Day 2 :
Keynote Forum
Bodoque J M
University of Castilla-La Mancha, Spain
Keynote: Restoring hydromorphological functionality to improve natural purification capacity of a heavily modified water body
Time : 09:00-09:30
Biography:
Bodoque J M obtained his PhD in Geology from Complutense University of Madrid, Spain. He undertook his Postdoctoral studies at the Department of Civil Engineering, Texas A&M University, USA. Currently, he is a Professor of the Faculty of Environmental Sciences and Biochemistry at the University of Castilla-La Mancha His main research is focused on Hydrology and Geomorphology, which has resulted in more than 40 papers in international peer reviewed journals related to fluvial geomorphology, flood risk assessment and management, soil erosion, water quality and ecological restoration.
Abstract:
We determined the natural purification ability of a floodplain where irrigated agriculture is a dominant and hydraulic connection with the associated river is limited. Denitrification activity was characterized by using different methodological approaches based on i) End-Members Mixing Analysis; ii) characterization of macroinvertebrates of the hyporheic zone; iii) analysis of the denitrification potential; iv) analysis of the bacterial community structure; and v) hydrologic modeling. All the approaches, except EMMA analysis, lead to the same conclusion. Denitrification is almost non-existent because the study site does not have the hydric soil and oxygen-limited conditions needed to enable denitrification. Invertebrates did not show statistically significant differences (P-value higher than 0.05) between the diversity indices corresponding to each of the sampling campaigns. However, significant differences (P-value less than 0.01) were found between the piezometers closest to the river banks and the rest; this may be interpreted because of low hydraulic connectivity. Denitrification potential did not show significant statistical differences (P-value less than 0.01) between the sampling campaigns conducted. This shows that besides the absence of connectivity, irrigation is not able to significantly activate denitrification. Additionally, results from the characterization of the bacterial community structure are consistent with floodplains where denitrification is not effective since most bacterial communities are not linked with NO3. Hydrologic modeling showed that decay change is very low, on the order of 0.01 mgN/L.day, although it would improve around 10% if ordinary floods occur. During the summer months theoretical concentrations of nitrates were lower than expected (e.g. ΔNO3 = - 41 in August 2013), according to the EMMA analysis, which might be due to the intensity of irrigation is spatiotemporally variable in the study site. Our results show that floodplain denitrification has been drastically reduced due to the suppression of flood-pulses. In this context, the creation of riverine wetlands where the hydrological regime is restored would lead to a decay of nitrates whose dynamic evolution increases with flooding, as scenarios tested by hydrological modeling have demonstrated.
Figure 1. Conceptual model implemented.
Keynote Forum
Irena Ymeti
University of Twente, The Netherlands
Keynote: Monitoring the effect of drying-wetting cycles on soil aggregate breakdown using SPECIM hyperspectral camera
Time : 09:30-10:00
Biography:
Irena Ymeti is following the PhD program at the Earth Systems Analysis department at ITC, University of Twente, The Netherlands and working on monitoring soil aggregate breakdown using remote sensing technology. She started to work at the Institute of Geosciences, Energy, Water and Environment at the Polytechnic University of Tirana, Albania building a geo-information (GIS) and RS laboratory for processing and analyzing data for earth science applications.
Abstract:
To monitor soil surface changes, such as aggregate breakdown, it is important to understand the interaction between soil surface and the surrounding environment at high temporal resolution. Within different spatial, temporal and spectral resolution remote sensing (RS) provides continuous data that are suitable for assessment and monitoring of environmental conditions. Using a SPECIM hyperspectral camera under laboratory conditions at a micro-plot scale, we aim to detect and estimate soil aggregate changes over time. We designed an indoor experiment by exposing triplicates of four soils susceptible to detachment (silty loam with various amount of organic matter content and silty loam mixed with hematite) to drying, field capacity and wetting conditions. Twelve soil samples were kept at field capacity for the entire period that the experiment ran. The rest of soil samples were imposed to drying and wetting conditions which were alternated with field capacity condition every three days. All the soil samples were scanned with the SPECIM hyperspectral camera each three days. We collected images data from April to June 2016. When an image has a sufficient high spatial resolution, pixels are smaller than the object so grouping of pixels is possible in order to obtain real-world homogeneous features. Therefore, object-based image analysis (OBIA) is a suitable approach for soil aggregate change detection. However, finding an appropriate method for monitoring soil aggregate breakdown using object-based image analysis for hyperspectral data is required. Moreover, our focus will be on quantifying soil aggregate break down over time using hyperspectral imagery.
Keynote Forum
Emmanuel Mousset
Universite de Lorraine, France
Keynote: Advanced electrochemical treatments for soil remediation
Time : 12:20-13:05
Biography:
Emmanuel Mousset has his expertise in developing advanced electrochemical processes for environmental applications, e.g. soil remediation and wastewater treatment. He got his PhD under supervision of Prof. M A Oturan in the framework of Erasmus mundus ETeCoS3 programme. As tenured CNRS researcher expert in the field, he has been invited in several conferences. He developed the kinetics of primary soil pollutant and the intermediates have been monitored and modeled which allowed predicting the evolution of these molecules. He demonstrated that this kinetics of pollutants degradation depend on the kind of washing agent employed (i.e. its chemical structure) to extract the pollutant from the soil. He also highlighted the ecotoxicity and biodegradability enhancement of the soil washing effluent treated by advanced electrochemical treatment after a certain electrolysis time. From this approach, new scientific and technological insights have emerged and have been patented and awarded.
Abstract:
Statement of the Problem: The remediation of polluted soil and sites is a major of concern not only for the consequence on the ecosystem but also for the contamination of groundwater as resource of drinking water. In this context, many studies have been devoted to find the most cost-efficient solution for soil remediation. Most of the organic pollution is composed of aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (HAPs) but most of them are not biodegradable, which make not efficient enough the biological treatment. Physical techniques only contain the pollution but does not eliminate it while thermal treatment still remain expensive and denature the soil composition. Chemical oxidation methods have been proposed as well, but the addition of oxidants into the soil make the technique uncertain regarding the degradation yield and the hazardous oxidation by-products that can be formed.
Methodology & Theoretical Orientation: Soil washing (SW) and soil flushing (SF) technology using agents to extract and solubilize the pollutants have emerged and have shown promising results. Since these methods only transfer the pollution from soil matrix to liquid matrix, a post-treatment is required. The combination of SW/SF with electrochemical advanced oxidation process (EAOP) have been therefore proposed. EAOP have the advantage to not require the addition of oxidant that are produced continuously and in situ through electrochemical reactions.
Findings: Three major insights emanate from this combination: the surfactant structure has an importance in the pollutant degradation efficiency and the reusability of the washing agent, the integrated process can be performed at neutral pH and without addition of iron source for Fenton reaction, and the biodegradability enhancement with electrolysis time of SW/SF solutions.
Conclusion & Significance: These results gave new possibility of soil remediation by minimizing the use of reagent and by maximizing the pollutants degradation rates and yields.
