Nutrients removal in hybrid fluidised bed bioreactors operated with aeration cycles

2007 ◽  
Vol 55 (8-9) ◽  
pp. 51-58 ◽  
Author(s):  
M.A. Martín Martín ◽  
L. López Enríquez ◽  
M. Fernández-Polanco ◽  
S. Villaverde ◽  
P.A. García-Encina
Keyword(s):  
Total Nitrogen ◽  
Industrial Wastewater ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Operating Conditions ◽  
Synthetic Wastewater ◽  
Fluidised Bed ◽  
Total N ◽  
Biological Communities ◽  
Gradient Gel Electrophoresis ◽  
Polymerase Chain

Two hybrid fluidised bed reactors filled with sepiolite and granular activated carbon (GAC) were operated with short cycled aeration for removing organic matter, total nitrogen and phosphorous, respectively. Both reactors were continuously operated with synthetic and/or industrial wastewater containing 350–500 mg COD/L, 110–130 mg NKT/L, 90–100 mg NH3-N/L and 12–15 mg P/L for 8 months. The reactor filled with sepiolite, treating only synthetic wastewater, removed COD, ammonia, total nitrogen and phosphorous up to 88, 91, 55 and 80% with a hydraulic retention time (HRT) of 10 h, respectively. These efficiencies correspond to removal rates of 0.95 kgCODm−3d−1 and 0.16 kg total N m−3d−1.The reactor filled with GAC was operated for 4 months with synthetic wastewater and 4 months with industrial wastewater, removing 98% of COD, 96% of ammonia, and 66% of total nitrogen, with an HRT of 13.6 h. No significant phosphorous removing activity was observed in this reactor. Microbial communities growing with both reactors were followed using polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE) techniques. The microbial fingerprints, i.e. DGGE profiles, indicated that biological communities in both reactors were stable along the operational period even when the operating conditions were changed.

scholarly journals Investigations on the Effects of Dietary Essential Oils and Different Husbandry Conditions on the Gut Ecology in Piglets after Weaning

2009 ◽  
Vol 2009 ◽  
pp. 1-9 ◽  
Author(s):  
P. Janczyk ◽  
R. Pieper ◽  
V. Urubschurov ◽  
K. R. Wendler ◽  
W. B. Souffrant
Keyword(s):  
Essential Oils ◽  
Dry Matter ◽  
Distal Part ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Control Diet ◽  
Short Chain Fatty Acids ◽  
Growth Promoters ◽  
Gradient Gel Electrophoresis ◽  
Antibiotic Growth Promoters ◽  
Polymerase Chain

Essential oils (EO) are being considered as possible alternatives to in-feed antibiotic growth promoters in pig nutrition. The effects of an EO mixture consisting of limonene, eugenol and pinene (10.0, 2.0, and 4.8 mg/kg diet, resp.) on gut physiology and ecology were studied in piglets. The experiment was conducted at low (commercial farm) and high hygienic conditions (experimental farm), to elucidate interactions between EO supplementation and husbandry methods. Piglets were weaned at 28 days of age, when they were offered either a control diet (C) or C with EO. Four piglets were sacrificed in each group on day 29, 30, 33 and 39. Digesta from the third distal part of the small intestine and from the colon were sampled and analysed for pH, dry matter, lactic acid, short chain fatty acids and ammonia concentrations. Enterobacteria, enterococci, lactobacilli and yeast counts were obtained by plating. Genomic DNA was extracted from digesta and polymerase chain reaction—denaturing gradient gel electrophoresis was performed. Individual microbial communities were identified at each farm. Age affected the intestinal parameters. No effects of the EO with exception for a significant reduction in colon bacterial diversity at 39 days of age could be recorded at experimental farm.

The assessment of the coke wastewater treatment efficacy in rotating biological contractor

2015 ◽  
Vol 73 (5) ◽  
pp. 1202-1210 ◽  
Author(s):  
G. Cema ◽  
S. Żabczyński ◽  
A. Ziembińska-Buczyńska
Keyword(s):  
Biological Treatment ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Rotating Biological Contactor ◽  
Coke Wastewater ◽  
Promising Tool ◽  
Start Up ◽  
Gradient Gel Electrophoresis ◽  
Real Wastewater ◽  
Polymerase Chain ◽  
Anammox Process

Coke wastewater is known to be relatively difficult for biological treatment. Nonetheless, biofilm-based systems seem to be promising tool for such treatment. That is why a rotating biological contactor (RBC) system focused on the Anammox process was used in this study. The experiment was divided into two parts with synthetic and then real wastewater. It was proven that it is possible to treat coke wastewater with RBC but such a procedure requires a very long start-up period for the nitritation (190 days), as well as for the Anammox process, where stable nitrogen removal over 70% was achieved after 400 days of experiment. Interestingly, it was possible at a relatively low (20.2 ± 2.2 °C) temperature. The polymerase chain reaction–denaturing gradient gel electrophoresis (PCR-DGGE) based monitoring of the bacterial community showed that its biodiversity decreased when the real wastewater was treated and it was composed mainly of GC-rich genotypes, probably because of the modeling influence of this wastewater and the genotypes specialization.

A comparitive study of ammonia-oxidizing bacteria in lab-scale industrial wastewater treatment reactors

2003 ◽  
Vol 48 (3) ◽  
pp. 17-24 ◽  
Author(s):  
A.K. Rowan ◽  
G. Moser ◽  
N. Gray ◽  
J.R. Snape ◽  
D. Fearnside ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Industrial Wastewater ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Direct Sequencing ◽  
Ammonia Oxidizing Bacteria ◽  
Industrial Wastewater Treatment ◽  
Phylogenetic Affiliation ◽  
Gradient Gel Electrophoresis ◽  
Nitrosococcus Mobilis ◽  
Ammonia Oxidising Bacteria

The diversity and community structure of the b-proteobacterial ammonia oxidising bacteria (AOB) in a range of different lab-scale industrial wastewater treatment reactors were compared. Three of the reactors treat waste from mixed domestic and industrial sources whereas the other reactor treats waste solely of industrial origin. PCR with AOB selective primers was combined with denaturing gradient gel electrophoresis to allow comparative analysis of the dominant AOB populations and the phylogenetic affiliation of the dominant AOB was determined by cloning and sequencing or direct sequencing of bands excised from DGGE gels. Different AOB were found within and between different reactors. All AOB sequences identified were grouped within the genus Nitrosomonas. Within the lab-scale reactors there appeared to be selection for a low diversity of AOB and predominance of a single AOB population. Furthermore, the industrial input in both effluents apparently selected for salt tolerant AOB, most closely related to Nitrosococcus mobilis and Nitrosomonas halophila.

PCR-DGGE analysis of denitrifying bacteria in a metallurgic wastewater treatment process

2002 ◽  
Vol 46 (1-2) ◽  
pp. 333-336 ◽  
Author(s):  
N. Noda ◽  
S. Yoshie ◽  
T. Miyano ◽  
S. Tsuneda ◽  
A. Hirata ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Precious Metals ◽  
Packed Bed ◽  
Population Diversity ◽  
Operating Conditions ◽  
Industrial Wastes ◽  
Wastewater Treatment Process ◽  
Dgge Analysis ◽  
Gradient Gel Electrophoresis

The wastewater generated from the processes of recovering precious metals from industrial wastes contains high concentrations of acids such as nitric acid and of salts. Biological nitrogen removal from this wastewater was attempted by using a circulating bioreactor system equipped with an anoxic packed bed or an anoxic fluidized bed and an aerobic three-phase fluidized bed. The system was found to effectively remove nitrogen from the diluted wastewater (T-N; 1,000–4,000 mg litre−1). The microbial population structure of activated sludge in an anoxic reactor was analyzed by denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S ribosomal DNA (rDNA) fragments. DGGE analysis under different operating conditions demonstrated the presence of some distinguishable bands in the separation pattern, which were most likely derived from many different species constituting the microbial communities. Furthermore, the population diversity varied in accordance with the nitrate-loading rate, water temperature and reactor condition. Some major DGGE bands were excised, reamplified and directly sequenced. It was revealed that the dominant population in the anoxic reactor were affiliated with the β subclass of the class Proteobacteria.

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