Removal and Transformation of Pollutants in a Two-Line Denitrifying Phosphorus Removal Process Treating Low C/N Municipal Wastewater: Influence of Hydraulic Retention Time

2018 ◽  
Vol 229 (3) ◽  
Author(s):  
Hongbo Liu ◽  
Yangyang Yao ◽  
Suyun Xu
Keyword(s):  
Retention Time ◽  
Phosphorus Removal ◽  
Municipal Wastewater ◽  
Hydraulic Retention Time ◽  
Denitrifying Phosphorus Removal ◽  
Removal Process

Biological Phosphorus Removal in Fixed Films Reactors

1992 ◽  
Vol 25 (12) ◽  
pp. 165-174 ◽  
Author(s):  
R. Franci Gonçalves ◽  
F. Rogalla
Keyword(s):  
Retention Time ◽  
Phosphorus Removal ◽  
Hydraulic Retention Time ◽  
Phosphorus Release ◽  
Organic Substrate ◽  
Biological Phosphorus Removal ◽  
Removal Process ◽  
Fixed Film ◽  
Film Reactor ◽  
Biological Phosphorus

Possible procedures to achieve biological phosphorus removal in a fixed film reactor are discussed and the feasibility of phosphorus removal process in a fixed film reactor under continous flow is demonstrated. The behaviour of an upflow aerated filter operating under continuous feed and alternate aerobic/anaerobic conditions is analyzed. The influence of the duration of anaerobic and aerobic contact periods and of organic substrate loadings on the phosphorus removal process is verified. During the anaerobic state, the longer the duration, or the higher the substrate load, the better the phosphorus release and consequently the higher the uptake in the aerobic phase. The excess of accumulated phosphorus in the aerobic phase over released phosphorus in the anaerobic phase approaches 33 %. For each mg of phosphorus released, 5 mg filtered COD are consumed. Continuous phosphorus removal on two biofilters in series was performed by alternating aeration conditions, always introducing the influent to the anaerobic reactor.The tests carried out on laboratory scale showed that this system carrys out complete nitrification and removal of 80% of the phosphorus with a maximum hydraulic retention time of 5 hours. The hydraulic retention time and the residence time of the biomass in the reactor are independent and, therefore, the time the bacteria are exposed to alternate A/O conditions can be optimized. The very low concentrations of suspended solids in the effluent of the biofilter enable residual levels below 1 mg PO4-P/l to be obtained. Further investigations are carried out on full scale and to introduce denitrification in the same reactor.

Anaerobic thermophilic digestion of sewage sludge with a thickened sludge recycle

2012 ◽  
Vol 65 (3) ◽  
pp. 403-409 ◽  
Author(s):  
A. Ya. Vanyushina ◽  
Yu. A. Nikolaev ◽  
A. M. Agarev ◽  
M. V. Kevbrina ◽  
M. N. Kozlov
Keyword(s):  
Retention Time ◽  
Municipal Wastewater ◽  
Hydraulic Retention Time ◽  
Biogas Production ◽  
Wastewater Sludge ◽  
Recycling Process ◽  
Digested Sludge ◽  
Volatile Solids ◽  
Solids Retention ◽  
Thermophilic Digestion

The process of anaerobic thermophilic digestion of municipal wastewater sludge with a recycled part of thickened digested sludge, was studied in semi-continuous laboratory digesters. This modified recycling process resulted in increased solids retention time (SRT) with the same hydraulic retention time (HRT) as compared with traditional digestion without recycling. Increased SRT without increasing of HRT resulted in the enhancement of volatile substance reduction by up to 68% in the reactor with the recycling process compared with 34% in a control conventional reactor. Biogas production was intensified from 0.3 L/g of influent volatile solids (VS) in the control reactor up to 0.35 L/g VS. In addition, the recycling process improved the dewatering properties of digested sludge.

Simultaneous removal of nitrogen and phosphorus in a two-biofilter system

2000 ◽  
Vol 41 (12) ◽  
pp. 101-106 ◽  
Author(s):  
D. Pak ◽  
W. Chang
Keyword(s):  
Retention Time ◽  
Phosphorus Removal ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Aerobic Condition ◽  
Nitrogen Loading ◽  
Simultaneous Removal ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Factors Affecting

A two-biofilter system operated under alternate conditions of anaerobic/aerobic was tested to simultaneously remove nitrogen and phosphorus from sewage. The factors affecting simultaneous removal of nitrogen and phosphorus by the two-biofilter system were investigated. Those factors appeared to be influent COD/T-N and COD/T-P ratio, nitrogen loading rate and hydraulic retention time. Nitrite and nitrate produced in the biofilter in aerobic condition affected phosphorus removal by the two-biofilter system. The amount of biomass wasted during the backwash procedure also affected total nitrogen and phosphorus removal by the system.

scholarly journals Start-up of UASB reactors treating municipal wastewater and effect of temperature/sludge age and hydraulic retention time (HRT) on its performance

2015 ◽  
Vol 8 (6) ◽  
pp. 780-786 ◽  
Author(s):  
Hina Rizvi ◽  
Nasir Ahmad ◽  
Farhat Abbas ◽  
Iftikhar Hussain Bukhari ◽  
Abdullah Yasar ◽  
...  
Keyword(s):  
Retention Time ◽  
Municipal Wastewater ◽  
Hydraulic Retention Time ◽  
Effect Of Temperature ◽  
Start Up ◽  
Uasb Reactors
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