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Assistant Professor at the Technical Superior Institute of Lisbon since 2001. The principal areas of interest are sanitary engineering, urban drainage systems, modeling and integrated management, monitoring and warning systems, wastewater treatment.
Currently, in sub-Saharan African countries, 65 to 100% of the urban population is served by on-site sanitation systems, typically pit latrines and septic tanks. Faecal sludge dewatering in drying beds is one of the most commonly adopted low-cost treatment technologies in developing countries due to favourable climate conditions in terms of temperature and radiation and because their operation and maintenance are simple. Nevertheless, research in tropical dry zones regarding these processes is scarce. In this paper, a mathematical model for faecal sludge dewatering in sludge drying beds (SDBs) focusing on gravity drainage and evaporation processes is presented and discussed. Experimental campaigns were carried out at a pilot site in Tete, Mozambique, to determine the model parameters. The results suggest that the model can be used to estimate, in similar situations, the dewatering process of different types of faecal sludge. The present research might be considered as a contribution to the design and operation of SDBs, supporting sludge management and allowing the estimation of drying times and optimal loading cycles, namely, the sludge thickness and final moisture content.
Osvaldo Moiambo; Raúl Mutevuie; Filipa Ferreira; José Matos. Modelling Faecal Sludge Dewatering Processes in Drying Beds Based on the Results from Tete, Mozambique. Sustainability 2021, 13, 8981 .
AMA StyleOsvaldo Moiambo, Raúl Mutevuie, Filipa Ferreira, José Matos. Modelling Faecal Sludge Dewatering Processes in Drying Beds Based on the Results from Tete, Mozambique. Sustainability. 2021; 13 (16):8981.
Chicago/Turabian StyleOsvaldo Moiambo; Raúl Mutevuie; Filipa Ferreira; José Matos. 2021. "Modelling Faecal Sludge Dewatering Processes in Drying Beds Based on the Results from Tete, Mozambique." Sustainability 13, no. 16: 8981.
In this paper, an expedited multi-criteria decision analysis framework, capable of tackling several dimensions for the choice of sanitation services, at an early planning stage is presented. The approach combines geographic information systems aided analysis for onsite solutions, with a multi-criteria decision analysis tool capable of suggesting and ranking several viable offsite treatment alternatives, according to the desired criteria. The framework was applied to four coastal cities in Northern Angola, one of the sub-Saharan countries of the west coast of Africa, thus obtaining an indication for city-wide solutions, as an aid to achieve the goal of ensuring full sanitation coverage in those four locations. It included possible onsite collection and storage interfaces, namely Ventilated Improved Pit latrines, fossa alterna, septic tanks or conventional sewer systems. The study also contributed to an informed decision regarding optimal offsite treatment facility type, namely based on dedicated or combined wastewater and faecal sludge treatment (co-treatment), as well as different options for locations and sanitation technologies. Alternatives were compared and ranked according to ten main criteria concerning social, economic, technological and environmental aspects. This work helped demonstrate the usefulness of decision-aiding tools in the multi-stakeholder and complex context of sanitation in a developing country.
Rita Matos; Filipa Ferreira; Liliana Alves; Elsa Ramos; Lucrécio Costa; José Matos. Multi-Criteria Framework for Selection of City-Wide Sanitation Solutions in Coastal Towns in Northern Angola. Sustainability 2021, 13, 5627 .
AMA StyleRita Matos, Filipa Ferreira, Liliana Alves, Elsa Ramos, Lucrécio Costa, José Matos. Multi-Criteria Framework for Selection of City-Wide Sanitation Solutions in Coastal Towns in Northern Angola. Sustainability. 2021; 13 (10):5627.
Chicago/Turabian StyleRita Matos; Filipa Ferreira; Liliana Alves; Elsa Ramos; Lucrécio Costa; José Matos. 2021. "Multi-Criteria Framework for Selection of City-Wide Sanitation Solutions in Coastal Towns in Northern Angola." Sustainability 13, no. 10: 5627.
Urban environments are challenged with unprecedented anthropogenic and natural pressures, the latter being accelerated by the growing awareness of the consequences of climate change. The concept of urban resilience has been growing in response, since it allows us to understand city behaviour as a system of systems, improving its response to extreme climate‑related events. This paper presents the EU H2020 Resilience to Cope with Climate Change in Urban Areas (RESCCUE) project approach in Lisbon’s research site, regarding the Hazur® resilience assessment methodology. This methodology focuses on the interdependencies between services and infrastructures, and on the recovery times needed to restore its normal functionalities. This approach allows the integration of several work packages of the RESCCUE project, from climate change projections to adaptation strategies selection. The assessment was conducted for 19 services and 146 infrastructures, including water (supply and drainage systems), power, mobility, waste, telecommunication, environment, and the social sector. The principal climate-related hazard analysed at the Lisbon research site was urban flooding. The main result consists of a deep understanding of the relations between different services and the consequent cascade effects triggered by flooding events. Stakeholders’ involvement, beyond the project consortium, was fundamental for the success of the methodology implementation.
João Barreiro; Ruth Lopes; Filipa Ferreira; Rita Brito; Maria Telhado; José Matos; Rafaela Matos. Assessing Urban Resilience in Complex and Dynamic Systems: The RESCCUE Project Approach in Lisbon Research Site. Sustainability 2020, 12, 8931 .
AMA StyleJoão Barreiro, Ruth Lopes, Filipa Ferreira, Rita Brito, Maria Telhado, José Matos, Rafaela Matos. Assessing Urban Resilience in Complex and Dynamic Systems: The RESCCUE Project Approach in Lisbon Research Site. Sustainability. 2020; 12 (21):8931.
Chicago/Turabian StyleJoão Barreiro; Ruth Lopes; Filipa Ferreira; Rita Brito; Maria Telhado; José Matos; Rafaela Matos. 2020. "Assessing Urban Resilience in Complex and Dynamic Systems: The RESCCUE Project Approach in Lisbon Research Site." Sustainability 12, no. 21: 8931.
The work presented herein was carried out to assess the effect of intermittent pumping events in sewer headspace pressure differentials, as well as their relationship with hydrogen sulfide gas concentration. A full scale gravity sewer in Portugal, located downstream of several pumping stations, was used as the guiding case study. Under normal system operation, pressure difference between the outside atmosphere and the sewer headspace seemed to influence the in and out-gassing of gas pollutants emitted through the venting stack. Wastewater pumping cycles generated maximum pressure differentials of roughly 100 Pa, which in turn originated maximum air velocities of 1.76 m s−1 exiting the venting stack. Each pumping event was followed by a pressure drop of about 50 Pa, quickly attaining null concentrations of H2S at the venting stack. A statistically significant relationship between pressure differentials and air exit velocity was observed, which allowed obtaining an empirical equation for expedite prediction of airflows emitted to the outside atmosphere (R2 = 0.77). Conversely, the same effect was not observed along the length of the sewer pipe, unlike the findings of other studies. The effect of a full flowing pipe at the downstream end of the gravity trunk sewer was also noticeable in downstream sewer pressurization and gas build-up. It was concluded that the magnitude of the gas pollutant emissions may heavily depend on the impacts of hydraulic flows and pumping characteristics in headspace pressure differences, denoting the need for better approaches when designing and installing venting stacks.
Rita Ventura Matos; Filipa Ferreira; José Saldanha Matos. Influence of Intermittence and Pressure Differentials in Hydrogen Sulfide Concentration in a Gravity Sewer. Water 2019, 11, 1780 .
AMA StyleRita Ventura Matos, Filipa Ferreira, José Saldanha Matos. Influence of Intermittence and Pressure Differentials in Hydrogen Sulfide Concentration in a Gravity Sewer. Water. 2019; 11 (9):1780.
Chicago/Turabian StyleRita Ventura Matos; Filipa Ferreira; José Saldanha Matos. 2019. "Influence of Intermittence and Pressure Differentials in Hydrogen Sulfide Concentration in a Gravity Sewer." Water 11, no. 9: 1780.
Production and build-up of sulfide in wastewater systems, especially downstream of rising mains, may lead to severe odour nuisance, toxic environments and high risk of corrosion. Due to increased population migration towards cities and lower area availability for treatment facilities, rising mains for the conveyance of wastewater sludge are becoming more frequent, and research on sulfide build-up in such cases is needed. In this paper the findings of the work carried out in a full scale wastewater sludge rising main, operated during different seasons and under distinct conditions are presented (comprising both the start-up and normal operation stages of the facility). Results showed a sulfide build-up rate of 3.24 g S−2 m−2 d−1 in the summer and of 2.30 g S−2 m−2 d−1 during the winter. The ratio of sulfate reduction to sulfide production (SO4−2/S−2) was of roughly 3 to 1, as expected. Furthermore, obtained results allowed adjusting a second order polynomial empirical equation for the forecasting of sulfide build-up within the sludge rising main. The obtained equation for sludge significantly differs from existing equations obtained for wastewater. Moreover, this work also allowed obtaining new insight into the positive influence of biofilm and hydraulic retention time in the biological sulfide generation, as well as into its variation along the length of the rising main.
Rita Ventura Matos; Natércia Matias; Filipa Ferreira; João Santos Silva; José Saldanha Matos. Assessment of sulfide production in a full scale wastewater sludge rising main. Journal of Environmental Management 2018, 209, 505 -514.
AMA StyleRita Ventura Matos, Natércia Matias, Filipa Ferreira, João Santos Silva, José Saldanha Matos. Assessment of sulfide production in a full scale wastewater sludge rising main. Journal of Environmental Management. 2018; 209 ():505-514.
Chicago/Turabian StyleRita Ventura Matos; Natércia Matias; Filipa Ferreira; João Santos Silva; José Saldanha Matos. 2018. "Assessment of sulfide production in a full scale wastewater sludge rising main." Journal of Environmental Management 209, no. : 505-514.
Over the last decades, considerable progress has been made in the understanding of the sulfur cycle in sewer systems. In spite of a wealth of experimental and field studies that have addressed the release of hydrogen sulfide from free surface flows in gravity sewers and the corresponding air-water mass transfer, little is known about hydrogen sulfide emission under highly turbulent conditions (e.g., drop structures, hydraulic jumps). In this study, experimental work was carried out to analyze the influence of characteristics of drops on reaeration. Physical models were built, mimicking typical sewer drop structures and allowing different types of drops, drop heights, tailwater depths and flow rates. In total, 125 tests were performed. Based on their results, empirical expressions translating the relationship between the mass transfer of oxygen and physical parameters of drop structures were established. Then, by applying the two-film theory with two-reference substances, the relation to hydrogen sulfide release was defined. The experiments confirmed that the choice of the type of drop structure is critical to determine the uptake/emission rates. By quantifying the air-water mass transfer rates between free-fall and backdrop types of drop, the latter resulted in considerably lower oxygen uptake rates.
Natércia Matias; Asbjèrn Haaning Nielsen; Jes Vollertsen; Filipa Ferreira; José Matos. Erratum: Water Science and Technology 75 (10), 2257–2267: Liquid-gas mass transfer at drop structures, Natércia Matias, Asbjørn Haaning Nielsen, Jes Vollertsen, Filipa Ferreira and José Saldanha Matos, doi: 10.2166/wst.2017.103. Water Science and Technology 2017, 76, 1584 -1594.
AMA StyleNatércia Matias, Asbjèrn Haaning Nielsen, Jes Vollertsen, Filipa Ferreira, José Matos. Erratum: Water Science and Technology 75 (10), 2257–2267: Liquid-gas mass transfer at drop structures, Natércia Matias, Asbjørn Haaning Nielsen, Jes Vollertsen, Filipa Ferreira and José Saldanha Matos, doi: 10.2166/wst.2017.103. Water Science and Technology. 2017; 76 (6):1584-1594.
Chicago/Turabian StyleNatércia Matias; Asbjèrn Haaning Nielsen; Jes Vollertsen; Filipa Ferreira; José Matos. 2017. "Erratum: Water Science and Technology 75 (10), 2257–2267: Liquid-gas mass transfer at drop structures, Natércia Matias, Asbjørn Haaning Nielsen, Jes Vollertsen, Filipa Ferreira and José Saldanha Matos, doi: 10.2166/wst.2017.103." Water Science and Technology 76, no. 6: 1584-1594.
Over the last decades, considerable progress has been made in the understanding of the sulfur cycle in sewer systems. In spite of a wealth of experimental and field studies that have addressed the release of hydrogen sulfide from free surface flows in gravity sewers and the corresponding air-water mass transfer, little is known about hydrogen sulfide emission under highly turbulent conditions (e.g., drop structures, hydraulic jumps). In this study, experimental work was carried out to analyze the influence of characteristics of drops on reaeration. Physical models were built, mimicking typical sewer drop structures and allowing different types of drops, drop heights, tailwater depths and flow rates. In total, 125 tests were performed. Based on their results, empirical expressions translating the relationship between the mass transfer of oxygen and physical parameters of drop structures were established. Then, by applying the two-film theory with two-reference substances, the relation to hydrogen sulfide release was defined. The experiments confirmed that the choice of the type of drop structure is critical to determine the uptake/emission rates. By quantifying the air-water mass transfer rates between free-fall and backdrop types of drop, the latter resulted in considerably lower oxygen uptake rates.
Natércia Matias; Asbjørn Haaning Nielsen; Jes Vollertsen; Filipa Ferreira; José Matos. Liquid-gas mass transfer at drop structures. Water Science and Technology 2017, 75, 2257 -2267.
AMA StyleNatércia Matias, Asbjørn Haaning Nielsen, Jes Vollertsen, Filipa Ferreira, José Matos. Liquid-gas mass transfer at drop structures. Water Science and Technology. 2017; 75 (10):2257-2267.
Chicago/Turabian StyleNatércia Matias; Asbjørn Haaning Nielsen; Jes Vollertsen; Filipa Ferreira; José Matos. 2017. "Liquid-gas mass transfer at drop structures." Water Science and Technology 75, no. 10: 2257-2267.
The presence and fate of hydrogen sulfide in wastewater systems were studied in two stretches of an intercepting sewer system located in a coastal village, in Portugal. A range of hydraulic parameters were obtained and liquid and gas phase measurements were carried out, both continuously and through intensive sampling campaigns. Upstream, where flow rates were relatively low, dissolved sulfide concentrations around 12 mg S L−1 and hydrogen sulfide gas concentrations above 250 ppm were observed, along with limited corrosion damage. It is believed this is due to the low relative humidity detected along the atmosphere of the studied sewer system. Downstream, gas concentrations were always below 40 ppm. Despite that, high signs of corrosion were detected, particularly in manholes with drop structures. It is thought that condensation of spray produced by the fall is the main cause of the phenomenon. Another relevant observation was the rapid decline in dissolved sulfide contents along gravity trunk sewers following the discharge of rising mains, with loss rates as high as 40 mg S L−1 h−1. Air-flow velocities corresponded to 15–50% of wastewater flows, an observation which agrees with other authors' publications addressing relatively small pipes and moderate water flows.
Natércia Matias; Rita Ventura Matos; Filipa Ferreira; Jes Vollertsen; José Matos. Release of hydrogen sulfide in a sewer system under intermittent flow conditions: the Ericeira case study, in Portugal. Water Science and Technology 2017, 75, 1702 -1711.
AMA StyleNatércia Matias, Rita Ventura Matos, Filipa Ferreira, Jes Vollertsen, José Matos. Release of hydrogen sulfide in a sewer system under intermittent flow conditions: the Ericeira case study, in Portugal. Water Science and Technology. 2017; 75 (7):1702-1711.
Chicago/Turabian StyleNatércia Matias; Rita Ventura Matos; Filipa Ferreira; Jes Vollertsen; José Matos. 2017. "Release of hydrogen sulfide in a sewer system under intermittent flow conditions: the Ericeira case study, in Portugal." Water Science and Technology 75, no. 7: 1702-1711.
J. Pisoeiro; A. Galvão; Helena Pinheiro; Filipa Ferreira; José Matos. Determining stoichiometric parameters of detached biomass from a HSSF-CW using respirometry. Ecological Engineering 2017, 98, 388 -393.
AMA StyleJ. Pisoeiro, A. Galvão, Helena Pinheiro, Filipa Ferreira, José Matos. Determining stoichiometric parameters of detached biomass from a HSSF-CW using respirometry. Ecological Engineering. 2017; 98 ():388-393.
Chicago/Turabian StyleJ. Pisoeiro; A. Galvão; Helena Pinheiro; Filipa Ferreira; José Matos. 2017. "Determining stoichiometric parameters of detached biomass from a HSSF-CW using respirometry." Ecological Engineering 98, no. : 388-393.
Hydrogen sulfide emissions from wastewater affect human health and equipment durability, thus presenting a complex issue for utilities. Several VOC emission models have been used before to predict H2S in collection systems and water resources recovery operations, even if with restrictions. By contrast, fewer studies focus on biosolids emissions and modelling. This paper presents a dynamic modelling approach to predict H2S concentration in a tank headspace of a wastewater biosolids recovery facility. Data from one of the largest Portuguese water resources recovery facilities was collected under different facility operating modes. The developed model adequately predicted H2S concentration, with R2 values of 0.89 and 0.78, for different periods of the year, thus showing how modelling may reliably contribute to utility operation decisions.
Rita Ventura Matos; Natércia Matias; Filipa Ferreira; José Matos. Dynamic Modeling of Hydrogen Sulfide within Enclosed Environments in Biosolids Recovery Facilities. Water Environment Research 2016, 88, 2209 -2218.
AMA StyleRita Ventura Matos, Natércia Matias, Filipa Ferreira, José Matos. Dynamic Modeling of Hydrogen Sulfide within Enclosed Environments in Biosolids Recovery Facilities. Water Environment Research. 2016; 88 (12):2209-2218.
Chicago/Turabian StyleRita Ventura Matos; Natércia Matias; Filipa Ferreira; José Matos. 2016. "Dynamic Modeling of Hydrogen Sulfide within Enclosed Environments in Biosolids Recovery Facilities." Water Environment Research 88, no. 12: 2209-2218.
This study aimed at analysing the performance of horizontal subsurface flow constructed wetlands (CWs) to treat combined sewer overflow (CSO). Four horizontal subsurface flow CWs, organized in two groups (A and B) each with a planted (Phragmites australis) and a non-planted bed, were loaded with simulated CSO, with group B receiving twice the hydraulic load of group A. Beds were monitored for pH, dissolved oxygen, conductivity, redox potential, chemical oxygen demand (COD), total suspended solids (TSS) and enterococci. Porosity variations were also estimated. Monitoring was conducted during spring and wintertime, with regular and irregular loading frequencies. Results showed an average treatment efficiency of 90-100 % for TSS, 60-90 % for COD and 2-6 log for enterococci. Removal rates were especially relevant in the first 24 h for COD and TSS. TSS and enterococci removal did not exhibit the influence of macrophytes or the applied hydraulic load while COD's removal efficiency was lower in the higher load group and in planted beds.
J. Pisoeiro; Ana Galvão; F. Ferreira; J. Matos. Potential for CSO treatment with horizontal flow constructed wetlands: influence of hydraulic load, plant presence and loading frequency. Environmental Science and Pollution Research 2016, 23, 20591 -20599.
AMA StyleJ. Pisoeiro, Ana Galvão, F. Ferreira, J. Matos. Potential for CSO treatment with horizontal flow constructed wetlands: influence of hydraulic load, plant presence and loading frequency. Environmental Science and Pollution Research. 2016; 23 (20):20591-20599.
Chicago/Turabian StyleJ. Pisoeiro; Ana Galvão; F. Ferreira; J. Matos. 2016. "Potential for CSO treatment with horizontal flow constructed wetlands: influence of hydraulic load, plant presence and loading frequency." Environmental Science and Pollution Research 23, no. 20: 20591-20599.
Online monitoring programs based on spectroscopy have a high application potential for the detection of hazardous wastewater discharges in sewer systems. Wastewater hydraulics poses a challenge for in situ spectroscopy, especially when the system includes storm water connections leading to rapid changes in water depth, velocity, and in the water quality matrix. Thus, there is a need to optimize and fix the location of in situ instruments, limiting their availability for calibration. In this context, the development of calibration models on bench spectrophotometers to estimate wastewater quality parameters from spectra acquired with in situ instruments could be very useful. However, spectra contain information not only from the samples, but also from the spectrophotometer generally invalidating this approach. The use of calibration transfer methods is a promising solution to this problem. In this study, calibration models were developed using interval partial least squares (iPLS), for the estimation of total suspended solids (TSS) and chemical oxygen demand (COD) in sewage from Ultraviolet-visible spectra acquired in a bench scanning spectrophotometer. The feasibility of calibration transfer to a submersible, diode array equipment, to be subsequently operated in situ, was assessed using three procedures: slope and bias correction (SBC); single wavelength standardization (SWS) on mean spectra; and local centering (LC). The results showed that SBC was the most adequate for the available data, adding insignificant error to the base model estimates. Single wavelength standardization was a close second best, potentially more robust, and independent of the base iPLS model. Local centering was shown to be inadequate for the samples and instruments used.
Rita S. Brito; Helena Pinheiro; Filipa Ferreira; José Matos; Alexandre Pinheiro; Nidia Lourenco. Calibration Transfer Between a Bench Scanning and a Submersible Diode Array Spectrophotometer for In Situ Wastewater Quality Monitoring in Sewer Systems. Applied Spectroscopy 2016, 70, 443 -454.
AMA StyleRita S. Brito, Helena Pinheiro, Filipa Ferreira, José Matos, Alexandre Pinheiro, Nidia Lourenco. Calibration Transfer Between a Bench Scanning and a Submersible Diode Array Spectrophotometer for In Situ Wastewater Quality Monitoring in Sewer Systems. Applied Spectroscopy. 2016; 70 (3):443-454.
Chicago/Turabian StyleRita S. Brito; Helena Pinheiro; Filipa Ferreira; José Matos; Alexandre Pinheiro; Nidia Lourenco. 2016. "Calibration Transfer Between a Bench Scanning and a Submersible Diode Array Spectrophotometer for In Situ Wastewater Quality Monitoring in Sewer Systems." Applied Spectroscopy 70, no. 3: 443-454.
Rita Ventura Matos; Filipa Ferreira; J. Saldanha Matos; A. Oliveira; Luís David; M. Rodrigues; G. Jesus; J. Rogeiro; J. Costa; T. Mota; R. Brito; P. Póvoa; C. David; J. Santos. Implementation of an early warning system in urban drainage infrastructures for direct discharges and flood risk management. Urban Water II 2014, 139, 329 -338.
AMA StyleRita Ventura Matos, Filipa Ferreira, J. Saldanha Matos, A. Oliveira, Luís David, M. Rodrigues, G. Jesus, J. Rogeiro, J. Costa, T. Mota, R. Brito, P. Póvoa, C. David, J. Santos. Implementation of an early warning system in urban drainage infrastructures for direct discharges and flood risk management. Urban Water II. 2014; 139 ():329-338.
Chicago/Turabian StyleRita Ventura Matos; Filipa Ferreira; J. Saldanha Matos; A. Oliveira; Luís David; M. Rodrigues; G. Jesus; J. Rogeiro; J. Costa; T. Mota; R. Brito; P. Póvoa; C. David; J. Santos. 2014. "Implementation of an early warning system in urban drainage infrastructures for direct discharges and flood risk management." Urban Water II 139, no. : 329-338.
Wastewater drainage systems asset management decisions, in particular regarding rehabilitation interventions, are largely dependent on close-circuit television (CCTV) inspection results. However, the results of CCTV inspections are affected by several sources of uncertainty. Within the present communication, the inspector's uncertainty is quantified by comparing periodic inspection reports from three trunk sewers of a Portuguese sewer system. The inspections were carried out by the same experienced inspector using the same equipment. Therefore, the uncertainties from the lack of experience and the difference of the inspector and equipment were ruled out. The protocol uncertainty is also quantified comparing the results obtained with the Water Research Center (WRc) and the National Research Council of Canada (NRC) protocols condition ratings. Both operational and structural condition rating were analysed, but emphasis was given to the later since it dictates the repair and replacement interventions.
V. Sousa; Filipa Ferreira; Ines Meireles; Nuno Almeida; José Matos. Comparison of the inspector and rating protocol uncertainty influence in the condition rating of sewers. Water Science and Technology 2013, 69, 862 -867.
AMA StyleV. Sousa, Filipa Ferreira, Ines Meireles, Nuno Almeida, José Matos. Comparison of the inspector and rating protocol uncertainty influence in the condition rating of sewers. Water Science and Technology. 2013; 69 (4):862-867.
Chicago/Turabian StyleV. Sousa; Filipa Ferreira; Ines Meireles; Nuno Almeida; José Matos. 2013. "Comparison of the inspector and rating protocol uncertainty influence in the condition rating of sewers." Water Science and Technology 69, no. 4: 862-867.
Odor nuisance and sulfide corrosion in sewers carrying septic wastewater are accelerated at points of turbulence such as drops in manholes, but accurate methods or empirical expressions to evaluate the gas stripping rate at those particular sites are still missing. With the aim of improving the current knowledge on the influence of free-fall drops on the release of hydrogen sulfide gas, an experimental set-up was built allowing different free-fall drops heights and flows. Three types of experiments were carried out: reaeration tests without sulfide; sulfide oxidation tests; and hydrogen sulfide release tests. With the increase of the free-fall drop height or of the flow, a higher rate of air-to-water mass oxygen transfer was observed. Results regarding sulfide oxidation tests with reaeration through the free-fall have shown that the oxidation rate was correlated with flow. In the hydrogen sulfide release tests, the maximum concentration in the atmosphere reached 500 ppm. Results also showed that increasing the flow rate decreased the time at which the maximum concentrations in the atmosphere were observed.
N. M. Matias; José Matos; Filipa Ferreira. Hydrogen sulfide gas emission under turbulent conditions – an experimental approach for free-fall drops. Water Science and Technology 2013, 69, 262 -268.
AMA StyleN. M. Matias, José Matos, Filipa Ferreira. Hydrogen sulfide gas emission under turbulent conditions – an experimental approach for free-fall drops. Water Science and Technology. 2013; 69 (2):262-268.
Chicago/Turabian StyleN. M. Matias; José Matos; Filipa Ferreira. 2013. "Hydrogen sulfide gas emission under turbulent conditions – an experimental approach for free-fall drops." Water Science and Technology 69, no. 2: 262-268.
R. Salgado Brito; Helena Pinheiro; Filipa Ferreira; José Matos; Nidia Lourenco. In situUV-Vis spectroscopy to estimate COD and TSS in wastewater drainage systems. Urban Water Journal 2013, 11, 261 -273.
AMA StyleR. Salgado Brito, Helena Pinheiro, Filipa Ferreira, José Matos, Nidia Lourenco. In situUV-Vis spectroscopy to estimate COD and TSS in wastewater drainage systems. Urban Water Journal. 2013; 11 (4):261-273.
Chicago/Turabian StyleR. Salgado Brito; Helena Pinheiro; Filipa Ferreira; José Matos; Nidia Lourenco. 2013. "In situUV-Vis spectroscopy to estimate COD and TSS in wastewater drainage systems." Urban Water Journal 11, no. 4: 261-273.
The use of constructed wetlands as a valuable and attractive method for combined sewer overflow (CSO) treatment has been demonstrated in several studies. In Portugal, a Mediterranean country having usually a long dry period, there are still no applications of this technology. The purpose of this research is to gather information and know-how required for the design and management of this type of infrastructure. A pilot-scale experimental setup for CSO treatment was installed and evaluated in situ, in terms of organic matter, total suspended solids and microorganism removal with emphasis on the results of the start-up. After 1 day of retention average removal efficiencies of 73–79% and 82–89% were obtained in terms of chemical oxygen demand (COD) and total suspended solids (TSS), respectively. During the remaining retention time a slower removal was observed. After 7 days, the COD removal efficiencies reached 86–91% and the TSS removal efficiencies reached 93–97%. On average, after 1 day, reductions of 1.2–2.0 log and 1.9–2.4 log, respectively, for total coliforms and Enterococcus were observed. For a retention time of 7 days these reductions attained 4.0–4.9 log and 4.4–5.3 log, respectively.
R. Amaral; Filipa Ferreira; Ana Galvão; José Matos. Constructed wetlands for combined sewer overflow treatment in a Mediterranean country, Portugal. Water Science and Technology 2013, 67, 2739 -2745.
AMA StyleR. Amaral, Filipa Ferreira, Ana Galvão, José Matos. Constructed wetlands for combined sewer overflow treatment in a Mediterranean country, Portugal. Water Science and Technology. 2013; 67 (12):2739-2745.
Chicago/Turabian StyleR. Amaral; Filipa Ferreira; Ana Galvão; José Matos. 2013. "Constructed wetlands for combined sewer overflow treatment in a Mediterranean country, Portugal." Water Science and Technology 67, no. 12: 2739-2745.
Rita S. Brito; Filipa Ferreira; Nidia D. Lourenco; Helena M. Pinheiro; José S. Matos. Espectrofotometria para monitorização da qualidade de água residual em drenagem urbana. Revista Recursos Hídricos 2013, 34, 5 -16.
AMA StyleRita S. Brito, Filipa Ferreira, Nidia D. Lourenco, Helena M. Pinheiro, José S. Matos. Espectrofotometria para monitorização da qualidade de água residual em drenagem urbana. Revista Recursos Hídricos. 2013; 34 (1):5-16.
Chicago/Turabian StyleRita S. Brito; Filipa Ferreira; Nidia D. Lourenco; Helena M. Pinheiro; José S. Matos. 2013. "Espectrofotometria para monitorização da qualidade de água residual em drenagem urbana." Revista Recursos Hídricos 34, no. 1: 5-16.
Filipa Ferreira; José S. Matos. Qualidade de águas pluviais na zona baixa de Alcântara, em Lisboa. Revista Recursos Hídricos 2012, 33, 59 -72.
AMA StyleFilipa Ferreira, José S. Matos. Qualidade de águas pluviais na zona baixa de Alcântara, em Lisboa. Revista Recursos Hídricos. 2012; 33 (2):59-72.
Chicago/Turabian StyleFilipa Ferreira; José S. Matos. 2012. "Qualidade de águas pluviais na zona baixa de Alcântara, em Lisboa." Revista Recursos Hídricos 33, no. 2: 59-72.
Although the application of complex integrated models to wastewater systems is useful, it is often difficult to implement and not always suitable for the design of new systems or for their rehabilitation. Integrated simple approaches that allow assessing the environmental performance of urban wastewater systems may be advantageous, especially during the initial phases of the system planning process. This paper presents an original, straightforward approach that can be used for planning, design and operation of urban wastewater systems. The INtegrated Simplified Approach (INSA) combines the concepts of performance indicators with mass balances and can be applied to wastewater systems as a management support tool, particularly in situations where there is lack of data, economic limitations or time constraints. The INSA was applied to the Algés-Alcântara wastewater system to evaluate its environmental performance and to simulate the individual or combined impact of the rehabilitation measures proposed, thus defining their priority. The results clearly indicate that, despite the investment already made upgrading the wastewater treatment plant (WWTP), the proposed interventions must be implemented to ensure an acceptable environmental performance of the system. In addition, the results demonstrate the significant pollution loads present in stormwater, frequently higher than the pollution loads discharged into receiving waters during dry weather.
F. Ferreira; J. Matos; A. Galvão; M.A. Cardoso. Assessing the environmental performance of urban wastewater systems using the INSA model: Application to the Algés-Alcântara wastewater system, in Portugal. Journal of Environmental Management 2011, 92, 2944 -2952.
AMA StyleF. Ferreira, J. Matos, A. Galvão, M.A. Cardoso. Assessing the environmental performance of urban wastewater systems using the INSA model: Application to the Algés-Alcântara wastewater system, in Portugal. Journal of Environmental Management. 2011; 92 (11):2944-2952.
Chicago/Turabian StyleF. Ferreira; J. Matos; A. Galvão; M.A. Cardoso. 2011. "Assessing the environmental performance of urban wastewater systems using the INSA model: Application to the Algés-Alcântara wastewater system, in Portugal." Journal of Environmental Management 92, no. 11: 2944-2952.