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At least 19 recordsLinked to original sources
PubMed2003

Investigation of pond velocities using dye and small drogues: a case study of the Nelson City waste stabilisation pond.

The city of Nelson, New Zealand, has a 27 hectare oxidation pond as its primary wastewater treatment facility. Recent changes in the configuration of the pond and installation of a mixer/aerator raised concerns that pond treatment rates and effluent quality may be affected by high internal pond velocities and short retention times. This paper presents the findings of an investigation into wastewater velocity and movement within the pond using qualitative dye dispersion and tracking of small-scale "holey-sock" drogues. Simultaneous deployment of drogues and dye allowed methods to be compared, since small-scale drogues have not commonly been used in wastewater ponds. Dye dispersion was assessed using low-level aerial photography from a tethered helium blimp to track short term movement and mixing, while a datalogger and fluorometer were used to measure pond retention time. Drogue movement was tracked in conjunction with the dye study from a small boat using hand-held GPS. The dye study found that: (i) the first portion of pond influent discharged from the pond after 37.5 hours, substantially quicker than the theoretical pond retention time of 27 days. However, the measured retention time was with a mixer in place and the theoretical time was without a mixer; (ii) the position of the paddle wheel mixer/aerator was not optimally placed for mixing the influent and a quiescent region existed adjacent to the influent point; and (iii) the low-level aerial photography was an effective method of evaluating larger pond systems. The "holey-sock" drogue studies showed that: (i) the drogues accurately followed the movement and velocity of dyed influent within the pond; (ii) wastewater velocity and movement was dominated by the paddle wheel mixer/aerator; and (iii) wind direction had a minor influence on wastewater velocity and movement in areas not directly affected by the paddle wheel mixer/aerator. The study demonstrated that the combined use of dye and drogues was a relatively low-cost and effective means of determining internal pond velocities and movement. Future studies using similar methods will be useful in helping validate computer-modelled movement and velocity.

Biodegradation, Environmental↗
PubMed2001

226Ra and 228Ra activities associated with agricultural drainage ponds and wetland ponds in the Kankakee Watershed, Illinois-Indiana, USA.

Background radioactivity is elevated in many agricultural drainage ponds and also constructed wetland ponds in the Kankakee watershed. During 1995-1999, gross-alpha and -beta activities were measured up to 455 and 1650 mBq L-1, respectively. 226Ra and 228Ra averaged 139 and 192 mBq L-1 in controlled drainage ponds compared to 53 and 58 mBq L-1 for 226Ra and 228Ra, respectively, in native wetland ponds. Analyses of applied ammonium phosphate fertilizers near both native and controlled ponds indicate comparable 226Ra/228Ra and 228Ra/232Th activity ratios with only the surface waters in the controlled ponds. For example, 226Ra/228Ra activity ratios in controlled ponds ranged from 0.791 to 0.91 and group with a local fertilizer batch containing FL phosphate compounds with 226Ra/228Ra activity ratios of 0.831-1.04. Local soils of the Kankakee watershed have 226Ra/228Ra activity ratios of 0.541-0.70. Calculated Ra fluxes of waters, in drainage ditches associated with these controlled ponds, for 226Ra ranged from 0.77 to 9.00 mBq cm-2 d-1 and for 228Ra ranged from 1.22 to 8.43 mBq cm-2 d-1. Ra activity gradients were measured beneath these controlled ponds both in agricultural landscapes and in constructed wetlands, all being associated with drainage ditches. Ra had infiltrated to the local water table but was below regulatory maximum contaminant limits. Still, measurable Ra activity was measured downgradient of even the constructed wetlands in the Kankakee watershed, suggesting that the attenuation of Ra was low. However, no Ra excess was observed in the riparian zone or the Kankakee River downgradient of the native wetland ponds.

Agriculture↗
PubMed2001

Polishing ponds for post-treatment of digested sewage. Part 1: Flow-through ponds.

Polishing ponds are used to improve the quality of effluents from efficient anaerobic sewage treatment plants like UASB reactors, so that the final effluent quality becomes compatible with legal or desired standards. The residual organic material and suspended solids concentrations in the digested sewage are reduced, but often the main objective of polishing ponds is to improve the hygienic quality, measured by the concentration of two indicator organisms: helminth eggs and faecal coliforms (FC). The FC removal is normally the slowest process and for that reason becomes the main design criterion for a polishing pond. By contrast in conventional waste stabilisation pond (WSP) systems the organic material removal is the governing design parameter. The feasibility of operating a single polishing pond for the post-treatment of UASB effluent is shown in this paper and the final effluent quality as a function of the retention time is discussed. Even under the most adverse weather conditions (several weeks of rain) the population of algae remained stable and produced enough oxygen to maintain a predominantly aerobic environment. The final effluent TSS and BOD concentrations were not very low for retention times of less than 1 week, but this could be attributed to the presence of algae in the final effluent. Filtered effluent BOD and TSS concentrations were very low. For retention times of more than 1 week algae were efficiently removed from the liquid phase by the action of predators and algae flocculation and settling, so that a final effluent with a very low BOD and TSS concentrations was produced. To maximise the FC removal efficiency the polishing pond was constructed with the objective of approaching a plug flow regime. However, the observed efficiency was well below the expected value for all retention times, which was attributable to imperfections of the flow regime. From tracer studies it was established that the dispersion number was in the range of 0.14 to 0.16, which means that moderate mixing occurred, even though the pond was designed to avoid mixing as much as possible. Also the dead volume fraction ranging from 0.12 to 0.15 was quite considerable. Due to these imperfections the required retention time for an effluent to be used in unrestricted irrigation was produced for a retention time of about 10 days, twice the value of the minimum retention time for a batch or true plug flow pond. Although the plug flow regime could not be approached in practice, the required retention time of 10 days is still very much shorter than the value used in conventional WSPs (20 to 30 days).

Animals↗
PubMed2003

Advanced pond system: performance with high rate ponds of different depths and areas.

Many domestic Wastewater Stabilisation Ponds (WSPs) or oxidation ponds in New Zealand require upgrading to reduce pollution of receiving waters. Advanced Pond Systems (APS) consisting of an Advanced Facultative Pond, High Rate Pond, Algae Settling Pond and Maturation Pond may provide a cost effective upgrade option. This paper presents the results of a 2-year study of the performance of two pilot APS systems with High Rate Ponds of different depths and areas. The HRPs of the APS systems both had the same flow rate (5 m3 d(-1)), volume (37.5 m3) and thus hydraulic retention time (7.5 d). However, the East HRP had an operating depth of 0.30 m and a surface area of 128 m2, and the West HRP had an operating depth of 0.45 m and a surface area of 85 m2. APS system performance was compared in terms of improvement of water quality. For nearly all parameters measured, there was little difference in performance between the two systems suggesting that the system with the smaller area could be used without affecting treatment. Comparison of final effluent with typical effluent of New Zealand WSPs showed that APS effluent was of higher quality and much less variable over time.

Cost-Benefit Analysis↗
PubMed1972

Numerical taxonomy of coryneform bacteria isolated from pond-reared shrimp (Penaeus aztecus) and pond water.

Gram-positive, catalase-positive, nonsporeforming, pleomorphic rods isolated from pond-reared shrimp and pond water were compared with type cultures of the Corynebacteriaceae. Classification of the type cultures based on 66 cell and colony characters proved comparable to one based on 163 morphological, biochemical, and physiological characters. This similarity was not observed with pond isolates. With the aid of numerical analysis, pond isolates could be placed into six major groups based on certain biochemical and physiological tests. Coryneform bacteria isolated from shrimp and water exhibited little similarity to the type cultures. The pond isolates probably are members of the Corynebacteriaceae not previously studied in detail.

Arthrobacter↗
PubMed2006

Effect of low quality effluent from wastewater stabilization ponds to receiving bodies, case of Kilombero sugar ponds and Ruaha river, Tanzania.

A study was conducted in a sewage system at Kilombero Sugar Company to review its design, configuration, effectiveness and the quality of influent and effluent discharged into the Ruaha river (receiving body). The concern was that, the water in the river, after effluent has joined the river, is used as drinking water by villages located downstream of the river. Strategic sampling at the inlet of the oxidation pond, at the outlet and in the river before and after the effluent has joined the receiving body (river) was undertaken. Samples from each of these locations were taken three times, in the morning, noon and evening. The sample were then analysed in the laboratory using standard methods of water quality analysis. The results showed that the configuration and or the layout of the oxidation ponds (treatment plant) were not in accordance with the acceptable standards. Thus, the BOD5 of the effluent discharged into the receiving body (Ruaha River) was in the order of 41 mg/l and therefore not meeting several standards as set out both by Tanzanian and international water authorities. The Tanzanian water authorities, for example, requires that the BOD5 of the effluent discharged into receiving bodies be not more that 30 mg/l while the World Health Organization (WHO) requires that the effluent quality ranges between 10 - 30 mg/l. The paper concludes that proper design of treatment plants (oxidation ponds) is of outmost importance especially for factories, industries, camps etc located in rural developing countries where drinking water from receiving bodies like rivers and lakes is consumed without thorough treatment. The paper further pinpoint that both owners of treatment plants and water authorities should establish monitoring/management plan such that treatment plants (oxidation ponds) could be reviewed regarding the change on quantity of influent caused by population increase.

Environmental Monitoring↗
PubMed2003

The reasons behind the performance superiority of a high rate algal pond over three facultative ponds in series.

Results from a tracer study were used to determine and to compare actual and standard (k(20 degrees C)) first order reaction rate constants for COD removal in a High Rate Algal Pond (HRAP) and in 3 facultative ponds (FP) in series. An annual average k(20 degreesC) of 0.123 day(-1) was found for the HRAP while the values of 0.097, 0.025 and 0.003 d(-1) were found for facultative ponds 1, 2 and 3 respectively. Also, comparing nominal and tracer study hydraulic retention times showed large differences for the FP but not for the HRAP indicating that the former were suffering from severe short-circuiting. Loading rate within the range of operation exhibited a positive correlation with k(20 degrees C) for the HRAP but did not show such a relationship for any of the FP. Optimal chlorophyll-a concentration was found to be 3 mg/l for the HRAP and only 1.1 mg/l for the FP. Pollutant specific removal rates (SRR), that translate the hydrodynamic efficiency and the rate of COD biodegradation into pond performance per m2 and per day were calculated. They show that the adoption of the HRAP in place of a series of 3 FP reduces the net land area requirement (LAR) by at least 40%.

Biodegradation, Environmental↗
PubMed2003

Influences of pond geochemistry, temperature, and freeze-thaw on terminal anaerobic processes occurring in sediments of six ponds of the McMurdo Ice Shelf, near Bratina Island, Antarctica.

The effects of freeze-thaw, freezing and sediment geochemistry on terminal anaerobic processes occurring in sediments taken from below cyanobacterial mats in meltwater ponds of the McMurdo Ice Shelf in Antarctica were investigated. Depending on the geochemical and physical status of the sediments (i.e., frozen or thawed), as well as passage of sediment through a freeze-thaw cycle, terminal carbon and electron flow shifted in which the proportions of hydrogen and acetate utilized for methanogenesis and sulfate reduction changed. Thus, in low-sulfate (or chloride) sediment which was thawed and incubated at 4 degrees C, total carbon and electron flow were mediated by acetate-driven sulfate reduction and H(2)-driven methanogenesis. When the same sediments were incubated frozen, both methanogenesis and sulfate reduction decreased. However, under these conditions methanogenesis was favored over sulfate reduction, and carbon flow from acetate to methane increased relative to sulfate reduction; >70% of methane was contributed by acetate, and more than 80% of acetate was oxidized by pathways not coupled to sulfate reduction. In high-sulfate pond sediments, sulfate reduction was a major process mediating terminal carbon and electron flow in both unfrozen and frozen incubations. However, as with low-sulfate sediments, acetate oxidation became uncoupled from sulfate reduction with freezing. Geochemical and temperature effects could be expressed by linear models in which the log (methanogenesis to sulfate reduction) was negative log linear with respect to either temperature or the log of the sulfate (or chloride) concentration. From these relationships it was possible to predict the ratio for a given temperature (low-sulfate sediments) or sulfate (chloride) concentration. Small transitory changes, such as elevated sulfate reduction coupled to increased acetate turnover, resulted from application of a freeze-thaw cycle to low-salinity pond sediments. The results demonstrate how ecophysiological processes may change in anaerobic systems under extreme conditions (e.g., freezing) and provide new insights into microbial events occurring under these conditions.

Anaerobiosis↗
PubMed2003

Research on waste stabilisation ponds in the United Kingdom--initial results from pilot-scale facultative ponds.

Three pilot-scale facultative ponds were constructed at Esholt wastewater treatment works in Bradford, West Yorkshire, UK. The ponds were operated in parallel to test the effect of surface BOD loading on performance and the maintenance of facultative conditions. The performance criteria adopted were BOD, SS and ammonia removal. The criterion for facultative conditions was the presence of an algal population maintaining aerobic conditions at the pond surface. Filtered BOD removal was found to be more than 90%, non-seasonal, and related to areal BOD loading. SS removal was also found to be non-seasonal, at around 95% but not related to areal BOD load. Ammonia removal was seasonal (32-48% October to March; 60-81% March to July) and related to areal BOD load. At the test loadings (60, 110 and 169 kg/ha.d) an algal population was not maintained in winter. The initial results indicate that a much lower loading is required to maintain facultative conditions than to optimise BOD and SS removal.

Ammonia↗
PubMed2005

Research on waste stabilization ponds in the United Kingdom: sludge accumulation in pilot-scale primary facultative ponds.

Three pilot-scale facultative ponds, located at Esholt wastewater treatment works in Bradford, West Yorkshire, UK were operated in parallel for 53 months, each with different BOD loadings and hydraulic retention times. Measurements of the sludge accumulation were made at 6-monthly intervals commencing at 3 months after start-up. In addition grab sludge samples were collected and analysed for total solids, volatile solids and faecal coliforms. After the first year of operation the sludge accumulation rate was 0.74 m3 yr(-1) for all three ponds (p=816), independent of BOD loading and HRT; the per capita accumulation rates were within the range 0.08-0.16 m3 person(-1) yr(-1). Evidence of degradation was found in the sludge from the percentage of volatile solids in the dry solids, but insignificant removal of faecal coliforms.

Animals↗
PubMed2003

Design of water hyacinth ponds for removing algal particles from waste stabilization ponds.

In this study it was demonstrated that when water hyacinth ponds (WHPs) are used for polishing the effluent from waste stabilization ponds (WSPs), suspended solids (mostly algal particles) are efficiently separated, which also resulted in the reduction of insoluble forms of COD and nutrients. The high pH of the WSPs effluent was easily adjusted to 6-7 as it passed through the WHPs. However, the use of water hyacinth rapidly reduced dissolved oxygen at the first cell to less than three mg/L or very frequently to a level of anaerobic state. Reduction of suspended solids at the WHPs mainly depends on the detention time and pH. An empirical separation model incorporating the detention time and pH dependence was developed.

Biodegradation, Environmental↗
PubMed2005

Comparison of maturation ponds and constructed wetlands as the final stage of an advanced pond system.

The treatment performance of a maturation pond (MP), the typical final polishing stage of an Advanced Pond System (APS), is compared with that of a surface-flow constructed wetland (CW) over 19 months. Both received approximately 67 mm d-1 of wastewater after passage through upstream stages of the APS. The MP, with greater sunlight exposure, had higher algal biomass (and associated suspended solids) than the CW, showed higher dissolved oxygen (DO) concentrations and greater diurnal variation in DO and pH. Neither polishing stages reduced nutrients markedly, with the CW exporting slightly more NH(3)-N and DRP, and less NO(3)-N than the MP. Disinfection was more efficient in the MP (geometric mean 1 log load removal, 12 MPN (100ml)-1) compared to the CW (0.47 log load removal, 53 MPN (100ml)-1). Incorporation of a final rock filter (28% of area) reduced median solids levels to < 10 g m(-3) in both the MP and CW. A hybrid between MPs and CWs with alternating zones of open-water (for enhanced disinfection and zooplankton grazing of algal solids) and wetland vegetation (promoting sedimentation and denitrification, and providing refugia for zooplankton) may provide more consistent effluent quality that either stage alone.

Ammonia↗
PubMedDate not supplied

Nitrogen and phosphorus cycling in shrimp ponds and the measures for sustainable management.

Six ponds of age 3 were selected 45 km north from Suzhou in the Tailake region, and research conducted on nitrogen and phosphorus cycling in P. vannanmei (Penaeus vannanme) ponds and M. nipponense (Macrobrachium nipponense) hatchery ponds under normal management. Two treatments each had three replications. The results confirmed that feed was the major path of nitrogen and phosphorus input, each accounted for 61.24% (193.81 kg ha(-1)) and 81.08% (45.20 kg ha(-1)) of the total nitrogen and phosphorus input for P. vannanme ponds; the values for M. nipponense ponds were 43.93% (86.31 kg ha(-1)) and 57.67% (14.61 kg ha(-1)), respectively. Water pumped into ponds contributed on average 83.57 kg ha(-1) nitrogen and 8.48 kg ha(-1) phosphorus for P. vannanmei ponds, and 87.48 kg ha(-1) nitrogen and 7.00 kg ha(-1) phosphorus for M. nipponense hatchery ponds. Shrimp harvest recovered 102.81 kg ha(-1) nitrogen (32.94% of the total nitrogen input) and 7.94 kg ha(-1) phosphorus (14.23% of the total phosphorus input) for P. vannanme ponds; and 43.94 kg ha(-1) nitrogen and 4.46 kg ha(-1) phosphorus for M. nipponense hatchery ponds. The sum of nitrogen losses through volatilization, denitrification and sedimentation was 173.62 and 122.39 kg ha(-1), 54.86% and 62.29% of the total nitrogen input for P. vannanme ponds and M. nipponense hatchery ponds, respectively. Sediment accumulated 41.46 and 14.63 kg ha(-1) phosphorus, 74.37% and 64.85% of the total phosphorus input for P. vannanm ponds and M. nipponense hatchery ponds. Draining and seeping caused 40.06 kg ha(-1) nitrogen (12.66% of total nitrogen input) and 6.36 kg ha(-1) phosphorus (11.40% of total phosphorus input) loss to the surrounding water from P. vannanme ponds in 114 days; 30.14 kg ha(-1) nitrogen (15.34% of the total input) and 4.45 kg ha(-1) phosphorus (17.57% of the total input) to channel water from M. nipponense hatchery ponds in 87 days, respectively. Countermeasures for sustainable pond management include improving feeds and feeding, sediment treatments, machine aerating, chemicals with no pollution, and integrated fish-shrimp cultivation. Management of water resources for pond and methods to reduce nitrogen and phosphorus loading into surrounding water from drainage are elucidated.

Aquaculture↗
PubMedDate not supplied

Antibiotic resistance from wastewater oxidation ponds.

In an extensive, multiyear study of antibiotic resistance from wastewater oxidation ponds, five mobile home park wastewater oxidation ponds in Clarke and Oconee counties were shown to be discharging high numbers of antibiotic-resistant bacteria into the waterways of North Georgia. This effluent contributed to higher nitrogen, phosphorus, and fecal coliform levels in creeks downstream from the ponds. A survey of residents revealed that many people did not complete their antibiotic prescriptions, and the majority flushed leftover antibiotic medications down the toilet. In the pond discharges, resistance was found to eighteen antibiotics: amikacin, amoxicillin/clavulanic acid, ampicillin, apramycin, cefoxitin, ceftiofur, ceftriaxone, cephalothin, chloramphenicol, ciprofloxacin, gentamicin, imipenem, kanamycin, naladixic acid, streptomycin, sulphamethoxazole, trimethoprim/sulphamethoxazole, and tetracycline. The discharged bacteria contained both integrons and plasmids, the latter being transferable to a laboratory strain of Escherichia coil (E. coli). A turtle was found living at a pond discharge site with multiply-antibiotic-resistant bacteria in its feces. Last year, RNA fingerprinting conclusively documented the survival of three multiply-resistant important pathogenic bacteria. Ceftriaxone-resistant Stenotrophomonas maltophilia and Pseudomonas aerogenosa and a ciprofloxacin-resistant E. coli were traced through oxidation pond stages and into the discharge, thus documenting that the pathogens survived the treatment process. In addition, a potential pathogen, a serotype group D Salmonella spp., was found in the discharge. In this study, tetracycline-resistance genes C and G were detected in the first and second stages of the oxidation pond and the discharge went directly into the environment. These genes are generally found in intestinal bacteria, so it can be inferred that they are from a human source. Antimicrobial residue from the beta-lactam family of antibiotics was found in all oxidation pond stages and in the creek above the pond. Tetracycline residue was found in the first and second stages of the pond. In addition to the antibiotics, genes coding for antibiotic resistance and the antibiotics themselves were documented to survive oxidation pond treatment. Tetracycline-resistant genes were identified in the oxidation pond stages and in the discharge going into the environment. A model was also developed to study oxidation pond function in the laboratory. A biofilm was created using a highly antibiotic-resistant Salmonella typhimurium 3/97, and pond water was added. The biofilm was processed via a rotating disk bioreactor specifically designed to study biofilms in nature, but with conditions that were more favorable to bacterial inhibition than those in nature. Cultures revealed that, under these optimal conditions, S. typhimurium 3/97 was still present in this in vitro system. Thus, the competitive inhibition process that helps to remove bacteria in oxidation ponds did not effectively remove an important bacterium, S. typhimurium 3/97, in this mock oxidation pond. The bioreactor model developed in this study can be used to further investigate discharges from oxidation ponds. From this data, it is apparent that the problem is two-fold. A cost-effective technique must be developed that inactivates antibiotic-resistant bacteria in oxidation pond discharges and also removes the antibiotics. A public awareness campaign was initiated by the author to encourage proper use and disposal of antibiotics, as flushing them is a common practice in the United States.

Drug Resistance, Microbial↗
PubMed2005

[Phosphorus sorption capacities of the pond sediments in a headstream agricultural watershed].

The land uses in watersheds have important influence on the sediments of lakes and wetlands. Field and laboratory experiments were conducted to research the phosphorus adsorption by the pond sediments in the pond system in a headstream watershed. Being scattered in different ambient land uses and receiving soil particles from various sources, the pond system provides an excellent research example for the phosphorus sorption characteristics. It was found that the pond sediments had strong phosphorus sorption capacities. The phosphorus adsorption maximum (Smax) ranged from 228 to 974 mg x kg(-1), equilibrium phosphorus concentration (EPC0) ranged from 0.004 to 0.032mg L(-1). The mean degree of phosphorus saturation (DPS) of the pond sediments was only 9.5%. The situation of the ponds can influence the physico-chemical properties of sediments and their sorption characteristics. For Smax, Hill pond >Nonirrigation pond> Rice pond> River pond> Village pond. On the contrary, for EPC0, Hill pond< Nonirrigation pond< Rice pond < River pond < Village pond. The phosphorus adsorption maximum (Smax) was significantly correlated ly correlated with the KCl-extractable phosphorus (KCl-P, r2 = 0.83, p < 0.001). Multiple regression analysis shows that Fe(ox) and KCl-P are the key factors, which can influence phosphorus sorption of the pond sediments.

Adsorption↗
PubMed2001

Performance of constructed evaporation ponds for disposal of smelter waste water: a case study at Portland Aluminum, Victoria, Australia.

The construction of evaporative ponds and wetlands for the disposal of waste water high in ionic concentrations is a waste disposal strategy currently considered by many industries. However, the design, construction and management of these ponds and wetlands are not straightforward as complex chemical interactions result in both spatial and temporal changes in water quality. The effects of evaporation and drainage on the water quality in two constructed ponds, an adjacent man-made wetland and local groundwater at Portland Aluminium were investigated. The minimum volume of water entering the ponds during the study period was 0.96 +/- 0.16 ML per month. The predicted theoretical evaporative capacity of the two ponds was calculated to be 0.30 +/- 0.07 ML per month. More water enters the ponds than it is theoretically possible to evaporate under the ambient weather conditions at Portland, yet the ponds do not overflow, suggesting percolation through the pond lining. No spatial differences in solute concentrations (fluoride, sulphate, bicarbonate, carbonate, sodium, potassium, calcium, and magnesium ions) were found within the waters of either pond, although temporal differences were apparent. The results support the conclusion that the ponds are not impermeable, and that much of the waste water entering the ponds is being lost through seepage. The impacts on local groundwater chemistry of this seepage are addressed. Significant correlations exist between solute presence within and between the ponds. wetland and groundwater. Fluoride and sulphate concentrations were significantly higher in pond waters throughout the duration of the experiment. Pond sediments revealed a high degree of spatial and temporal heterogeneity in the concentration of all monitored ions resulting from the chemical heterogeneity of the material making up the pond linings. Adsorption isotherms for fluoride indicate that the adsorption capacity of the pond linings remains high for this ion. Implications for the management of waste water by this strategy are discussed.

Aluminum↗