Publications by authors named "Maarten W Saaltink"

5 Publications

  • Page 1 of 1

Vapor flow control in dune sediments under dry bare soil conditions.

Sci Total Environ 2021 Sep 30;786:147404. Epub 2021 Apr 30.

Instituto Geológico y Minero de España, Plaza de España, 41013 Seville, Spain.

The study presents daily values of inward and outward vapor flux crossing the soil-atmosphere boundary in dependence on meteorological parameters and soil moisture. Measurements of vapor flux, soil moisture and meteorological parameters were evaluated during days without rainfall between 2015 and 2019. Vapor flux data were obtained at 1 min intervals by a precision lysimeter installed in the Doñana National Park, southwest Spain. Meteorological data were measured on-site at 10-min intervals, including temperature, relative humidity, wind velocity and net radiation. After manual and automatic noise elimination of the lysimeter data, time series of a summer and winter period were generated for selected relevant parameters. Furthermore, daily cumulative data of inward and outward vapor flux were calculated for the entire period and analyzed for their control by meteorological parameters and soil moisture. Results show moderate correlations of daily outward vapor flux on the diurnal amplitudes of temperature and humidity whereas daily inward vapor indicates moderate correlations with temperature and soil moisture. A correction coefficient for potential evaporation to estimate actual evaporation was determined based on soil moisture and air temperature.
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http://dx.doi.org/10.1016/j.scitotenv.2021.147404DOI Listing
September 2021

Evaluation of self-combustion risk in tire derived aggregate fills.

Waste Manag 2011 Sep-Oct;31(9-10):2133-41. Epub 2011 May 17.

Department of Geotechnical Engineering and Geosciences UPC, Barcelona, Spain.

Lightweight tire derived aggregate (TDA) fills are a proven recycling outlet for waste tires, requiring relatively low cost waste processing and being competitively priced against other lightweight fill alternatives. However its value has been marred as several TDA fills have self-combusted during the early applications of this technique. An empirical review of these cases led to prescriptive guidelines from the ASTM aimed at avoiding this problem. This approach has been successful in avoiding further incidents of self-combustion. However, at present there remains no rational method available to quantify self-combustion risk in TDA fills. This means that it is not clear which aspects of the ASTM guidelines are essential and which are accessory. This hinders the practical use of TDA fills despite their inherent advantages as lightweight fill. Here a quantitative approach to self-combustion risk evaluation is developed and illustrated with a parametric analysis of an embankment case. This is later particularized to model a reported field self-combustion case. The approach is based on the available experimental observations and incorporates well-tested methodological (ISO corrosion evaluation) and theoretical tools (finite element analysis of coupled heat and mass flow). The results obtained offer clear insights into the critical aspects of the problem, allowing already some meaningful recommendations for guideline revision.
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http://dx.doi.org/10.1016/j.wasman.2011.04.014DOI Listing
December 2011

Bacterial transformation and biodegradation processes simulation in horizontal subsurface flow constructed wetlands using CWM1-RETRASO.

Bioresour Technol 2011 Jan 17;102(2):928-36. Epub 2010 Sep 17.

Catalan Institute for Water Research, H2O Building, Scientific and Technological Park of the University of Girona, c/ Emili Grahit 101, E-17003 Girona, Spain.

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 configurations were simulated. According to the simulations, anaerobic processes were more widespread in the simulated wetland and contributed to a higher COD removal rate [72-79%] than anoxic [0-1%] and aerobic reactions [20-27%] did. In all the cases tested, the reaction that most contributed to COD removal was methanogenesis [58-73%]. All results provided by the model were in consonance with literature and experimental field observations, suggesting a good performance and reliability of CWM1-RETRASO. According to the good simulation predictions, CWM1-RETRASO is the first mechanistic model able to successfully simulate the processes described by the CWM1 model in HSSF CWs.
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http://dx.doi.org/10.1016/j.biortech.2010.09.038DOI Listing
January 2011

Experimental and modeling investigation of multicomponent reactive transport in porous media.

J Contam Hydrol 2011 Mar 3;120-121:27-44. Epub 2009 Dec 3.

Department of Environmental Sciences and Energy Research, Weizmann Institute of Science, Rehovot, Israel.

We present an experimental and modeling study of solute transport in porous media in the presence of mixing-induced precipitation of a solid phase. Conservative and reactive transport experiments were performed in a quasi-two-dimensional laboratory flow cell, filled with homogeneous and heterogeneous porous media. Conservative experiments were performed by injecting solutions containing sodium chloride and calcium chloride into the domain. In reactive transport experiments, inlet solutions of calcium chloride and sodium carbonate were injected in parallel, resulting in calcium carbonate precipitation where the solutions mix. Experimental results were used as a benchmark to examine the performance of a reactive transport numerical model. Good agreement between model predictions and experimental results was obtained for the conservative transport experiments. The reactive transport experiments featured the formation of a calcium carbonate mineral phase within the mixing zone between the two solutions, which controlled the spatial evolution of calcium carbonate in the domain. Numerical simulations performed on high resolution grids for both the homogeneous and heterogeneous porous systems underestimated clogging of the system. Although qualitative agreement between model results and experimental observations was obtained, accurate model predictions of the spatial evolution of calcium concentrations at sample points within the flow cell could not be achieved.
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http://dx.doi.org/10.1016/j.jconhyd.2009.11.002DOI Listing
March 2011

Analysis of a deep well recharge experiment by calibrating a reactive transport model with field data.

J Contam Hydrol 2003 Aug;65(1-2):1-18

Department of Geotechnical Engineering and Geosciences, School of Civil Engineering, Technical University of Catalonia (UPC), C/ Jordi Girona 1-3, Building D-2, 08034 Barcelona, Spain.

This paper describes the modeling of the hydrogeochemical effects of deep well recharge of oxic water into an anoxic pyrite-bearing aquifer. Kinetic expressions have been used for mineral dissolution-precipitation rates and organic matter oxidation. Hydrological and chemical parameters of the model were calibrated to field measurements. The results showed that oxidation of pyrite (FeS(2)) and, to a lesser extent, organic matter dominate the changes in quality of the recharged water during its passage through the aquifer. The recharge leads to the consumption of oxygen and nitrate and the formation of sulfate and ferrihydrite. Complexation reactions, cation exchange and precipitation and dissolution of calcite, siderite and rhodochrosite were also identified through the modeling. Despite problems of non-uniqueness of the calibrated parameters, the model was used successfully to depict the geochemical processes occurring in the aquifer. Non-uniqueness can be avoided by constraining the model as much as possible to measurements and/or data from literature, although they cannot be considered always as fixed values and should be considered as stochastic variables instead.
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http://dx.doi.org/10.1016/S0169-7722(02)00236-XDOI Listing
August 2003