Effect of Internal Recycle Ratio on the Phosphorus Removal Efficiency of Anaerobic/Anoxic/Oxic (A2/O) to Low Concentration of Organic Substance Wastewater

2011 ◽  
Vol 393-395 ◽  
pp. 688-691
Author(s):  
Ning Wang ◽  
Ying He Jiang ◽  
Bo Fu Li

In the pilot-scale plant, the effect of internal recycle ratios (300%, 200%, 100%, and 0%) on the biological phosphorus removal was represented. The denitrifying phosphorus removal in anoxic tank was improved with low internal recycle, under the inhibition of high concentration of NOx-N. To low level strength wastewater (average COD 185.6 mg/L, average BOD 115.2 mg/L), the low level carbon source maintained the relatively steady phosphorus removal rates.

2004 ◽  
Vol 49 (5-6) ◽  
pp. 257-264 ◽  
Author(s):  
S.R. Chae ◽  
S.H. Lee ◽  
J.O. Kim ◽  
B.C. Paik ◽  
Y.C. Song ◽  
...  

As the sewerage system is incomplete, sewage in Korea lacks easily biodegradable organics for nutrient removal. In this country, about 11,400 tons of food waste of high organic materials is produced daily. Therefore, the potential of food waste as an external carbon source was examined in a pilot-scale BNR (biological nutrient removal) process for a half year. It was found that as the supply of the external carbon increased, the average removal efficiencies of T-N (total nitrogen) and T-P (total phosphorus) increased from 53% and 55% to 97% and 93%, respectively. VFAs (volatile fatty acids) concentration of the external carbon source strongly affected denitrification efficiency and EBPR (enhanced biological phosphorus removal) activity. Biological phosphorus removal was increased to 93% when T-N removal efficiency increased from 78% to 97%. In this study, several kinds of PHAs (poly-hydroxyalkanoates) in cells were observed. The observed PHAs was composed of 37% 3HB (poly-3- hydroxybutyrate), 47% 3HV (poly-3-hydroxyvalerate), 9% 3HH (poly-3-hydroxyhexanoate), 5% 3HO (poly-3-hydroxyoctanoate), and 2% 3HD (poly-3-hydroxydecanoate).


2006 ◽  
Vol 41 (1) ◽  
pp. 72-83 ◽  
Author(s):  
Zhe Zhang ◽  
Eric R. Hall

Abstract Parameter estimation and wastewater characterization are crucial for modelling of the membrane enhanced biological phosphorus removal (MEBPR) process. Prior to determining the values of a subset of kinetic and stoichiometric parameters used in ASM No. 2 (ASM2), the carbon, nitrogen and phosphorus fractions of influent wastewater at the University of British Columbia (UBC) pilot plant were characterized. It was found that the UBC wastewater contained fractions of volatile acids (SA), readily fermentable biodegradable COD (SF) and slowly biodegradable COD (XS) that fell within the ASM2 default value ranges. The contents of soluble inert COD (SI) and particulate inert COD (XI) were somewhat higher than ASM2 default values. Mixed liquor samples from pilot-scale MEBPR and conventional enhanced biological phosphorus removal (CEBPR) processes operated under parallel conditions, were then analyzed experimentally to assess the impact of operation in a membrane-assisted mode on the growth yield (YH), decay coefficient (bH) and maximum specific growth rate of heterotrophic biomass (µH). The resulting values for YH, bH and µH were slightly lower for the MEBPR train than for the CEBPR train, but the differences were not statistically significant. It is suggested that MEBPR simulation using ASM2 could be accomplished satisfactorily using parameter values determined for a conventional biological phosphorus removal process, if MEBPR parameter values are not available.


1982 ◽  
Vol 14 (1-2) ◽  
pp. 31-45 ◽  
Author(s):  
J L Barnard

This paper discusses the need for anaerobiases as a pre-requisite for phosphorus removal in activated sludge plants and the effect of nitrates on the anaerobic conditions. If the plant could be operated to avoid nitrification, biological phosphorus removal presents no problems. When nitrification is required, the nitrates must be reduced to a low level through internal denitrification. If sufficient carbon is available to ensure complete removal of the nitrates and anaerobic conditions in a specific zone in the plant, good phosphate removal can be ensured. Below COD : TKN ratios of 10 : 1 it is becoming more difficult to control the plant and special care should be taken to determine not only the quantity of organic carbon available as electron donors for removal of the nitrates but also the form in which it arrives at the plant.


2006 ◽  
Vol 54 (10) ◽  
pp. 169-176 ◽  
Author(s):  
Z. Geng ◽  
E.R. Hall

Characterization of fouled membranes is the first step towards a good understanding of membrane fouling nature and thus formulating effective engineering measures for fouling prevention and control. In this study, fouled membrane fibres collected from a pilot scale membrane enhanced biological phosphorus removal (MEBPR) process were systematically examined. Several analytical tools, including scanning electron microscopy (SEM), conventional optical microscopy (COM), energy dispersive X-ray (EDX) microanalysis, matrix assisted laser desorption/ionization – mass spectrometry (MALDI-MS) analysis, and conventional chemical analysis techniques were used. The results indicated that membrane fouling in the MEBPR process was mainly of an organic nature, and most extractable foulants were carbohydrates and humic or humic-like substances. Unlike in other wastewater treatment membrane bioreactors, microbial growth on fouled membranes was not substantial, probably due to the vigorous aeration applied and the strong hydrodynamic conditions within the membrane pore structure. After a period of sludge filtration, membrane surfaces became more hydrophobic and the resultant hydrophobic interactions between the fouled membranes and mixed liquor constituents might have accelerated the fouling process.


1994 ◽  
Vol 29 (10-11) ◽  
pp. 135-143 ◽  
Author(s):  
R. F. Gonçalves ◽  
L. Le Grand ◽  
F. Rogalla

This paper introduces biological phosphorus removal (Bio-P) from wastewater on a submerged biofilter. Pilot scale research was carried out over a period of two years using a floating upflow aerated filter, originally designed for nitrification and denitrification of sewage. The factors which influence Bio-P on fixed film processes and the possible biofilter configurations which eliminate C, N and P are discussed. The procedures are applicable to all types of treatment plants using biofilters, both new and already in existence, making no distinction between the different processes available today, co-current and counter-current filters. Biological phosphorus removal can be associated to the different treatment levels required: organic matter removal; secondary nitrification secondary nitrification and denitrification. For the third option - complete nutrient removal, treatment is completed with a hydraulic retention time in the filter bed of under four hours. Because of the simultaneous filtration with effluent SS below 10 mg/l, low phosphorus residuals can be achieved by Bio-P alone. The modifications required for setting up this operating procedure on any treatment plant are presented.


Sign in / Sign up

Export Citation Format

Share Document