Cacilda Thais Janson Mercante - Academia.edu (original) (raw)
Papers by Cacilda Thais Janson Mercante
Journal of Water Resource and Protection, 2014
The concern in mitigating the negative impact generated by the discharge of nutrients in the rece... more The concern in mitigating the negative impact generated by the discharge of nutrients in the receiving water body is a challenge for the sustainable development of Brazilian fish farms. Thus, the purpose of this study was to evaluate the water quality and environmental impact caused by trout farming system effluent with focus on discharge of phosphorus. Sampling was performed on a weekly basis in triplicate from September to November 2010. Sample sites were distributed according to the water flow: upstream from trout farming system, water supply, effluent, artificial wetland, mixing zone and downstream (60 m from effluent). In the field, pH, conductivity, dissolved oxygen, water temperature and turbidity were measured. In laboratory, nitrogen and phosphorus series, chlorophyll a, total solids suspended and their organic and inorganic fractions were analyzed. For the good growth of trout in production system, the abiotic factors described in the water quality monitoring demonstrated acceptable values. Environmentally, after passing through the production system and artificial wetland, there was an increase in concentrations of total phosphorus, total nitrogen, orthophosphate, ammonium, chlorophyll a, total solids suspended and their organic and inorganic fractions (P < 0.05). These results are related with the quality of feed, feeding management and the inefficiency of the artificial wetland. Therefore, it is necessary to use best quality feed to meet the nutritional requirements of trout, maintaining an optimal feed conversion and reducing pollution generated by effluent.
Revista Ibero-Americana de Ciências Ambientais
O tratamento de efluentes da aquicultura visa atender às exigências das novas legislações e às pr... more O tratamento de efluentes da aquicultura visa atender às exigências das novas legislações e às pressões de órgãos ambientais e da própria sociedade. Portanto, estudos que abordem a conservação do meio ambiente e a viabilidade econômica são fundamentais para o sucesso da atividade, uma vez que são itens indispensáveis para a sustentabilidade da aquicultura. O presente estudo avaliou a viabilidade econômica da implantação do sistema de ilhas flutuantes artificiais (IFAs) para o tratamento de efluentes de piscicultura por meio da aplicação de diferentes indicadores econômicos. O experimento foi realizado em dois sistemas (com e sem IFAs, em triplicatas) ao longo de um ciclo de produção semi-intensivo de tilápias do Nilo. Os valores médios do custo de produção e os seguintes indicadores econômicos foram calculados referente à condução do ciclo produtivo por hectare de espelho d’água: receita líquida financeira, índice de lucratividade, taxa interna de retorno e valor presente líquido. A...
Brazilian Journal of Biology, 2017
We aimed in this study utilize environmental indicators as a quantitative method to evaluate and ... more We aimed in this study utilize environmental indicators as a quantitative method to evaluate and discuss the nitrogen (TN) and phosphorus (TP) flux by a production stage grow-out (termination) of Nile tilapia (Oreochromis niloticus) in fishpond. The TN and TP load, the mass balance, the input of TN and TP via feed and the converted nutrients in fish biomass are the environmental indicators applied in this study. During the production cycle (128 days), the system exported 15,931 g TN and 4,189 g TP that were related to the amount of feed supplied (r Pearson = 0.8825 and r = 0.8523, respectively), corroborated by the feed conversion ratio (1.61:1). The indicators showed that 26% TN and 45% TP were reversed into fish biomass, 62% TN and 40% TP were retained in the fishpond, and 12% TN and 15% TP were exported via effluent. The largest contribution of nutrients generated by the system and exported via effluent was observed in phase III and IV. This result is supported by the feed conver...
Brazilian journal of biology = Revista brasleira de biologia, Jan 24, 2016
The phosphorus and nitrogen discharge via effluent of intensive trout farming system was quantifi... more The phosphorus and nitrogen discharge via effluent of intensive trout farming system was quantified through the use of environmental indicators. The nutrient loads, the mass balance, the estimated amount of nutrients in feed and the amount of nutrients converted in fish biomass were calculated based on the concentrations of phosphorus (P) and nitrogen (N) in the feed and in the water. Of the offered feed, 24.75 kg were available as P and 99.00 kg as N, of these, 9.32 kg P (38%) and 29.12 kg N (25%) were converted into fish biomass and 15.43 kg P (62%) and 69.88 kg N (75%) were exported via effluent. The loads and the mass balance show the excessive discharge of nutrients via effluent, corroborated by the feed conversion ratio (2.12:1) due to the low efficiency of feed utilization, therefore, it is proposed the use of this zootechnical parameter as environmental indicator. In addition, feed management practices are not adequate, highlighting the low frequency of feeding during the da...
Ambiente e Agua - An Interdisciplinary Journal of Applied Science, 2021
In this study, the ecotechnology artificial floating islands (AFIs), colonized by Eichhornia cras... more In this study, the ecotechnology artificial floating islands (AFIs), colonized by Eichhornia crassipes, have been tested as a tool for water quality improvement of fishponds. The experiment was carried out in semi-intensive production during the grow-out period of Nile tilapia, comprising one production cycle. It was completely randomized with two treatments (with and without AFIs) and three replications. Temperature, dissolved oxygen, conductivity, pH, turbidity, total dissolved solids (TDS), transparency (Secchi) and concentrations of chlorophyll a (CL a), total nitrogen (TN), total ammonia nitrogen (TAN), total phosphorus (TP) and orthophosphate (PO43--P) were analyzed fortnightly in the fishponds. Two groups ordered based on environmental characteristics were formed by applying the Principal Component Analysis (70.68% of explicability). The fishponds with AFIs were assigned to higher values of Secchi and lower values of pH, turbidity, TDS and concentrations of nutrients. On the ...
Journal of Environmental Protection, 2014
From the estimation of the mass balance model, which can also be classified as "black box" model,... more From the estimation of the mass balance model, which can also be classified as "black box" model, it is possible to infer the impact of management on the system considered. This study aimed to evaluate water pollution generated by wastewater from a polyculture system of tilapia and shrimp and discuss the management employee and their relation to the quality of the effluent released. It used a pond measuring 1500 m 2 , average depth 1.6 meters, where 12 cages of 1 m 3 populated with tilapia juveniles were installed 33 days after the shrimps' population. The tilapia juveniles were distributed in densities from 200 to 400 fish per cubic meter, reaching the density of 2.4 fish per square meter within the total pond area. Shrimp post-larvae were released outside the cages within the pond area in a density of 3.3 organisms per square meter. Total density considering fish and shrimps was of 5.7 organisms per square meter in the pond area. Water samples were taken weekly in affluent and effluent of the pond (January-August/2009). The mass balance model was calculated from the difference between the estimated load for the output and input of the pond. The average flow rate was 4.46 L/s. The average loads nitrogen was 0.072 Kg/day (affluent) and 0.179 Kg/day (effluent) and phosphorus 0.0136 Kg/day (affluent) and 0.031 Kg/day (effluent). The mass balance resulted in mean values of 0.11 ± 0.06 Kg/day for total nitrogen and 0.017 ± 0.010 Kg/day for total phosphorus indicating that the system exported nutrients. The use of Best Management Practices (BMP) likes better feed and water management as a way to minimize nutrient export.
... metropolitan region of São Paulo city, Brazil: an analysis of the eutrophication process. MER... more ... metropolitan region of São Paulo city, Brazil: an analysis of the eutrophication process. MERCANTE, CTJ1 ; CABIANCA, MA1 ; SILVA, D.1 ; COSTA, SV1 &amp;amp;amp; ESTEVES, KE1 ... Bol. Téc. CEPTA, 14:35-45. Esteves, KE &amp;amp;amp; Ishikawa, CM 2003. ... RiMa, IIE, São Carlos. 284p. UNEP. 2001. ...
Acta Limnologica Brasiliensia, 2014
INTRODUCTION: Frog farming, if not well managed, may cause environmental damages. The use of anti... more INTRODUCTION: Frog farming, if not well managed, may cause environmental damages. The use of antibiotics, the organic discharge and the introduction of exotic species can disseminate risks such as eutrophication, changes in the water quality and organic pollution, factors that affect the human consumption. AIM: Evaluating the water quality of a bullfrog farming system, discussing their relations to production and the environment based on the current legislation. METHODS: Sampling was performed on a monthly basis from November 2006 to March 2007 during growth and fattening phases of bullfrog (Lithobates catesbeianus). Sample sites were distributed according to the water flow: upstream from the mixing zone, affluent (supply water), bay, effluent, mixing zone and downstream from the mixing zone. In the field, pH, electrical conductivity, dissolved oxygen, temperature and turbidity were measured. In laboratory, nitrogen, phosphorus and chlorophyll a concentrations were analyzed. RESULTS...
The phosphorus and nitrogen discharge via effluent of intensive trout farming system was quantifi... more The phosphorus and nitrogen discharge via effluent of intensive trout farming system was quantified through the use of environmental indicators. The nutrient loads, the mass balance, the estimated amount of nutrients in feed and the amount of nutrients converted in fish biomass were calculated based on the concentrations of phosphorus (P) and nitrogen (N) in the feed and in the water. Of the offered feed, 24.75 kg were available as P and 99.00 kg as N, of these, 9.32 kg P (38%) and 29.12 kg N (25%) were converted into fish biomass and 15.43 kg P (62%) and 69.88 kg N (75%) were exported via effluent. The loads and the mass balance show the excessive discharge of nutrients via effluent, corroborated by the feed conversion ratio (2.12:1) due to the low efficiency of feed utilization, therefore, it is proposed the use of this zootechnical parameter as environmental indicator. In addition, feed management practices are not adequate, highlighting the low frequency of feeding during the day, excessive amount and low quality of feed offered. These results demonstrate the need for adequate feed management and the need for careful monitoring of effluent. Indicadores ambientais na avaliação de efluentes de truta arco-íris (Oncorhynchus mykiss) criados em sistema de raceway através do fósforo e nitrogênio Resumo A descarga de fósforo e nitrogênio via efluente do sistema intensivo de truticultura foi quantificada através da utilização de indicadores ambientais. As cargas de nutrientes, o balanço de massa, a quantidade estimada de nutrientes na ração e a quantidade de nutrientes convertidos em biomassa de peixes foram calculados com base nas concentrações de fósforo (P) e nitrogênio (N) na ração e na água. Da ração oferecida, 24,75 kg estavam disponíveis como P e 99,00 kg como N, destes, 9,32 kg de P (38%) e 29,12 kg de N (25%) foram convertidos em biomassa de peixe e 15,43 kg P (62%) e 69,88 kg N (75%) foram exportados via efluente. As cargas e o balanço de massa mostram a descarga excessiva de nutrientes via efluente, corroborado pela taxa de conversão alimentar (2,12:1), devido à baixa eficiência na utilização da ração, portanto, propõe-se a utilização deste parâmetro zootécnico como indicador ambiental. Além disso, as práticas de manejo alimentar não são adequadas, destacando a baixa frequência de alimentação durante o dia, quantidade excessiva e baixa qualidade da alimentação ofertada. Esses resultados demonstram a necessidade de manejo alimentar adequado e de monitoramento do efluente. Palavras-chave: cargas de nutrientes, balanço de massa, taxa de conversão alimentar, eutrofização, Oncorhynchus mykiss (Walbaum).
Journal of Water Resource and Protection, 2014
The concern in mitigating the negative impact generated by the discharge of nutrients in the rece... more The concern in mitigating the negative impact generated by the discharge of nutrients in the receiving water body is a challenge for the sustainable development of Brazilian fish farms. Thus, the purpose of this study was to evaluate the water quality and environmental impact caused by trout farming system effluent with focus on discharge of phosphorus. Sampling was performed on a weekly basis in triplicate from September to November 2010. Sample sites were distributed according to the water flow: upstream from trout farming system, water supply, effluent, artificial wetland, mixing zone and downstream (60 m from effluent). In the field, pH, conductivity, dissolved oxygen, water temperature and turbidity were measured. In laboratory, nitrogen and phosphorus series, chlorophyll a, total solids suspended and their organic and inorganic fractions were analyzed. For the good growth of trout in production system, the abiotic factors described in the water quality monitoring demonstrated acceptable values. Environmentally, after passing through the production system and artificial wetland, there was an increase in concentrations of total phosphorus, total nitrogen, orthophosphate, ammonium, chlorophyll a, total solids suspended and their organic and inorganic fractions (P < 0.05). These results are related with the quality of feed, feeding management and the inefficiency of the artificial wetland. Therefore, it is necessary to use best quality feed to meet the nutritional requirements of trout, maintaining an optimal feed conversion and reducing pollution generated by effluent.
Revista Ibero-Americana de Ciências Ambientais
O tratamento de efluentes da aquicultura visa atender às exigências das novas legislações e às pr... more O tratamento de efluentes da aquicultura visa atender às exigências das novas legislações e às pressões de órgãos ambientais e da própria sociedade. Portanto, estudos que abordem a conservação do meio ambiente e a viabilidade econômica são fundamentais para o sucesso da atividade, uma vez que são itens indispensáveis para a sustentabilidade da aquicultura. O presente estudo avaliou a viabilidade econômica da implantação do sistema de ilhas flutuantes artificiais (IFAs) para o tratamento de efluentes de piscicultura por meio da aplicação de diferentes indicadores econômicos. O experimento foi realizado em dois sistemas (com e sem IFAs, em triplicatas) ao longo de um ciclo de produção semi-intensivo de tilápias do Nilo. Os valores médios do custo de produção e os seguintes indicadores econômicos foram calculados referente à condução do ciclo produtivo por hectare de espelho d’água: receita líquida financeira, índice de lucratividade, taxa interna de retorno e valor presente líquido. A...
Brazilian Journal of Biology, 2017
We aimed in this study utilize environmental indicators as a quantitative method to evaluate and ... more We aimed in this study utilize environmental indicators as a quantitative method to evaluate and discuss the nitrogen (TN) and phosphorus (TP) flux by a production stage grow-out (termination) of Nile tilapia (Oreochromis niloticus) in fishpond. The TN and TP load, the mass balance, the input of TN and TP via feed and the converted nutrients in fish biomass are the environmental indicators applied in this study. During the production cycle (128 days), the system exported 15,931 g TN and 4,189 g TP that were related to the amount of feed supplied (r Pearson = 0.8825 and r = 0.8523, respectively), corroborated by the feed conversion ratio (1.61:1). The indicators showed that 26% TN and 45% TP were reversed into fish biomass, 62% TN and 40% TP were retained in the fishpond, and 12% TN and 15% TP were exported via effluent. The largest contribution of nutrients generated by the system and exported via effluent was observed in phase III and IV. This result is supported by the feed conver...
Brazilian journal of biology = Revista brasleira de biologia, Jan 24, 2016
The phosphorus and nitrogen discharge via effluent of intensive trout farming system was quantifi... more The phosphorus and nitrogen discharge via effluent of intensive trout farming system was quantified through the use of environmental indicators. The nutrient loads, the mass balance, the estimated amount of nutrients in feed and the amount of nutrients converted in fish biomass were calculated based on the concentrations of phosphorus (P) and nitrogen (N) in the feed and in the water. Of the offered feed, 24.75 kg were available as P and 99.00 kg as N, of these, 9.32 kg P (38%) and 29.12 kg N (25%) were converted into fish biomass and 15.43 kg P (62%) and 69.88 kg N (75%) were exported via effluent. The loads and the mass balance show the excessive discharge of nutrients via effluent, corroborated by the feed conversion ratio (2.12:1) due to the low efficiency of feed utilization, therefore, it is proposed the use of this zootechnical parameter as environmental indicator. In addition, feed management practices are not adequate, highlighting the low frequency of feeding during the da...
Ambiente e Agua - An Interdisciplinary Journal of Applied Science, 2021
In this study, the ecotechnology artificial floating islands (AFIs), colonized by Eichhornia cras... more In this study, the ecotechnology artificial floating islands (AFIs), colonized by Eichhornia crassipes, have been tested as a tool for water quality improvement of fishponds. The experiment was carried out in semi-intensive production during the grow-out period of Nile tilapia, comprising one production cycle. It was completely randomized with two treatments (with and without AFIs) and three replications. Temperature, dissolved oxygen, conductivity, pH, turbidity, total dissolved solids (TDS), transparency (Secchi) and concentrations of chlorophyll a (CL a), total nitrogen (TN), total ammonia nitrogen (TAN), total phosphorus (TP) and orthophosphate (PO43--P) were analyzed fortnightly in the fishponds. Two groups ordered based on environmental characteristics were formed by applying the Principal Component Analysis (70.68% of explicability). The fishponds with AFIs were assigned to higher values of Secchi and lower values of pH, turbidity, TDS and concentrations of nutrients. On the ...
Journal of Environmental Protection, 2014
From the estimation of the mass balance model, which can also be classified as "black box" model,... more From the estimation of the mass balance model, which can also be classified as "black box" model, it is possible to infer the impact of management on the system considered. This study aimed to evaluate water pollution generated by wastewater from a polyculture system of tilapia and shrimp and discuss the management employee and their relation to the quality of the effluent released. It used a pond measuring 1500 m 2 , average depth 1.6 meters, where 12 cages of 1 m 3 populated with tilapia juveniles were installed 33 days after the shrimps' population. The tilapia juveniles were distributed in densities from 200 to 400 fish per cubic meter, reaching the density of 2.4 fish per square meter within the total pond area. Shrimp post-larvae were released outside the cages within the pond area in a density of 3.3 organisms per square meter. Total density considering fish and shrimps was of 5.7 organisms per square meter in the pond area. Water samples were taken weekly in affluent and effluent of the pond (January-August/2009). The mass balance model was calculated from the difference between the estimated load for the output and input of the pond. The average flow rate was 4.46 L/s. The average loads nitrogen was 0.072 Kg/day (affluent) and 0.179 Kg/day (effluent) and phosphorus 0.0136 Kg/day (affluent) and 0.031 Kg/day (effluent). The mass balance resulted in mean values of 0.11 ± 0.06 Kg/day for total nitrogen and 0.017 ± 0.010 Kg/day for total phosphorus indicating that the system exported nutrients. The use of Best Management Practices (BMP) likes better feed and water management as a way to minimize nutrient export.
... metropolitan region of São Paulo city, Brazil: an analysis of the eutrophication process. MER... more ... metropolitan region of São Paulo city, Brazil: an analysis of the eutrophication process. MERCANTE, CTJ1 ; CABIANCA, MA1 ; SILVA, D.1 ; COSTA, SV1 &amp;amp;amp; ESTEVES, KE1 ... Bol. Téc. CEPTA, 14:35-45. Esteves, KE &amp;amp;amp; Ishikawa, CM 2003. ... RiMa, IIE, São Carlos. 284p. UNEP. 2001. ...
Acta Limnologica Brasiliensia, 2014
INTRODUCTION: Frog farming, if not well managed, may cause environmental damages. The use of anti... more INTRODUCTION: Frog farming, if not well managed, may cause environmental damages. The use of antibiotics, the organic discharge and the introduction of exotic species can disseminate risks such as eutrophication, changes in the water quality and organic pollution, factors that affect the human consumption. AIM: Evaluating the water quality of a bullfrog farming system, discussing their relations to production and the environment based on the current legislation. METHODS: Sampling was performed on a monthly basis from November 2006 to March 2007 during growth and fattening phases of bullfrog (Lithobates catesbeianus). Sample sites were distributed according to the water flow: upstream from the mixing zone, affluent (supply water), bay, effluent, mixing zone and downstream from the mixing zone. In the field, pH, electrical conductivity, dissolved oxygen, temperature and turbidity were measured. In laboratory, nitrogen, phosphorus and chlorophyll a concentrations were analyzed. RESULTS...
The phosphorus and nitrogen discharge via effluent of intensive trout farming system was quantifi... more The phosphorus and nitrogen discharge via effluent of intensive trout farming system was quantified through the use of environmental indicators. The nutrient loads, the mass balance, the estimated amount of nutrients in feed and the amount of nutrients converted in fish biomass were calculated based on the concentrations of phosphorus (P) and nitrogen (N) in the feed and in the water. Of the offered feed, 24.75 kg were available as P and 99.00 kg as N, of these, 9.32 kg P (38%) and 29.12 kg N (25%) were converted into fish biomass and 15.43 kg P (62%) and 69.88 kg N (75%) were exported via effluent. The loads and the mass balance show the excessive discharge of nutrients via effluent, corroborated by the feed conversion ratio (2.12:1) due to the low efficiency of feed utilization, therefore, it is proposed the use of this zootechnical parameter as environmental indicator. In addition, feed management practices are not adequate, highlighting the low frequency of feeding during the day, excessive amount and low quality of feed offered. These results demonstrate the need for adequate feed management and the need for careful monitoring of effluent. Indicadores ambientais na avaliação de efluentes de truta arco-íris (Oncorhynchus mykiss) criados em sistema de raceway através do fósforo e nitrogênio Resumo A descarga de fósforo e nitrogênio via efluente do sistema intensivo de truticultura foi quantificada através da utilização de indicadores ambientais. As cargas de nutrientes, o balanço de massa, a quantidade estimada de nutrientes na ração e a quantidade de nutrientes convertidos em biomassa de peixes foram calculados com base nas concentrações de fósforo (P) e nitrogênio (N) na ração e na água. Da ração oferecida, 24,75 kg estavam disponíveis como P e 99,00 kg como N, destes, 9,32 kg de P (38%) e 29,12 kg de N (25%) foram convertidos em biomassa de peixe e 15,43 kg P (62%) e 69,88 kg N (75%) foram exportados via efluente. As cargas e o balanço de massa mostram a descarga excessiva de nutrientes via efluente, corroborado pela taxa de conversão alimentar (2,12:1), devido à baixa eficiência na utilização da ração, portanto, propõe-se a utilização deste parâmetro zootécnico como indicador ambiental. Além disso, as práticas de manejo alimentar não são adequadas, destacando a baixa frequência de alimentação durante o dia, quantidade excessiva e baixa qualidade da alimentação ofertada. Esses resultados demonstram a necessidade de manejo alimentar adequado e de monitoramento do efluente. Palavras-chave: cargas de nutrientes, balanço de massa, taxa de conversão alimentar, eutrofização, Oncorhynchus mykiss (Walbaum).