Linked Life Data

15566201

Source:http://linkedlifedata.com/resource/pubmed/id/15566201

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
2004-11-29
pubmed:abstractText
This study evaluates the effect of chlorination bulking control on water quality and phosphate release/uptake in an anaerobic-oxic activated sludge system. A series of batch experiments with different specific NaOCl mass dose were conducted to determine the sludge settling properties, supernatant water quality and phosphate metabolism behavior of filamentous bulking sludge. The harvested sludge was from a continuous-flow anaerobic-oxic (A/O) activated sludge pilot-plant, i.e., enhanced biological phosphorus removal (EBPR) system, operated with 15 days of sludge retention time. The filamentous bacteria in the A/O pilot plant were identified to be Thiothrix according to Eikelboom's classification techniques, which was in accordance with the high influent sulfate concentration of this study (50 mg/L sulfate). Increasing NaOCI concentration, as revealed by experimental results, obviously decreased the sludge settling properties (SVI values and zone settling velocities) and meanwhile significantly reduced supernatant water quality (COD, SS, TP) mainly due to higher suspended solids caused by floc disruption. Moreover, the nine-hour batch experiments indicated that high NaOCI dosage (40 mg/gMLSS) completely deteriorated phosphate metabolism of EBPR sludge. Such a high dosage of chlorination further confirmed overdosing through disappearance of intracellular PHB and death of protozoa by microscopic investigation. Still, phosphate release/uptake behavior of EBPR sludge properly functions at low NaOCl dosage (5 mg/g MLSS). Besides, phosphate metabolism worsens rapidly before the SVI value reaches its lowest level. These findings imply that determining NaOCI requirement with merely SVI values can readily result in chlorination overdosing. Proper NaOCI dosage requires a delicately balanced consideration between sludge settling improvement, water quality demand and phosphate metabolism. Batch test of phosphate release/uptake is apparently a prerequisite to conclude an appropriate NaOCl dosage for bulking control.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0273-1223
pubmed:author
pubmed:issnType
Print
pubmed:volume
50
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
177-83
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Effect of chlorination bulking control on water quality and phosphate release/uptake in an anaerobic-oxic activated sludge system.
pubmed:affiliation
Department of Environmental & Safety Engineering, National Yunlin University of Science & Technology, Touliu, 640, Yunlin, Chinese Taiwan. changwc@yuntech.edu.tw
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't