Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7068544 | Bioresource Technology | 2018 | 17 Pages |
Abstract
The effectiveness of the Free Nitrous Acid (FNA) sludge treatment was tested in the range from 0 to 3.0â¯mgâ¯N-HNO2/L with acidified and neutral pH. 4â¯h pre-treatment times were used and the specific methane production (SMP) investigated. Results show that between 50 and 100â¯mg/L of N-NO2â/L disappeared during the FNA pre-treatment, reducing its effectiveness. A minimum level of nitrite (174â¯mgâ¯N-NO2â/L tested in this study), independently of pH/FNA, was necessary to assure the presence of the chemical throughout the duration of the pre-treatment. Sludge viability was compromised while WAS solubilization and SMP were enhanced with nitrite concentrations of 174â¯mgâ¯N-NO2â/L or higher, even at low FNA levels (<0.15â¯mgâ¯N-HNO2/L). Results show that acidified pH is not needed to enhance methane production, making the pretreatment more economically and environmentally attractive.
Keywords
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Process Chemistry and Technology
Authors
S. Zahedi, M. Romero-Güiza, Pilar Icaran, Z. Yuan, M. Pijuan,