Evaluation of Zn, Cu and Pb sorption-desorption phenomena in kaolinite-sand media filtration pilot scale installation

The retention of Zn, Cu and Pb from highway runoff with reactive filter media was studied. Besides the physical retention of traditional filter beds, a reactive filter bed enhances the dissolved heavy metals retention processes due to sorption and precipitation, transferring pollutants from the dissolved form to the media matrix. A synthetic effluent was used to simulate highway runoff and, for filter bed media, sand and kaolinite were used. Results obtained for those three heavy metals show a very high reactive filter media retention capacity and a very high resistance to desorption processes

Technological platform for catchment water safety planning

Water safety plans is a concept proposed by the World Health Organisation for risk assessment and risk management in drinking water systems. This concept includes the identification of hazards and control points throughout the water cycle from the catchment to the point of consumption. Deterioration in surface and groundwater quality due to sources of pollution impacting the water intake should be identified and monitored allowing effective management and operation of drinking water systems. Land use information, monitoring databases, and hydrodynamics and water quality river modelling can be used to estimate and forecast the spatial and temporal mass transport and attenuation hazards that impact a given drinking water intake. This work presents a technological platform based on the Delft-FEWS software in which databases and models were implemented for supporting catchment water safety plans in different river basins of the NW region of Portuga

Technological platform for catchment water safety planning

Water safety plans (WSP) is a concept introduced by the World Health Organisation (WHO, 2004) for risk assessment and risk management in drinking water systems. This approach has been increasing embraced by water suppliers, governments and other stakeholders. Raw water quality is a key factor for ensuring good and safe drinking water. Water use, land use and polluting human activity in the catchment area all have significant impacts on surface and groundwater quality, and thus the level and complexity of treatment plants necessary to ensure that the water leaving the works is safe and acceptable to consumers. Protection of raw water sources should be seen as the first, and often the most important, barrier to prevent microbial, chemical and radiological contamination of drinking water sources (Vieira et al., 2011). Due to continuously emerging threats to the drinking water quality from organic matter, pesticides, fertilizers, pharmaceuticals, trace metals, and other types of contaminants, much effort has been put in the development of knowledge that is capable to effectively identify potential risks. Information on catchment characteristics (e.g. geology, hydrology, meteorology, land use, competing water uses), surface water bodies (e.g. flow rate, water quality and seasonality) and groundwater (e.g. aquifer flow rate, flow direction and aquifer vulnerability to pollution) and application of models to quantify the spatial and temporal dynamics of transport and attenuation of hazards that arise from the pollution sources across a catchment are of paramount importance for evaluating and prioritizing risks in raw water sources (Vieira & Pinho, 2014; WHO, 2016). This paper presents the use of the Delft-FEWS platform (Werner et al., 2012) in implementing an early warning system supported by proper hydrodynamics and water quality models for supporting catchment water safety plans in two river basins of the NW region of Portugal

Improving operational management of wastewater systems: a case study

Wastewater treatment facilities collecting wastewater from longstanding sewer networks of five municipalities in the Ave River basin (located in NW Portugal) are especially vulnerable to water inflows since they have considerable extensions of sewers installed in stream and riverbeds. TRATAVE, the company responsible for operating the system, designed and implemented a monitoring network to measure discharges along the entire drainage network and treatment facilities in order to reduce those water inflows. Several flow measurement devices were installed at strategic locations within the sewer network and integrated with a SCADA system responsible for its operation. A decision support system (DSS) is being implemented using the Delft-FEWS platform, integrating monitoring data and models. Based on monitored data and model results, an estimation of infiltration volumes during wet periods is presented. Moreover, the capabilities of the DSS are illustrated in: (i) location of manholes losses along sewer networks during wet periods; (ii) identification and location of unknown connections to the sewer network using wastewater balances; and (iii) design of a PID controller for a pumping station using on-line tank water level measurement. Acquired knowledge resulting from the DSS greatly improved the utility performance both in terms of economic revenue and environmental protectionThe authors thank TRATAVE for the financial support in the installation of measurement devices, the first author’s scholarship for PhD tuition fees, and in making available the monitoring data used in this research

Modelling of sanitary sewer systems integrating rainfall-derived infiltration and inflow

Wastewater utilities often have management difficulties when excessive wet-weather flow leads to serious impacts in public health and environment as well as disturbing operational conditions in wastewater treatment plants (WWTP). This phenomenon, resulting from rainfall-derived infiltration and inflow (RDII), occurs mainly due to defects in pipes and manholes (infiltration) and to illicit connections from downspouts, foundation drains or cross-connections with storm sewers (inflow), contributing to sanitary sewer overflows (SSOs). These difficulties related to SSOs negatively affect: (i) the capacity and operation of sanitary sewer collection; (ii) the performance and treatment efficiency of WWTP; (iii) the risk of a public health hazards and environmental contamination. This well-known wastewater managerial problem is very difficult to locate and quantify in practice since the needed adequate measurement equipment often entails unsustainable costs for utilities. Wastewater flow mathematical modelling integrating a digital cadastral database using Geographic Information Systems (GIS) constitutes a sound methodology in predicting sanitary sewer systems performance which is a critical issue within SSOs reduction and remediation programs. This paper presents the implementation of a methodology based on hydroinformatic tools to determine the contribution of RDII in complex municipal sewer systems in order to establish adequate urban wastewater management policies that will effectively mitigate SSOs. USEPA SWMM, and digital cadastral database with field verification were applied in a simulation study of the small scale sanitary sewer network of Espinho (Braga, Portugal) whose results will be used in a larger scale to create a city-wide model for wastewater systems management

Integrating hydraulic modelling and GIS for wastewater systems management: a case study

The increasing costs related to operation and maintenance of urban wastewater systems has led to a special attention of utilities in promoting studies to address the key problem of water infiltration, inflow and improper connections entering the separate drainage networks. This is a common and hard to predict operational situation that needs to be identified and minimized as it negatively affects the managerial conditions of the network and the downstream wastewater treatment plant efficiency. The implementation of mathematical models for determining the hydrodynamics behaviour of dry weather and wet weather flows in sewers appears to be a sound methodology to identify the causes for those adverse management conditions. This methodology was applied in a small urban wastewater network of the city of Braga (Portugal). The free user program USEPA SWMM was applied with the integration of GIS information related to the wastewater collection system

Integrating hydraulic modelling and GIS for wastewater systems management: a case study

The increasing costs related to operation and maintenance of urban wastewater systems has led to a special attention of utilities in promoting studies to address the key problem of water infiltration, inflow and improper connections entering the separate drainage networks. This is a common and hard to predict operational situation that needs to be identified and minimized as it negatively affects the managerial conditions of the network and the downstream wastewater treatment plant (WWTP) efficiency. Management difficulties in separate drainage networks seldom occur when unexpected groundwater inflow, stormwater infiltration, and flows from improper connections enter into the dedicated sanitary sewer systems. Although the consequences that improper flows may have on wastewater systems are known, the problem is difficult to locate and quantify. The use of modelling tools is of special relevance to the planning, management and rehabilitation of these types of systems, which can be very useful for: (i) evaluating the capacity of existing systems in real time; (ii) testing alternative solutions to solve problems detected; or testing different procedures to operate the systems in extreme events scenarios. The implementation of mathematical models for determining the hydrodynamics behaviour of dry-weather and wet-weather flows in sewers was applied in a small urban wastewater network of the city of Braga in Portugal (Figure 1). The free user program US EPA SWMM was applied with the integration of GIS InterAqua information related to the wastewater collection system

Modelling of Sanitary Sewer Systems integrating Rainfall-Derived Infiltration and Inflow

Municipal wastewater management difficulties may occur when excessive wet weather flow determine sanitary sewer overflows (SSOs) mainly caused by the contribution of rainfall-derived infiltration and inflow (RDII) into sanitary sewers. This excess of wet weather flow can lead to serious problems to public health and environment as well as to suboptimal operation of wastewater treatment plants. This paper presents the implementation of a methodology based on hydroinformatic tools to determine the contribution of RDII in complex municipal sewer systems in order to establish adequate urban wastewater management policies that will effectively mitigate SSOs. USEPA SWMM, and digital cadastral database with field verification were applied in a simulation study of a small scale sanitary sewer network whose results will be used in a larger scale to create a city-wide model for wastewater systems management

Analysis of estuarine flood levels based on numerical modelling. The Douro river estuary case study

Estuarine hydrodynamics present intermittent and complex circulation patterns. In this context, from the point of view of the coastal management associated with flood risks in riverine areas, numerical models allow predicting scenarios under specific hypotheses. This work simulates flood events occurring in the Douro river estuary recurring to numerical modelling tools. This estuary, located in the northern region of Portugal, periodically suffered severe flooding, with the associated losses and damages for the local protected landscape areas and hydraulic structures. The occurrence of these events justify the importance of a complete characterization of the areas that present risk of inundation and how they can be affected. A 2D-horizontal numerical model implemented with the Delft3D software was developed for this estuarine region including also the adjacent coastal zone. Available in-situ data were used for model calibration and validation processes. The obtained results are consistent with the in-situ measured water levels, allowing to understand the dynamics of the estuary during flood events. The robustness of the implemented numerical model allows to anticipate flood scenarios effects and associated water levels. The simulations results can then be used for sustainable management of this estuarine zone that presents high social, economic and environmental values.This research was partially supported by the Research Line ECOSERVICES, integrated in the Structured Program of R&D&I INNOVMAR: Innovation and Sustainability in the Management and Exploitation of Marine Resources (NORTE-01- 0145-FEDER-000035), funded by the Northern Regional Operational Programme (NORTE2020) through the European Regional Development Fund (ERDF), and by the Brazilian National Council for Scientific and Technological Development (CNPq) through a scholarship granted to the 1st author (Process 200016 / 2014-8)

Sete Fontes: a challenge to promote the heritage legacy and facing water sources scarcity in the city of Braga - Portugal

An ancient drinking water supply system, called Sete Fontes (Seven Springs), was built in the mid eighteenth century in the city of Braga. The system is composed by underground galleries, cisterns, waterspouts, fountains, and (covered) stone aqueduct channels with about 3500m long. This national monument, still existing and active, preserves both the original memorial role (representative of a boost to urban and baroque architecture), and the original function(improvement of quality of life), being a witness of the evolution of hydraulic engineering concepts, which greatly contributed to the improvement of urban infrastructures and the protection of public health. This paper also presents an overview of the history of the water supply system of the city of Braga, from the Roman period to the contemporary age, with special focus on Sete Fontes water sources characterization (morphological, hydrogeological, hydraulic, and water quality). This heritage legacy is invaluable not only for its history and cultural significance, while maintaining its authenticity and integrity, but also due to its confirmed water quality that can be an added value, taking a new relevance to address future scarcity scenarios of safe water sources in a climate change context.info:eu-repo/semantics/publishedVersio