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Project PTDC/ECM/70216/2006 – “Low Cost In-Situ Arsenic Mitigation Tecnologies using Iron Based Sorbents”
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- 14. CONFERENCES SCIENTIFIC COMMISSION OF INTERNATIONAL CONFERENCES
- 1998 CONSOIL 98 , SIXTH INTERNATIONAL FZK/TNO CONFERENCE ON CONTAMINATED SOIL
- CHEMICAL SPECIATION OF METALS AND BIOAVALABILITY
- Conferência Cyted, Arsenic Removal Technologies, Rede Iberoarsan, Montevideo, October 2009.
Project PTDC/ECM/70216/2006 – “Low Cost In-Situ Arsenic Mitigation Tecnologies using Iron Based Sorbents”. Function: Main proponent and superviser. Participating entities: CIGAR, I.N.E.T.I. Triennial project approved by an international expert panel selected by F.C.T with a classification of Very Good. Although there are arsenic contaminations of anthropogenic origin (mining, wood preservatives,…) the main causes are natural and motivated by the dissolution of minerals in surface or underground waters. Arsenics is present in natural waters either in its reduced state As(III) or in the oxidized form As(V), both toxic. Toxicity depends upon the oxidation state and, in general terms, As(III) is 60 times more toxic than As(V). Acute poisoning occurs after ingestion higher than 100 mg, while the chronic poisoning occurs after the ingestion of small quantities during a long period and the effects become visible after 5 years. The existence of As in drinking water can originate the endemic regional chronic hydroarsenicosis (ERCA) which shows as melanosis, keratosis degenerating into various types of cancer. European Union has recently lowered the permissible maximum concentration for drinking water from 0.05 mg/L to 0.01 mg/L. The average crustal abundance of arsenic is 1.5 mg/kg, being the composition of natural As minerals the following: 60% are arsenates, 20% sulfides and sufosalts, and the remaining 20% are arsenides. arsenites, oxides, alloys and polymorphs of elemental arsenic. Concentrations of As in natural waters are highly dependent on the existence of arsenic sources and the local geochemical conditions. There are areas with very high concentrations in As in Bangladesh, India, China, Taiwan, Argentina, Chile, El Salvador, México, Nicaragua and Peru. The problem is also relevant in Spain (Catalonian Pyrenees, Valladolid, Madrid, Segovia, etc.) and also in North and Central Portugal. Nowadays chemical analysis can be performed by the application of improved analytical methods such as inductively coupled plasma-mass spectrometry (HG-ICP-MS), inductively coupled plasma-atomic emission spectrometry (HG-ICP-AES), and hydride generation-atomic fluorescence spectrometry (HG-AFS). We propose in this project to develop the voltametric techniques using the hanging mercury drop electrode (HMDE) which are specially adequate for the ionic speciation in natural and groundwater matrices. This methodology has a very low cost in terms of the necessary instruments when compared to the methods mentioned above and allows the direct speciation of As without any sophisticated sample treatment (allowing to keep the original As(III) to As(V) ratio without perceptible changes). It is a method appropriated to be applied in areas and laboratories with lower economic capacity; it can be easily taught and later used on an everyday base by technicians with average qualifications. The limits of detection are sufficiently low to match the objectives of this project. There are three primary categories of available treatment processes. Sorption Treatment Processes - Ion Exchange - Activated Alumina - Iron Based Sorbents Membrane Treatment Processes - Reverse Osmosis Precipitation/Filtration Processes - Enhanced Conventional Gravity Coagulation/Filtration - Coagulation-Assisted Microfiltration (CMF) - Coagulation-Assisted Direct Filtration (CADF) - Oxidation/Filtration - Enhanced Lime Softening Activated alumina is expensive and needs a pH correction and specialized staff . The coagulation-precipitation processes also need previous pH correction and the limit concentration of 0,01 mg/L is difficult to attain. The ion exchange resins need important investments and its applicability depends upon the competition with other anions present in the water. The reverse osmosis allows the simultaneous removal of other ions but has extremely high costs. We intend to research emerging economic technologies – specially the usage of granular iron hydroxides and hybrid sorbents - generally designated by Iron Based Sorbents (IBS). The research will focus on the usage of multifunctional permeable reactive barriers (MPRB) based on IBS and comprehending a two stage treatment: the previous oxidation of As and its in-situ fixation by IBS. The barriers to be considered will be of the funnel and gate type. The active sorbent will fill up the gate. As the reaction is irreversible the gates must be easily movable for substitution. It is aimed to reach an economic technology which can be adapted to small communities or to isolated populations. PTDC/ECM/68056/2006 – REMEDIATION OF CONTAMINATED SOILS COMBINING VAPOUR EXTRACTION AND BIOLOGICAL PROCESSES: TIME AND EFFICIENCY FORECASTING; Triennial project approved by an international expert panel selected by F.C.T with a classification of Very Good; Participating Research Centres: ICETA Instituto de Ciências e Tecnologias Agrárias e Agro-Alimentares e CIGAR. Financing 52 555 €. Quality: Participant. The incorrect deposition of some wastes, inadequate practices in some industrial activities and environmental accidents haves can cause environmental problems related with soil contamination. A typical Portuguese contamination case is the leaking of gasoline products from underground storage tanks located in gas stations. This problem becomes more serious due the number of existing gas stations and the fact that a small amount of an organic compound is enough to contaminate big volumes of soil and groundwater becoming a serious risk to public health. For this kind of contamination, there are several in-situ technologies, namely soil vapour extraction (SVE) and bioremediation (BR). SVE is a simple, efficient and relatively economical; it uses the application of vacuum to soil contaminated with volatile organic compounds. The vacuum produces the movement of the contaminant towards extraction wells that conduces it to adequate treatment units. BR uses the degradative power of special micro-organisms to destruct organic contaminants present in soil. This technology has low costs, high efficiencies however is relatively slow. The combination of these two technologies have as objective, in the first stage, using the initial high efficiency of SVE decreasing the possible inhibition of the high contaminant load on the micro-organisms, and in a second stage, using BR that allow better efficiencies with no significant costs. One of the great difficulties in choosing the most appropriate remediation technology is the lack of models that can predict the remediation time accurately, originating economical errors in projects. Aiming at the creation of an accurate prediction tool, this project has as objectives: i) identify the most appropriate micro-organisms to degrade the proposed COVs; ii) simulate contaminated soils previously remediated by SVE; iii) bioremediate the prepared soils analyzing the remediation time and process efficiency; iv) using artificial neural networks (ANN), obtain a model that can predict bioremediation time and efficiency of contaminated soils pre-treated with SVE, based on the soil´s physical and chemical properties; v) integrate simple mechanistic models to predict bioremediation time; vi) bioremediate real soils equally treated with SVE in order to validate the developed model; vii) study the best optimum of both techniques to obtain the most effective and economical remediation. The project considers soils constituted by sand, clay and organic matter contaminated with petroleum compounds (Benzene, Toluene, Ethylbenzene and Xylene). Appropriate chromatographic methodologies to monitor the process and quantify pollutants will be developed. Projecto Pultreficaz - OPTIMIZAÇÃO DE PROCESSO DE PULTRUSÃO, Projecto QREN, Promotor Alto; Participantes: ISEP e CIGAR. Membros do Cigar afectos ao projecto: António M. A. Fiúza e M. Lurdes Dinis; Financiamento para o Cigar: 180 000€. The aim of the present project is focused on improve the existing equipments at ALTO, transforming them on a more competitive ones, by adjusting the thermal management, by reducing the setup times consumption of the process and by doing a valorization of the residues produced during the industrial process. 14. CONFERENCES SCIENTIFIC COMMISSION OF INTERNATIONAL CONFERENCES
Participation in several International conferences with world relevance within its speciality domain, namely those organized by the Nuclear Energy Agency of the OECD, by the International Atomic Energy Agency, Uranium Institute and Consoil. Some examples of the most recent participations: 1998 CONSOIL 98, SIXTH INTERNATIONAL FZK/TNO CONFERENCE ON CONTAMINATED SOIL, Edinburgh, Scotland. 1999 R’99 RECOVERY, RECYCLING AND RE-INTEGRATION, UNEP Congress (United Nations Environmental Programme), held in Geneva, February 1999.
2001FIRST EUROPEAN BIOREMEDIATION CONFERENCE, Chania, Crete, Greece,
2002CONSOIL 2003, 8th INTERNATIONAL FZK / TNO CONFERENCE ON CONTAMINATED SOIL, Gent, Belgium, 2003
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