Ithaka Institute

Arbaz, Switzerland

Ithaka Institute

Arbaz, Switzerland
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Kupryianchyk D.,Norwegian Geotechnical Institute | Hale S.,Norwegian Geotechnical Institute | Zimmerman A.R.,University of Florida | Harvey O.,University of Southern Mississippi | And 8 more authors.
Chemosphere | Year: 2016

Carbonaceous materials like biochars are increasingly recognized as effective sorbent materials for sequestering organic pollutants. Here, we study sorption behavior of two common hydrophobic organic contaminants 2,2',5,5'-tetrachlorobiphenyl (CB52) and phenanthrene (PHE), on biochars and other carbonaceous materials (CM) produced at a wide range of conditions and temperatures from various feedstocks. The primary aim was to establish structure-reactivity relationships responsible for the observed variation in CM and biochar sorption characteristics. CM were characterized for their elemental composition, surface area, pore size distribution, aromaticity and thermal stability. Freundlich sorption coefficients for CB52 and PHE (i.e. LogKF,CB52 and KF,PHE, respectively) to CM showed a variation of two to three orders of magnitude, with LogKF,CB52 ranging from 5.12 ± 0.38 to 8.01 ± 0.18 and LogKF,PHE from 5.18 ± 0.09 to 7.42 ± 1.09. The highest LogKF values were observed for the activated CM, however, non-activated biochars produced at high temperatures (>700 °C) sorbed almost as strongly (within 0.2-0.5 Log units) as the activated ones. Sorption coefficients significantly increased with pyrolysis temperature, CM surface area and pore volume, aromaticity, and thermal stability, and decreased with H/C, O/C, (O + N)/C content. The results of our study contribute to the understanding of processes underlying HOC sorption to CM and explore the potential of CM as engineered sorbents for environmental applications. © 2015 Elsevier Ltd.


PubMed | University of Zürich, University of Stockholm, U.S. Geological Survey, Ithaka Institute and 5 more.
Type: | Journal: Chemosphere | Year: 2015

Carbonaceous materials like biochars are increasingly recognized as effective sorbent materials for sequestering organic pollutants. Here, we study sorption behavior of two common hydrophobic organic contaminants 2,2,5,5-tetrachlorobiphenyl (CB52) and phenanthrene (PHE), on biochars and other carbonaceous materials (CM) produced at a wide range of conditions and temperatures from various feedstocks. The primary aim was to establish structure-reactivity relationships responsible for the observed variation in CM and biochar sorption characteristics. CM were characterized for their elemental composition, surface area, pore size distribution, aromaticity and thermal stability. Freundlich sorption coefficients for CB52 and PHE (i.e. LogK(F,CB52) and K(F,PHE), respectively) to CM showed a variation of two to three orders of magnitude, with LogK(F,CB52) ranging from 5.12 0.38 to 8.01 0.18 and LogK(F,PHE) from 5.18 0.09 to 7.42 1.09. The highest LogK(F) values were observed for the activated CM, however, non-activated biochars produced at high temperatures (>700 C) sorbed almost as strongly (within 0.2-0.5 Log units) as the activated ones. Sorption coefficients significantly increased with pyrolysis temperature, CM surface area and pore volume, aromaticity, and thermal stability, and decreased with H/C, O/C, (O + N)/C content. The results of our study contribute to the understanding of processes underlying HOC sorption to CM and explore the potential of CM as engineered sorbents for environmental applications.


Mackie K.A.,University of Hohenheim | Schmidt H.P.,Ithaka Institute | Muller T.,University of Hohenheim | Kandeler E.,University of Hohenheim
Science of the Total Environment | Year: 2014

We investigated the ability of summer (Avena sativa [oat], Trifolium incarnatum [crimson clover], Chenopodium [goosefoot]) and winter (Vicia villosa [hairy vetch], Secale Cereale L. [Rye], Brassica napus L. partim [rape]) cover crops, including a mixed species treatment, to extract copper from an organic vineyard soil in situ and the microbial communities that may support it. Clover had the highest copper content (14.3mgCukg-1 DM). However, it was the amount of total biomass production that determined which species was most effective at overall copper removal per hectare. The winter crop rye produced significantly higher amounts of biomass (3532kgDMha-1) and, therefore, removed significantly higher amounts of copper (14,920mgCuha-1), despite less accumulation of copper in plant shoots. The maximum annual removal rate, a summation of best performing summer and winter crops, would be 0.033kgCuha-1y-1. Due to this low annual extraction efficiency, which is less than the 6kgCuha-1y-1 permitted for application, phytoextraction cannot be recommended as a general method of copper extraction from vineyards. Copper concentration did not influence aboveground or belowground properties, as indicated by sampling at two distances from the grapevine row with different soil copper concentrations. Soil microorganisms may have become tolerant to the copper levels at this site. Microbial biomass and soil enzyme activities (arylsulfatase and phosphatase) were instead driven by seasonal fluxes of resource pools. Gram+ bacteria were associated with high soil moisture, while fungi seemed to be driven by extractable carbon, which was linked to high plant biomass. There was no microbial group associated with the increased phytoextraction of copper. Moreover, treatment did not influence the abundance, activity or community structure of soil microorganisms. © 2014 Elsevier B.V.


Mackie K.A.,University of Hohenheim | Marhan S.,University of Hohenheim | Ditterich F.,University of Hohenheim | Schmidt H.P.,Ithaka Institute | Kandeler E.,University of Hohenheim
Agriculture, Ecosystems and Environment | Year: 2015

The use of copper (Cu) fungicides in agriculture has led to Cu accumulation in European topsoils. This study is the first to investigate the in situ efficacy of biochar and biochar-compost as Cu immobilizers, reducing Cu uptake by plants and increasing microbial abundance and activity, in a temperate vineyard topsoil (0-10cm). After application of biochar, compost and biochar-compost in April 2011, plant and soil samples were taken in November 2011, April 2012, August 2012, and November 2012. Similar amounts of exchangeable Cu fractions (CuDTPA) in all treatments showed that there was no significant effect on Cu immobilization in soil. In contrast, cover crops grown between vine rows were observed to take up a significant amount of Cu (38.7mg Cu kg-1), reducing soil Cu concentrations over time. Treatments with biochar and/or compost initially increased total carbon, with compost and biochar-compost additionally increasing extractable organic carbon in soil. Compost and biochar-compost significantly increased microbial biomass, phospholipid fatty acids (PLFAs), enzyme activities (phosphatase, arylsulfatase) and bacterial taxa abundances (Actinobacteria, α-Proteobacteria, β-Proteobacteria, Firmicutes, Gemmatimonadetes). A high abundance of gram+ Actinobacteria in all treatments suggested that they are adapted to heavy metals, likely due to their specific cell membrane structures. Additionally, each treatment was characterized by a specific microbial community composition. Compost and biochar-compost increased the relative abundance of Firmicutes, while control and biochar increased Acidobacteria, Gemmatimonadetes and Actinobacteria. In conclusion, biochar and/or compost were not viable Cu remediation options, but compost and biochar-compost provided ecosystem services by reinforcing the microbial community. © 2014 Elsevier B.V.


Schmidt H.-P.,Ithaka Institute | Kammann C.,Justus Liebig University | Niggli C.,Ithaka Institute | Evangelou M.W.H.,ETH Zurich | And 2 more authors.
Agriculture, Ecosystems and Environment | Year: 2014

Most European vineyard soils exhibit low soil fertility. They are highly vulnerable to erosion, low in soil organic matter content and, therefore, in water holding capacity and nitrate retention. The applications of biochar and biochar-compost are said to address some of these issues. We tested the ability of these amendments to improve soil quality and plant production quality in a 30-year-old vineyard in Valais, Switzerland. The amendments of biochar alone (8 t ha-1, produced from wood at 500 °C), aerobic compost (55 t ha-1) and biochar-compost (8 t ha-1 + 55 t ha-1, mixed before the composting process) were compared to an un-amended control soil. During the years 2011, 2012 and 2013 various vine and green cover growth, vine health and grape quality parameters were monitored. Biochar and biochar-compost treatments induced only small, economically irrelevant and mostly non-significant effects over the three years. We concluded that topsoil application of higher amounts of biochar has no immediate economic value for vine growing in poor fertility, alkaline, temperate soil. © 2014 Elsevier B.V. All rights reserved.


Glaser B.,Martin Luther University of Halle Wittenberg | Wiedner K.,Martin Luther University of Halle Wittenberg | Seelig S.,Kukate 2 | Schmidt H.-P.,Ithaka Institute | Gerber H.,PYREG GmbH
Agronomy for Sustainable Development | Year: 2015

Biochars are new, carbon-rich materials that could sequester carbon in soils improve soil properties and agronomic performance, inspired by investigations of Terra Preta in Amazonia. However, recent studies showed contrasting performance of biochar. In most studies, only pure biochar was used in tropical environments. Actually, there is little knowledge on the performance of biochar in combination with fertilizers under temperate climate. Therefore, we conducted an experiment under field conditions on a sandy Cambisol near Gorleben in Northern Germany. Ten different treatments were established in 72-m2 plots and fivefold field replicates. Treatments included mineral fertilizer, biogas digestate, microbially inoculated biogas digestate and compost either alone or in combination with 1 to 40 Mg ha−1 of biochar. Soil samples were taken after fertilizer application and maize harvest. Our results show that the biochar addition of 1 Mg ha−1 to mineral fertilizer increased maize yield by 20 %, and biochar addition to biogas digestate increased maize yield by 30 % in comparison to the corresponding fertilizers without biochar. The addition of 10 Mg ha−1 biochar to compost increased maize yield by 26 % compared to pure compost. The addition of 40 Mg ha−1 biochar to biogas digestate increased maize yield by 42 % but reduced maize yield by 50 % when biogas digestate was fermented together with biochar. Biochar-fertilizer combinations increased K, Mg and Zn and reduced Na, Cu, Ni and Cd uptake into maize. Overall, our findings demonstrate that biochar-fertilizer combinations have a better performance than pure fertilizers, in terms of yield and plant nutrition. Therefore, an immediate substitution of mineral fertilizers is possible to close regional nutrient cycles. © 2014, INRA and Springer-Verlag France.

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