Cristina Domenech

University of Barcelona | UB

Agricultural run‐off exposes recipient water bodies to nitrate (NO3⁻) pollution. Biological denitrification is a suitable method for removing NO3⁻ in water resources that can be induced by the use of industrial organic liquid waste as an electron donor source. In light of this, batch and column laboratory experiments were performed to assess the po...

Nitrite reduction has often been treated as a biotic process in water treatment systems, but it also occurs abiotically, and it is difficult to distinguish both reactions as they can co-occur at field-scale. The potential reduction of NO2- was tested in 3 anaerobic experimental scenarios using a NO2- bearing solution amended with: i) siderite (FeCO...

Ni and Co have been listed as critical energy metals for a sustainable economic development by several government agencies. Ni-Co laterite deposits are among the first resources of both metals in the world. The correct identification of Ni-and Co-bearing mineral phases is essential to increase the efficiency of extraction of both metals in these de...

Moa Bay is a world-class Ni laterite mining district with reserve estimates of 53.4 Mt at 1.16 % grade Ni. The vast majority of the deposits belong to the oxide type, and are mined for their Ni-bearing Fe-oxyhydroxides in the oxide zone. One exception is Yamanigüey which can be classified as a hydrous Mg silicate Ni-laterite deposit. The study of a...

Nitrate (NO3-) is one of the most common water pollutants. Extensive application of synthetic and organic fertilizers linked to agriculture is a major source of NO3-pollution. Constructed wetlands (CWs) are considered promising, low low-cost, and easy operation systems to remove NO3- from agricultural runoff. Main processes that might contribute to...

Two different types of industrial wine residues were used to remediate nitrate-contaminated water. Additionally, geochemical modelling was used to investigate the long-term behaviour of nitrate and nitrite.

The sudden shift during the COVID-19 lockdown from face-to-face to online teaching clearly impacted degree programmes in Geology characterized by a substantial practical teaching methodology. This study analyses the suitability of online teaching in the degree at Geology of the University of Barcelona by: (a) describing the strengths, weaknesses, o...

Soil Aquifer Treatment (SAT) is used to increase groundwater resources and enhance the water quality of wastewater treatment plant (WWTP) effluents. The resulting water quality needs to be assessed. In this study, we investigate attenuation pathways of nitrogen (N) compounds (predominantly NH4⁺) from a secondary treatment effluent in pilot SAT syst...

Platinum-group elements (PGEs) occur in ophiolitic chromitite in the Dominican Republic as platinum-group minerals (PGMs) in spatial association with hydrothermal uvarovite and chromian clinochlore. Bulk-rock total PGE content in a single analyzed chromitite sample is of 6.54 g/t. Three main PGM types are distinguished: euhedral magmatic laurite co...

Cobalt demand is increasing due to its key role in the transition to clean energies. Although the main Co ores are the sediment-hosted stratiform copper deposits of the Democratic Republic of the Congo, Co is also a by-product of Ni–Co laterite deposits, where Co extraction efficiency depends, among other factors, on the correct identification of C...

In this study we tested the dissolution kinetics of three garnierite types (serpentine-, talc- and sepiolite-dominated) at pH of 3 and 5 and room temperature by means of flow-through experiments. The samples selected for the study cover a wide range of mineralogical composition (Xtalc, between 0.34 and 0.78) and Ni content (between 0.8 and 2.4 atom...

The mineralogy and mineral chemistry of REE phosphates and REE carbonates has been investigated in three localities of the Bahoruco karst bauxites, Dominican Republic, by means of powder X-ray diffraction (XRD), petrographic microscopy, scanning electron microscopy (SEM-EDS) and electron microprobe (EMP). The identified REE minerals include primary...

Soil Aquifer Treatment (SAT) is used to increase groundwater resources and enhance the water quality of wastewater treatment plant (WWTP) effluents. The resulting water quality needs to be assessed. In this study, we investigate attenuation pathways of nitrogen (N) compounds (predominantly NH4+) from a secondary treatment effluent in pilot SAT syst...

Although experimental work predicts that platinum-group elements (PGE) are soluble in hydrothermal fluids at temperatures <500 ºC during serpentinization in ophiolite complexes, mineralization-mechanisms driving to the formation of hydrothermal epigenetic PGE mineralizations are still poorly understood. In this communication we describe hydrotherma...

This study presents a multi-disciplinary approach for the hydrogeological assessment and characterization of water resources in typical arid and semi-arid areas with high anthropogenic pressure, and where environmental conditions and political context prevent extensive field surveys. The use of a three-dimensional (3D) hydrogeological conceptual mo...

Nickel laterite deposits developed on ultramafic rocks have traditionally been a significant source of Ni and Co and recently of Sc. Although the Loma de Hierro deposit (Venezuela) has been in operation for more than 50 years, it lacks detailed studies on the mineralogical and geochemical composition of the lateritic profile. In this study, we pres...

Iron cycling in groundwater is mediated by both biotic and abiotic processes which affect the fate of groundwater contaminants. Biotic Fe(II) oxidation occurs mainly by nitrate-reducing Fe(II) oxidation (NRFO) bacteria in an anoxic condition. There is the concurrence of biotic-abiotic processes during NRFO and the more reactive NO2- is used as the...

In the Main Ethiopian Rift Valley (MER) high levels of fluoride (F-) in drinking water supply, commonly associated to the geologic substratum, are recognized as one of the major public health problems in most rural villages, where the majority of population exhibit various degrees of fluorosis symptoms. To better define the origin and dynamic of th...

The effects of contaminant sources removal in 2005 (i.e. barrels, tank, pit and wastewater pipe sources) on carbon tetrachloride (CT) and chloroform (CF) concentration in groundwater were assessed at several areas of a fractured multi-contaminant aquifer (Òdena, Spain) over a long-term period (2010–2014). Changes in redox conditions, in these chlor...

A dual element CCl isotopic study was performed for assessing chlorinated methanes (CMs) abiotic transformation reactions mediated by iron minerals and Fe(0) to further distinguish them in natural attenuation monitoring or when applying remediation strategies in polluted sites. Isotope fractionation was investigated during carbon tetrachloride (CT)...

Managed aquifer recharge (MAR) is a well-known technique for improving water quality and increasing groundwater resources. Denitrification (i.e. removal of nitrate) can be enhanced during MAR by coupling an artificial recharge pond with a permeable reactive layer (PRL). In this study, we examined the suitability of a multi-isotope approach for asse...

Field-derived anoxic microcosms were used to characterize chloroform (CF) and carbon tetrachloride (CT) natural attenuation to compare it with biostimulation scenarios in which vitamin B12 was added (B12/pollutant ratio of 0.01 and 0.1) by means of by-products, carbon and chlorine compound-specific stable-isotope analysis, and the active microbial...

Fe–Ni-bearing serpentine from the saprolite horizon is the main Ni ores in hydrous silicate-type Ni laterites and formed by chemical weathering of partially serpentinized ultramafic rocks under tropical conditions. During lateritization, Mg, Si, and Ni are leached from the surface and transported downwards. Fe2+ is oxidized to Fe3+ and fixed as ins...

Oxide-type Ni-laterite deposits are characterized by a dominant limonite zone with goethite as the economically most important Ni ore mineral and a thin zone of hydrous Mg silicate-rich saprolite beneath the magnesium discontinuity. Fe, less soluble, is mainly retained forming goethite, while Ni is redeposited at greater depth in a Fe(III) and Ni-r...

Hydrous Mg silicate-type Ni-laterite deposits, like those in the Falcondo district, Dominican Republic, are dominated by Ni-enriched serpentine and garnierite. Recently, abundant Ni-smectite in the saprolite zone have been discovered in Loma Ortega, one of the nine Ni-laterite deposits in Falcondo. A first detailed study on these Ni-smectites has b...

To use compound-specific isotope analysis for confidently assessing organic contaminant attenuation in the environment, isotope fractionation patterns associated with different transformation mechanisms must first be explored in laboratory experiments. To deliver this information for the common groundwater contaminant chloroform (CF), this study in...

For two decades the nature of Fe-rich, oxygen-bearing, Ru–Os compounds found in the supergene environment has been debated. Ru–Os–Fe-oxides and nano-intergrowths of ruthenium with magnetite have been proposed. We applied FE-SEM, EMPA, μ-Raman spectroscopy and synchrotron tts- μXRD to Ru–Os–Fe compounds recovered from Ni-laterites from the Dominican...

Compound-specific chlorine isotope analysis of tetrachloromethane (CCl4) and trichloromethane (CHCl3) was explored by both, gas chromatography - isotope ratio mass spectrometry (GC-IRMS) and GC - quadrupole MS (GC-qMS), where GC-qMS was validated in an interlaboratory comparison between Munich and Neuchâtel with the same type of commercial GC-qMS i...

Anaerobic batch and flow-through experiments were performed to assess the capacity of two organic substrates to promote denitrification of nitrate-contaminated groundwater within managed artificial recharge systems (MAR) in arid or semi-arid regions. Denitrification in MAR systems can be achieved through artificial recharge ponds coupled with a per...

Management concern of the wastes generated during the production of sulphuric acid by pyrite roasting was low or nonexistent during the second half of the twentieth century in Spain. An on-site remediation work has been performed to stabilize about 15,000 m³ of ashes produced after the roasting of pyrites that have been identified as a source of ac...

Nitrate pollution is a widespread issue affecting global water resources with significant economic and health effects. Knowledge of both the corresponding pollution sources and of processes naturally attenuating them is thus of crucial importance in assessing water management policies and the impact of anthropogenic activities. In this study, an ap...

Contamination from agricultural sources and, in particular, nitrate pollution, is one of the main concerns in groundwater management. However, this type of pollution entails the entrance of other substances into the aquifer, as well as it may promote other processes. In this study, we deal with hydrochemical and isotopic analysis of groundwater sam...

In this study,concentration and δ13C and δ37Cl values of chloroform (CF) and carbon tetrachloride (CT) measured in groundwater samples are related to redox conditions to elucidate natural attenuation processes in a polluted site. Shifts in δ13C and δ37Cl of CF and CT were detected over time.δ13CCF values found in the potential sources were -34.5 ±...

The main Ni ores in hydrous silicate type Ni-laterites are Fe-Ni-bearing serpentines from the saprolite horizon, which are formed by weathering of partially serpentinised ultramafic rocks under tropical conditions. This serpentine (namely serpentine I) is of hydrothermal origin and yields similar Ni and lower Fe than the primary olivine. It has an...

Radionuclide retardation processes during transport are expected to play an important role in the safety assessment of subsurface disposal facilities for radioactive waste. The linear distribution coefficient (Kd) is often used to represent radionuclide retention, because analytical solutions to the classic advection–diffusion-retardation equation...

Cerro de Maimón, in the central Dominican Republic, is currently the only VMS deposit under production in the Caribbean region. It is hosted in the Maimón Formation, of early Cretaceous age, which is part of the oldest and chemically most primitive island-arc in the Caribbean. From bottom to top, this deposit can be divided into (i) a primary sulfi...

Experiments on the dissolution kinetics of natural pyrrhotite (FeS1-x-) and pyrite (FeS2) under imposed redox conditions to evaluate the oxygen uptake capacity of both minerals were carried out at 25°C and 1 bar. Experimental data indicate that in both cases, Fe(II) released from dissolution of these Fe-bearing sulphides is kinetically oxidized to...

The evaluation of the redox conditions in an intermediate and low level radioactive waste repository such as SFR1 (Sweden) is of high relevance in the assessment of its future performance. The SFR1 repository contains heterogeneous types of wastes, of different activity levels and with very different materials, both in the waste itself and as immob...

Significant shifts in isotopic composition of tetrachloroethene (PCE), trichloroethene (TCE), chloroform (CF) and carbon tetrachloride (CT)coupled with long-term concentration and geochemical data revealed the occurrence of natural attenuation processesin a fractured bedrock aquifer heavily polluted with a complex mixture of volatile organic compou...

Granular activated carbon (GAC) is commonly used as adsorbent in water treatment plants given its high capacity for retaining organic pollutants in aqueous phase. The current knowledge on GAC behaviour is essentially empirical, and no quantitative description of the chemical relationships between GAC surface groups and pollutants has been proposed....

It is widely recognised that distribution coefficient (K d) values generally have a narrow field of validity, and that the uncertainty of the K d outside this field increases significantly. The work performed by Amphos 21 in the framework of WP4 of the CROCK project has focused on finding a reliable and easy approach to minimise the uncertainty of...

The evaluation of the redox conditions in the Swedish ILW-LLW repository, SFR-1, is of high relevance in the performance assessment. The SFR-1 repository contains heterogeneous types of wastes, of different activity levels and with different materials in the waste and in the matrices and packaging. Steel and concrete-based materials are ubiquitous...