The effects of increased organic nitrogen concentration or increased loading rate on H₂ production during the anaerobic digestion of dairy cattle manure /
effect of elevated [] concentrations on various
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| Format: | Thesis Book |
| Language: | English |
| Published: |
[Place of publication not identified] :
[publisher not identified] ;
1998.
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| Subjects: |
| Summary: | effect of elevated [] concentrations on various anaerobic fermentation processes. The objective of this workers to investigate the effectiveness of monitoring hydrogen gas production for predicting upsets in anaerobic digesters operating on dairy cattle manure. In an organic nitrogen overload experiment, urea was added to the experimental digested to obtain increased ammonia concentrations (600, 1500, or 3000 mg N/Q. In an organic overload experiment, digesters were subjected to a step increase in feed volatile solids concentration that was 2, 4, or 8 times the initial pseudo steady sate loading rate (5 g VS/Q. An increase in urea concentration resulted in an initial cessation of Ha production followed by an increase in [] formation. Additions of 600, 1500, or 3000 mg N/L initially resulted in the reduction of [] biogas concentrations. After 24 hours, the [] concentration increased for the 600 and 1500 mg N/L, but production remained inhibited in the 3000 mg N/L group. Urea additions also resulted in reduced methane concentration and total biotas production. Volatile solids reduction also decreased during these periods. The digester effluent pH and alkalinity increased due to the increased [] formed with added urea. Step increases in organic loading rate (OLR) resulted in an immediate increase in hydrogen production for the largest loading rates and delayed smaller increases for lower loading rates. increased while methane concentration decreased. COD and coddle solids reduction also decreased. Alkalinity and pH both decreased in digester effluent due to increased volatile fatty acid production. Based on these results, changes in Ha concentration was a tuneful parameter for monitoring changes due to increased NH: or increased OLR in dairy cattle manure anaerobic digesters. |
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| Item Description: | Vita. "Major subject: Agricultural Engineering". In title, symbols are used. |
| Physical Description: | xi, 81 leaves : illustrations ; 28 cm. Issued also on microfiche from Lange Micrographics. |
| Bibliography: | Includes bibliographical references (leaves 72-80). |