New method for studying the hydraulic behaviour of tanks in series — Application to aerated lagoons and waste stabilization ponds

1996 ◽  
Vol 33 (8) ◽  
1987 ◽  
Vol 19 (12) ◽  
pp. 389-391 ◽  
Author(s):  
A. Hall ◽  
A. C. Duarte ◽  
J. P. Oliveira

In any campus where there is an excess of land or where a decorative pond is available, it is often possible to establish a system of waste stabilization ponds (WSP) to be used as an open air research laboratory, as source of water for watering the campus grounds and as a demonstration unit for the community at large. One such system, comprising one photosynthetic and one macrophyte pond in parallel, followed by one fish and one irrigation pond in series, was built at the Faro Polythecnic in Portugal. The ponds are proceeded by an underground unit formed by three septic tanks in series followed by two upflow anaerobic filters in parallel. This system is expected to receive 120m3/day of a mixed effluent coming from the sanitary facilities, the refectory and the fish processing laboratory, with concentrations of about 600mg/l in both BOD and SS.


1991 ◽  
Vol 23 (7-9) ◽  
pp. 1495-1502 ◽  
Author(s):  
Marcelo Juanico

The effect of the hydraulic flow pattern on the performance of Waste Stabilization Ponds is analyzed by modelling. The analysis is made on two parameters with different removal constants (Bacteria and BOD) and for the cases of steady hydraulic loading and when hydraulic loading changes on weekends. Plug-flow ponds perform much better than perfect mixed ones for removal of parameters with high removal constants such as bacteria. Plug-flow and perfect mixed ponds perform very similarly when the removal constant is low as for BOD. Changes in the hydraulic loading regime due to weekend effect do not modify the variability of outflow quality from plug-flow ponds. These changes do affect the variability of outflow quality from perfect mixed ponds only in the case of parameters with high removal constants such as bacteria. Polishing ponds Intended for bacterial removal should be designed for plug-flow. Facultative ponds intended for BOD removal may be designed for perfect mixed, partial mixed or plug-flow. Several small ponds with short residence time located In series, or the parcellation of a single big pond with widely spaced baffles, would avoid short circuiting of effluents between inlet and outlet. However, this design does not assure a plug-flow pattern, and it may lead to the formation of dead areas and the reduction of the actual residence time of effluents within the system.


2007 ◽  
pp. 419-428
Author(s):  
R.M. Al-Sa 'ed ◽  
N. Mahmoud ◽  
A. Abu-Madi ◽  
O.R. Zimmo

This paper evaluates the feasibility of using local rock filter as natural media in waste stabilization ponds, A pilot-scale algae-rock filter ponds (ARPs) system was investigated, in parallel with algae-based ponds (ABPs) over a period of 6 months to evaluate the treatment efficacy of both systems. Each system entailed 4 equal ponds in series and was continuously fed with domestic wastewater from Birzeit University. The removal rates of organic matter, nutrients and faecal coliforms were monitored within each treatment system. The results obtained revealed that ARPs system was more efficient in the removal of organic matter (TSS and COD; 86% and 84%, respectively) and fecal coliforms (4 log10) than ABPs (81%, 81%, 3 log10, respectively). Nitrogen was reduced in the ARPs to an average of24 mg N/1; in contrast the ABPs effluent contained 32 mg N/1. Compared to ABP system, passive aerated ARPs option is an efficient, a low-cost and land-saving alternative with effluent quality suitable for restricted agricultural use in rural areas.


2002 ◽  
Vol 45 (1) ◽  
pp. 9-15 ◽  
Author(s):  
A.M. Ingallinella ◽  
G. Sanguinetti ◽  
R.G. Fernández ◽  
M. Strauss ◽  
A. Montangero

A one year study was carried out in a waste stabilization ponds system where septage and sewage are cotreated. The system consists of two septage ponds which operate alternately followed by two ponds in series which receive the combined effluent. The septage ponds also act as evaporation ponds for the accumulated sludge. The monitoring program was divided in two phases. The results of the first phase indicate that the effluent of septage ponds has an adequate quality to be discharged into the waste stabilization ponds designed to treat sewage and that is possible to use the septage ponds to dry the accumulated sludge. Further investigation is needed to find suitable post-treatment of the sludge in order to use it in agriculture.


2000 ◽  
Vol 42 (10-11) ◽  
pp. 139-147 ◽  
Author(s):  
G. B. Athayde Júnior ◽  
D. D. Mara ◽  
H. W. Pearson ◽  
S. A. Silva

This paper describes faecal coliform (FC) removal in pilot-scale Wastewater Storage and Treatment Reservoirs (WSTR) in northeast Brazil. FC decay during the filling phase of WSTR was very reduced, suggesting that these reactors should be filled as quickly as possible, and subjected to the highest organic loading that will not cause odour emissions. The highest loading employed in this study was 659 kgBOD5/ha.d, causing no nuisance conditions. During the resting phase, FC decay rate decreased exponentially and Chick's law was modified. The time into the resting phase for FC to reach 103 cfu/100 mL ranged from 15 to 25 days as WSTR depth varied from 2.00 to 6.50 m. The performance of sequential batch-fed waste stabilization ponds (SBFWSP) in removing FC was compared to that of waste stabilization ponds (WSP) operated in series. It was shown that, in general, SBFWSP were cheaper than WSP in series, with the bacteriological quality of the effluent in the former being more reliably predicted than in the latter operational regime. When provision of volume to store the winter effluents is considered, a WSP system presents a higher benefit/cost ratio than a hybrid WSP-WSTR system, but the adoption of the latter can double the annual net return for a rainy season of 5 months for instance. In the case of use of the hybrid WSP-WSTR system, the net return would be US$ 0.17 – 0.22 per cubic metre of available wastewater, depending on the length of the rainy season (3 – 5 months considered) as compared to US$ 0.12 from the WSP system alone.


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 .


1995 ◽  
Vol 31 (12) ◽  
pp. 91-101 ◽  
Author(s):  
Y. Racault ◽  
C. Boutin ◽  
A. Seguin

In 1992, a survey was conducted on the performance of waste stabilization ponds in France. The data selected come from a sample of 178 ponds, with an average capacity of 600 p.e., throughout France. For each plant, one or several input--output load measurements over a 24-h period are available. The average organic load level received is approximately 25 kg BOD/ha.d, representing 50% of the nominal load. The quality of the treated water is presented based on the type of sewerage system feeding the ponds. The results appear dispersed, however; in 70% of the cases the concentrations in COD and BOD on filtered samples are under 120 mg/l and 40 mg/l, respectively, and the concentration in TSS under 120 mg/l (discharge standards in France for waste stabilization ponds). The reductions in nitrogen and phosphorus nutrients are on average from 60% to 70%. The influence of different parameters (sewerage system type, organic load, season, age of plant, etc.) was studied. The results appear noticeably worse when the ponds receive wastewater from a strictly separate sewerage system.


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