Esther Llorens

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The surface flow constructed wetland (SF CW) in Can Cabanyes (Granollers, Catalonia, northeastern Spain) was created as a part of a series of activities aimed at restoring a highly impacted fluvial peri-urban zone. The system is fed with a small part of the secondary effluent, which is not completely nitrified, from an urban wastewater treatment plant.(More)
The increase in stream nutrient loads from anthropogenic sources has become a serious problem, especially in developed regions. Humans affect streams by modifying the landscape in ways that increase the transport of nutrients to surface waters, by directly dumping urban or industrial sewage into the stream, or by modifying streams in ways that reduce their(More)
Sludge management has become a key issue in wastewater treatment, representing some 20-60% of the operational costs of conventional wastewater treatment plants. The high water content of the sludge results in large daily flow rates to be handled and treated. Thus, the search for methods to improve sludge volume reduction continues to be of major interest.(More)
Nowadays, bad river water quality has become a serious problem, especially in developed regions, due to the high nutrient loads from anthropogenic sources dumped into the rivers. Pollution sources can have different origins: point or non-point sources. As point sources can be well identified, these can be controlled, but the identification and control of(More)
A new model was developed in order to simulate the most significant arsenic retention processes that take place in constructed wetlands (CWs) treating high arsenic waters. The present contribution presents the implementation phases related to plants (arsenic uptake and accumulation, root arsenic adsorption, and root oxygen release), showing the first(More)
Optimization of sludge management can help reducing sludge handling costs in wastewater treatment plants. Sludge drying reed beds appear as a new and alternative technology which has low energy requirements, reduced operating and maintenance costs, and causes little environmental impact. The objective of this work was to evaluate the efficiency of three(More)
As part of the European-Commission-funded STREAMES project, a system is being developed with the objective of capturing knowledge from water managers and environmental-science experts, regarding nutrients-excess effects in streams and of combining this knowledge into a user-friendly tool to assist water managers in evaluating streams' nutrient-retention(More)
The software RCB-arsenic was developed previously to simulate the metalloid behavior in a constructed wetland (CW). The model simulates water flow and reactive transport by contemplating the major processes of arsenic (As) retention inside of CW. The objective of this study was to validate the RCB-arsenic model by simulating the behavior of horizontal flow(More)
The performance and reliability of the CWM1-RETRASO model for simulating processes in horizontal subsurface flow constructed wetlands (HSSF CWs) and the relative contribution of different microbial reactions to organic matter (COD) removal in a HSSF CW treating urban wastewater were evaluated. Various different approaches with diverse influent(More)
A promising approach to the simulation of flow and conversions in the complex environment of horizontal subsurface flow constructed wetlands (HSSF-CWs) is the use of reactive transport models, in which the transport equation is solved together with microbial growth and mass-balance equations for substrate transformation and degradation. In this study, a(More)