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  • 51. Muusse, Martine
    et al.
    Langford, Katherine
    Tollefsen, Knut Erik
    Cornelissen, Gerard
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Haglund, Peter
    Hylland, Ketil
    Thomas, Kevin V.
    Characterization of AhR agonist compounds in roadside snow2012In: Analytical and Bioanalytical Chemistry, ISSN 1618-2642, E-ISSN 1618-2650, Vol. 403, no 7, p. 2047-2056Article in journal (Refereed)
    Abstract [en]

    Aryl hydrocarbon receptor (AhR) agonistic contaminants were identified in roadside snow samples. Snow was collected in Oslo, Norway, and compared to a background sample collected from a mountain area. The water and particulate fractions were analysed for AhR agonists using a dioxin-responsive, chemically activated luciferase expression (CALUX) cell assay and by gas chromatography coupled to high-resolution time-of-flight mass spectrometry with targeted analysis for polycyclic aromatic hydrocarbons (PAHs) and broad-spectrum non-target analysis. The AhR agonist levels in the dissolved fractions in the roadside samples were between 15 and 387 pg/L CALUX toxic equivalents (TEQ(CALUX)). An elevated AhR activity of 221 pg TEQ(CALUX) per litre was detected in the mountain sample. In the particle-bound fractions, the TEQ(CALUX) was between 1,350 and 7,390 pg/L. One possible explanation for the elevated levels in the dissolved fraction of the mountain sample could be the presence of black carbon in the roadside samples, potentially adsorbing dioxin-like compounds and rendering them unavailable for AhR interaction. No polychlorinated dibenzodioxins and dibenzofurans or polychlorinated biphenyls were detected in the samples; the occurrence of PAHs, however, explained up to 9 % of the AhR agonist activity in the samples, whilst comprehensive two-dimensional gas chromatography coupled to mass spectrometry GCxGC-ToF-Ms identified PAH derivatives such as polycyclic aromatic ketones and alkylated, nitrogen sulphur and oxygen PAHs in the particle fractions. The (large) discrepancy between the total and explained activity highlights the fact that there are other as yet unidentified AhR agonists present in the environment.

  • 52.
    Näslund, J.
    et al.
    Stockholm University, Faculty of Science, Department of Systems Ecology.
    Samuelsson, Göran S.
    Stockholm University, Faculty of Science, Department of Systems Ecology.
    Gunnarsson, Jonas S.
    Stockholm University, Faculty of Science, Department of Systems Ecology.
    Nascimento, Francisco J. A.
    Stockholm University, Faculty of Science, Department of Systems Ecology.
    Nilsson, H. C.
    Cornelissen, Gerard
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Schaanning, M. T.
    Ecosystem effects of materials proposed for thin-layer capping of contaminated sediments2012In: Marine Ecology Progress Series, ISSN 0171-8630, E-ISSN 1616-1599, Vol. 449, p. 27-U46Article in journal (Refereed)
    Abstract [en]

    Ecotoxicological effects of 2 carbonaceous and 7 mineral capping materials suggested for in situ remediation of contaminated sediments in the Grenland fjords, Norway, were investigated in a mesocosm experiment. The primary objective was to compare the various materials with regard to potentially harmful effects on the benthic ecosystem. The materials assessed were activated carbon, Kraft-lignin, sand and clay materials, and 3 industrial by-products. Using sediment box-core samples with intact benthic communities, effects on structural (bacterial, macro-and meiofauna diversity) and functional (sediment-to-water nutrient fluxes, oxygen fluxes and bacterial production) endpoints were assessed. Significant deviations from the control (no capping) were detected for all of the tested materials for at least one endpoint. Generally, materials similar to the indigenous sediment (clay, sand) had relatively low deviations from the control, whereas industrial products (plaster, 2 types of crushed marble) resulted in deviations for most endpoints and large reductions in community richness and abundance. For example, at the end of the experimental period, the number of macrofauna taxa was <10 in these treatments, compared to >27 in uncapped mesocosm and field control sediments. The results from the study show that reducing harmful ecosystem effects from thin-layer capping by selecting capping materials based on robust, multi-endpoint mesocosm bench-tests is both possible and recommendable. Potential ecosystem impacts are particularly important to consider when large areas and areas with adequate ecological status are considered for thin-layer capping.

  • 53. Obia, Alfred
    et al.
    Borresen, Trond
    Martinsen, Vegard
    Cornelissen, Gerard
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Norwegian University of Life Sciences (NMBU), Norway; Norwegian Geotechnical Institute (NGI), Norway.
    Mulder, Jan
    Vertical and lateral transport of biochar in light-textured tropical soils2017In: Soil & Tillage Research, ISSN 0167-1987, E-ISSN 1879-3444, Vol. 165, p. 34-40Article in journal (Refereed)
    Abstract [en]

    Field experiments were conducted in Arenosols (loamy fine sand) and Acrisols (sandy loam) in Zambia to quantify vertical and lateral transport of biochar (BC) using the BC and soil C-13 isotope signatures and total organic carbon contents. There were three experimental treatments composing of no BC, <= 0.5 and 0.5-1 mm BCs each with three replicates arranged in completely randomized design. The applied BCs were made from rice husk, except 0.5-1 mm BC in sandy loam, which was from maize cob. One year after mixing BC homogeneously in the 0-5 cm surface layer, soil down to 20 cm depth was sampled. The downward migration of BC was significant down to 8 cm depth in sandy loam and down to 6 cm in loamy fine sand. Below these depths, there was no significant difference in BC amounts between the BC amended and the reference plots. There was a general tendency for greater downward migration for the <= 0.5 mm than for 0.5-1 mm BC. Total BC recovery at 0-5 cm depth in the BC-treated soils amounted to 45-66% of the total applied amount of BC. As only 10-20% was recovered in the deeper soil layers, 24-45% of the applied BC could not be accounted for in the soil profile. Although, decomposition and downward migration to below 20 cm depth may contribute to the loss of BC from the surface soil, much can be attributed to lateral transfer through erosion. This is the first study that explicitly focuses on the theme of BC dispersion and shows that in Arenosols and Acrisols of the tropics, the downward migration of BC is limited.

  • 54. Obia, Alfred
    et al.
    Cornelissen, Gerard
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Mulder, Jan
    Dorsch, Peter
    Effect of Soil pH Increase by Biochar on NO, N2O and N-2 Production during Denitrification in Acid Soils2015In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 10, no 9, article id e0138781Article in journal (Refereed)
    Abstract [en]

    Biochar (BC) application to soil suppresses emission of nitrous-(N2O) and nitric oxide (NO), but the mechanisms are unclear. One of the most prominent features of BC is its alkalizing effect in soils, which may affect denitrification and its product stoichiometry directly or indirectly. We conducted laboratory experiments with anoxic slurries of acid Acrisols from Indonesia and Zambia and two contrasting BCs produced locally from rice husk and cacao shell. Dose-dependent responses of denitrification and gaseous products (NO, N2O and N-2) were assessed by high-resolution gas kinetics and related to the alkalizing effect of the BCs. To delineate the pH effect from other BC effects, we removed part of the alkalinity by leaching the BCs with water and acid prior to incubation. Uncharred cacao shell and sodium hydroxide (NaOH) were also included in the study. The untreated BCs suppressed N2O and NO and increased N-2 production during denitrification, irrespective of the effect on denitrification rate. The extent of N2O and NO suppression was dose-dependent and increased with the alkalizing effect of the two BC types, which was strongest for cacao shell BC. Acid leaching of BC, which decreased its alkalizing effect, reduced or eliminated the ability of BC to suppress N2O and NO net production. Just like untreated BCs, NaOH reduced net production of N2O and NO while increasing that of N-2. This confirms the importance of altered soil pH for denitrification product stoichiometry. Addition of uncharred cacao shell stimulated denitrification strongly due to availability of labile carbon but only minor effects on the product stoichiometry of denitrification were found, in accordance with its modest effect on soil pH. Our study indicates that stimulation of denitrification was mainly due to increases in labile carbon whereas change in product stoichiometry was mainly due to a change in soil pH.

  • 55. Obia, Alfred
    et al.
    Mulder, Jan
    Martinsen, Vegard
    Cornelissen, Gerard
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Norwegian University of Life Sciences (NMBU), Norway; Norwegian Geotechnical Institute (NGI), Norway.
    Borresen, Trond
    In situ effects of biochar on aggregation, water retention and porosity in light-textured tropical soils2016In: Soil & Tillage Research, ISSN 0167-1987, E-ISSN 1879-3444, Vol. 155, p. 35-44Article in journal (Refereed)
    Abstract [en]

    Biochar (BC) has been reported to improve soil physical properties mainly in laboratory and greenhouse pot experiments. Here we study, under field conditions, the effect of BC and its particle sizes on soil aggregate stability, bulk density (BD), water retention, and pore size distribution in two experiments in Zambia. A) Farmer practice experiment in sandy loam with maize cob BC in conservation farming planting basins under maize and soybeans crops. B) Maize cob and rice husk BC particle size experiments (<= 0.5, 0.5-1 and 1-5 mm particle sizes) in loamy sand and sand. In the farmer practice experiment, BC increased aggregate stability by 7-9% and 17-20% per percent BC added under maize and soybeans crops respectively (p < 0.05) after two growing seasons. Total porosity and available water capacity (AWC) increased by 2 and 3% respectively per percent BC added (p < 0.05) under both crops, whereas BD decreased by 3-5% per percent BC added (p < 0.01). In the maize cob BC particle size experiment after one growing season, dose was a more important factor than particle size across the soils tested. Particle size of BC was more important in loamy sand than in sand, with <= 0.5 and 1-5 mm sizes producing the strongest effects on the measured properties. For example, BD decreased while total porosity increased (p < 0.01) for all BC particle sizes in sand whereas only 1-5 mm BC significantly decreased BD and increased total porosity in loamy sand (p < 0.05). However, AWC was significantly increased by only <= 0.5 and 1-5 mm BCs by 7-9% per percent BC added in both loamy sand and sand. Rice husk BC effect after one year followed similar pattern as maize cob BC but less effective in affecting soil physical properties. Overall, reduced density of soil due to BC-induced soil aggregation may aid root growth and with more water available, can increase crop growth and yields.

  • 56. Oen, Amy M. P.
    et al.
    Beckingham, Barbara
    Ghosh, Upal
    Elmquist Krusa, Marie
    Luthy, Richard G.
    Hartnik, Thomas
    Henriksen, Thomas
    Cornelissen, Gerard
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM). Norwegian Geotechnical Institute (NGI), Norway; University of Life Sciences (UMB), Norway.
    Sorption of Organic Compounds to Fresh and Field-Aged Activated Carbons in Soils and Sediments2012In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 46, no 2, p. 810-817Article in journal (Refereed)
    Abstract [en]

    Activated carbon (AC) amendment to polluted sediment or soil is an emerging in situ treatment technique that reduces freely dissolved porewater concentrations and subsequently reduces the ecological and human health risk of hydrophobic organic compounds (HOCs). An important question is the capacity of the amended AC after prolonged exposure in the field. To address this issue, sorption of freshly spiked and native HOCs to AC aged under natural field conditions and fresh AC amendments was compared for one soil and two sediments. After 12-32 months of field aging, all AC amendments demonstrated effectiveness for reducing pore water concentrations of both native (30-95%) and spiked (10-90%) HOCs compared to unamended sediment or soil. Values of K-AC for field-aged AC were lower than freshly added AC for spiked HOCs up to a factor of 10, while the effect was less for native HOCs. The different behavior in sorbing native HOCs compared to freshly spiked HOCs was attributed to differences in the sorption kinetics and degree of competition for sorption sites between the contaminants and pore-clogging natural organic matter. The implications of these findings are that amended AC can still be effective in sorbing additional HOCs some years following amendment in the field. Thus, a certain level of long-term sustainability of this remediation approach is observed, but conclusions for decade-long periods cannot be drawn solely based on the present study.

  • 57. Oen, Amy M. P.
    et al.
    Janssen, Elisabeth M. L.
    Cornelissen, Gerard
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Breedveld, Gijs D.
    Eek, Espen
    Luthy, Richard G.
    In Situ Measurement of PCB Pore Water Concentration Profiles in Activated Carbon-Amended Sediment Using Passive Samplers2011In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 45, no 9, p. 4053-4059Article in journal (Refereed)
    Abstract [en]

    Vertical pore water profiles of in situ PCBs were determined in a contaminated mudflat in San Francisco Bay, CA, 30 months after treatment using an activated carbon amendment in the upper layer of the sediment. Pore water concentrations were derived from concentrations of PCBs measured in two passive samplers; polyethylene (PE, 51 mu m thick) and polyoxymethylene (POM, 17 mu m thick) at different sediment depths. To calculate pore water concentrations from PCB contents in the passive samplers, an equilibrium approach and a first-order uptake model were applied, using five performance reference compounds to estimate pore water sampling rates. Vertical pore water profiles showed good agreement among the measurement and calculation methods with variations within a factor of 2, which seems reasonable for in situ measurements. The close agreements of pore water estimates for the two sampler materials (PE and POM) and the two methods used to translate uptake in samplers to pore water concentrations demonstrate the robustness and suitability of the passive sampling approach. The application of passive samplers in the sediment presents a promising method for site monitoring and remedial treatment evaluation of sorbent amendment or capping techniques that result in changes of pore water concentrations in the sediment subsurface.

  • 58. Okkenhaug, Gudny
    et al.
    Amstatter, Katja
    Bue, Helga Lassen
    Cornelissen, Gerard
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM). Norwegian Univ Life Sci UMB, Dept Plant & Environm Sci IPM, Norway.
    Breedveld, Gijs D.
    Henriksen, Thomas
    Mulder, Jan
    Antimony (Sb) Contaminated Shooting Range Soil: Sb Mobility and Immobilization by Soil Amendments2013In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 47, no 12, p. 6431-6439Article in journal (Refereed)
    Abstract [en]

    Antimony (Sb) in lead bullets poses a major environmental risk in shooting range soils. Here we studied the effect of iron (Fe)-based amendments on the mobility of Sb in contaminated soil from shooting ranges in Norway. Untreated soil showed high Sb concentrations in water extracts from batch tests (0.22-1.59 mg L-1) and soil leachate from column tests (0.3-0.7 mg L-1), occurring exclusively as Sb(V). Sorption of Sb to different iron-based sorbents was well described by the Freundlich equation (Fe-2(SO4)(3), log K-F = 6.35, n = 1.51; CFH-12 (Fe oxyhydroxide), log K-F = 4.16-4.32, n = 0.75-0.76); Fe-0 grit, log K-F = 3.26, n = 0.47). These sorbents mixed with soil (0.5 and 2% w/w), showed significant sorption of Sb in batch tests (46-92%). However, for Fe-2(SO4)(3) and CFH-12 liming was also necessary to prevent mobilization of lead, copper, and zinc. Column tests showed significant significant retention of Sb (89-98%) in soil amended with CFH-12 (2%) mixed with limestone (1%) compared to unamended soil. The sorption capacity of soils amended with Fe-0 (2%) increased steadily up to 72% over the duration period of the column test (64 days), most likely due to the gradual oxidation of Fe-0 to Fe oxyhydroxides. Based on the experimental results, CFH-12 and oxidized Fe-0 are effective amendments for the stabilization of Sb in shooting range soils.

  • 59. Okkenhaug, Gudny
    et al.
    Grasshorn Gebhardt, Karl-Alexander
    Amstaetter, Katja
    Lassen Bue, Helga
    Herzel, Hannes
    Mariussen, Espen
    Rossebø Almås, Åsgeir
    Cornelissen, Gerard
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Norwegian University of Life Sciences (NMBU), Norway; Norwegian Geotechnical Institute (NGI), Norway.
    Breedveld, Gijs D.
    Rasmussen, Grete
    Mulder, Jan
    Antimony (Sb) and lead (Pb) in contaminated shooting range soils: Sb and Pb mobility and immobilization by iron based sorbents, a field study2016In: Journal of Hazardous Materials, ISSN 0304-3894, E-ISSN 1873-3336, Vol. 307, p. 336-343Article in journal (Refereed)
    Abstract [en]

    Small-arm shooting ranges often receive a significant input of lead (Pb), copper (Cu) and antimony (Sb) from ammunition. The goal of the present study was to investigate the mobility, distribution and speciation of Pb and Sb pollution under field conditions in both untreated and sorbent-amended shooting range soil. Elevated Sb (19-349 mu g L-1) and Pb (7-1495 mu g Pb L-1) concentrations in the porewater of untreated soil over the four-year test period indicated a long-term Sb and Pb source to the adjacent environment in the absence of remedial measures. Mixing ferric oxyhydroxide powder (CFH-12) (2%) together with limestone (1%) into the soil resulted in an average decrease of Sb and Pb porewater concentrations of 66% and 97%, respectively. A similar reduction was achieved by adding 2% zerovalent iron (Fe) to the soil. The remediation effect was stable over the four-year experimental period indicating no remobilization. Water- and 1 M NH4NO3-extractable levels of Sb and Pb in field soil samples indicated significant immobilization by both treatments (89-90% for Sb and 89-99% for Pb). Results from sequential extraction analysis indicate fixation of Sb and Pb in less accessible fractions like amorphous iron oxides or even more crystalline and residual mineral phases, respectively. This work shows that amendment with Fe-based sorbents can be an effective method to reduce the mobility of metals both in cationic and anionic form in polluted shooting range soil.

  • 60. Oleszczuk, Patryk
    et al.
    Hale, Sarah E.
    Lehmann, Johannes
    Cornelissen, Gerard
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Activated carbon and biochar amendments decrease pore water concentrations of polycyclic aromatic hydrocarbons (pahs) in sewage sludge2012In: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 111, p. 84-91Article in journal (Refereed)
    Abstract [en]

    The aim of the research was to determine the influence of biochar and activated carbon (AC) on the freely dissolved concentration of polycyclic aromatic hydrocarbons (PAHs) in sewage sludge. Two different biochars (MSB and PMW) and two ACs (CP1 and BP2) were used in the present experiment. Addition of AC/biochar to sewage sludge caused significant decrease of freely dissolved PAHs concentration. Depending on the dose, the reduction of freely dissolved PAHs ranged from 56% to 95% (ACs) and from 0% to 57% (biochars). Only for the biochars was there a significant difference between short 7-d and long 30/60-d mixing time. It is concluded that both AC and biochar are effective at reducing PAH pore-water concentrations, the more expensive and non-carbon negative AC having the greatest effect.

  • 61. Oleszczuk, Patryk
    et al.
    Rycaj, Marcin
    Lehmann, Johannes
    Cornelissen, Gerard
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Influence of activated carbon and biochar on phytotoxicity of air-dried sewage sludges to Lepidium sativum2012In: Ecotoxicology and Environmental Safety, ISSN 0147-6513, E-ISSN 1090-2414, Vol. 80, p. 321-326Article in journal (Refereed)
    Abstract [en]

    The goal of the research was to determine the phytotoxicity (using Lepidium sativum) of two activated carbon/biochar-amended sewage sludges. Apart from the impact of the AC/biochar dose, the influence of biochar particle diameter (< 300, 300-500 and > 500 mu m) and the influence of the contact time (7, 60, 90 days) between AC/biochar and sewage sludges on their phytotoxicity was also assessed. No negative impact of sewage sludges on seed germination was observed (P > 0.05). The application of AC or biochar to the sludges positively affected root growth by reducing the harmful effect by 7.8 to 42% depending on the material used. Furthermore, the reduction range clearly depended on the type of sewage sludge. No differences were observed in the inhibition of the toxic effect between both biochar types used and the biochar particle size. The extension of the contact time between AC/biochar and sewage sludges had a negative impact on root growth.

  • 62. Oleszczuk, Patryk
    et al.
    Zielinska, Anna
    Cornelissen, Gerard
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM). Norwegian Geotechnical Institute, Norway; Norwegian University of Life Sciences, Norway.
    Stabilization of sewage sludge by different biochars towards reducing freely dissolved polycyclic aromatic hydrocarbons (PAHs) content2014In: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 156, p. 139-145Article in journal (Refereed)
    Abstract [en]

    The objective of the study was to identify the effect of various biochars on the content of freely dissolved (C-free) PAHs in sewage sludge. Apart from the evaluation of biochars obtained from various materials, the study also included the determination of the effects of biochar particle sizes and biochar production temperature on their ability to bind PAHs in sewage sludge. Increase in biochar dose caused a gradual reduction of C-free PAHs content, but only up to the biochar dose of 5%. Depending on the kind of initial material from which the biochar was produced, the reduction of C-free PAHs content in sewage sludge varied from 17.4% to 58.0%. Both the temperature and the particle size of biochar had an effect on PAH free concentration reduction. Biochars characterised by a low polarity index (O/C or (O + N)/C) reduced the level of C-free PAHs better than biochars with a higher polarity index value.

  • 63.
    Samuelsson, Göran S.
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Hedman, Jenny E.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Krusa, Marie Elmquist
    Gunnarsson, Jonas S.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Cornelissen, Gerard
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Capping in situ with activated carbon in Trondheim harbor (Norway) reduces bioaccumulation of PCBs and PAHs in marine sediment fauna2015In: Marine Environmental Research, ISSN 0141-1136, E-ISSN 1879-0291, Vol. 109, p. 103-112Article in journal (Refereed)
    Abstract [en]

    Three types of thin-layer caps with activated carbon (AC) were tested in situ in experimental plots (10 x 10 m) in Trondheim harbor, Norway, using AC + clay, AC-only or AC + sand. One year after capping, intact sediment cores were collected from the amended plots for ex situ surveys of the capping efficiency in reducing the PAH and PCB aqueous concentrations and bioaccumulation by the polychaete Hediste diversicolor and the clam Abra nitida. Reduced pore water concentrations were observed in all AC treatments. The capping efficiency was in general AC + clay > AC-only > AC + sand. AC + clay reduced bioaccumulation of PAH and PCB congeners between 40% and 87% in the worms and between 67% and 97% in the clams. Sediment capped with AC-only also led to reduced bioaccumulation of PCBs, while AC + sand showed no reduction in bioaccumulation. Thus the best thin-layer capping method in this study was AC mixed with clay.

  • 64. Schmidt, Hans Peter
    et al.
    Pandit, Bishnu Hari
    Martinsen, Vegard
    Cornelissen, Gerard
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. University of Life Sciences (NMBU), Norway; Norwegian Geotechnical Institute (NGI), Norway.
    Conte, Pellegrino
    Kammann, Claudia I.
    Fourfold Increase in Pumpkin Yield in Response to Low-Dosage Root Zone Application of Urine-Enhanced Biochar to a Fertile Tropical Soil2015In: Agriculture (Basel), ISSN 2077-0472, Vol. 5, no 3, p. 723-741Article in journal (Refereed)
    Abstract [en]

    A widely abundant and invasive forest shrub, Eupatorium adenophorum, was pyrolyzed in a cost- efficient flame curtain kiln to produce biochar. The resulting biochar fulfilled all the requirements for premium quality, according to the European Biochar Certificate. The biochar was either applied alone or mixed with fresh cow urine ( 1: 1 volume) to test its capacity to serve as slow release fertilizer in a pumpkin field trial in Nepal. Treatments included cow- manure compost combined with ( i) urine- only; ( ii) biochar- only or ( iii) urine- loaded biochar. All materials were applied directly to the root zone at a biochar dry matter content of 750 kg . ha- 1 before seeding. The urine- biochar treatment led to a pumpkin yield of 82.6 t . ha- 1, an increase of more than 300% compared with the treatment where only urine was applied, and an 85% increase compared with the biochar- only treatment. This study showed for the first time that a low- dosage root zone application of urine- enhanced biochar led to substantial yield increases in a fertile silt loam soil. This was tentatively explained by the formation of organic coating of inner pore biochar surfaces by the urine impregnation, which improved the capacity of the biochar to capture and exchange plant nutrients.

  • 65. Smebye, Andreas
    et al.
    Ailing, Vanja
    Vogt, Rolf D.
    Gadmar, Tone C.
    Mulder, Jan
    Cornelissen, Gerard
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM). Norwegian Geotechnical Institute (NGI), Norway; Norwegian University of Life Sciences (NMBU), Norway.
    Hale, Sarah E.
    Biochar amendment to soil changes dissolved organic matter content and composition2016In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 142, p. 100-105Article in journal (Refereed)
    Abstract [en]

    Amendments of biochar, a product of pyrolysis of biomass, have been shown to increase fertility of acidic soils by enhancing soil properties such as pH, cation-exchange-capacity and water-holding-capacity. These parameters are important in the context of natural organic matter contained in soils, of which dissolved organic matter (DOM) is the mobile and most bioavailable fraction. The effect of biochar on the content and composition of DOM in soils has received little research attention. This study focuses on the effects of amendments of two different biochars to an acidic acrisol and a pH-neutral brown soil. A batch experiment showed that mixing biochar with the acrisols at a 10 wt.% dose increased the pH from 4.9 to 8.7, and this resulted in a 15-fold increase in the dissolved organic carbon concentration (from 4.5 to 69 mg L-1). The pH-increase followed the same trend as the release of DOM in the experiment, causing higher DOM solubility and desorption of DOM from mineral sites. The binding to biochar of several well-characterised reference DOM materials was also investigated and results showed a higher sorption of aliphatic DOM to biochar than aromatic DOM, with DOM-water partitioning coefficients (Kd-values) ranging from 0.2 to 590 L kg(-1). A size exclusion occurring in biochar's micropores, could result in a higher sorption of smaller aliphatic DOM molecules than larger aromatic ones. These findings indicate that biochar could increase the leaching of DOM from soil, as well as change the DOM composition towards molecules with a larger size and higher aromaticity.

  • 66.
    Sobek, Anna
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Arp, Hans Peter H.
    Wiberg, Karin
    Hedman, Jenny
    Cornelissen, Gerard
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Aerosol-Water Distribution of PCDD/Fs and PCBs in the Baltic Sea Region2013In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 47, no 2, p. 781-789Article in journal (Refereed)
    Abstract [en]

    Atmospheric deposition is a major pathway of PCDD/Fs to the Baltic Sea. We studied the aerosol-water distribution for aerosols collected close to the Baltic Sea in order to investigate the availability of pollutants sorbed to aerosols deposited on water. Aerosols were analyzed for both total concentration (Soxhlet extraction) and the freely dissolved water concentration (extraction with 17-mu m polyoxymethylene equilibrium passive samplers). Concentrations of PCDD/F and sum PCB-7 in aerosols were 65-1300 pg/g dw TEQ and 22-100 ng/g dw, respectively. Organic carbon (OC)-normalized aerosol water distribution ratios (K-aer-water,K-OC) were consistently lower (factor 2-60) than previously determined sediment organic carbon water distribution ratios (K-sed,K-OC). Hence PCDD/Fs and PCBs entering the Baltic Sea through aerosol deposition seem to be more available for desorption to the water phase than PCDD/Fs and PCBs sorbed to sediment. Further, we investigated whether aerosol water distribution may be predicted from the air aerosol partitioning constant multiplied by the Henry's Law constant. This proposed model for aerosol water distribution underestimated measured values for PCBs by factors of 1-17 and for PCDD/Fs by more than a factor 10. These findings can be used to improve future fate modeling of PCBs and PCDD/Fs in marine environments and specifically the Baltic Sea.

  • 67.
    Sobek, Anna
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Wiberg, K.
    Sundqvist, K. L.
    Haglund, P.
    Jonsson, Per
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Cornelissen, Gerard
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM). Norwegian Geotechnical Institute, Norway; Norwegian University of Life Sciences, Norway.
    Coastal sediments in the Gulf of Bothnia as a source of dissolved PCDD/Fs and PCBs to water and fish2014In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 487, p. 463-470Article in journal (Refereed)
    Abstract [en]

    High levels of PCDD/Fs and PCBs in Baltic Sea biota have been a matter of great concern during the last decades. We measured the freely dissolved concentrations of PCDD/Fs and PCBs in sediment pore water and bottom water in eight areas along the Swedish coast of the Gulf of Bothnia, by using state-of-the-art passive samplers. Chemical activity ratios (calculated from freely dissolved concentrations in pore water and bottom water based on chemical activity ratios) for PCDD/Fs were higher than 1 at all stations (PCDD/Fs average 27; stdev 22). High activity ratios suggest that the sediments have a potential to act as a source of dissolved PCDD/Fs to the water column. Activity ratios for PCBs varied between 0.3 and 17 (average 2; stdev 4). The concentrations of PCDD/Fs and PCBs in bottom water were significantly correlated with concentrations in sediment pore water (p < 0.00001 to p = 0.03) as well as with concentrations in juvenile perch caught in the same areas (p < 0.00001 to p = 0.02). To our knowledge, this is the first study demonstrating a correlation between in-situ measured freely dissolved PCDD/F concentrations and lipid-normalized contents in stationary fish. Our results confirm that freely dissolved concentrations should be used as chemical predictors of bioaccumulation. The results from this study imply that continued efforts to reduce levels of PCDD/Fs and PCBs in coastal sediments will have positive effects on concentrations of these contaminants in lower trophic levels of Baltic Sea ecosystems.

  • 68. Sparrevik, Magnus
    et al.
    Adam, Chris
    Martinsen, Vegard
    Jubaedah,
    Cornelissen, Gerard
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM). Norwegian Geotechnical Institute (NGI), Norway; University of Life Sciences, Norway.
    Emissions of gases and particles from charcoal/biochar production in rural areas using medium-sized traditional and improved retort kilns2015In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 72, p. 65-73Article in journal (Refereed)
    Abstract [en]

    Charcoal is used for cooking in many parts of the developing world. Charcoal from agricultural materials can also be used as a soil amendment to enhance agricultural production, and is often termed biochar in this case. Charcoal may be produced in various types and scales of systems, but for rural tropical areas, traditional kiln technologies without treatment of the pyrolysis gases dominate. Traditional charcoal industry is considered to be both inefficient and polluting, emitting harmful off-gases containing methane, carbon monoxide and particles. Retort kilns, which recirculate and combust the pyrolysis gases internally have been claimed to overcome this problem. Even though retort technology has frequently been discussed, this paper is the first study determining gas emission factors for operational retort kilns in rural tropical areas. The mean emission factors for the retort ldlns found in this study using identical feedstock were (in g kg(-1) charcoal); carbon dioxide (CO2) = 1950 +/- 209, carbon monoxide (CO) = 157 +/- 64, nonmethane volatile organic components (NMVOC) = 6.1 +/- 3.4, methane (CH4) = 24 +/- 17, total solid particles (TSP) = 12 +/- 18, products of incomplete combustion (plc) = 200 +/- 97 and nitric oxides (NOx) = 1.8 +/- 1.0. The corresponding value for the non-retort ldlns tested was in general higher; CO2 = 2380 +/- 973, CO = 480 +/- 141, NMVOC = 13 +/- 3.8, CH4 = 54 +/- 29, TSP = 7.9 +/- 2.6, PIC = 554 +/- 138 and NOx = 4.3 +/- 1.6. The difference between the kiln types was statistically significant (p < 0.05) for CO, NMVOC, PIC and NOx. However, the retort kilns consumed ignitable fuel such as wood in the start-up phase to reach pyrolysis temperature resulting in insignificant difference in yield between retort and non-retort kilns. In addition, retort kilns are more costly than traditional kilns, which may be challenging for implementation. It is therefore important to continue design development, especially with regard to wood consumption during the start-up phase.

  • 69. Sparrevik, Magnus
    et al.
    Field, John L.
    Martinsen, Vegard
    Breedveld, Gijs D.
    Cornelissen, Gerard
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Life Cycle Assessment to Evaluate the Environmental Impact of Biochar Implementation in Conservation Agriculture in Zambia2013In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 47, no 3, p. 1206-1215Article in journal (Refereed)
    Abstract [en]

    Biochar amendment to soil is a potential technology for carbon storage and climate change mitigation. It may, in addition, be a valuable soil fertility enhancer for agricultural purposes in sandy and/or weathered soils. A life cycle assessment including ecological, health and resource impacts has been conducted for field sites in Zambia to evaluate the overall impacts of biochar for agricultural use. The life cycle impacts from conservation farming using cultivation growth basins and precision fertilization with and without biochar addition were in the present study compared to conventional agricultural methods. Three different biochar production methods were evaluated: traditional earth-mound kilns, improved retort kilns, and micro top-lit updraft (TLUD) gasifier stoves. The results confirm that the use of biochar in conservation farming is beneficial for climate change mitigation purposes. However, when including health impacts from particle emissions originating from biochar production, conservation farming plus biochar from earth-mound kilns generally results in a larger negative effect over the whole life cycle than conservation farming without biochar addition. The use of cleaner technologies such as retort kilns or TLUDs can overcome this problem, mainly because fewer particles and less volatile organic compounds, methane and carbon monoxide are emitted. These results emphasize the need for a holistic view on biochar use in agricultural systems. Of special importance is the biochar production technique which has to be evaluated from both environmental/climate, health and social perspectives.

  • 70. Sparrevik, Magnus
    et al.
    Lindhjem, Henrik
    Andria, Verania
    Fet, Annik Magerholm
    Cornelissen, Gerard
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM). Norwegian University of Life Sciences.
    Environmental and Socioeconomic Impacts of Utilizing Waste for Biochar in Rural Areas in Indonesia-A Systems Perspective2014In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 48, no 9, p. 4664-4671Article in journal (Refereed)
    Abstract [en]

    Biochar is the product of incomplete combustion (pyrolysis) of organic material. In rural areas, it can be used as a soil amendment to increase soil fertility. Fuel-constrained villagers may however prefer to use biochar briquettes as a higher-value fuel for cooking over applying it to soils. A systems-oriented analysis using life cycle assessment (LCA) and cost benefit analysis (CBA) was conducted to analyze these two alternative uses of biochar, applying the study to a rural village system in Indonesia. The results showed soil amendment for enhanced agricultural production to be the preferential choice with a positive benefit to the baseline scenario of -26 ecopoints (LCA) and -173 USD (CBA) annually pr. household. In this case, the positive effects of carbon sequestration to the soil and the economic value of the increased agricultural production outweighed the negative environmental impacts from biochar production and the related production costs. Use of biochar in briquettes for cooking fuel yielded negative net effects in both the LCA and CBA (85 ecopoints and 176 USD), even when positive health effects from reduced indoor air pollution were included. The main reasons for this are that emissions during biochar production are not compensated by carbon sequestration and that briquette making is labor-intensive. The results emphasize the importance of investigating and documenting the carbon storage effect and the agricultural benefit in biochar production-utilization systems for a sustainable use. Further research focus on efficient production is necessary due to the large environmental impact of biochar production. In addition, biochar should continue to be used in those soils where the agricultural effect is most beneficial.

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