Faecal coliform die-off in wastewater storage and treatment reservoirs

2000 ◽  
Vol 42 (10-11) ◽  
pp. 139-147 ◽  
Author(s):  
G. B. Athayde Júnior ◽  
D. D. Mara ◽  
H. W. Pearson ◽  
S. A. Silva
Keyword(s):  
Rainy Season ◽  
Pilot Scale ◽  
Faecal Coliform ◽  
Cost Ratio ◽  
Waste Stabilization Ponds ◽  
Net Return ◽  
Benefit Cost Ratio ◽  
Stabilization Ponds ◽  
Waste Stabilization ◽  
In Series

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.

scholarly journals Enhancement of waste stabilization ponds efficacy using local fixed film materials

2007 ◽  
pp. 419-428
Author(s):  
R.M. Al-Sa 'ed ◽  
N. Mahmoud ◽  
A. Abu-Madi ◽  
O.R. Zimmo
Keyword(s):  
Organic Matter ◽  
Rural Areas ◽  
Low Cost ◽  
Domestic Wastewater ◽  
Pilot Scale ◽  
Fecal Coliforms ◽  
Waste Stabilization Ponds ◽  
Stabilization Ponds ◽  
Waste Stabilization ◽  
In Series

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.

scholarly journals Waste Stabilization Ponds as Teaching and Research Tools

1987 ◽  
Vol 19 (12) ◽  
pp. 389-391 ◽  
Author(s):  
A. Hall ◽  
A. C. Duarte ◽  
J. P. Oliveira
Keyword(s):  
Research Laboratory ◽  
Fish Processing ◽  
Waste Stabilization Ponds ◽  
Teaching And Research ◽  
Septic Tanks ◽  
Irrigation Pond ◽  
Stabilization Ponds ◽  
Waste Stabilization ◽  
In Series ◽  
To Receive

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.

Nitrogen removal in baffled waste stabilization ponds

1996 ◽  
Vol 33 (7) ◽  
pp. 173-181 ◽  
Author(s):  
S. Muttamara ◽  
U. Puetpaiboon
Keyword(s):  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Plug Flow ◽  
Specific Area ◽  
Pilot Scale ◽  
Bacterial Biofilm ◽  
Waste Stabilization Ponds ◽  
Stabilization Ponds ◽  
N Removal ◽  
Waste Stabilization

This study evaluated nitrogen removal in Baffled Waste Stabilization Ponds (BWSPs) comprising laboratory and pilot-scale ponds with different number of baffles. The aim was to promote the waste stabilization pond practice for wastewater treatment in tropical countries by increasing nitrogen and organic carbon removal efficiency or reducing the land area requirement through the use of baffles which increased the biofilm biomass concentrations. The experiments started with a tracer study to find out the hydraulic characteristics of each pond. It was shown that the dispersion number decreased with increasing flow length and number of baffles which indicated more plug flow conditions. The deviation of actual HRT from theoretical HRT was computed and the flow pattern suggested the existence of an optimum spacing of baffles in BWSP units. The investigations further revealed that more than 65% TN and 90% NH3-N removal efficiencies were achieved at HRT of 5 days in a 6 baffled pond, which corresponds to the specific area of 34.88 m2m3. TN and NH3-N removal increased with increasing number of baffles in the BWSP units. Combined algal/bacterial biofilm grown on the baffles immersed in the ponds showed potential for increasing the extent of nitrification. COD removal increased with higher number of baffles with its maximum removal efficiency at 6 baffles. Compared with normal WSP, BWSP gave higher TN, NH3-N, COD and BOD5 removal efficiency. The effluent SS concentrations from the laboratory-scale 6 baffled pond were less than 20 mg/L at HRT of 3 days or more.

Should Waste Stabilization Ponds be Designed for Perfect-Mixing or Plug-Flow?

1991 ◽  
Vol 23 (7-9) ◽  
pp. 1495-1502 ◽  
Author(s):  
Marcelo Juanico
Keyword(s):  
Flow Pattern ◽  
Residence Time ◽  
Plug Flow ◽  
Weekend Effect ◽  
Waste Stabilization Ponds ◽  
Hydraulic Loading ◽  
Stabilization Ponds ◽  
Waste Stabilization ◽  
In Series ◽  
Two Parameters

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.

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
Keyword(s):  
Single Cells ◽  
Ammonia Removal ◽  
Faecal Coliform ◽  
Northeast Brazil ◽  
Waste Stabilization Ponds ◽  
Effluent Reuse ◽  
Waste Stabilization ◽  
In Series ◽  
Per Capita ◽  
Sewerage Network

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.

Treatment of Wastewater by Stabilization Ponds – Application to Tunisian Conditions

1993 ◽  
Vol 28 (10) ◽  
pp. 193-199 ◽  
Author(s):  
A. Ghrabi ◽  
M. Ferchichi ◽  
C. Drakidès
Keyword(s):  
Sediment Accumulation ◽  
Domestic Wastewater ◽  
Pilot Scale ◽  
Total Coliform ◽  
Ammonia Nitrogen ◽  
Irrigation Season ◽  
Waste Stabilization Ponds ◽  
Stabilization Ponds ◽  
Domestic Wastewater Treatment ◽  
Waste Stabilization

An experimental study of the domestic wastewater treatment in a series of four pilot-scale stabilization ponds was conducted. The objective was to adapt the treatment by waste stabilization ponds (WSP) to Tunisian conditions. The obtained results show that the average values of removal are about 72% for BOD, 65% for COD and more than 50% for ammonia nitrogen. The phosphate concentration was influenced by release of phosphate from decomposition sediment The elimination of total coliform, faecal coliform and faecal streptococci is between 99.3% and 99.99%. The most rate reduction was registered during the warm months which coincide with the irrigation season. The sediment accumulation is taken mainly in the first pond: the deposition rate is high (5 cm/year). In the three maturation ponds, it ranges from 1.3 to 1.6 cm/year. The WSP can be designed to satisfy Tunisian conditions. Because of favourable climate, loading can be much higher than those reported in the literature and some of the disadvantages of the pond system can be reduced. So we can economize in evaporation of effluent which is considered as a resource of irrigation in agriculture and we can reduce the surface area.

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