Esta pesquisa foi desenvolvida nas lagoas facultativas das estações de tratamento de esgoto dos municípios de Pariquera-Açu (PA) e Jacupiranga (JA), com diferentes configurações, sendo a primeira composta por lagoa anaeróbia seguida de facultativa com chicanas e a outra por lagoa aerada mecanicamente seguida de facultativa. Estas lagoas são consideradas ambientes hipereutróficos, pois apresentam grande quantidade de matéria orgânica oriunda dos esgotos domésticos e industriais. O conhecimento da estrutura da comunidade fitoplanctônica e sua avaliação em diferentes horários do fotoperíodo são relevantes pois estes organismos são responsáveis pela produção de oxigênio necessário para a degradação da matéria orgânica. Esta pesquisa teve como objetivo principal o estudo sazonal e diário da estrutura da comunidade fitoplanctônica e da produção primária nestas lagoas. Para atingir este objetivo foi caracterizada a estrutura da comunidade, em relação a biomassa e diversidade, e determinada a produção primária com incubações in situ através do método do oxigênio dissolvido. O estudo foi realizado em quatro épocas do ano (variação sazonal) no período das 7 às 16 horas, com amostragens de 3 em 3 horas (diária). Não foram observadas variações temporais e espaciais na estrutura da comunidade fitoplanctônica nas duas lagoas facultativas. Apenas as cianobactérias (principalmente a Synechocystis aquatilis e Phormidium sp) e clorofíceas (Kirchneriella lunaris, Chlorella Kessleri, Monoraphidium contortum, Monoraphidium sp, Chlamydomonas sp, Eutetramorus planctonicus e Micractinium pusillum) foram predominantes, nestas lagoas, porém em períodos alternados. Foram observados altos valores de produção primária bruta (15.891 mg\'O IND.2\'/\'M POT.3\'.h em PA; 5.700 mg\'O IND.2\'/\'M POT.3\'.h em JA) na interface água-sedimento das duas lagoas devido, provavelmente, ao padrão de mistura da coluna de água. Foram também observados altos valores de respiração da comunidade (abril, julho e setembro), devido à alta concentração de matéria orgânica presente nestes sistemas e, portanto, maior decomposição, indicando predominância de processos heterotróficos. / This research was developed in facultative ponds of the waste water treatment plant of Pariquera-Açu and Jacupiranga cities with different configurations, being the first composed by anaerobic pond followed by facultative with chicanas and the another composed by aerated mechanic pond followed by facultative. These ponds are considered hypereutrophic environments because it shows a large quantity of organic matter derived from the domestic and industrial sewage. The knowledge of phytoplanktonic community structure and its evaluation in different times of photoperiod are relevant since such organisms was responsible by production of oxygen necessary to the degrade of organic matter. This research had the main goal the seasonal and daily study of the phytoplanktonic community and the primary production in these ponds. To reach this objective the structure of the community was characterized in relation to biomass and density, and determined the primary production with incubations in situ through the dissolved oxygen method. The study was made in four periods of the year (seasonal variation) between the 7 a.m. to 4 p.m., with samplings of 3-to-3 hours (daily). It was not observed temporal and spatial variations in the phytoplanktonic community structure in the facultative ponds. Only cyanobacteria (mainly Synechocystis aquatilis and Phormidium sp) and chlorophycea (Kirchneriella lunaris, Chlorella Kessleri, Monoraphidium contortum, Monoraphidium sp, Chlamydomonas sp, Eutetramorus planctonicus and Micractinium pusillum) were predominant in these ponds, however, in alternated periods. It was observed high rates of gross primary production (15891 mg\'O IND.2\'/\'M POT.3\'.h, PA; 5700 mg\'O IND.2\'/\'M POT.3\'.h, JA) in the interface water-sediment of both ponds due, probably, to the standard of mixed conditions of water column. It was also observed high rates of community respiration (April, July and September), due to the high concentration of organic matter present in these systems and, therefore, greater decomposition, indicating predominance of heterotrophic processes.

O estudo da comunidade microbiana que participa do processo de estabilização da matéria orgânica presente nos efluentes sanitários é fundamental para o melhor conhecimento dos tipos de sistemas de tratamento biológico. A avaliação da dinâmica de algas e bactérias presentes no sistema australiano de lagoas de estabilização da cidade de Novo Horizonte (SP) foi o principal objetivo deste trabalho. Para esta avaliação foram determinadas as densidades destes organismos (contagem direta) e a taxa de produção fitoplanctônica (medida pela produção de oxigênio dissolvido) e comparadas às condições abióticas, em escala nictemeral (coletas a cada 6 horas), sazonal (4 épocas do ano), espacial longitudinal (5 estações ao longo do sistema) e vertical (3 profundidades nas lagoas facultativas). Os resultados obtidos indicaram diferenças sazonais na qualidade do efluente final e no desempenho das lagoas. Mesmo com estas diferenças, o efluente final pode ser considerado como potencialmente eutrofizante quanto à concentração de matéria orgânica e de fósforo total. As lagoas facultativas apresentaram condição de anaerobiose na maior parte da coluna de água, o que contribuiu com a não eficiência do sistema / The study of the microbial community (algae and bacteria) that participates of the organic matter stabilization process in the effluent sanitary it is important for the best knowledge of the types of the biological treatment systems. The evaluation of the dynamics of the algae and bacteria in the Australian wastewater stabilization ponds of the Novo Horizonte city (SP) was the main objective of this research. For this evaluation, the densities of these organisms (direct counting) and the primary production rate were determined (measured for the production of oxygen dissolved) and compared to the abiotics conditions, in nictemeral scale (it collects to each 6 hours), seasonal (four periods of the year), longitudinal (5 stations through the system) and vertical spatial (three depths in the facultative ponds). The results indicated seasonal differences in the final effluent quality and in the ponds performance. Although these differences, the final effluent can be considered as potentially eutrophic according to the organic matter and total phosphorus concentrations. The facultative ponds showed an anaerobic condition on the great part of the water column, which contributed with the low efficiency of the system

No description available.

Macroinvertebrate communities inhabiting an exotic, Myriophyllum spicatum, and a native, Heteranthera dubia macrophyte were studied from March 1999 to June 2000 in experimental ponds. Although macrophyte architecture explained some variation in macroinvertebrate abundance between the two macrophytes, most variation was explained by the sampling months. Total number of macroinvertebrates was found to be positively correlated with epiphyton biomass which differed significantly between the two plant types and among sampling months. Taxa richness did not vary between the two plant types. Chironomid larvae were the most abundant organisms and dominated by Apedilum elachistus on both plant communities. Annual production of five chironomid species was estimated by the size-frequency method. Production estimates (P) in g dry wt m-2 yr-1 of plant surface area for the predator Tanypodinae larvae were: Larsia decolarata, P= 0.77 and 0.67, Labrundinia virescens, P= 0.59 and 0.35 on M. spicatum and H. dubia, respectively. Larvae of Cricotopus sylvestris and Psectrocladius vernalis were collected from M. spicatum from March to mid-June. Production of C. sylvestris was found to be 0.46 g dry wt m-2, whereas it was 0.07 g dry wt m-2 for P. vernalis for this period. Apedilum elachistus exhibited the highest productivity: 9.9 g dry wt m-2 yr-1 of plant surface area on M. spicatum, and 8.5 g dry wt m-2 yr-1 on H. dubia. These production estimates are among the highest production values reported for a single species. Additionally, post-ovipositing development times for five chironomid species collected from Myriophyllum and Heteranthera were determined. Three different temperatures (15°, 20° and 25°C) were chosen to rear eggs under 12L: 12D photoperiod. Egg development times ranged between 1-4 days. Larval development times ranged from 44 days at 20°C for Tanypus neopunctipennis to as few as 9 days at 20°C for Larsia decolorata.

Waste Stabilisation Ponds (WSPs) are characterised by low phosphorus (P) removal capacity. Heterotrophic bacteria are principal microbial agents in WSPs in addition to algae. As treatment proceeds in WSPs, algal growth increases and pH rises, this has lead to believe that P removal is mainly through sedimentation as organic P algal biomass and precipitation as inorganic P. In activated sludge treatment plants (AS), microbial P removal has been improved and is termed as enhanced biological phosphorus removal. There was a need to establish whether it was possible to enhance P removal in WSPs. A performance assessment of pond system at the University of Dare s Salaam (UDSM), Tanzania, has shown that 90% of the P removed was in the primary pond (facultative) and the rest in the maturation pond (aerobic). In these studies, a pure strain A. hydrophyla was isolated from an activated sludge wastewater treatment plant in Sweden. This plant has a train that functions with enhanced biological phosphorus removal. The strain was tested for P uptake in minimal media supplemented with glucose, succinate or acetate, grown aerobically and anaerobically/aerobically. This strain was able to take up P without having been subjected to the anaerobic phase. It was observed that P uptake was enhanced after the anaerobic phase with media supplemented with glucose, but not with succinate or acetate. Phosphorus uptake repeatedly followed the bacterial growth pattern with correlation coefficients of more than 95%. Therefore P removal has a direct correlation with bacterial growth. Two isolates Acinetobacter sp. (isolated from the primary facultative pond) and E .coli (isolated from the maturation pond) were obtained from a tropical WSP treatment system at the UDSM. They were subjected to aerobic P uptake experiment similar to those of A.hydrophyla. The uptake per unit absorbance of bacterial growth was found to be comparable to that of A.hydrophyla, isolated from AS. These results showed that heterotrophic activity is important in WSPs. It is possible to enhance P removal in these systems by designing the primary ponds for maximum heterotrophic activity and probably enrichment. / QC 20101119

In this study I assess spatial and temporal patterns of sediment deposition in Pecausett Pond, located along the tidal extent of the Connecticut River, in order to assess the role of tides in the transport and storage of sediment and associated contaminants within floodplain tidal ponds. Findings reveal that tidal ponds have significantly higher rates of sedimentation compared to neighboring marshes due to the fact that these ponds have more accommodation space and receive uninterrupted tidal exchange with the main river. Tidal tie channels introduce a pulse of suspended sediment and contaminants from the main river into these ponds each flood tide, with sedimentation rates fast enough to allow settling before the subsequent ebb tide can transport these sediments back to the main river (i.e. tidal pumping). Some studies performed on the tidal floodplain of the Connecticut River show high deposition rates and have attributed periods of high accumulation to anomalously high river discharge events. However, this project shows that tides are more likely the major mechanism responsible for transporting and storing sediment and associated contaminants at backwater sites located along the tidal floodplain. Deposition rates in this 3-4 m deep pond exceed 2 cm/yr. These rates are far too high to maintain equilibrium morphology for much longer. However, ground penetrating radar surveys from the study site reveal truncated stratigraphy common to erosional unconformities, which suggest that mechanisms for sediment remobilization and removal may exist. Periods of episodic erosion therefore may be helping to maintain the morphology in this shallow environment, and allow for the high rates of short-term deposition. Further, a sudden increase in percent inorganic potentially associated with the opening or clearance of the tie-channel is observed at a sediment depth approximately between 1.9 to 2.2 m. A radiocarbon date obtained below this transition is consistent with a significant drop in sedimentation prior to this tie-channel development. High rates of sedimentation in Pecausett Pond are therefore likely relatively recent phenomena, transpiring over the last few centuries following early colonization.

No description available.

Although high rate algae ponds (HRAPs) are a proven wastewater treatment technology with numerous environmental, social, and economic benefits, their widespread use has been hindered by inconsistent and unreliable settling performance. Hence, the goal of this thesis is to investigate how specific operational parameters affect the settling performance of HRAPs. Nine HRAPs (30 m2 surface area, 0.3 m depth) were operated as three triplicate sets, with each set run on either a 2, 3, or 4 day HRT continuously from January 25, 2012 through April 11, 2013. Settling performance was determined (i) by measuring the TSS of Imhoff cone supernatant after 2 and 24 hours of settling and (ii) by measuring the TSS of tube settler effluent. Ponds operating on 2 - 3 day HRTs (loading rate was 24 - 36 g/m3-day csBOD5 and food to microorganism (F/M) ratio was 0.13 - 0.21 day-1) were able to settle consistently with residual TSS averaging less than 40 mg/L after 2 hours of settling time. Tube settlers showed potential as effective harvesting devices; ponds operating on a 2-day HRT averaged 27.9 ± 9.2 mg/L TSS in tube settler effluent at an overflow rate (OFR) of 9.4 L/min-m2. Microscopy analysis was performed and relationships were made between settling performance and algae dominance and floc structure.

No description available.

No description available.