Document Detail


Microbial ecology and performance of ammonia oxidizing bacteria (AOB) in biological processes treating petrochemical wastewater with high strength of ammonia: effect of Na(2)CO(3) addition.
MedLine Citation:
PMID:  19182331     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
This study evaluated nitrification performance and microbial ecology of AOB in a full-scale biological process, powder activated carbon treatment (PACT), and a pilot-scale biological process, moving bed biofilm reactor (MBBR), treating wastewater collected from a petrochemical industry park. The petrochemical influent wastewater characteristics showed a relative low carbon to nitrogen ratio around 1 with average COD and ammonia concentrations of 310 mg/L and 325 mg-N/L, respectively. The average nitrification efficiency of the full-scale PACT process was around 11% during this study. For the pilot-scale MBBR, the average nitrification efficiency was 24% during the Run I operation mode, which provided a slightly better performance in nitrification than that of the PACT process. During the Run II operation, the pH control mode was switched from addition of NaOH to Na(2)CO(3), leading to a significant improvement in nitrification efficiency of 51%. In addition to a dramatic change in nitrification performance, the microbial ecology of AOB, monitored with the terminal restriction fragment length polymorphism (T-RFLP) molecular methodology, was found to be different between Runs I and II. The amoA-based TRFLP results indicated that Nitrosomonas europaea lineage was the dominant AOB population during Run I operation, while Nitrosospira-like AOB was dominant during Run II operation. To confirm the effects of Na(2)CO(3) addition on the nitrification performance and AOB microbial ecology observed in the MBBR process, batch experiments were conducted. The results suggest that addition of Na(2)CO(3) as a pH control strategy can improve nitrification performance and also influence AOB microbial ecology as well. Although the exact mechanisms are not clear at this time, the results showing the effects of adding different buffering chemicals such as NaOH or Na(2)CO(3) on AOB populations have never been demonstrated until this study.
Authors:
L M Whang; K H Yang; Y F Yang; Y L Han; Y J Chen; S S Cheng
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Water science and technology : a journal of the International Association on Water Pollution Research     Volume:  59     ISSN:  0273-1223     ISO Abbreviation:  Water Sci. Technol.     Publication Date:  2009  
Date Detail:
Created Date:  2009-02-02     Completed Date:  2009-03-31     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9879497     Medline TA:  Water Sci Technol     Country:  England    
Other Details:
Languages:  eng     Pagination:  223-31     Citation Subset:  IM    
Affiliation:
Department of Environmental Engineering, National Cheng Kung University, Tainan, Chinese Taiwan. whang@mail.ncku.edu.tw
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MeSH Terms
Descriptor/Qualifier:
Ammonia / metabolism*
Bacteria / drug effects*,  metabolism*
Bioreactors / microbiology*
Carbonates / pharmacology*
Hydrogen-Ion Concentration
Models, Theoretical
Oxidation-Reduction
Waste Disposal, Fluid / methods*
Chemical
Reg. No./Substance:
0/Carbonates; 497-19-8/sodium carbonate; 7664-41-7/Ammonia

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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