cd and Zn concentrations in rapeseed roots and stems with leaves were recorded. Accumulation differences between the liquid and solid fertilizer applications were negligible.
|
|
| 6. |
- Kasiuliene, Alfreda, et al.
(author)
-
Iron coated peat as a sorbent for the simultaneous removal of arsenic and metals from contaminated water
- 2018
-
In: Environmental Arsenic in a ChangingWorld - 7th International Congress and Exhibition Arsenic in the Environment, 2018. - London : CRC Press/Balkema. - 9781138486096 ; , s. 439-440, s. 439-440
-
Conference paper (peer-reviewed)abstract
- This study aimed at combining peat, an industrial residue, with Fe(II)-Fe(III) compound to produce a sorbent suitable for a simultaneous removal of arsenic (As) and metals (cadmium, copper, nickel, lead, zinc) from a contaminated water. Using a newly produced sorbent – iron-peat – the removal of As from contaminated water was almost 17 times higher than using an uncoated peat. On the other hand, the removal of metals by the iron-peat was slightly less efficient in comparison to the uncoated peat. Simultaneous removal of As and metals could be seen as an advantage over multiple-step treatment of contaminated groundwater.
|
|
| 7. |
- Kasiuliene, Alfreda, et al.
(author)
-
Leaching of metal(loid)s from ashes of spent sorbent and stabilisation effect of calcium-rich additives
- 2020
-
In: Environmental Science and Pollution Research. - : Springer. - 0944-1344 .- 1614-7499. ; 27:23, s. 29248-29256
-
Journal article (peer-reviewed)abstract
- Contaminated water with multiple contaminants, including As, Cr, Cu and Zn, was treated with a sorbent prepared by coating peat with Fe oxides. Because As has a relatively little explored market, the regeneration of the spent sorbent was not feasible. Meanwhile, the disposal of As wastes in landfills can cause landfill leachate treatment problems. Under the reducing conditions prevailing at landfills, As(V) is reduced to As(III), which is a toxic and more mobile form. In this study, incineration was explored as a management option to treat the spent sorbent that was loaded with As, Cr, Cu and Zn. The first objective of this study was to evaluate the leaching of these metal(loid)s from the ashes and compare it with the leaching from the spent sorbents before incineration. The second objective was to evaluate the leaching behaviour when the spent sorbent was co-incinerated with a Ca-rich additive (lime). To achieve these objectives, the obtained ashes were subjected to leaching tests, sequential extraction, and X-ray diffraction analyses. After the incineration, the ash content ranged from 9 to 19% of the initial mass of the spent sorbents. The leaching of As, Cu and Zn decreased compared with that from the spent sorbents before the thermal treatment because of the high incineration temperatures and/or co-incineration with lime. However, the leaching of Cr increased, which would hinder the disposal of the obtained ashes in a landfill because the limit value for disposal at a landfill for hazardous wastes was exceeded by 50 times. However, co-incineration with 10 wt% lime significantly decreased the leaching of Cr as a result of the formation of water-insoluble Ca-Cr compounds.
|
|
| 8. |
- Kasiuliene, Alfreda
(author)
-
Peat Coated with Iron Oxides : Purification of Metal(loid)-Contaminated Water and Treatment of the Spent Adsorbent
- 2019
-
Doctoral thesis (other academic/artistic)abstract
- In Sweden due to the industrial activities, such as wood impregnation, multiple point sources of arsenic (As) contamination in soil and water bodies are scattered over the country. Metals, such as chromium (Cr), copper (Cu), lead (Pb), nickel (Ni), cadmium (Cd) or zinc (Zn) at varying concentrations are usually present as well. Since adsorption is a common method to purify contaminated water, research and development of adsorbents have been actively carried out in the last few decades. However, seldom spent sorbent is safely handled afterwards and often end up in landfill, thus creating new problems and posing new risks to humans and environment.The aim of this study was to develop a waste-based adsorbent for simultaneous removal of As and associated metals: Cr, Cu and Zn, and to analyse sustainable ways how to manage the spent adsorbent without creating secondary pollution.In the model system two well-establish adsorbents: Fe oxides (deriving from FeCl3) and peat (waste-based), were combined and the concept of simultaneous removal of cationic and anionic contaminants was tested in a batch adsorption experiment. Due to Fe coating, removal of As and Cr increased by 80% and 30%, respectively, as compared to non-coated peat. Removal of Cu and Zn was higher (up to 15%) on non-coated peat than on Fe-coated peat. Similar results were obtained in the up-scaled column adsorption experiment, where Fe salt was substituted with a waste-based Fe hydrosol. Within the same pH environment (pH=5), Fe-coated peat effectively adsorbed all four investigated contaminants (As, Cr, Cu and Zn). Non-coated peat was effective for Cr, Cu and Zn. While, Fe oxides (coated on sand) adsorbed only As.Three management strategies for spent adsorbents, obtained after column adsorption experiment, were investigated in this study. i) Long-term deposit in a landfill was simulated by exposing spent adsorbents to a reducing environment and evaluating metal(loid) leaching. Leaching of As increased manifold (up to 60% in a 200-day experiment) as compared to the standardized batch leaching experiment under oxidizing conditions. It was determined that about one third of As(V) was reduced to As(III), which is more mobile and toxic. ii) Valorisation of the spent adsorbent was attempted through hydrothermal carbonisation. It was expected that obtained hydrochar could be used as a beneficial soil amendment. However, treatment resulted in the process liquid and the hydrochar both having high loads of As, Cu and Zn. Additional treatment of process water and hydrochar imply higher management costs for spent adsorbents. iii) Possibility of thermal destruction was investigated by combusting spent adsorbents. After the treatment volume of the waste (ash) was by 80-85% smaller as compared to spent adsorbents. Combustion at higher temperature (1100 °C vs 850 °C) resulted into a weaker metal(loid) leaching from ashes. Furthermore, co-combustion with calcium (Ca)-rich lime (waste-based) decreased leaching of all four investigated elements, Cr in particular, below the limit values for waste being accepted at landfills for hazardous waste. Therefore, combustion enabled possibility of safe and long-term deposit of As-bearing ashes. At the same time, less As would be circulating in society. For the future work, studies that could broaden the spectrum of contaminants targeted by Fe-coated peat would be beneficial. At the same time it is important not only to find alternative utilisation methods for Fe-coated peat, but also investigate other management options for the spent adsorbents.
|
|
| 9. |
- Kasiuliene, Alfreda, et al.
(author)
-
Treatment of metal (loid) contaminated solutions using iron-peat as sorbent : is landfilling a suitable management option for the spent sorbent?
- 2019
-
In: Environmental Science and Pollution Research. - : Springer. - 0944-1344 .- 1614-7499. ; 26:21, s. 21425-21436
-
Journal article (peer-reviewed)abstract
- This study firstly aimed to investigate the potential of simultaneous metal (loid) removal from metal (oid) solution through adsorption on iron-peat, where the sorbent was made from peat and Fe by-products. Up-flow columns filled with the prepared sorbent were used to treat water contaminated with As, Cu, Cr, and Zn. Peat effectively adsorbed Cr, Cu, and Zn, whereas approximately 50% of inlet As was detected in the eluent. Iron-sand was effective only for adsorbing As, but Cr, Cu, and Zn were poorly adsorbed. Only iron-peat showed the simultaneous removal of all tested metal (loid)s. Metal (loid) leaching from the spent sorbent at reducing conditions as means to assess the behaviour of the spent sorbent if landfilled was also evaluated. For this purpose, a standardised batch leaching test and leaching experiment at reducing conditions were conducted using the spent sorbent. It was found that oxidising conditions, which prevailed during the standardised batch leaching test, could have led to an underestimation of redox-sensitive As leaching. Substantially higher amounts of As were leached out from the spent sorbents at reducing atmosphere compared with oxidising one. Furthermore, reducing environment caused As(V) to be reduced into the more-toxic As (III).
|
|
| 10. |
- Kumpiene, Jurate, et al.
(author)
-
LONG-TERM stability of arsenic in iron amended contaminated soil
- 2021
-
In: Environmental Pollution. - : Elsevier. - 0269-7491 .- 1873-6424. ; 269
-
Journal article (peer-reviewed)abstract
- This study aimed at elucidating the long-term efficiency of soil remediation where chemical stabilization of arsenic (As) contaminated soil using zerovalent iron (Fe) amendments was applied. A combination of chemical extraction and extended X-Ray absorption fine structure (EXAFS) spectroscopy technique was applied on soils collected from five laboratory and field experiments in Sweden and France. All soils were treated with 1 wt% of zerovalent Fe grit 2–15 years prior to the sampling. The results indicate that all studied soils, despite the elapsed time since their amendment with Fe grit, had substantial amounts of ferrihydrite and/or lepidocrocite. These metastable and the most reactive Fe (oxyhydr)oxides (mainly ferrihydrite) were still present in substantial amounts even in the soil that was treated 15 years prior to the sampling and contributed most to the As immobilisation in the amended soils. This increases confidence in the long-term efficiency of As immobilisation using zerovalent Fe amendments. Both applied methods, sequential extraction and EXAFS, were in line for most of the samples in terms of their ability to highlight As immobilisation by poorly crystalline Fe phases.
|
|
| 11. |
- Tian, Shuangshuang, et al.
(author)
-
Transformation mechanism of nutrient elements in the process of biochar preparation for returning biochar to soil
- 2017
-
In: Chinese Journal of Chemical Engineering. - : Elsevier. - 1004-9541 .- 2210-321X. ; 25:4, s. 477-486
-
Journal article (peer-reviewed)abstract
- Returning biochar to soil is a heavily researched topic because biochar functions well for soil improvement. There is a significant loss of nutrients, which occurs during biochar preparation before biochar is returned to soil, thereby seriously undermining biochar's efficacy. Therefore, the transformation mechanisms of biochar pH, mass, nutrients and metals during pyrolysis under different atmospheres and temperatures were studied such that the best method for biochar preparation could be developed. Several conclusions can be reached: (1) a CO2 atmosphere is better than a N2 atmosphere for biochar preparation, although preparation in a CO2 atmosphere is not a common practice for biochar producers; (2) 350 °C is the best temperature for biochar preparation because the amount of nutrient loss is notably low based on the premise of straw transferred into biochar; and (3) transforming mechanisms of pH, N, P and K are also involved in the biochar preparation process.
|
|
