Leonor Amaral | Universidade Nova de Lisboa (original) (raw)

Papers by Leonor Amaral

Research paper thumbnail of Seasonal variation of nutrient removal in a full-scale horizontal constructed wetland

Energy Procedia, Oct 1, 2017

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Research paper thumbnail of Seasonal Variation of Nutrient Removal in a Full-Scale Artificial Aerated Hybrid Constructed Wetland

Water, 2016

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Research paper thumbnail of Forecasting saltwater intrusion volume and sulfate content in a wastewater collection system. Case study: Barreiro/Moita WWTP, Portugal

Journal of Water and Climate Change, 2021

The presence of salt water from the Tagus Estuary has been identified in the influent at Barreiro... more The presence of salt water from the Tagus Estuary has been identified in the influent at Barreiro/Moita Wastewater Treatment Plant (WWTP), Portugal. The intrusion occurs throughout damaged sections and direct vectors in the wastewater collection system, during high tide levels, changing the wastewater characteristics and impacting the WWTP process. This study designed models to quantify this problem, enabling more effective countermeasures within the right timing. The proposed models estimate the average volume of salt water and sulfate () load for each high tide period. The laboratory results show strong correlations between the influent electrical conductivity (EC) and percentage of salt water in WWTP inflow (0.9909), and between EC and concentration in WWTP influent (0.9797). The forecast models also show good correlation between the high tide levels with volume of salt water (0.9145) and load (0.9162) entering the system. Considering the total monthly inflow, the highest percent...

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Research paper thumbnail of Assessment for which tide level saltwater intrusion occurs in a sewer network. Case study: Barreiro/Moita WWTP, Portugal

Water Practice and Technology, 2020

Salt water from the Tagus Estuary has been identified in the influent at Barreiro/Moita Wastewate... more Salt water from the Tagus Estuary has been identified in the influent at Barreiro/Moita Wastewater Treatment Plant (WWTP), Portugal. The saltwater intrusion occurs during high tide levels in the estuary throughout damaged sections and direct vectors in the sewer network, changing the wastewater characteristics impacting the WWTP processes. This work has designed a methodology to assess from which tide level in the Tagus Estuary saltwater intrusion occurs in the sewer network by measuring WWTP influent's electric conductivity (EC). The methodology identifies saltwater intrusion for tide levels higher than 3.10 m, increasing significantly for tide levels higher than 4.00 m. During this study, 86% of the days registered at least one high tide level higher than 3.10 m, and 8% higher than 4.00 m, demonstrating a considerable occurrence of saltwater intrusion in the system with a tendency to increase due to the mean sea level rise registered in the Tagus Estuary. To prevent it, it is ...

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Research paper thumbnail of Effect of Phragmites australis growth on the performance of horizontal subsurface flow constructed wetlands during the start-up phase

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Research paper thumbnail of Microplastics from Wastewater Treatment Plants—Preliminary Data

Springer Water, 2017

Wastewater treatment plants (WWTIP) are a potential source of microplastics [1,2]. Several types ... more Wastewater treatment plants (WWTIP) are a potential source of microplastics [1,2]. Several types of microplastics, namely microbeads, fibres and fragments, were analysed in two WWTP effluent serving different Portuguese communities. A bigger station treating mixed domestic and industrial wastewater averaging 18000 m day and a smaller station with treating mostly domestic wastewater averaging 7250 m day. A total of 6065 microplastics were observed in 5,5 litres of wastewater sampled. 90% of the microplastics analysed were fragments and 88% were collected from treated effluent (1687 items in average per litre). Fibres presented a higher percentage in the affluent (88%), comparing to treated effluent (12%). Regarding sizes, microplastics with less than 0, 5 mm were the most representative in both WWTP. Fibres with 1 to 2 mm were more common. This study intends to contribute with a standardized methodology to analyse microplastics in wastewater, from sampling to identification, measuring and handling processes in the laboratory.

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Research paper thumbnail of Manual Treatment of Urban Wastewater by Chemical Precipitation for Production of Hydroponic Nutrient Solutions

Journal of Ecological Engineering, 2020

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Research paper thumbnail of Efficacy assessment of peracetic acid in the removal of synthetic 17α-ethinyl estradiol contraceptive hormone in wastewater

Journal of Environmental Sciences, 2019

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Research paper thumbnail of Biofilms in RBC with Constant Ages and Thicknesses

Journal of Environmental Engineering, 2019

AbstractWith the exception of some strict kinetic formalism, biofilm thickness constitutes a basi... more AbstractWith the exception of some strict kinetic formalism, biofilm thickness constitutes a basic parameter for analyzing the mechanisms of mass transfer as a result of microbiological growth. A r...

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Research paper thumbnail of 17α-Ethinylestradiol and 17β-estradiol removal from a secondary urban wastewater using an RBC treatment system

Environmental monitoring and assessment, Jan 2, 2018

The presence of micropollutants that include endocrine-disrupting compounds (EDC) in aquatic envi... more The presence of micropollutants that include endocrine-disrupting compounds (EDC) in aquatic environments is currently one of the most relevant aspects of water quality due to their adverse effects on aquatic organisms and human health. From the several categories of EDC, 17β-estradiol (E2) is a natural hormone, which is prevalent in vertebrates, associated with the female reproductive system and maintenance of the sexual characters. 17α-Ethinylestradiol (EE2) is a synthetic hormone produced from the natural hormone E2 and is an essential component of oral contraceptives. These compounds are susceptible to bioconcentration and have high potential to bioaccumulation. Wastewater treatment plants are the main point source of E2 and EE2 into aquatic environments, but conventional wastewater treatment systems are not specifically designed for steroid removal. To overcome this problem, biological tertiary treatment may be a solution for the removal of emergent pollutants such as E2 and EE...

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Research paper thumbnail of A Preliminary Assessment of the Present Status of Portuguese Landfills

ABSTRACT In this work we present a preliminary assessment on some landfills from Portugal through... more ABSTRACT In this work we present a preliminary assessment on some landfills from Portugal through following the content in the upflown and dowflown leachate of four target analytes: camphor, octylphenol, diethylphthalate and tributylphosphate. In addition we have tried to simplify the sample treatment using ultrasonic energy in the solid-liquid extraction from the extracting (C 18) column. We have found camphor and octylphenol in the leachates studied whilst diethylphthalate and tributylphosphate were below our detection limits. The use of ultrasonic energy was found inadequate because artifacts were formed that interfere in the subsequent analysis. Some of the landfill leachate treatment plants surveyed are able to diminish the target compounds at the effluent. On the overall our results suggest that it is necessary to undergo a detailed survey in Portugal regarding the performance of landfills plant treatments and its impact in the environment or the nearby zones.

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Research paper thumbnail of Biodegradation or simple adsorption to the support material? Development of a simple, fast and low-cost technique

Environmental Monitoring and Assessment, 2013

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Research paper thumbnail of A Characterization of Selected Endocrine Disruptor Compounds in a Portuguese Wastewater Treatment Plant

Environmental Monitoring and Assessment, 2006

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Research paper thumbnail of Evaluation of the effectiveness of horizontal subsurface flow constructed wetlands for different media

Journal of Environmental Sciences, 2010

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Research paper thumbnail of Influence of bed media characteristics on ammonia and nitrate removal in shallow horizontal subsurface flow constructed wetlands

Bioresource Technology, 2009

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Research paper thumbnail of Impact of Mass Loading Rate and Vegetation on the Performance of Horizontal Subsurface Flow Constructed Wetlands

ABSTRACT Constructed wetlands (CW) are sustainable wastewater treatment processes, especially for... more ABSTRACT Constructed wetlands (CW) are sustainable wastewater treatment processes, especially for small communities. In order to evaluate the effect of mass loading rates and the presence of plants on the removal of organic matter and ammonia in horizontal subsurface flow CW, two set of experiments were carried out at different organic and ammonia loading rates in two mesocosms, one without plants, other colonized with Phragmites australis. Regardless the mass loading rates, the COD removal was significantly greater in the bed containing plants (70.3% and 75.6%, respectively, for the lower and the higher organic loads) than in the bed without plants (38.5% and 44.4%, respectively). The removal of NH4-N was also significantly higher in the planted bed (59.3% and 47.8%, respectively, for the lower and the higher nitrogen loads) than in bed without plants (34% and 33%, respectively). The removal of organic matter and ammonia was higher in the first section of the bed (first 33 cm) in the unplanted system (> 75%) and was more distributed through the bed in the planted system, which seems to have been associated with the growth of roots and rhizomes that support the biofilm as well as the release of oxygen in the root zone.

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Research paper thumbnail of Assessing the estrogenic potency in a Portuguese wastewater treatment plant using an integrated approach

Journal of Environmental Sciences, 2010

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Research paper thumbnail of Effect of vegetation on the performance of horizontal subsurface flow constructed wetlands with lightweight expanded clay aggregates

International Journal of Environmental Science and Technology, 2012

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Research paper thumbnail of Effect of vegetation on the performance of horizontal subsurface flow constructed wetlands with lightweight expanded clay aggregates

International Journal of Environmental Science and Technology, 2013

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Research paper thumbnail of Effectiveness and Temporal Variation of a Full-Scale Horizontal Constructed Wetland in Reducing Nitrogen and Phosphorus from Domestic Wastewater

ChemEngineering

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Research paper thumbnail of Seasonal variation of nutrient removal in a full-scale horizontal constructed wetland

Energy Procedia, Oct 1, 2017

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Research paper thumbnail of Seasonal Variation of Nutrient Removal in a Full-Scale Artificial Aerated Hybrid Constructed Wetland

Water, 2016

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Research paper thumbnail of Forecasting saltwater intrusion volume and sulfate content in a wastewater collection system. Case study: Barreiro/Moita WWTP, Portugal

Journal of Water and Climate Change, 2021

The presence of salt water from the Tagus Estuary has been identified in the influent at Barreiro... more The presence of salt water from the Tagus Estuary has been identified in the influent at Barreiro/Moita Wastewater Treatment Plant (WWTP), Portugal. The intrusion occurs throughout damaged sections and direct vectors in the wastewater collection system, during high tide levels, changing the wastewater characteristics and impacting the WWTP process. This study designed models to quantify this problem, enabling more effective countermeasures within the right timing. The proposed models estimate the average volume of salt water and sulfate () load for each high tide period. The laboratory results show strong correlations between the influent electrical conductivity (EC) and percentage of salt water in WWTP inflow (0.9909), and between EC and concentration in WWTP influent (0.9797). The forecast models also show good correlation between the high tide levels with volume of salt water (0.9145) and load (0.9162) entering the system. Considering the total monthly inflow, the highest percent...

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Research paper thumbnail of Assessment for which tide level saltwater intrusion occurs in a sewer network. Case study: Barreiro/Moita WWTP, Portugal

Water Practice and Technology, 2020

Salt water from the Tagus Estuary has been identified in the influent at Barreiro/Moita Wastewate... more Salt water from the Tagus Estuary has been identified in the influent at Barreiro/Moita Wastewater Treatment Plant (WWTP), Portugal. The saltwater intrusion occurs during high tide levels in the estuary throughout damaged sections and direct vectors in the sewer network, changing the wastewater characteristics impacting the WWTP processes. This work has designed a methodology to assess from which tide level in the Tagus Estuary saltwater intrusion occurs in the sewer network by measuring WWTP influent's electric conductivity (EC). The methodology identifies saltwater intrusion for tide levels higher than 3.10 m, increasing significantly for tide levels higher than 4.00 m. During this study, 86% of the days registered at least one high tide level higher than 3.10 m, and 8% higher than 4.00 m, demonstrating a considerable occurrence of saltwater intrusion in the system with a tendency to increase due to the mean sea level rise registered in the Tagus Estuary. To prevent it, it is ...

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Research paper thumbnail of Effect of Phragmites australis growth on the performance of horizontal subsurface flow constructed wetlands during the start-up phase

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Research paper thumbnail of Microplastics from Wastewater Treatment Plants—Preliminary Data

Springer Water, 2017

Wastewater treatment plants (WWTIP) are a potential source of microplastics [1,2]. Several types ... more Wastewater treatment plants (WWTIP) are a potential source of microplastics [1,2]. Several types of microplastics, namely microbeads, fibres and fragments, were analysed in two WWTP effluent serving different Portuguese communities. A bigger station treating mixed domestic and industrial wastewater averaging 18000 m day and a smaller station with treating mostly domestic wastewater averaging 7250 m day. A total of 6065 microplastics were observed in 5,5 litres of wastewater sampled. 90% of the microplastics analysed were fragments and 88% were collected from treated effluent (1687 items in average per litre). Fibres presented a higher percentage in the affluent (88%), comparing to treated effluent (12%). Regarding sizes, microplastics with less than 0, 5 mm were the most representative in both WWTP. Fibres with 1 to 2 mm were more common. This study intends to contribute with a standardized methodology to analyse microplastics in wastewater, from sampling to identification, measuring and handling processes in the laboratory.

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Research paper thumbnail of Manual Treatment of Urban Wastewater by Chemical Precipitation for Production of Hydroponic Nutrient Solutions

Journal of Ecological Engineering, 2020

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Research paper thumbnail of Efficacy assessment of peracetic acid in the removal of synthetic 17α-ethinyl estradiol contraceptive hormone in wastewater

Journal of Environmental Sciences, 2019

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Research paper thumbnail of Biofilms in RBC with Constant Ages and Thicknesses

Journal of Environmental Engineering, 2019

AbstractWith the exception of some strict kinetic formalism, biofilm thickness constitutes a basi... more AbstractWith the exception of some strict kinetic formalism, biofilm thickness constitutes a basic parameter for analyzing the mechanisms of mass transfer as a result of microbiological growth. A r...

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Research paper thumbnail of 17α-Ethinylestradiol and 17β-estradiol removal from a secondary urban wastewater using an RBC treatment system

Environmental monitoring and assessment, Jan 2, 2018

The presence of micropollutants that include endocrine-disrupting compounds (EDC) in aquatic envi... more The presence of micropollutants that include endocrine-disrupting compounds (EDC) in aquatic environments is currently one of the most relevant aspects of water quality due to their adverse effects on aquatic organisms and human health. From the several categories of EDC, 17β-estradiol (E2) is a natural hormone, which is prevalent in vertebrates, associated with the female reproductive system and maintenance of the sexual characters. 17α-Ethinylestradiol (EE2) is a synthetic hormone produced from the natural hormone E2 and is an essential component of oral contraceptives. These compounds are susceptible to bioconcentration and have high potential to bioaccumulation. Wastewater treatment plants are the main point source of E2 and EE2 into aquatic environments, but conventional wastewater treatment systems are not specifically designed for steroid removal. To overcome this problem, biological tertiary treatment may be a solution for the removal of emergent pollutants such as E2 and EE...

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Research paper thumbnail of A Preliminary Assessment of the Present Status of Portuguese Landfills

ABSTRACT In this work we present a preliminary assessment on some landfills from Portugal through... more ABSTRACT In this work we present a preliminary assessment on some landfills from Portugal through following the content in the upflown and dowflown leachate of four target analytes: camphor, octylphenol, diethylphthalate and tributylphosphate. In addition we have tried to simplify the sample treatment using ultrasonic energy in the solid-liquid extraction from the extracting (C 18) column. We have found camphor and octylphenol in the leachates studied whilst diethylphthalate and tributylphosphate were below our detection limits. The use of ultrasonic energy was found inadequate because artifacts were formed that interfere in the subsequent analysis. Some of the landfill leachate treatment plants surveyed are able to diminish the target compounds at the effluent. On the overall our results suggest that it is necessary to undergo a detailed survey in Portugal regarding the performance of landfills plant treatments and its impact in the environment or the nearby zones.

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Research paper thumbnail of Biodegradation or simple adsorption to the support material? Development of a simple, fast and low-cost technique

Environmental Monitoring and Assessment, 2013

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Research paper thumbnail of A Characterization of Selected Endocrine Disruptor Compounds in a Portuguese Wastewater Treatment Plant

Environmental Monitoring and Assessment, 2006

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Research paper thumbnail of Evaluation of the effectiveness of horizontal subsurface flow constructed wetlands for different media

Journal of Environmental Sciences, 2010

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Research paper thumbnail of Influence of bed media characteristics on ammonia and nitrate removal in shallow horizontal subsurface flow constructed wetlands

Bioresource Technology, 2009

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Impact of Mass Loading Rate and Vegetation on the Performance of Horizontal Subsurface Flow Constructed Wetlands

ABSTRACT Constructed wetlands (CW) are sustainable wastewater treatment processes, especially for... more ABSTRACT Constructed wetlands (CW) are sustainable wastewater treatment processes, especially for small communities. In order to evaluate the effect of mass loading rates and the presence of plants on the removal of organic matter and ammonia in horizontal subsurface flow CW, two set of experiments were carried out at different organic and ammonia loading rates in two mesocosms, one without plants, other colonized with Phragmites australis. Regardless the mass loading rates, the COD removal was significantly greater in the bed containing plants (70.3% and 75.6%, respectively, for the lower and the higher organic loads) than in the bed without plants (38.5% and 44.4%, respectively). The removal of NH4-N was also significantly higher in the planted bed (59.3% and 47.8%, respectively, for the lower and the higher nitrogen loads) than in bed without plants (34% and 33%, respectively). The removal of organic matter and ammonia was higher in the first section of the bed (first 33 cm) in the unplanted system (> 75%) and was more distributed through the bed in the planted system, which seems to have been associated with the growth of roots and rhizomes that support the biofilm as well as the release of oxygen in the root zone.

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Research paper thumbnail of Assessing the estrogenic potency in a Portuguese wastewater treatment plant using an integrated approach

Journal of Environmental Sciences, 2010

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Effect of vegetation on the performance of horizontal subsurface flow constructed wetlands with lightweight expanded clay aggregates

International Journal of Environmental Science and Technology, 2012

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Effect of vegetation on the performance of horizontal subsurface flow constructed wetlands with lightweight expanded clay aggregates

International Journal of Environmental Science and Technology, 2013

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Research paper thumbnail of Effectiveness and Temporal Variation of a Full-Scale Horizontal Constructed Wetland in Reducing Nitrogen and Phosphorus from Domestic Wastewater

ChemEngineering

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