Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Peat Coated with Iron Oxides: Purification of Metal(loid)-Contaminated Water and Treatment of the Spent Adsorbent
Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.ORCID-id: 0000-0001-5375-8825
2019 (Engelska)Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

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.

Ort, förlag, år, upplaga, sidor
Luleå: Luleå University of Technology, 2019.
Serie
Doctoral thesis / Luleå University of Technology 1 jan 1997 → …, ISSN 1402-1544
Nyckelord [en]
iron-peat, adsorption, arsenic, metals, combustion, hydrothermal carbonisation, landfilling
Nationell ämneskategori
Miljöledning Annan naturresursteknik
Forskningsämne
Avfallsteknik
Identifikatorer
URN: urn:nbn:se:ltu:diva-76325ISBN: 978-91-7790-462-5 (tryckt)ISBN: 978-91-7790-463-2 (digital)OAI: oai:DiVA.org:ltu-76325DiVA, id: diva2:1359453
Disputation
2019-12-05, D770, Luleå, 10:00 (Engelska)
Opponent
Handledare
Tillgänglig från: 2019-10-09 Skapad: 2019-10-09 Senast uppdaterad: 2019-11-14Bibliografiskt granskad
Delarbeten
1. Removal of metal(oid)s from contaminated water using iron-coated peat sorbent
Öppna denna publikation i ny flik eller fönster >>Removal of metal(oid)s from contaminated water using iron-coated peat sorbent
Visa övriga...
2018 (Engelska)Ingår i: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 198, s. 290-296Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

This study aimed at combining iron and peat to produce a sorbent suitable for a simultaneous removal of cations and anions from a solution. Peat powder, an industrial residue, was coated with iron by immersing peat into iron salt solutions. The adsorption efficiency of the newly produced sorbent towards As, Cr, Cu and Zn was tested by means of batch adsorption experiments at a constant pH value of 5. Coating of Fe on peat significantly increased the adsorption of As (from <5% to 80%) and Cr (from <3% to 25%) in comparison to uncoated peat. Removal of cations on coated peat slightly decreased (by 10–15%), yet remained within acceptable range. Electron Microscopy combined with X-Ray Energy Dispersive Spectroscopy revealed that iron coating on the peat was rather homogenous and As and Cr were abundantly adsorbed on the surface. By contrast, Cu and Zn displayed a sparing distribution on the surface of the iron coated peat. These results indicate that iron-peat simultaneously target sufficient amounts of both cations and anions and can be used for a one-step treatment of contaminated groundwater

Ort, förlag, år, upplaga, sidor
Elsevier, 2018
Nationell ämneskategori
Annan naturresursteknik
Forskningsämne
Avfallsteknik
Identifikatorer
urn:nbn:se:ltu:diva-67545 (URN)10.1016/j.chemosphere.2018.01.139 (DOI)000427338800033 ()29421741 (PubMedID)2-s2.0-85041488356 (Scopus ID)
Anmärkning

Validerad;2018;Nivå 2;2018-02-07 (andbra)

Tillgänglig från: 2018-02-07 Skapad: 2018-02-07 Senast uppdaterad: 2019-10-09Bibliografiskt granskad
2. Treatment of metal (loid) contaminated solutions using iron-peat as sorbent: is landfilling a suitable management option for the spent sorbent?
Öppna denna publikation i ny flik eller fönster >>Treatment of metal (loid) contaminated solutions using iron-peat as sorbent: is landfilling a suitable management option for the spent sorbent?
2019 (Engelska)Ingår i: Environmental Science and Pollution Research, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 26, nr 21, s. 21425-21436Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

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).

Ort, förlag, år, upplaga, sidor
Springer, 2019
Nyckelord
Arsenic, metals, trace elements, sorption, landfill leachate, low redox
Nationell ämneskategori
Annan naturresursteknik
Forskningsämne
Avfallsteknik
Identifikatorer
urn:nbn:se:ltu:diva-74016 (URN)10.1007/s11356-019-05379-5 (DOI)000482211100030 ()31119550 (PubMedID)
Anmärkning

Validerad;2019;Nivå 2;2019-09-09 (johcin)

Tillgänglig från: 2019-05-23 Skapad: 2019-05-23 Senast uppdaterad: 2020-06-05Bibliografiskt granskad
3. Hydrothermal carbonisation of peat-based spent sorbents loaded with metal(loid)s
Öppna denna publikation i ny flik eller fönster >>Hydrothermal carbonisation of peat-based spent sorbents loaded with metal(loid)s
2019 (Engelska)Ingår i: Environmental Science and Pollution Research, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 26, nr 23, s. 23730-23738Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

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.

Ort, förlag, år, upplaga, sidor
Springer, 2019
Nyckelord
Metals, Adsorption, Thermal treatment, Iron-peat, Post-sorption management, HTC
Nationell ämneskategori
Annan naturresursteknik
Forskningsämne
Avfallsteknik
Identifikatorer
urn:nbn:se:ltu:diva-75121 (URN)10.1007/s11356-019-05653-6 (DOI)000477958300045 ()31203552 (PubMedID)
Anmärkning

Validerad;2019;Nivå 2;2019-08-20 (johcin)

Tillgänglig från: 2019-06-28 Skapad: 2019-06-28 Senast uppdaterad: 2020-06-05Bibliografiskt granskad
4. Leaching of Metal(loid)s From Ashes of Spent Sorbent and Stabilisation Effect of Calcium-Rich Additives
Öppna denna publikation i ny flik eller fönster >>Leaching of Metal(loid)s From Ashes of Spent Sorbent and Stabilisation Effect of Calcium-Rich Additives
Visa övriga...
2020 (Engelska)Ingår i: Environmental Science and Pollution Research, ISSN 0944-1344, E-ISSN 1614-7499Artikel i tidskrift (Refereegranskat) Epub ahead of print
Abstract [en]

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.

Ort, förlag, år, upplaga, sidor
Springer, 2020
Nyckelord
Arsenic, Heavy metals, Lime, Incineration, Iron-coated peat, Thermochemical equilibrium calculations
Nationell ämneskategori
Annan naturresursteknik Energiteknik
Forskningsämne
Avfallsteknik; Energiteknik
Identifikatorer
urn:nbn:se:ltu:diva-76322 (URN)10.1007/s11356-020-09269-z (DOI)32436093 (PubMedID)
Tillgänglig från: 2019-10-09 Skapad: 2019-10-09 Senast uppdaterad: 2020-06-05

Open Access i DiVA

fulltext(8880 kB)43 nedladdningar
Filinformation
Filnamn FULLTEXT01.pdfFilstorlek 8880 kBChecksumma SHA-512
bacc7d2084e26d221a7747578a880e1f4aa5046b8fc2fb0bd46ea71b5588f89590347ec99d8e1f4db52e5089f5982d30889cd5490ec3a566e97ce5ab4eef58ea
Typ fulltextMimetyp application/pdf

Personposter BETA

Kasiuliene, Alfreda

Sök vidare i DiVA

Av författaren/redaktören
Kasiuliene, Alfreda
Av organisationen
Geovetenskap och miljöteknik
MiljöledningAnnan naturresursteknik

Sök vidare utanför DiVA

GoogleGoogle Scholar
Totalt: 43 nedladdningar
Antalet nedladdningar är summan av nedladdningar för alla fulltexter. Det kan inkludera t.ex tidigare versioner som nu inte längre är tillgängliga.

isbn
urn-nbn

Altmetricpoäng

isbn
urn-nbn
Totalt: 260 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf