scholarly journals The effect of aerated rock filter geometry on the rate of nitrogen removal from facultative pond effluents

2011 ◽  
Vol 63 (5) ◽  
pp. 841-844 ◽  
Author(s):  
R. Hamdan ◽  
D. D. Mara

Rock filters are an established technology for polishing waste stabilization pond effluents. However, they rapidly become anoxic and consequently do not remove ammonium-nitrogen. Horizontal-flow aerated rock filters (HFARF), developed to permit nitrification and hence ammonium-N removal, were compared with a novel vertical-flow aerated rock filter (VFARF). There were no differences in the removals of BOD5, TSS and TKN, but the VFARF consistently produced effluents with lower ammonium-N concentrations (<0.3 mg N/L) than the HFARF (0.8−1.5 mg N/L) and higher nitrate-N concentrations (24–29 mg N/L vs. 17–24 mg N/L).

2005 ◽  
Vol 52 (7) ◽  
pp. 115-120 ◽  
Author(s):  
J. Cowman ◽  
C.I. Torres ◽  
B.E. Rittmann

The hydrogen-based membrane biofilm reactor (MBfR) is effective for reducing nitrate-N to N2 gas, but most wastewaters contain ammonium-N. Here, we document that an aerobic/anoxic MBfR system achieves nearly total N removal (<2 mgN/L) when the influent N is ammonium. The aerobic/anoxic MBfR couples two MBfR modules. The aerobic MBfR is supplied O2 and brings about nitrification of ammonium to nitrate or nitrite. The anoxic MBfR is supplied H2 and brings about denitrification to N2 gas. Total N removal is most strongly influenced by the O2 pressure in the aerobic module: too low O2 caused poor nitrification, while too high O2 inhibited denitrification in the anoxic module. Hydrogen pressure does not strongly affect total-N removal, and the best total-N removal occurs when the H2 and O2 pressures are similar.


2018 ◽  
Vol 3 (1) ◽  
pp. 7-14
Author(s):  
J. Kenneth, R. S. Suglo

Sewage generated in Ghana is commonly discharged into the environment without any form of treatment to reduce the degree ofcontamination and mitigate potential public health and environmental issues. Although some attempts have been made in someparts of Ghana to utilize the waste stabilization pond (WSP) system to treat domestic sewage, the ponds often fail to achievetheir purpose due to lack of basic maintenance and supervision. To assess the utility of the WSP system for treating sewage,wastewater samples were collected from the raw sewage, anaerobic, facultative and maturation ponds of WSPs at Obuasi inGhana, and analyzed for physicochemical and microbiological contaminants. The results show that the final pond effluent meetsrecommended microbiological and chemical quality guidelines. The waste stabilization pond system demonstrates high removalefficiencies of wastewater contaminants. The biochemical oxygen demand, total suspended solids, nitrate and faecal coliformsreduction efficiencies of 97.3%, 97.6%, 83.3% and 99.94% respectively are highly significant, and compare well with reportedremoval efficiencies in the literature. Additionally, the ponds have high reduction efficiencies for heavy metals and pathogenicmicroorganisms. The wastewater treatment system complies with standard wastewater management practices, and provides auseful method for treating and disposing wastewater in Ghana.


1995 ◽  
Vol 31 (12) ◽  
pp. 285-290 ◽  
Author(s):  
J. I. Oragui ◽  
H. Arridge ◽  
D. D. Mara ◽  
H. W. Pearson ◽  
S. A. Silva

Rotavirus removal in waste stabilization ponds is a relatively slow process: in a series of ten ponds (a 1-d anaerobic pond followed by nine 2-d ponds) its numbers were reduced from 1.4 × 105 per litre to zero, and in an “innovative” series (a 1-day anaerobic pond, 3-d facultative pond, 3.8-d, 3-d and 5-d maturation ponds) from 5.1 × 104 per litre to <5 per litre. Faecal coliforms were better indicators of rotaviruses than was Clostridium perfringens .


1987 ◽  
Vol 32 (3-4) ◽  
Author(s):  
Fermin Rivera ◽  
Patricia Bonilla ◽  
Sandra Soriano ◽  
JoseLuis Reyes ◽  
Fernando Lares ◽  
...  

2014 ◽  
Vol 7 (9) ◽  
pp. 1710-1714
Author(s):  
C.C. Egwuonwu ◽  
V.C. Okafor ◽  
N.C. Ezeanya ◽  
C. Nzediegwu ◽  
A. Suleiman ◽  
...  

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