435 resultados para Lagoa de Óbidos


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Dentre as várias plantas daninhas aquáticas imersas que proliferam nos reservatórios de usinas hidrelétricas, destaca-se em importância Ceratophyllum demersum, devido à sua grande capacidade de reprodução e produção de biomassa. Contudo, apesar de problemática, estudos relacionados com o mecanismo de propagação e persistência dessa espécie em ambiente aquático são bastante escassos no Brasil. Dessa forma, o objetivo deste estudo foi avaliar diferentes métodos de superação de dormência em sementes desta planta daninha aquática coletadas na Lagoa Vírgula, localizada no rio Tietê-SP. As sementes coletadas foram divididas em dois lotes, sendo um constituído por sementes acondicionadas em um recipiente contendo água destilada e o outro por sementes acondicionadas em sacos de papel em condições de câmara fria (16,8 ºC). Após 650 dias da coleta das sementes, foram realizados os testes de superação de dormência, utilizando os seguintes tratamentos: escarificação manual; imersão em ácido sulfúrico concentrado (98%) por 5, 15, 25 e 35 minutos; imersão em água quente (98 ºC); e testemunha A, constituída pelo lote de sementes acondicionadas em um recipiente contendo água destilada, e uma testemunha B, constituída pelo lote de sementes acondicionadas em saco de papel. Os resultados demonstraram que a espécie C. demersum produz sementes férteis e podem permanecer viáveis no sedimento por vários anos após a fecundação. A escarificação das sementes foi o método mais eficaz na superação da dormência, sendo significativamente superior aos demais tratamentos e apresentando 65,0% de germinação aos 79 DAT. Ficou evidente a necessidade de realização de mais estudos para determinação de uma metodologia mais adequada à avaliação de dormência em sementes de C. demersum.

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O objetivo deste estudo foi desenvolver um método para determinação de pontos de reprodução e de suas respectivas importâncias na disseminação das espécies E. densa, E. najas e C. demersum no reservatório de Jupiá. Foram monitorados dez locais nos quais se encontrou registro de altas infestações dessas espécies. Dois desses locais situam-se no rio Paraná, nas lagoas denominadas de Ferradura e Pernilongo; os outros oito sítios estão localizados no rio Tietê, nas lagoas marginais Testemunha, Barrenta, Vírgula e Flórida, e no leito do rio nos pontos Acima da Ponte dos Barrageiros, Abaixo da Ponte, Baía ao Lado da Ponte e em frente da Praia de Itapura. em cada um desses sítios de reprodução foram liberados e monitorados dez blocos de plantas aquáticas imersas por mês. Os blocos possuíam volume de 0,14 cm³ e receberam uma etiqueta plástica de identificação externa e uma bóia de cor laranja, com o objetivo de serem facilmente localizadas ou visualizadas à distância. Após a soltura, cada bloco foi georreferenciado por meio de um aparelho GPS, sendo o seu deslocamento avaliado a cada 15 dias. Os sítios Lagoa Vírgula, Lagoa Testemunha e Lagoa Barrenta destacaram-se quanto ao número de blocos (30, 20 e 19 blocos, respectivamente), que percorreram distâncias superiores a 500 m e, conseqüentemente, saíram de seus respectivos locais de reprodução. A grande maioria dos blocos permaneceu dentro da Lagoa Flórida; somente 12 blocos saíram e alcançaram o leito do rio Tietê. O sítio denominado Leito Acima da Ponte foi o que mais se destacou dentre os três localizados no leito do rio Tietê, pois forneceu 18 blocos de plantas, enquanto os sítios Abaixo da Ponte e Baía ao Lado da Ponte forneceram 15 e 14 blocos, respectivamente. O sítio Praia de Itapura foi o que apresentou menor importância em relação ao fornecimento de plantas imersas no rio Tietê, sendo localizadas apenas 11 bóias com deslocamento superior a 500 m. Os sítios de reprodução localizados no rio Paraná também contribuíram para o fornecimento de plantas imersas ao reservatório de Jupiá; nove blocos saíram da Lagoa Pernilongo e apresentaram deslocamentos superiores a 500 m. Entretanto, os sítios Lagoa Barrenta e Lagoa Ferradura foram aqueles que mais contribuíram com a chegada de plantas na tomada de água da UHE Eng. Souza Dias, uma vez que foram recolhidos, respectivamente, seis e quatro blocos de plantas provenientes desses locais de dispersão. A metodologia utilizada mostrou-se eficaz quanto à avaliação da movimentação de plantas aquáticas imersas dentro do reservatório de Jupiá.

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Environmental pollution has become a subject of public interest throughout the world. Not only have developed countries been affected by environmental problems but also the developing nations have started to suffer from the serious impacts of pollution. Within this context it is necessary to collect simplified environmental data to assist in the management of water resources by the appropriate authorities. These data are obtained through an environmental index that allows a space-time comparison of points distributed in the same aquatic body, or between different water bodies, for physico-chemical and bacteriological parameters. The aim of this present study was to determine the environmental status of the Lagoa de Baixo at Guamaré/RN, where a production unit of PETROBRAS RN/CE is located. For this purpose the Water Quality Index (WQI) was used in both an add and multiply form, the Trophic State Index (TSI) and the Environmental Quality Quotient (EQQ), as well as determining the concentrations of metals. The average values obtained for the WQI, in its two forms were 68,67 and 62,76 respectively which were inside the good qualification. According to the TSI the lagoon showed characteristics of a middle trophic state, and an impact level of regular as determined by the EQQ

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Stabilization ponds are an effective sewage treatment alternative for the climatic conditions prevailing in Brazil. In the present work, a primary facultative pond was studied, in the city of Natal, Rio Grande do Norte, Northeast Brazil. The aim of this study was to evaluate the sedimentation dynamics in the facultative pond. The pond was divided in three section or zones along its length starting from the inlet end namely A1, A2 and A3. The research was accomplished in three phases. In the first the mapping of the sludge layer was done, sludge core samples were also collected for analysis for total, fixed and volatile solids and the depth of the sludge layer was determined using a portable echo sounder. In the second solids sedimentation rates were measured using traps placed in the inlet and outlet zones and in the third phase resuspension sludge was evaluate using a tracer. The amount accumulated sludge since the start operation was 13.583 m3. The sedimentation constant averages changed between 0.93 to 2.94 and 3.90 to 5.80 for the depths of 0.5 and 1.0 m respectively. The relationship between volatile and fixed solids (SV/SF) increased along the pond. The removal efficiencies were 52.12%, 36.09%, and 37.50% for BOD, COD and SS, respectively. The sludge accumulation model proposed had a good adjustment with 0.17 m3/hab.year rate. The results presented here demonstrated that the wind had a direct influence on the sedimentation of solids in this pond affecting the efficiency and sludge accumulation

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Waste stabilization ponds (WSP) have been widely used for sewage treatment in hot climate regions because they are economic and environmentally sustainable. In the present study a WSP complex comprising a primary facultative pond (PFP) followed by two maturation ponds (MP-1 and MP-2) was studied, in the city of Natal-RN. The main objective was to study the bio-degradability of organic matter through the determination of the kinetic constant k throughout the system. The work was carried out in two phases. In the first, the variability in BOD, COD and TOC concentrations and an analysis of the relations between these parameters, in the influent raw sewage, pond effluents and in specific areas inside the ponds was studied. In the second stage, the decay rate for organic matter (k) was determined throughout the system based on BOD tests on the influent sewage, pond effluents and water column samples taken from fixed locations within the ponds, using the mathematical methods of Least Squares and the Thomas equation. Subsequently k was estimated as a function of a hydrodynamic model determined from the dispersion number (d), using empirical methods and a Partial Hydrodynamic Evaluation (PHE), obtained from tracer studies in a section of the primary facultative pond corresponding to 10% of its total length. The concentrations of biodegradable organic matter, measured as BOD and COD, gradually reduced through the series of ponds, giving overall removal efficiencies of 71.95% for BOD and of 52.45% for COD. Determining the values for k, in the influent and effluent samples of the ponds using the mathematical method of Least Squares, gave the following values respectively: primary facultative pond (0,23 day-1 and 0,09 day-1), maturation 1 (0,04 day-1 and 0,03 day-1) and maturation 2 (0,03 day-1 and 0,08 day-1). When using the Thomas method, the values of k in the influents and effluents of the ponds were: primary facultative pond (0,17 day-1 and 0,07 day-1), maturation 1 (0,02 day-1 and 0,01 day-1) and maturation 2 (0,01 day-1 and 0,02 day-1). From the Partial Hydrodynamic Evaluation, in the first section of the facultative pond corresponding to 10% of its total length, it can be concluded from the dispersion number obtained of d = 0.04, that the hydraulic regime is one of dispersed flow with a kinetic constant value of 0.20 day-1

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Due to the increasing activities and its disordered occupation, the catchment of the Pitimbu river is reason of concern for the population, since the river empties in the lagoon of the Jiqui where 30% of the water of this lagoon are caught for the supplying the city of Natal, playing an important fuction in the supply of water superficial for the capital of the Rio Grande do Norte. The superior stretch of the hydrography catchment of the Pitimbu river - Macaíba/RN, object of this study, is denoted by the eminently agricultural occupation with the use of the irrigated agriculture in the many properties that compose this stretch. Because of this becomes necessary to analyze the availability of the water resources in the catchment of the Pitimbu river, in the superior stretch, collating with the use and occupation of the existing terrain. The stretch in study was divided in eight points which had been performed tests throughout the water and analyzed the parameters physicist-chemistries and heavy metals that are praised by resolution CONAMA nº 357 e, visits in field with photographic survey for characterization of this verifying the situation where if it finds the river. The stretch presented some divergence in the parameters of pH and iron, however the results denote a characteristic of the region. The great amount of slide barrages throughout the river and the wet street was observed, had also verified near the edges the launching of garbage and, the great amount of aquatic vegetation. With this it is concluded that the water of the river can be used for human supplying, therefore inside presents a quality of drinking waters of the standards demanded for resolution CONAMA nº 357, in this way, the stretch in study could be adopted as an Envoiremental Area Protection (APA), to preserve and to guarantee, at least in this stretch, that its condition remains unchanged and continues to supply of permanent form a water of excellent quality

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The Pitimbu River Basin is concern reason, therefore this is one of the mains freshwater sources for the Natal city supplying. The Pitimbu waters river flow into Jiqui pond, as the main supplier of this, that supplies 16% of Natal population and there is a bigger importance despite the supplying of a parcel of Natal city made joining underground waters with the water proceeding from the Jiqui pond, being used for dilution waters of contaminated wells with nitrate. Even with the importance of the Pitimbu, there is a strong pressure of occupation of its edge according to a critical urban growth, becoming the situation worse and increasing the necessity of management of the use and occupation of the ground and keeping the control of the prompt pollution, as punctual as diffuse. There are many studies about Pitimbu River Basin, however they summarize themselves to some months or even in a few years. This work, that gathers these information, increasing the amplitude and making possible an evaluation of the attitude of the water in a period extended for an evaluation of values of variable quality of water referring to the standards, that usually happens about the variable frequency distribution, central tendency and measures of dispersion, as the coefficient of variation, coefficient of skewness and the coefficient of determination of certain variable on another one. This work to evaluates the quality conditions of the Pitimbu river waters by analyzing thirty five (35) variables Physical, chemical and biological in eight (8) points of water course since 1993 to 2007. Given this situation, all knowledge about the waters quality conditions obtained in this work, is a strong subsidy for management of use and ground occupation, considering the river basin as territorial unit of management, and as the water is public good domain, being a priority human use, It is necessary to guarantee to current and the future generations available water resources in appropriate standards of quality as the established standard and identifying possible reasons of pollution through statistics analysis

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The detention and infiltration ponds of urban drainage system has function to protect the population from undesirable effects of floods. In general these ponds are not completly used and it potential is wasted. As it are disseminated at different places at cities it can reduce costs with water transport and permit water preservation of best quality. Some it utilities includes use in green areas irrigation, industrial among than cooling towers and boiler, soil compaction, cleaning urban road, pisciculture and fire fighting system. The quality these water is influenced by anauthorized sewage in the drainage system. This study was performed in six detention and infiltration ponds at drainage system of Natal, which aim was to verify the non-portable use these ponds on urban environment. As indirect aim would to incentive the water utilization these ponds as a water source to another uses in urban environment. These ponds represents the characteristics of detention and infiltration of Natal city and consequently of Brazil. As the water quality, the ponds presents following characteristics: three has apparently good quality, other showed intermediate condition and two had water polluted. Were performed twenty sample in each ponds and the following parameters assessed: pH, temperature, dissolved oxygen, turbidity, electrical conductivity, coliform thermotolerant, ammonia, organic nitrogen, TKN, nitrate, total phosphorus and alkalinity, bicarbonate, chloride, total hardness, calcium and magnesium hardness, total solids, TSS, TDS, COD and SAR°. To utilization on pisciculture we recommend use in ponds which presents the best quality. Only one pond presented higher pollutants and it not being appropriated for use in cooling tower. The content of solids suspension restricted the water use in all ponds in boilers. As water use in soil compaction, cleaning urban road and fire fighting system the water from these ponds are not appropriated. However, the recommended limits from literature are to domestic sewage, due to this, the parameters are restrictive to diminish the sanitary risk that could be offered with it utilization. The infiltration velocity of water these assessed ponds restrict a moderato use, however the effects are potentiated only in soil less sandy, which not occur in Natal. It is recommend the unrestricted irrigation utilization in ponds with best quality of water, and a restricted irrigation to ponds with worst quality of water. As load of pollutants, it is recommended a complementary treatment in those ponds whit higher load to diminish sanitary risks. In only one pond was found one helminth eggs and due to the convention formula of results, it was found for all ponds less than 1 helminth/liter eggs.

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Stabilization pond system consisting in more sewage treatment used in Rio Grande do Norte (RN), Brazil, representing about 90% of all systems. Fecal bacteria are removed mainly facultative ponds and in maturation ponds. Many factors influence bacterial decay, such as the levels of pH and DO, temperature, light intensity, HDT and nutrient availability. The bacterial decay rate (Kb) is calculated considering many variables, but the hydraulic regime is a significant influence for microorganisms removal, and the dispersed flow which best characterizes a stabilization pond. However, some authors developed equations for the Kb accordant plug flow and complete mixing. This research study aimed to evaluate the bacterial decay of fecal coliform and Enterococcus sp. in stabilization ponds designed to treat domestic sewage, full-scale, in RN. All systems have assessed pretreatment, a facultative pond (LF) followed by two maturation (LM1 and LM2). The parameters availed were: temperature, pH, DO, BOD5, COD, fecal coliform, Enterococcus sp., Chlorophyll a, total suspended solids, fixed and volatile. In general, there were not significant differences for pH, DO and temperature in the ponds, except for the new systems, since they have low flow and hydraulic loads. The removal of organic matter in the ponds was low, about 70%, and nearly all are overloaded organic and operational problems. The bacterial removals were low, with average 96% for LF for fecal coliform, and 98% for Enterococcus sp.; LM1 were in itself a removal for fecal coliform about 71%, and 81% for Enterococcus sp.; LM2 have efficiency of 69% for fecal coliform, and 68% for Enterococcus sp. The equation proposed by Von Sperling (1999), according to the dispersed flow regime, generated empirical values of Kb more approximate to calculated values of Kb. On average, the calculated Kb to coliforms in the LF was 0.31 d-1, and for both maturation ponds were 0.35 d-1. For Enterococcus sp. the average was 0.40 d-1 for LF, 0.55 d-1 for LM1, and 0.58 d-1 for LM2. These results also showed that the Kb obtained in full-scale systems are smaller than those found in pilot-scale ponds. Moreover, one can say that the equation proposed by Marais (1974), according to the complete-mix regime, overestimates Kb. Actual results of Kb indicated that fecal coliforms are more resistant to adverse conditions present in stabilization ponds than Enterococcus sp., therefore, an indicator of microbiological safety and efficiency. The factors significant interventions in the rate of bacterial decay were concentrations of COD, the organic loading and HDT. The few Kb relationship between pH, DO and temperature were not significant. Finally, we conclude that it s essential to correct operation and maintenance, for not performing these activities is one of the main factors contributing to low rates of bacterial decay.

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Urban stormwater can be considered as potential water resources as well as problems for the proper functioning of the manifold activities of the city, resulting from inappropriate use and occupation of the soil, usually due to poor planning of the occupation of the development areas, with little care for the environmental aspects of the drainage of surface runoff. As a basic premise, we must seek mechanisms to preserve the natural flow in all stages of development of an urban area, preserving the soil infiltration capacity in the scale of the urban area, comprising the mechanisms of natural drainage, and noting preserving natural areas of dynamic water courses, both in the main channel and in the secondary. They are challenges for a sustainable urban development in a harmonious coexistence of modern developmental, which are consistent with the authoritative economic environmental and social quality. Integrated studies involving the quantity and quality of rainwater are absolutely necessary to achieve understanding and obtaining appropriate technologies, involving both aspects of the drainage problems and aspects of use of water when subjected to an adequate management of surface runoff , for example, the accumulation of these reservoirs in detention with the possibility of use for other purposes. The purpose of this study aims to develop a computer model, adjusted to prevailing conditions of an experimental urban watershed in order to enable the implementation of management practices for water resources, hydrological simulations of quantity and, in a preliminary way, the quality of stormwater that flow to a pond located at the downstream end of the basin. To this end, we used in parallel with the distributed model SWMM data raised the basin with the highest possible resolution to allow the simulation of diffuse loads, heterogeneous characteristics of the basin both in terms of hydrological and hydraulic parameters on the use and occupation soil. The parallel work should improve the degree of understanding of the phenomena simulated in the basin as well as the activity of the calibration models, and this is supported by monitoring data acquired during the duration of the project MAPLU (Urban Stormwater Management) belonging to the network PROSAB (Research Program in Basic Sanitation) in the years 2006 to 2008

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Stabilization pond is the main technology used for treatment wastewater, in northeast Brazil, due to lower cost of deployment, operation and maintenance compared to other technologies. Most systems of stabilization ponds has been in operation for some time, on average 10 years of operation, receiving high organic loads and do not have good removal efficiencies of the main parameters for which have been designed. Therefore it is necessary to work to quantify the efficiency of current systems. This study evaluated the biodegradability of organic matter in raw sewage, the removal of organic matter in reactors and determination of the kinetic constant removal of organic matter (k), both in reactors and in raw sewage, based on the analysis made in the laboratory and through mathematical methods proposed in the literature, in nine systems stabilization ponds, located in Rio Grande do Norte. In relation the degradation kinetics in stabilization ponds, it was observed that many papers published in the literature were obtained in pilot-scale systems, which often, due to the action of external factors such as wind and temperature, these can t be considered as a reference in the analysis of the kinetic constant K, so the need for more research into systems of scale. This study had three distinct phases and simultaneous, routine monitoring, study of the daily cycle and the determination of kinetic constant of degradation of organic matter (K). The monitoring showed that the removal efficiencies of organic matter on most systems were lower than suggested by the literature, the best efficiencies of around 76% (BOD) and 72% (COD) and the worst of the order of 48% (BOD) and 55% (COD). The calculation of K in raw sewage (Ke) was within the range of variation expected in the literature (0.35 to 0.60 days-1). Already for the results obtained for K in the reactors (Kr), there were well below the values recommended in the literature (0.25 to 0.40 d-1 for complete mix and from 0.13 to 0.17 d-1 for flow dispersed), in line with the overloads that organic systems are subject

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The simulation of SES-Natal Ponta Negra: mitigation of environmental risks and predictive maintenance strategy was developed in the context of several operational irregularities in the pumping stations and sewage systems in the system Ponta Negra. Thus, the environmental risks and complaints against the company due to overflows of sewage into the public thoroughfare became common. This neighborhood has shown in recent years an increase of resident higher than the initial expectation of growth. In this sense presumed the large population growth and generation of sewers higher than expected, associated to the use of corrective maintenance and misuse of the system may be the main causes of operational failures occurring in the SES. This study aimed at analyzing the hydraulic behavior of SES Ponta Negrathrough numerical simulation of its operation associated to future scenarios of occupation. The SES Ponta Negra has a long lengthof collection networks and 6 pumping stations interconnected, being EE 1, 2, 4 coastal way, and beach Shopping interconnected EE3 to receives all sewers pumped from the rest pumping station and pumped to the sewage treatment station of neighborhood which consists of a facultative pond followed by three maturation ponds with disposal of treated effluent into infiltration ditches. Oncethey are connected with each other, the study was conducted considering the days and times of higher inflow for all lifts. Furthermore, with the aim of measuring the gatherer network failures were conducted data survey of on the networks. Thephysical and operational survey data was conducted between January/2011 and janeiro/2012. The simulation of the SES was developed with the aim ofdemonstrating its functioning, eithercurrently and in the coming years, based in population estimates and sewage flow. The collected data represents the current framework of the pumping stations of the SES Ponta Negra and served as input to the model developed in MS Excel ® spreadsheet which allowed simulating the behavior of SES in future scenarios. The results of this study show thatBeach Shopping Pumping Station is actually undersized and presents serious functioning problemsthatmay compromise the environmental quality of surrounding area. The other pumping stations of the system will reach itsmaximum capacity between 2013 and 2015, although the EE1 and EE3 demonstrateoperation capacity, even precariously, until 2017. Moreover, it was observed that the misuse of the network system, due to the input of both garbage and stormwater, are major factors of failures that occur in the SES. Finally, it was found that the corrective maintenance appliance, rather than predictive,has proven to beinefficient because of the serious failuresin the system, causing damage to the environment and health risks to users

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Stabilization pond is the most used sewage treatment system in the country, corresponding to approximately 90% of all systems. The systems evaluated were stabilization ponds system of sewage treatment in the city of Natal / RN. This research aimed to analyze the possible uses through physical-chemical and bacteriological of these final effluent ponds for urban uses depending on the characteristics after passage around the treatment system. The parameters used were chosen according to those established by Chernicharo et al. (2006), in order to characterize the effluent. The parameters evaluated were: DO, temperature, pH, conductivity, organic nitrogen, ammonia, NTK, total phosphorus, and series of solid fecal coliforms. Generally, the characteristics of the effluent followed variability found in the literature. The results showed an efficiency that is technically feasible to use the effluent end of some of STPs analyzed when checked parameters alone, if fitting in unrestricted urban use, restricted use and urban land use

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The Pitimbu River Watershed (PRW), belonging to Potiguar capital metropolitan area, State of Rio Grande do Norte, contributes, among other purposes, to human using and animal watering. This watershed is extremely important because, besides filling up with freshwater approximately 30% of the south part of Natal (South, East and West Zones), contributes to the river shore ecosystem equilibrium. Face to the current conjuncture, this study aims to evaluate the urban development dynamics in the PRW, applying Cellular Automata as a modeling instrument, and to simulate future urban scenarios, between 2014 and 2033, using the simulation program SLEUTH. In the calibration phase, urban spots for 1 984, 1992, 2004 and 2013 years were used, with resolution from 100 meters. After the simulation, it was found a predominance of organic growth, expanding the BHRP from existing urban centers. The spontaneous growth occurred through the fullest extent of the watershed, however the probability of effective growth should not exceed 21%. It was observed that, there was a 68% increase for the period between 2014 and 2033, corresponding to an expansion area of 1,778 ha. For 2033, the source of Pitimbu River area and the Jiqui Lake surroundings will increase more than 78%. Finally, it was seen an exogenous urban growth tendency in the watershed (outside-in). As a result of this growth, hydraulics resources will become scarcer

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This research evaluated the microalgae removal produced in a stabilization pond system using biofilters as post-treatment, besides characterizing the effluents of stabilization ponds and filters in relation to concentrations of algal biomass (chlorophyll a and suspended solids), organic matter (BOD and COD), total phosphorus, orthophosphate, pH and dissolved oxygen, and tried to correlate physicochemical parameters with chlorophyll "a". It was held at the Ponta Negra ETE which is constituted by three stabilization ponds, with a primary facultative pond and two of maturation. For the algae removal were used two submerged bio-filters: the filter FPF (Facultative Pond Filter), fed with facultative pond effluent; and the filter MPF (Maturation Pond Filter), fed with second maturation pond effluent. The filling material of both filters was predominantly gravel no. 2, although it contains portions of gravel no. 1 and no. 3. The filters operating conditions were bad, they were nearly 10 years without maintenance, without cleaning or removal of sludge since the time of its construction, and part of the filling material may be obstruct. Despite poor operating conditions were obtained satisfactory results, in level of posttreatment. Removal efficiencies in relation to BOD and COD were 7 and 25% in FPF and 9 and 19% and in MPF, respectively. In relation to TSS efficiencies in MPF and FPF were 37 and 20%, respectively. As for the chlorophyll "a" removal, the FPF efficiency was 44% and the MPF was 40%. There was 50% of consumption of dissolved oxygen, on average, within the filters. Two profiles were performed in the filters, and it was possible to conclude that variations throughout the day were not statistically significant, and that, regardless of the time of collection, they would have the same representation comparing to the time of data collection (7 am) and the daily average, although individual variations throughout the day have been shown to be significant. Another important observation is that the correlations between Chlorophyll a and TSS were bigger and more significant in the effluent of the filters than in the effluent of the ponds