Soil remediation session 5 of Remtech Europe 2019
Session 5 is chaired by Nicola Harries and Joerg Frauenstein is about the Soil Remediation: Case studies and projects would come from Italy, Slovenia, Austria, USA, France. Nicola and Joerg will also animate the panel at the end of the session. Here you find some rumors about it.
1st speech is about Passive Flux Meters and Design Verification Program that will be presented by Paola Goria, Mariangela Donati, Kris Maerten (Regenesis). This presentation focuses on the pre-application Target Treatment Zone (TTZ) assessment steps that improve existing design assumptions before field application. Frequently innovative characterization and monitoring technologies, such as passive flux meters, are used in order to acquire highly significative data. Regarding reagent delivery and coverage, the most important TTZ characteristics are A) gross soil type, B) the nature and extent of the flux zones, and C) positional relationship between COC mass storage and transport/flux zone units. Sedimentary processes have a direct effect on the above relationships. These processes directly affect COC mass storage and distribution as well as remedial reagent selection and application methods. To assist design and application teams, a set of routine pre-application “Design Verification Testing” (DVT) steps have been developed and performed on select project sites (N=50)
2nd speech is a Large-scale demonstration of novel, entirely sustainable chelator-based washing of heavy metals contaminated soils presented by Domen Lestana, Simon Gluhar (University of Ljubljana), Neza Finzgar (Envit), Marko Gerl (Arhel). The patented technology features a novel reaction of alkaline substitution, precipitation, and adsorption of toxic metals on polysaccharides, and chelator acidic precipitation for process waters and chelator recycling in a closed loop. No wastewaters and max. 1% of solid wastes are generated. The post-remedial toxic emissions from soil are mitigated to the levels close or bellow limits of quantification by thorough soil rinsing and addition of zero-valent Fe (ZVI) into the soil slurry which enables for fast and permanent adsorption of small residual quantities of chelator and toxic metals chelates. The process is abiotic; for example, the poor EDTA biodegradability is not an issue even if an exceedingly high concentration of this extremely efficient chelator is used in soil washing. Furthermore, ZVI slurry addition simultaneously immobilizes oxy-anion forming contaminants such as As. ReSoil technology is cost-efficient due to reagent recycling and using inexpensive / waste auxiliary materials (lime, sulphuric acid, waste paper, scrap iron) and common process machinery.
3rd speech by Mike Mueller and Alberto Leombruni (Peroxychem) would address the combination of In situ chemical oxidation (ISCO) and in situ solidification/stabilization (ISS). These are two well established remedial technologies that can be applied together in a single event. These technologies use different methods to reduce the risks and hazards posed by various contaminants; ISCO degrades and transforms contaminants significantly reducing the contaminant mass whereas ISS solidifies, stabilizes and significantly reduces the flux of the contaminant from source zones. In addition, ISS amendments can be varied to help control post-application soil characteristics such as hydraulic conductivity and compressive soil strength. Alkaline activated persulfate, an ISCO technology, share many of the same materials used with ISS, these two technologies can be applied using soil mixing technologies resulting in a significantly reduced mass of contaminant (ISCO) that is stabilized and less mobile (ISS) with control over the critical final soil characteristics needed to render the site ready for redevelopment.
Source: MOUSTIC project
4th speech is about the MOUSTIC project and will be presented by Nicolas Fatin Rouge, Iheb Bouzid (Université de Bourgogne Franche-Comté), Yoan Pechaud, Vincent Langlois, Douglas Pino Herrera (UPEM), Malorie Dierick, Pierre-Yves Klein (REMEA), Quentin Giraud, Benoit Paris (INTERA). Finding technologies to remediate deep contaminated zones or those situated under building foundations represents a real challenge. Due to the low accessibility, there is a lack of efficient technologies for their clean-up and thus many contaminated sites cannot be brought to regulatory criteria within a reasonable time frame. The main hypothesis of the project was that, due to their unique physical properties, surfactant foams may potentially help to deliver remedial agents to low accessibility and anisotropic contaminated vadose zones, with relative uniform distribution. In this context, the major attempt of the MOUSTIC project was thus to overcome the current limits in terms of efficiency, cost, sustainability and feasibility for the in situ regeneration of unsaturated zones contaminated with petroleum hydrocarbons through the development and the assessment of new foam-based technology for the delivery of active solutions from lab to field. The MOUSTIC project allowed to:
- use and to control the benefiting properties of these foams to deliver active matter (oxidants, micro-organisms, nutrients) more homogeneously and within the overall space, in order to warrant an effective contaminant degradation in anisotropic and unsaturated soils;
- use the confining effect of foams to better degrade recalcitrant pollutants and avoid the release of toxic metabolites;
- compare the above benefits taking into account the usual methods of solution delivery, namely ISCO and S-ISCO;
- investigate and identify the operational conditions allowing to selectively degrade and mineralize pollutants in the presence of surfactants by oxidation and biodegradation and the synergistic effects between these two processes;
- test, monitor and assess this technology at the pilot-scale in a real contaminated site and to make a benefits/costs/risks assessment with respect to reference treatments;
- model properties for matter transport and transfer of those complex fluids, from the pore to the site scale using data from lab-scale and pilot-scale to calibrate the models.
Source: MOUSTIC project
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