Prospectus of waste stabilization ponds in Ceará, Northeast Brazil

2011 ◽  
Vol 63 (6) ◽  
pp. 1265-1270 ◽  
Author(s):  
F. J. A. da Silva ◽  
R. O. de Souza ◽  
F. J. F. de Castro ◽  
A. L. C. Araújo

WSP technology has been used in Ceará, Northeast Brazil, since middle 1970s. There are presently 96 ponds plants and most of them are comprised by single cells (40%) and series of 3 ponds (35%). They were under loaded due to incomplete house connections to the sewerage network and low per capita wastewater contributions. Highest removal rates of organic material, ammonia and faecal coliform were found in 3 pond series. Faecal coliform removal was in accordance with the literature and series of ponds reached numbers ≤105 cells/100 ml. In series with 4 and 5 ponds FC was below 103 cells/100 ml. Ammonia removal varied from 30 to 80% and total phosphorus the removal was not significant. An increase in the number of maturation ponds enhances nutrient and coliform removal. Up-grading schemes should be investigated as well as effluent reuse potential.

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.


1986 ◽  
Vol 18 (10) ◽  
pp. 31-35 ◽  
Author(s):  
J. I. Oragui ◽  
T. P. Curtis ◽  
S. A. Silva ◽  
D. D. Mara

The removal of excreted bacteria (faecal coliforms, faecal streptococci, Clostridium perfringens, total and sorbitol-fermenting bifidobacteria, salmonellae and thermophilic campylobacters) and viruses (enterovirus and rotavirus) in a series of deep anaerobic, facultative and maturation ponds (depth range: 2.8 - 3.4 m), with an overall retention time of 21 days and a mean mid-depth temperature of 27°C, was studied. Thermophilic campylobacters, bifidobacteria and salmonellae were not detected after 11, 16 and 21 days' retention respectively. Faecal coliforms, faecal streptcocci and Cl. perfringens were reduced by 4, 4 and 2 orders of magnitude respectively, and enteroviruses and rotaviruses both by 3 orders. The results indicate that pathogen removal in deep ponds is similar to that in ponds of normal depth.


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.


2005 ◽  
Vol 51 (12) ◽  
pp. 99-102 ◽  
Author(s):  
M. Johnson ◽  
D.D. Mara

Facultative waste stabilization ponds in the UK, loaded at 80 kg BOD/ha day, produce effluents which comply with the European Urban Waste Water Treatment Directive (i.e., ≤25 mg filtered BOD/l and ≤150 mg SS/l). However, the Environment Agency of England and Wales typically requires a higher effluent quality of ≤40 mg/l unfiltered BOD and ≤60 mg/l SS, both on a 95-percentile basis. An ammonium-nitrogen requirement might also be applied. Traditionally, maturation ponds and reedbeds have been used to upgrade facultative pond effluents, requiring large land areas. This paper describes and compares aerated and unaerated rock filter performance for BOD, SS, nitrogen and faecal coliform removals, and highlights the land-saving opportunities as maturation ponds and reedbeds become redundant.


1987 ◽  
Vol 19 (3-4) ◽  
pp. 569-573 ◽  
Author(s):  
J. I. Oragui ◽  
T. P. Curtis ◽  
S. A. Silva ◽  
D. D. Mara

The removal of excreted bacteria (faecal coliforms, faecal streptococci, Clostridium perfringens, total and sorbitol-fermenting bifidobacteria, salmonellae and thermophilic campylobacters) and viruses (enterovirus and rotavirus) in a series of deep anaerobic, facultative and maturation ponds (depth range: 2.8 - 3.4 m), with an overall retention time of 21 days and a mean mid-depth temperature of 27°C, was studied. Thermophilic campylobacters, bifidobacteria and salmonellae were not detected after 11, 16 and 21 days' retention respectively. Faecal coliforms, faecal streptcocci and Cl. perfringens were reduced by 4, 4 and 2 orders of magnitude respectively, and enteroviruses arid rotaviruses both by 3 orders. The results indicate that pathogen removal in deep ponds is similar to that in ponds of normal depth.


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.


Author(s):  
Matheus Sales Alves ◽  
Fernando José Araújo da Silva ◽  
André Luís Calado Araújo ◽  
Erlon Lopes Pereira

This paper assesses the reliability of Waste Stabilization Ponds (WSP) and proposes an alternative approach to WSP design based on the calculation of coefficient of reliability (COR) from an acceptable measure of violation of discharge standards. For that, data were collected from 10 full-scale systems operating in Northeast Brazil. All systems receive predominantly domestic effluent and are composed of one facultative pond and two serial maturation ponds. Different levels of restriction for effluent discharge were considered regarding the parameters: BOD, COD, total suspended solids, ammonia and thermotolerant coliforms. The Log-normal Probability Distribution Function (PDF) was able to represent the behavior of the concentration data in the effluent and, therefore, allowed the COR calculation. The COR was obtained from the coefficient of variation (CV) of the concentrations and the standardized normal variable associated with a 95% probability of non-exceedance. The observed dispersion of the results proved to be detrimental to the adoption of a single COR value for the evaluated parameters. In addition, the comparison between observed and design/operational concentration for optimal performance showed that the 95% reliability scenario represents a less achievable target for WSP systems.


1993 ◽  
Vol 27 (4) ◽  
pp. 727-728 ◽  
Author(s):  
J.I. Oragui ◽  
Helen Arridge ◽  
D.D. Mara ◽  
H.W. Pearson ◽  
S.A. Silva

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