Severity: Warning
Message: file_get_contents(https://...@gmail.com&api_key=61f08fa0b96a73de8c900d749fcb997acc09): Failed to open stream: HTTP request failed! HTTP/1.1 429 Too Many Requests
Filename: helpers/my_audit_helper.php
Line Number: 143
Backtrace:
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 143
Function: file_get_contents
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 209
Function: simplexml_load_file_from_url
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 3098
Function: getPubMedXML
File: /var/www/html/application/controllers/Detail.php
Line: 574
Function: pubMedSearch_Global
File: /var/www/html/application/controllers/Detail.php
Line: 488
Function: pubMedGetRelatedKeyword
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: Attempt to read property "Count" on bool
Filename: helpers/my_audit_helper.php
Line Number: 3100
Backtrace:
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 3100
Function: _error_handler
File: /var/www/html/application/controllers/Detail.php
Line: 574
Function: pubMedSearch_Global
File: /var/www/html/application/controllers/Detail.php
Line: 488
Function: pubMedGetRelatedKeyword
File: /var/www/html/index.php
Line: 316
Function: require_once
The production of VFA using as substrate the wastewater produced in a cooked mussel processing factory, containing large COD (13.7 ± 3.2 g COD/L), salt concentrations (21.8 ± 2.8 g NaCl/L) and characterized by low pH (4.6 ± 0.6) was evaluated. This wastewater was fed to a 5-L completely stirred tank reactor operated in continuous mode. The conversion efficiency of its COD content into volatile fatty acids (VFA) was evaluated. The maximum acidification of 43% (total VFA on soluble COD basis) was obtained when an organic loading rate of 2.5 ± 0.4 g COD/(L·d) was applied to the reactor and corresponded to a VFA volumetric productivity of 0.72 ± 0.07 g COD/(L·d). Under steady-state conditions, the obtained mixture of VFA was composed by 80:18:2 as acetic:propionic:butyric acids (percentage of VFA on soluble COD basis). Carbohydrates were degraded up to 96% while protein fermentation did not take place, probably due to the low pH value, limiting the maximum acidification of the wastewater. Batch experiments showed that the increase of the pH from 4.2 to 4.9 by the addition of NaHCO resulted in the improvement of the acidification and changed the VFA mixture composition. Thus, this study demonstrates the opportunity of using complex substrates, as cooked mussel processing wastewater, to produce rich-VFA streams under unfavourable operational conditions, such as high salinity and low pH.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.scitotenv.2020.139337 | DOI Listing |
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!