Effects of biochar addition to estuarine sediments
- 458 Downloads
Biochar is a carbon-rich product, able to enhance soil fertility and mitigate CO2 emissions. While biochar effects on agriculture are becoming known, its impact elsewhere, e.g., on estuarine ecosystems, has yet to be assessed. The main aim of the present study was to determine the effect of biochar on sediment–water retention, CO2 emissions from sedimentary organic carbon decomposition, sediment pH and electrical conductivity, in aerobic conditions similar to those observed at low tide.
Materials and methods
Sediments from the Mondego Estuary (Portugal) were mixed with pine gasification biochar at different doses (5, 10, 14 %) and immersed in water with different salinity values (15, 25, 30) for 96 h. The influence of biochar on water retention, the residence time of water and CO2 emissions between −0.75 and −1.5 MPa, total organic carbon, pH and electrical conductivity (EC) were determined. Carbon chemical composition and polycyclic aromatic hydrocarbon (PAH) concentrations were determined in sediments and biochar. Differences between biochar treatments after immersion in different water salinities were analysed using the Kruskal–Wallis test.
Results and discussion
Results showed that biochar was able to (a) increase sediment–water content in terms of quantity and residence time, (b) decrease CO2 emissions, but only with a specific soil–water content and at the highest biochar dose, (c) increase sediment pH at all biochar doses and (d) increase sediment EC at the highest biochar dose. In contrast, the percentage of carbon mineralised was not modified. Biochar carbon was rich in PAHs and less decomposable than sedimentary carbon. The increments observed in sediment pH and EC were unable to change sediment alkaline or saline status according to standard classifications.
Our results suggest that the remarkable water adsorption capacity of biochar–sediment mixtures may be considered the main factor in regulating CO2 emission rates from sediments, together with high PAH concentrations, which probably restrain the organic matter decomposition process.
KeywordsCO2 emissions PAHs Pine gasification biochar Sediments Water retention
This research was carried out as part of the SOCARRAT project (contract AGL2009-12343 of the Spanish Ministry of Science and Innovation). The authors wish to thank the Fundação para a Ciência e Tecnologia—the European Social and National Funds (POPH & QREN) (SFRH/BPD/36371/2007) and Universidad Nacional de Colombia at Palmira—Colciencias (FP44842-138-2015) for financial support through the postdoctoral grants to G. Ojeda. We appreciate the study system map (Fig. 1), designed by Z. Teixeira.
- IBI (International Biochar Initiative) (2014) Standardized Product Definition and Product Testing Guidelines for Biochar That Is Used in Soil (aka IBI Biochar Standards) Version 2.0. http://www.biochar-international.org/sites/default/files/Guidelines_for_Biochar_That_Is_Used_in_Soil_Final.pdf
- Carrero R, Navas F, Malvárez G, Guisado-Pintado E (2014) Artificial intelligence-based models to simulate land-use changes around an estuary. In: Green AN, Cooper JAG (eds) Proceedings 13th International Coastal Symposium (Durban, South Africa), Journal of Coastal Research, Special Issue No. 70, Sydney, AustraliaGoogle Scholar
- CCME (Canadian Council of Ministers of the Environment) (2010) Canadian Soil Quality Guidelines for Carcinogenic and Other Polycyclic Aromatic Hydrocarbons (Environmental and Human Health Effects). Scientific Criteria Document, Quebec, CanadaGoogle Scholar
- EC (European Community) (2000) Working document on sludge, third draft, ENV.E.3/LM, Brussels.Google Scholar
- Gateuille D, Evrard O, Lefevre I, Moreau-Guigon E, Alliot F, Chevreuil M, Mouchel JM (2014) Mass balance and decontamination times of Polycyclic Aromatic Hydrocarbons in rural nested catchments of an early industrialized region (Seine River basin, France). Sci Total Environ 470–471:608–617CrossRefGoogle Scholar
- Hammes K, Schmidt MWI, Smernik RJ, Currie LA, Ball WP, Nguyen TH, Louchouarn P, Houel S, Gustafsson O, Elmquist M, Cornelissen G, Skjemstad JO, Masiello CA, Song J, Peng P, Mitra S, Dunn JC, Hatcher PG, Hockaday WC, Smith DM, Hartkopf-Fröder C, Böhmer A, Lüer B, Huebert BJ, Amelung W, Brodowski S, Huang L, Zhang W, Gschwend PM, Flores-Cervantes DX, Largeau C, Rouzaud JN, Rumpel C, Guggenberger G, Kaiser K, Rodionov A, Gonzalez-Vila FJ, Gonzalez-Perez JA, de la Rosa JM, Manning DAC, López-Capél E, Ding L (2007) Comparison of quantification methods to measure fire-derived (black/elemental) carbon in soils and sediments using reference materials from soil, water, sediment and the atmosphere. Global Biogeochem Cy 21:GB3016CrossRefGoogle Scholar
- IBM Corp. Released (2011) IBM SPSS Statistics for Windows, Version 20.0. Armonk, IBM Corp, New YorkGoogle Scholar
- Kimmerer W, Weaver MJ (2013) Vulnerability of estuaries to climate changes. In: Reference Module in Earth Systems and Environmental Sciences – Climate Vulnerability. Elsevier, AmsterdamGoogle Scholar
- Lehmann J, Joseph S (2009) Biochar for environmental management: an Introduction. In: Lehmann J, Joseph S (eds) Biochar for environmental management: science and technology. Earthscan, London, pp 1–12Google Scholar
- Mitra S, Zimmerman AR, Hunsinger GB, Woerner WR (2013) Black carbon in coastal and large river systems. In: Bianchi TS, Allison MA, Cai WJ (eds) Biogeochemical dynamics at major river-coastal interfaces: linkages with global change. Oxford Publishing Company, New YorkGoogle Scholar
- Moyano FE, Vasilyeva N, Bouckaert L, Cook F, Craine J, Curiel Yuste J, Don A, Epron D, Formanek P, Franzluebbers A, Ilstedt U, Katterer T, Orchard V, Reichstein M, Rey A, Ruamps L, Subke J-A, Thomsen IK, Chenu C (2012) The moisture response of soil heterotrophic respiration: interaction with soil properties. Biogeosciences 9:1173–1182CrossRefGoogle Scholar
- Needles LA, Lester SE, Ambrose R, Andren A, Beyeler M, Connor MS, Eckman JE, Costa-Pierce BA, Gaines SD, Lafferty KD, Lenihan HS, Parrish J, Peterson MS, Scaroni AE, Weis JS, Wendt DE (2015) Managing bay and estuarine ecosystems for multiple services. Estuar Coast 38(Suppl 1):S35–S48CrossRefGoogle Scholar
- Nelson DW, Sommers LE (1982) Total carbon, organic carbon and organic matter. In: Page AL, Miller H, Keeney DR (eds) Method of Soil Analysis Part 2: Chemical and Microbiological Properties No. 9. Agronomy Series. Soil Science Society of America, Madison, pp 570–571Google Scholar
- Spokas KA, Reicosky DC (2009) Impacts of sixteen different biochars on soil greenhouse gas production. Annals Environ Sci 3:179–193Google Scholar
- Van Krevelen DW (1961) Coal: typology, chemistry, physics, constitution. Elsevier, AmsterdamGoogle Scholar