WATER CHEMISTRY

Author: RODRIGUEZ MOZAZ SARA.
Year: 2005.
University: BARCELONA.
Place of preparation: INSTITUTO DE INVESTIGACIÓN QUÍMICAS Y AMBIENTALES DE BARCELONA IIQAB- CSIC.

Summary: Based on the current problems of water pollution, especially drinking water, and demand for analytical methods for their control, in this thesis presents the development of advanced techniques of analysis for the determination of a series of compounds called disruptors endocrine (Endocrine Disruptors Compounds, EDCs) of growing concern at the moment (by altering the normal functioning of the endocrine system disorders in behavior, and alterations in the development and reproduction of living beings to be given) that include contaminants organic priority "conventional" of recognized risk to human health and for which there is already a law in place, as in the case of pesticides, organic compounds and other pollutants considered emerging as sex hormones and bisphenol A, whose potential for causing a negative impact on the living is becoming increasingly evident. The control of its presence in groundwater, surface and drinking requires appropriate technical analysis. Specifically, in this thesis presents the development of analysis techniques based on liquid chromatography coupled with mass spectrometry, and based on a inmunosensor optical River ANAlyser (RIANA). It also describes the development of a new and more advanced inmunosensor, AWACSS and its validation in the analysis of EDCs. The analytical methodologies developed in this paper for the control of such pollution in natural waters and are treated by their ability to analyze multi-resduo, automation, sensitivity, etc., and the use or development of advanced technologies, as tools advanced analytical ocn which aims to address the key demands (rapidity, sensitivity, reliability, cost, etc.). made in the environmental area by the various agencies and bodies responsible for monitoring water quality. Finally, it demonstrates the applicability of all the analytical methods developed in the control of pollutants under study in natural waters and along the process of treating drinking water from the plant p otabilizadora Sant Joan Despí.

Author: RÒTTING TOBIAS STEFAN.
Year: 2006.
University: POLITÉCNICA DE CATALUÑA.
Place of defense: INSTITUTO DE CIENCIAS DE LA TIERRA.
Place of preparation: EDIFICI D2 205 Campus NORD.

Summary: Acid mine drainage (AMD) and other metal-polluted anthropogenic discharges are a major cause of water contamination world-wide. Conventional treatment plants are expensive to operate, and application at remote sites may be impractical. Passive treatment systems, which only require naturally available energy sources and infrequent maintenance, may be an economical option to decontaminate these waters. Nevertheless, they are prone to clogging and passivation (loss of permeability or reactivity, respectively) when used to treat water with high metal concentrations or high acidity loads. Many passive treatment systems are based on calcite dissolution that removes trivalent metals such as Fe(III) and Al, but not divalent metals (e.g. Zn, Mn, Cu, Pb, Ni, Cd). To overcome these problems, a novel Dispersed Alkaline Substrate (DAS) was developed and tested in this dissertation. DAS consists of a fine-grained alkaline reagent (e. g. calcite or MgO [caustic magnesia] sand) mixed with a coarse inert matrix (e. g. wood chips). Calcite-DAS was capable of treating Acid Mine Drainage with an inflow net acidity of 1350-2300 mg/L as CaCO3, removing an average 1200 mg/L as CaCO3 in laboratory columns. The substrate functioned without clogging during over one year at an acidity load of 150 g acidity/m2·day, five times the loading rate recommended for conventional passive treatment systems. Al, Fe(III), Cu and Pb were virtually eliminated and some Zn, Ni and Cd were removed at low flow rates. The system was also tested at a field pilot plant constructed at Monte Romero mine (Huelva Province, SW Spain), where a 3 m3 calcite-DAS tank eliminated a median net acidity of 900 mg/L as CaCO3 at an acidity load of 600 g acidity/m2·day and an Al-load of 30 g/m2·day. However, the tank eventually clogged due to formation of an Al- and gypsum-rich hardpan within the substrate. Clogging by Al-precipitates probably could be retarded by lower Al-loads. Comparison with the laboratory columns and other publications show that acceptable Al-loads may be in the order of 5-10 g Al/m2·day. MgO-DAS laboratory columns depleted 310 mg/L Zn and 30 mg/L Mn below detection limit during over one year without clogging at a median Darcy flow rate of 0.1 m/day. In DAS containing only 12.5 % (v/v) of MgO with median particle size of 0.15 mm, 95% of the applied MgO dissolved in the zone where Zn and Mn accumulated. DAS performs better than other passive treatment systems based on gravel-sized alkaline reagents. DAS reactivity is greater than that of gravel-based treatment systems, because mixing with a coarse inert matrix allows the use of fine-grained alkaline reagents which provide a higher reactive surface. Due to their small size, the grains are dissolved before passivation. This ensures that, contrary to most gravel-based systems, most of the reactive is consumed, minimizing economic costs of passive treatment with DAS. The high acidity removal is possible because metals accumulate intentionally in DAS. Hydrolysis and precipitation release protons which promote further dissolution of reactive. The large pores of the inert DAS matrix and the dispersion (separation) of the alkaline grains minimize clogging problems. Therefore, DAS combines high reactivity, excellent metal removal, good hydraulic performance and efficient use of the alkaline reagent.