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PubMed1993

Stabilization ponds in the tropics: promotion of the sanitary reuse of water.

This article reports the results of efforts by PAHO's Environmental Health Program to lay the groundwork for designing wastewater stabilization ponds suited to tropical areas. The resulting design concepts are flexible (permitting pond construction to be adapted to a broad range of terrains, community sizes, and working temperatures) and directed at meeting WHO standards established for the microbial quality of effluents used in agriculture and aquaculture. The WHO standards (1) call for treated wastewater being used in agriculture or aquaculture to contain less than 1,000 fecal coliforms per 100 ml. The plans outlined here, which are calculated to meet those standards, seek to minimize the pond area and volume needed by using two high-load primary anaerobic ponds discharging into an elongated secondary pond with a length-to-width ratio of at least 15:1. In rough terrain the elongated pond can be allowed to meander, following the land's natural contours. However, where the terrain is level it is recommended that a system of partitions be used to maintain the 15:1 ratio for operating purposes while changing the actual ratio of the secondary pond's outer dimensions to something like 5:3. Basic equations presented in the text will be helpful in estimating the pond sizes needed to cope with different climatic conditions, community sizes, per capita rates of wastewater generation, and per capita biochemical oxygen demands. While these equations should prove of great assistance during initial planning and development of preliminary criteria, nothing in this article supplants the topographic and geotechnologic studies that will be needed in order to clearly determine what is feasible in any given case.

Agriculture↗
PubMed1987

Comparative effects of mine wastes on the benthos of an acid and an alkaline pond.

Benthic invertebrates collected from an acid (pH 3.2) and an alkaline (pH 7.9) tailing pond in the Rouyn-Noranda mining region were compared with those of a control pond in order to assess the effects of the pH on the benthic community structure and on metal accumulation by invertebrates. The acid pond showed high mean soluble concentrations of aluminium (2600 ppb), copper (230 ppb), iron (6500 ppb) and zinc (4900 ppb) in the water and high mean concentrations of copper (340 ppm), iron (15,238 ppm) and zinc (445 ppm) in the sediments. The benthic fauna was dominated by Chironomus spp and the water beetle Ilybius sp. The Shannon-Weaver diversity index was 0.04. The alkaline pond had high mean sediment concentrations of cadmium (21 ppm), iron (15,823 ppm), manganese (658 ppm) and nickel (146 ppm). A total of 37 insect genera and a diversity index of 3.4 were recorded for this pond. Of the seven metals studied only copper and aluminium showed greater accumulations in the biota of the contaminated ponds than in that of the control. Insects dominated the benthic fauna in both contaminated ponds and crustacea in the control.

Journal Article↗
PubMed2003

Comparison of ammonia volatilisation rates in algae and duckweed-based waste stabilisation ponds treating domestic wastewater.

Quantification of ammonia volatilisation from wastewater stabilisation ponds is important in order to understand its significance for overall nitrogen removal in these widely applied low-cost treatment systems. Ammonia volatilisation rates were measured in pilot plant facilities consisting of one line of four algae-based ponds in series and a parallel line of four ponds with a floating mat of duckweed (Lemna gibba). Ammonia volatilisation was assessed during a period of one and a half years. The method applied is accurate, convenient and is proposed for analysis of a wide range of gasses emitted from stabilisation ponds and possibly other aquatic systems. The ammonia volatilisation rates in algae-based ponds (ABPs) were higher than in duckweed-based ponds (DBPs). This can be explained by the lower values of NH(3) in DBPs due to shading and lower pH values, since the volatilisation rate highly correlated with free ammonia concentration (NH(3)) in pond water. The duckweed cover appeared not to provide a physical barrier for volatilisation of unionised ammonia, because whenever NH(3) concentrations were equal in ABP and DBP also the volatilisation rates were equal. Volatilisation was in the range of 7.2-37.4 mg-Nm(-2)d(-1) and 6.4 -31.5 mg-Nm(-2)d(-1) in the ABPs and DBPs, respectively. Average influent and effluent ammonium nitrogen measurements showed that the ammonia volatilisation during the study period in any system did not exceed 1.5% of total ammonium nitrogen removal. Therefore this study confirmed results from simultaneous experimental work in our laboratory indicating that nitrification/denitrification, rather than ammonia volatilisation, is the most important mechanism for N removal in ABPs and DBPs.

Ammonia↗
PubMed2002

Efficacy of water hyacinth compost in nursery ponds for larval rearing of Indian major carp, Labeo rohita.

The use of water hyacinth compost as manure in nursery ponds for larval rearing of Indian major carp, Labeo rohita was studied. Better performance with regard to growth and survivability of the larvae was recorded in the ponds treated with water hyacinth compost (Group A) than in either the ponds treated with inorganic fertilizers (Group B) or the ponds where no treatment was applied (Group C). The average percentages of survival in Groups A, B and C were 14.3, 11.2 and 5.0, respectively. Thus about 186% increase in the survivability was recorded in the ponds treated with water hyacinth compost (P < 0.01), whereas the increase was about 124% in the ponds treated with only inorganic fertilizers, when compared with the ponds which were without any treatment.

Animals↗
PubMed2004

Paleolimnological assessment of Grove and Plow Shop Ponds, Ayer, Massachusetts, USA--a superfund site.

Three sediment cores from each of severely polluted Grove and Plow Shop Ponds, Ayer, Massachusetts, USA, were dated using (210)Pb, characterized for plant macrofossil assemblages, and analyzed for H(2)O, loss-on-ignition, stable Pb isotopes, and concentrations of As, Ca, Cd, Cr, Cu, Fe, Hg, methyl-Hg, Ni, Pb, and Zn. A core from nearby kettle Spectacle Pond, Littleton, Massachusetts, was similarly characterized (except for plant macrofossil assemblages) to assess the regional air pollution signal in sediment for comparison with the six cores. Accumulation rates for metals (mass per area per year), the anthropogenic component (mass per area per year), and total accumulation of the anthropogenic component (mass per area) indicate that As, Cd, Cr, Cu, Hg, methyl-Hg, Ni, Pb, and Zn have accumulated in sediment as a consequence of point source pollution from within the drainage basins of Grove and Plow Shop Ponds. Three distinct sources of pollution are inferred. As is entering Plow Shop Pond via groundwater in the southwest. Cd, Ni, Pb, and Zn are entering the system predominantly at the eastern end of, or upstream from, Grove Pond. Pb also comes from the northwest corner of Grove Pond, the principal source of Cr, Cu, and Hg. These results are consistent with chemistry of modern surface sediments. The history of pollution extends back more than 100 years. Intra- and inter-core variability of concentrations and accumulation rates indicate that much of the pollution was likely in particulate form with little physical redistribution. Recently, concentrations and accumulation rates have generally decreased substantially for those elements present in excessive concentrations in the past. This is a consequence of accumulation of recent, less polluted sediment. In Spectacle Pond, the nearby reference lake, accumulation rates for As, Cd, Hg, and Pb, adjusted for background values and changes in sedimentation rate, increased above background starting in the late 19th century, peaked about 1980, and declined substantially to 2000. These decreases suggest that the anthropogenic (pollution) component of atmospheric deposition of these elements declined after 1980 by at least 50%(As), 80%(Cd), 80%(Hg), and 80%(Pb).

Air Pollutants↗
PubMed2002

Sensitivity analysis of stabilization pond system design parameters.

Two stabilization pond systems are examined. A sensitivity analysis is undertaken, aimed at investigating the influence of the pond depths on stabilization pond surface area and pond volume for the specific combination of temperature, wastewater characteristics and effluent requirements. The dependencies are presented in a functional form, allowing for the graphical solution of the unit pond volume, area, and hydraulic residence time as a function of the respective pond depths. Based on these graphs, designers can determine the most appropriate depth value for each type of pond that minimizes the required area or volume, or balances excavation versus land acquisition and floor lining costs, taking under consideration the topographic and other local characteristics of the site area.

Costs and Cost Analysis↗
PubMed2006

Constructed wetlands and waste stabilization ponds for small rural communities in the United Kingdom: a comparison of land area requirements, performance and costs.

Land area requirements for secondary subsurface horizontal-flow constructed wetlands (CW) and primary and secondary facultative ponds with either unaerated or aerated rock filters were determined for three levels of effluent quality: that specified in the Urban Waste Water Treatment Directive (UWWTD) (< or = 25 mg filtered BOD l(-1) and < or = 150 mg SS l(-1) for waste stabilization ponds (WSP) effluents, and < or = 25 mg unfiltered BOD l(-1) for CW effluents (mean values); and two common requirements of the Environment Agency: < or = 40 mg BOD l(-1) and < or = 60 mg SS l(-1), and < or = 10 mg BOD l(-1), < or = 15 mg SS l(-1) and < or = 5 mg ammonia-N l(-1) (95-percentile values). A secondary CW requires 60 percent more land than a secondary facultative pond to produce an UWWTD-quality effluent, 38 percent more land than a secondary facultative pond and an unaerated rock filter to produce a 40/60 effluent and, were it to be used to produce a 10/15/5 effluent, it would require approximately 480 percent more land than a secondary facultative pond and an aerated rock filter. Its estimated 2005 cost is pound 1100-2600 p.e.(-1), whereas that of a primary facultative pond and rock filter is approximately pound 400 p.e.(-1). On the basis of land area requirements, performance and cost, facultative ponds and unaerated or aerated rock filters are to be preferred to secondary subsurface horizontal-flow constructed wetlands.

Cost-Benefit Analysis↗
PubMed1989

A quantitative survey of Culicoides variipennis (Diptera: Ceratopogonidae) in dairy wastewater ponds in southern California.

Culicoides variipennis (Coquillett) larvae were sampled five times over a 10-wk period in late summer in each of 26 dairy wastewater ponds in western Riverside County, Calif. Slope, degree of cattle access, prevalence of visible manure solids, salinity, chemical oxygen demand, plankton volume, and whether the ponds were pumped for irrigation were determined concurrently. Larvae of C. variipennis were associated positively with plankton volume, degree of animal access, and salinity, and negatively with slope and the pumping of the ponds for irrigation. High densities of larvae were found in shoreline mud in shallow, "evaporation bed" type ponds that were not pumped (means = 106 larvae per 30 ml). In contrast, pumped ponds were deeper, had steeper slopes, and supported lower densities of C. variipennis (means = 52 larvae per 30 ml). The pumped ponds tended to hold water continuously (more stable in time), and to have lower phytoplankton volumes and lower values of chemical oxygen demand. Rapid water level fluctuations in the pumped ponds also may have reduced C. variipennis density.

Animals↗
PubMed1976

Toxicity of ammonia to algae in sewage oxidation ponds.

Ammonia, at concentrations over 2.0 mM and at pH values over 8.0, inhibits photosynthesis and growth of Scenedesmus obliquus, a dominant species in high-rate sewage oxidation ponds. Photosynthesis of Chlorella pyrenoidosa, Anacystis nidulans, and Plectonema boryanum is also susceptible to ammonia inhibition. Dark respiration and cell morphology were unaffected by any combination of pH and ammonia concentrations tested, thus limiting the apparent effect to inhibition of the normal function of the chloroplasts. Methylamine had the same effect as ammonia, and its penetration into the cells was found to be pH dependent. Therefore, the dependence of toxicity of amines to algae on pH apparently results from the inability to penetrate the cell membrane in the ionized form. When operated at 120-h detention time of raw wastewater, the high-rate oxidation pond maintained a steady state with respect to algal growth and oxygen concentration, and the concentration of ammonia did not exceed 1.0 mM. Shifting the pond to 48-h detention time caused an increase in ammonia concentration in the pond water to 2.5 mM, and the pond gradually turned anaerobic. Photosynthesis, which usually elevates the pH of the pond water to 9.0 to 10.0, could not proceed beyond pH 7.9 because of the high concentration of ammonia, and the algal population was washed out and reduced to a concentration that could maintain a doubling time of 48 h without photosynthesis bringing the pH to inhibitory levels. Under these conditions, the pH of the bond becomes a factor that limits the operational efficiency of the oxidation pond.

Ammonia↗
PubMed2006

Importance of waste stabilization ponds and wastewater irrigation in the generation of vector mosquitoes in Pakistan.

The objective of the current study was to investigate the role of waste stabilization ponds (WSP) and wastewater-irrigated sites for the production of mosquitoes of medical importance. Mosquito larvae were collected fortnightly from July 2001 to June 2002 in Faisalabad, Pakistan. In total, 3,132 water samples from WSP and irrigated areas yielded 606,053 Culex larvae of five species. In addition, 107,113 anophelines, representing eight species were collected. Anopheles subpictus (Grassi) and Culex mosquitoes, especially Culex quinquefasciatus (Say) and Culex tritaeniorhynchus (Giles), showed an overwhelming preference for anaerobic ponds, which receive untreated wastewater. Facultative ponds generated lower numbers of both Anopheles and Culex mosquitoes, whereas the last ponds in the series, the maturation ponds, were the least productive for both mosquito genera. An. subpictus and Anopheles stephensi (Liston) were the dominant Anopheles species in wastewater-irrigated sites, with Anopheles culicifacies (Giles) recorded in low numbers. This was also the pattern in nearby sites, irrigated with river water. Among the Culex species, Cx. tritaeniorhynchus was by far the most frequently recorded in both wastewater- and river water-irrigated sites with Cx. quinquefasciatus as the second most abundant species but restricted to wastewater-irrigated areas. Univariate logistic regression analysis showed that presence of An. subpictus and Culex mosquitoes was significantly associated with emergent grass vegetation and low salinity. Regular removal of emergent grass along the margins of the anaerobic ponds and changes in the concrete design of the ponds are likely to reduce the mosquito production, especially of Culex species.

Agriculture↗
PubMedDate not supplied

Ammonia volatilization from marsh-pond-marsh constructed wetlands treating swine wastewater.

Ammonia (NH3) volatilization is an undesirable mechanism for the removal of nitrogen (N) from wastewater treatment wetlands. To minimize the potential for NH3 volatilization, it is important to determine how wetland design affects NH3 volatilization. The objective of this research was to determine how the presence of a pond section affects NH3 volatilization from constructed wetlands treating wastewater from a confined swine operation. Wastewater was added at different N loads to six constructed wetlands of the marsh-pond-marsh design that were located in Greensboro, North Carolina, USA. A large enclosure was used to measure NH3 volatilization from the marsh and pond sections of each wetland in July and August of 2001. Ammonia volatilized from marsh and pond sections at rates ranging from 5 to 102 mg NH3-N m(-2) h(-1). Pond sections exhibited a significantly greater increase in the rate of NH3 volatilization (p < 0.0001) than did either marsh section as N load increased. At N loads greater than 15 kg ha(-1) d(-1), NH3 volatilization accounted for 23 to 36% of the N load. Furthermore, NH3 volatilization was the dominant (54-79%) N removal mechanism at N loads greater than 15 kg ha(-1) d(-1). Without the pond sections, NH3 volatilization would have been a minor contributor (less than 12%) to the N balance of these wetlands. To minimize NH3 volatilization, continuous marsh systems should be preferred over marsh-pond-marsh systems for the treatment of wastewater from confined animal operations.

Agriculture↗
PubMed2001

Laboratory investigation of supported permeable organic covers for the management of odour emissions from anaerobic piggery waste ponds.

Australian research has linked much of the odour arising from intensive livestock operations to pond treatment systems. A reduction in emissions from treatment ponds would therefore generally reduce odour emissions from intensive livestock operations. Published data indicates that the application of straw and other biological materials to effluent pond surfaces as a continuous cover reduces odour emissions. The effectiveness of these covers has not, however, been researched under controlled conditions. Using locally available materials, the efficacy of supported covers has been investigated using a series of laboratory anaerobic digesters treating typical piggery effluent. Research to date has focused on: identifying effective cover and cover support materials; quantifying odour reduction; identifying the impact use these covers may have on greenhouse gas emissions; devising practical and effective methods for constructing these covers. Results have confirmed that a variety of cover materials are effective in reducing pond odour emissions. Supporting the pond cover appears to extend the cover life expectancy. While greenhouse gas emissions appear to vary according to cover type, the overall significance of these emissions is not yet clear. The impact of permeable pond covers on overall pond performance requires additional research.

Agriculture↗
PubMed2002

How realistic are outdoor microcosms? A comparison of the biota of microcosms and natural ponds.

This study investigated the extent to which aquatic plant and macroinvertebrate assemblages in small outdoor microcosms (cylinders 1.25-m diameter x 1.25 m deep) resembled assemblages found in natural ponds in Britain. Comparisons were made in terms of community structure, species richness, and numbers of uncommon species. Multivariate analysis indicated that, although the microcosms had no exact natural analogues, their plant and animal assemblages were most like those of deep, circumneutral ponds. Unlike natural ponds, the microcosms supported relatively species-poor invertebrate assemblages, lacking uncommon species. Among individual taxa, microcosms supported similar numbers of species of Gastropoda, Isopoda, Amphipoda, and Odonata as natural ponds but significantly fewer Coleoptera, Hemiptera, and Trichoptera species. This was most likely due to the absence of a shallow littoral area in the microcosms. Because of their vertical sides, the microcosms supported no marginal wetland plants, but submerged and floating-leaved plant assemblages were similar in community type and species richness to natural ponds. Refinements to microcosm and mesocosm designs are identified that would enable experimental systems to more closely replicate the assemblages found in natural ponds. In particular, the incorporation of natural margins would be likely to lead to experimental communities that were closer analogues of natural ponds.

Animals↗
PubMed2002

Compartmental model for organic matter digestion in facultative ponds.

A model has been developed for the digestion of organic matter in facultative ponds in tropical regions. Complete mixing has been assumed for the aerobic and anaerobic compartments. Settling, aerobic layer oxidation, and anaerobic layer methanogenesis are the main processes for organic matter removal in the water column. Exchange processes between layers are dispersive or soluble exchange, solubilization and transport of organic matter from sediments to water column are also taken into account. Degradation of organic matter in the sediments produces gaseous emissions to the water column. The exchange between bubbles ascending and the water column was measured. The model was calibrated with data obtained from a pilot facultative pond built in Muña Reservoir in Bogotá. The pond was sampled during 4 months to compare data between its water hyacinth covered section and uncovered section. The results clearly show the relative importance of different BOD removal processes in facultative ponds and suggest modifications to further improve performance. The results from the model suggest that internal loadings to facultative ponds due to solubilization and return of organic matter from the sediments to the aerobic layer greatly influence the soluble BOD effluent concentration. Aerobic degradation activity in the facultative pond does not affect significantly the effluent concentration. Anaerobic degradation activity in the facultative pond can more easily achieve increases in the removal efficiencies of BOD.

Bacteria, Anaerobic↗
PubMed2002

Performance of a baffled facultative pond treating piggery wastes.

This paper shows the performance of a baffled facultative pond for the treatment of piggery wastes. The full-scale system is composed of an equalizer, one decanter (DP), two anaerobic ponds (LA1 and LA2), one facultative pond (LF), with five baffles, and one maturation pond with water hyacinths (LAG). The studies were conducted over a 12 month period in the west region of Santa Catarina, Brazil. The system was supplied daily with a volume of 3 m3/day of farm wastes. A good performance of the treatment system was obtained with average removal efficiencies of 98% for chemical oxygen demand, 93% for total solids, 98% for total phosphorus, 92% for total nitrogen, 7 log units of faecal coliforms and 5 log units of total coliforms. The facultative pond performed well, removing 43% of the chemical oxygen demand, 47% of total nitrogen and 54% of total phosphorus. It was found that the first baffle in the facultative pond was mainly responsible for the efficiency of this pond, and compared with another study the introduction of the baffles improved the removal efficiency by 20% for total phosphorus.

Agriculture↗
PubMed2002

Evaluation of the accumulation of sediment and heavy metals in a storm-water detention pond.

Accumulation of sediments and water quality were investigated in a wet storm-water detention pond in central Sweden. The drainage area surrounding the pond was covered by a section of highway and secondary roads. Sediment samples were collected from the pond and heavy-metal concentrations analysed subsequently in the laboratory. The depth of accumulated sediments was measured at several points around the pond. The investigation showed that during the 18 months that had passed since the pond was constructed, a 5-8 cm layer of sediments had accumulated near the inlet, and a 1.5 cm layer near the outlet of the pond. Storm water passing through the detention pond showed an average reduction rate of 26-84% for total metal content, 67% for total N, 78% for total P and 92% for COD.

Geologic Sediments↗
PubMed2003

Parasite removal by natural wastewater treatment systems: performance of waste stabilisation ponds and constructed wetlands.

Parasite removal and low cost systems for wastewater treatment have become increasingly important requirements in developed and developing countries to safeguard public health from wastewater-associated intestinal diseases. Pilot and field-scale ponds and wetlands in Brazil and Egypt have been investigated for the fate and removal of eggs of human intestinal parasites from domestic wastewater. In northeast Brazil, parasite removal was investigated for a series of five waste stabilisation ponds treating raw wastewater. In Egypt, parasite removal was studied for Gravel Bed Hydroponic constructed wetlands treating partially treated wastewater. Influents to ponds and wetlands contained a variety of parasite helminth eggs (e.g. Ascaris, hookworm, Trichuris, and Hymenolepis spp.). The ponds consistently removed parasite eggs though rate of removal by individual ponds may have been related to influent egg numbers and extent of short-circuiting. Parasite eggs were reduced on average by 94% and 99.9% in the anaerobic and facultative ponds respectively. No eggs were found in effluent from the second maturation pond. In the wetland system, parasite removal varied with reedbed length. The majority of parasite eggs were retained within the first 25 m. Parasite eggs were reduced on average by 98% after treatment in 50 m beds and completely removed after treatment in 100 m beds.

Animals↗
PubMed2003

Hybrid treatment systems--anaerobic ponds and trickling filters in Zimbabwe.

The most economic combination of unit treatment processes for a new sewage treatment works in Zimbabwe was found to be anaerobic ponds followed by trickling filters. The regulations governing irrigation with treated effluent permitted the omission of humus tanks or further treatment. Two stage anaerobic ponds are desludged by gravity through fixed sludge outlet pipework. Sludge is disposed of by irrigation of a Eucalyptus plantation. Novel features of the inlet works and pond outlets are also described. The works has functioned for eight years without major problems, but the assumption that humus tanks or settling ponds were not required may have been mistaken. The sludge removal system has worked well. Without the sludge pipework, it is estimated that desludging of the primary ponds would have been required after two years of operation, but they have now operated successfully for eight years. The combination of anaerobic ponds and trickling filters should be considered where land availability or site conditions make facultative ponds difficult or expensive to construct.

Bacteria, Anaerobic↗