Anaerobic digestion of sugar beet
Sweden and Europe aims at increasing the use of renewable energy. Biogas represents one way to reach this goal. Biogas, produced from organic waste or crop materials, can be used for production of heat and electricity and as fuel for vehicles. The biogas process is also advantageous as it mediate t...
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| Formato: | Otro |
| Lenguaje: | sueco Inglés |
| Publicado: |
2008
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| Materias: | |
| Acceso en línea: | https://stud.epsilon.slu.se/11782/ |
| _version_ | 1855571938228830208 |
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| author | Haraldsson, Lena |
| author_browse | Haraldsson, Lena |
| author_facet | Haraldsson, Lena |
| author_sort | Haraldsson, Lena |
| collection | Epsilon Archive for Student Projects |
| description | Sweden and Europe aims at increasing the use of renewable energy. Biogas represents one
way to reach this goal. Biogas, produced from organic waste or crop materials, can be used for production of heat and electricity and as fuel for vehicles. The biogas process is also advantageous as it mediate the recirculation of nutrient from waste products to arable fields. This can be achieved by spreading the nutrient rich bio manure, which is left after digestion, on arable fields. Organic material, used as substrate in a biogas process, can contain different contaminating organisms such as different fungi. Some fungi are plant pathogens and if these survive the biogas process and is spread on arable land they might infect the new crop, thus leading to reduced yields and an increased need for fungicides. If storage pathogens are spread they may survive on organic debris on the ground and damage the harvested crop during storage. Therefore it is important to evaluate potential risks when materials infected with plant pathogenic fungi are used as substrate in a biogas process. Furthermore, if fungi are killed, the biogas process offers an alternative way of using crops with not good enough quality for food or feed production. Presently, it is however at unclear what levels of gas production that can be reached with such "low quality" materials.
The aim of this study was to investigate fate of plant pathogens during mesophilic anaerobic digestion and also to investigate gas production potential of infected and uninfected sugar beet, both fresh beet roots and those stored for one year. Survival studies were performed for three different sugar beet field pathogens, Aphanomyces cochlioides, Pythium ultimum and Rhizoctonia solani, causing emergence diseases, and for two different storage pathogens Fusarium culmorum and Botrytis cinerea. The gas production potential was determined in a batch test system started with inoculum from two different large scale biogas plants.
The measurement of gas production potential showed that both uninfected fresh and stored sugar beets produced more methane (per g added Volatile Solid) than beet material infected by the different fungal pathogens. Survival studies performed with spores of Fusarium culmorum and Botrytis cinerea demonstrated a very short survival time, less than 2.5 hours. For two sugar beet pathogens, Aphanomyces cochlioides and Pythium ultimum, it was not possible to obtain the most resistant survival structure, the oospores, and the survival test was therefore performed with only mycelia and/or oogonia. Both these structures survived for a very short time.
In order to predict the fate of these fungi in a biogas process, more studies are needed. However, even though it was not possible to test all fungal structures of interest, the results so far suggest that it is unlikely that fungi would pose a great problem in bio manure. Before the material is digested and used as bio manure it passes several steps, sanitation, anaerobic digestion, post-digestion, aerobic storage, with varied environments. Therefore, it seems unlikely that a fungus can adapt and survive through all of those steps. Conclusively, a biogas production process could be a good way to dispose of contaminated organic material. However, it is important to consider the lower methane yield when planning the biogas plant. |
| format | Otro |
| id | RepoSLU11782 |
| institution | Swedish University of Agricultural Sciences |
| language | Swedish Inglés |
| publishDate | 2008 |
| publishDateSort | 2008 |
| record_format | eprints |
| spelling | RepoSLU117822017-10-17T10:10:48Z https://stud.epsilon.slu.se/11782/ Anaerobic digestion of sugar beet Haraldsson, Lena Dept. of Microbiology Food science and technology Sweden and Europe aims at increasing the use of renewable energy. Biogas represents one way to reach this goal. Biogas, produced from organic waste or crop materials, can be used for production of heat and electricity and as fuel for vehicles. The biogas process is also advantageous as it mediate the recirculation of nutrient from waste products to arable fields. This can be achieved by spreading the nutrient rich bio manure, which is left after digestion, on arable fields. Organic material, used as substrate in a biogas process, can contain different contaminating organisms such as different fungi. Some fungi are plant pathogens and if these survive the biogas process and is spread on arable land they might infect the new crop, thus leading to reduced yields and an increased need for fungicides. If storage pathogens are spread they may survive on organic debris on the ground and damage the harvested crop during storage. Therefore it is important to evaluate potential risks when materials infected with plant pathogenic fungi are used as substrate in a biogas process. Furthermore, if fungi are killed, the biogas process offers an alternative way of using crops with not good enough quality for food or feed production. Presently, it is however at unclear what levels of gas production that can be reached with such "low quality" materials. The aim of this study was to investigate fate of plant pathogens during mesophilic anaerobic digestion and also to investigate gas production potential of infected and uninfected sugar beet, both fresh beet roots and those stored for one year. Survival studies were performed for three different sugar beet field pathogens, Aphanomyces cochlioides, Pythium ultimum and Rhizoctonia solani, causing emergence diseases, and for two different storage pathogens Fusarium culmorum and Botrytis cinerea. The gas production potential was determined in a batch test system started with inoculum from two different large scale biogas plants. The measurement of gas production potential showed that both uninfected fresh and stored sugar beets produced more methane (per g added Volatile Solid) than beet material infected by the different fungal pathogens. Survival studies performed with spores of Fusarium culmorum and Botrytis cinerea demonstrated a very short survival time, less than 2.5 hours. For two sugar beet pathogens, Aphanomyces cochlioides and Pythium ultimum, it was not possible to obtain the most resistant survival structure, the oospores, and the survival test was therefore performed with only mycelia and/or oogonia. Both these structures survived for a very short time. In order to predict the fate of these fungi in a biogas process, more studies are needed. However, even though it was not possible to test all fungal structures of interest, the results so far suggest that it is unlikely that fungi would pose a great problem in bio manure. Before the material is digested and used as bio manure it passes several steps, sanitation, anaerobic digestion, post-digestion, aerobic storage, with varied environments. Therefore, it seems unlikely that a fungus can adapt and survive through all of those steps. Conclusively, a biogas production process could be a good way to dispose of contaminated organic material. However, it is important to consider the lower methane yield when planning the biogas plant. Både Sverige och Europa har som mål att öka andelen förnyelsebar energi och ett sätt att uppnå detta är genom en ökad biogasproduktion. Biogas kan produceras genom rötning av gödsel, energigrödor eller organiskt avfall. Den kan användas till uppvärmning, elektricitet och som fordonsbränsle. Kvar efter rötningen finns en näringsrik rötrest. Genom att använda denna restprodukt som gödningsmedel till jordbruksgrödor är det möjligt att få cirkulation av näringsämnen. Det organiska materialet som används i biogasproduktionen kan innehålla olika föroreningar, som till exempel svampar. En del svampar är växtskadegörare och dessa kan, om de överlever rötningen och sprids med rötresten, infektera en ny gröda. Som en följd kan detta leda till skördesänkningar och ett ökat behov av bekämpningsmedel. Om lagringssvampar sprids med rötresterna kan dessa kanske överleva i marken och, om de följer med grödan vid skörd, också orsaka skador under lagring. På grund av detta är det viktigt att utvärdera vilka risker som finns med att använda svampinfekterat material för biogasproduktion. Om svamparna däremot dör kan en biogasprocess vara ett bra sätt att ta hand om organiskt material med dålig kvalitet, som inte kan användas till mat eller foderproduktion. I dagsläget är det dock oklart hur stor gasproduktion ett sådant material ger jämfört med oinfekterat material. Syftet med detta arbete var att undersöka överlevnaden av svampar under mesofil rötning samt att undersöka gasproduktionspotentialen för oinfekterade och infekterade sockerbetor, både färska betor och sådana som lagrats ett år har testats. Tre olika fältsvampar, Aphanomyces cochlioides, Pythium ultimum och Rhizoctonia solani, som orsakar groddbränna på sockerbetor, och två lagringssvampar, Fusarium culmorum och Botrytis cinerea undersöktes i överlevnadsstudierna. Gasproduktionspotentialen bestämdes genom satsvisa biogassystem som startades med rötrester från två olika storskaliga biogasreaktorer. Mer total gas och metan producerades från de oinfekterade betorna (per g tillsatt organiskt material) än de som infekterats med olika svampar, detta gällde både för färska och lagrade betor. Överlevnadsstudierna med sporer från Fusarium culmorum och Botrytis cinerea visade att de överlever mindre än 2,5 h. För två av skadegörarna på sockerbetor, Aphanomyces cochlioides och Pythium ultimum, gick det inte att odla överlevnadsstrukturer, oosporer. Därför gjordes överlevnadsstudier med mycel och oogonia. Båda dessa strukturer överlevde emellertid mycket kort tid. För bedöma potentiell överlevnad av dessa växtpatogener behövs fler studier. Trots att det i studien inte gick att pröva överlevnaden av alla intressanta svampar och deras strukturer indikerar ändå resultaten att de sannolikt inte utgör något större kvalitetsproblem i rötresten. Dessutom består rötningsprocessen oftast av flera olika steg: hygienisering, rötning, efterrötning och aerob lagring innan den används som gödselmedel. I dessa steg är miljöförhållandena väldigt olika och därför är det inte troligt att en svamp klarar alla dessa olika miljöer. Eftersom svampen antagligen inte är ett problem så borde biogasproduktion vara ett bra sätt använda infekterat material. Det är dock viktigt att vid beräkningar och dimensionering av biogasreaktorn och dess ekonomi ta hänsyn till att en lägre metanmängd produceras från detta material. 2008-09-04 Other NonPeerReviewed application/pdf sv https://stud.epsilon.slu.se/11782/1/haraldsson_l_171017.pdf Haraldsson, Lena, 2008. Anaerobic digestion of sugar beet : fate of plant pathogens and gas potential. UNSPECIFIED, Uppsala. Uppsala: (NL, NJ) > Dept. of Microbiology <https://stud.epsilon.slu.se/view/divisions/4024.html> urn:nbn:se:slu:epsilon-s-7907 eng |
| spellingShingle | Dept. of Microbiology Food science and technology Haraldsson, Lena Anaerobic digestion of sugar beet |
| title | Anaerobic digestion of sugar beet |
| title_full | Anaerobic digestion of sugar beet |
| title_fullStr | Anaerobic digestion of sugar beet |
| title_full_unstemmed | Anaerobic digestion of sugar beet |
| title_short | Anaerobic digestion of sugar beet |
| title_sort | anaerobic digestion of sugar beet |
| topic | Dept. of Microbiology Food science and technology |
| url | https://stud.epsilon.slu.se/11782/ https://stud.epsilon.slu.se/11782/ |