Severity: Warning
Message: file_get_contents(https://...@pubfacts.com&api_key=b8daa3ad693db53b1410957c26c9a51b4908&a=1): Failed to open stream: HTTP request failed! HTTP/1.1 429 Too Many Requests
Filename: helpers/my_audit_helper.php
Line Number: 176
Backtrace:
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 176
Function: file_get_contents
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 250
Function: simplexml_load_file_from_url
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 3122
Function: getPubMedXML
File: /var/www/html/application/controllers/Detail.php
Line: 575
Function: pubMedSearch_Global
File: /var/www/html/application/controllers/Detail.php
Line: 489
Function: pubMedGetRelatedKeyword
File: /var/www/html/index.php
Line: 316
Function: require_once
Reject water, which is the liquid fraction produced after dewatering of anaerobically digested activated sludge on the municipal wastewater treatment plants (MWWTPs), contributes up to 80% of the nitrogen and phosphorus loads to the MWWTP. It was proposed to combine the removal of nitrogen from reject water using the sequential biooxidation of NH(4)(+) and bioreduction of NO(3)(-) with precipitation of phosphate by Fe(2+) ions produced due to bioreduction of Fe(3+) in iron ore. Bioreduction of NO(3)(-) decreased Fe(3+) bioreduction rate in reject water from 37 to 21mg Fe(2+)/Ld due to competition between NO(3)(-) and Fe(3+) for electron donors. Addition of acetate as electron donor increased both bioreduction rates of Fe(3+) and NO(3)(-) but acetate interfered with the competition between nitrate and phosphate anions reacting with ferrous cations decreasing efficiency of the phosphate removal from reject water. The stages of denitrification and ferric bioreduction/phosphate precipitation must be performed sequentially.
Download full-text PDF |
Source |
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http://dx.doi.org/10.1016/j.biortech.2010.01.039 | DOI Listing |
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