Isabel Martín

Study of the distribution of 204 organic contaminants between the aqueous phase and the suspended particulate matter in treated wastewater for proper environmental control

Abstract A distribution study of 204 organic contaminants, including polar and nonpolar pesticides, polycyclic aromatic hydrocarbons (PAHs), and phenolic compounds, between the two phases composing municipal wastewater (WW) from a small community (aqueous phase and suspended particulate matter (SPM)) has been performed to establish whether the compounds can be more prone to be in the aqueous or in the solid phase, depending on their hydrophobicity. Therefore, a general procedure is proposed to evaluate this issue. This study shows that nonpolar pesticides and PAHs are distributed between the aqueous phase and the SPM (e.g. pyrethroids are mainly found in the SPM), whereas polar pesticides and phenolic compounds are mainly present in the aqueous phase. This fact made clear the relevance of the analysis of both phases in WW samples, bearing in mind that if SPM is discarded, an important fraction of some contaminants is not determined and therefore, it does not assess the total load of pollutants discharged,...

Removal of emerging organic contaminants in a poplar vegetation filter

Vegetation filters (VFs), a type of land application system, are a robust technology based on natural treatment mechanisms for the removal of wastewater contaminants. Their capacity to attenuate emerging organic contaminants (EOCs) has not yet been evaluated. The present study reports the results of a 2-year EOC monitoring carried out using a poplar VF receiving wastewater primarily treated by an Imhoff tank. The compounds selected included analgesics, a β-adrenergic blocker, stimulants, an anticonvulsant, an anti-depressant, an anti-inflammatory, an antibiotic and analgesic and stimulant metabolites. EOCs were analysed in the Imhoff tank effluent, in the infiltrated water at a depth of 90cm and in the groundwater at a depth of 10m. The results demonstrated that EOC attenuation was more significant in the first 90cm than in the rest of the soil profile. The removal efficiency for all of the selected EOCs was higher than 90% with the exception of ketoprofen, which may pose a higher threat of groundwater contamination. The observed attenuation correlated with the hydrophobicity and charge state of the EOCs. The higher persistence of the metabolites 4-AAA and 4-FAA shows that progression in the degradation pathway does not always imply a mitigation of contamination.

Sustainable water reuse. The case of rural areas and small settlements

The GtoG project is working for creating a recycling culture of gypsum products, changing the way this waste is usually treated in construction, renovation and demolition works, with the aim of achieving higher gypsum recycling rates in Europe and promoting selective deconstruction practices. For this purpose and under the leadership of Eurogypsum (the European Plaster and Plasterboard Manufacturers Association) five demolition companies, one demolition consultant, two gypsum waste processors, five plasterboard manufacturers and three academic partners, from 7 European countries, work together constituting the project consortium. A preliminary study on current practices was completed in 2013. Subsequently in 2014, a set of demonstration activities on deconstruction, processing of gypsum waste and reincorporation of recycled gypsum were conducted. Finally, during this year 2015, different results have been delivered, such as the European Handbook of best practices for controlled deconstruction of gypsum systems and the Report on best practice indicators for deconstruction, recycling and reincorporation practices. The final results will include an Inventory of best practices and the Roadmap for the future implementation of a sustainable value chain.T Film Composite polyamide membranes have been worldwide used in desalination andwater recycling plants. However, once their lifespan is exhausted they are often disposed into the landfills which are the last priority according to the main pyramidal waste management principlesof the European Directive 2008/98/EC on waste (prevention, preparing for reuse, recycling, recovery and disposal). The present study, as part of the LIFE+ ENV/ES/000751TRANSFOMEM European project, investigates the transformation of end-of-life membranesthat were treating brackish water or seawater to be recycled as nanofiltration (NF) and ultrafiltration (UF) membranes. Such process is a simple, low energy, surface modification technique based on polyamide chemical attack by free chlorine. The ppm-h concept it was evaluated which implies different exposure times of end-of-life membranes at diverseconcentrations of sodium hypochlorite (NaOCl) solutions. All the transformation experimentswere carried out at alkaline conditions (pH>10) at room temperature and without stirring. Two different exposure doses were set in order to obtain nanofiltration and ultrafiltration membrane performances. The membrane performances were evaluated filtering synthetic brackish water containing NaCl, MgSO4 and dextrose. The surface properties of the transformed membranes were also analyzed by scanning electron microscopy (SEM) and attenuated total reflection-Fourier Transform Infrared (ATR-FTIR). Results showed that ppm-h concept is not valid for allcases.T simultaneous aerobic removal of a mixture of BTEX (benzene, toluene, ethyl benzene, o,m,p-xylene), cisdichloroethylene (cis-DCE) and trichloroethylene (TCE) from the artificially contaminated water using an indigenous bacterial isolate identified as Pseudomonas plecoglossicida immobilized on waste scrap tires was investigated. Suspended and immobilized conditions were compared for the enhanced removal of these volatile organic compounds. For the immobilized system, toluene, benzene and ethylbenzene were completely removed while the highest removal efficiencies of 99.0±0.1%, 96.8±0.3%, 73.6±2.5%, and 61.6±0.9% were obtained for o-xylene,m,p-xylene, TCE and cis-DCE respectively. The sorption kinetics of contaminants toward tire surface was also evaluated and the sorption capacity generally followed the order of toluene> benzene> m,p-xylene> o-xylene> ethylbenzene> TCE> cisDCE. Scrap tires showed a good capability for the simultaneous sorption and bioremoval of BTEX/cis-DCE/TCE mixture implying a promising waste material for the removal of contaminants mixture from industrial wastewater or contaminated groundwater.T is continued pressure on chemical and pharmaceutical industries to reduce chemical waste and improve the selectivity and efficiency of synthetic processes. The need to implement green chemistry principles is a driving force towards the development of recoverable and recyclable catalysts. A typical chemical process generates products and wastes from raw materials such as substrates, solvents and reagents. The prevention of waste can be achieved if most of the reagents and the solvent are recyclable. The design and synthesis of recoverable catalysts is a highly challenging interdisciplinary field combining chemistry, materials science engineering with economic and environmental objectives. Recyclability can either be achieved when the catalyst is bound to a solid phase, or when its solubility characteristics are modified so that it can readily be separated from the product by extraction during work-up. For example, catalysts and reagents such as acids and bases that are bound to a solid phase can be filtered off, and can be regenerated and reused in a subsequent run. Case studies concerning the recoverable and recyclable catalysts for chemical processes like oxidation of alcohols and ketones, alkylation of aromatic compounds and Diels-Alder reaction will be presented. The main emphasis will be placed on the application of ionic liquids as both homogeneous and heterogeneous catalysts. Recycling of ionic liquids prevents them from ending up in the aquatic environment, as their low volatility prevents them from release into the atmosphere. Additionally the possibility of designing of recyclable biocatalysts will be demonstrating.M studies have been focusing on the production of microbial lipid to generate biodiesel from sterile wastewater while removing part of organic matters. Our previous study showed that lipids could be produced from non-sterile distillery wastewater using the increased initial cell density of oleaginous yeast Rhodosporidium toruloides while generating lots of spent seed culture medium. This study explores the reuse potential of spent seed culture medium while saving resource and cost. When the medium was used for the 2nd and 3rd times without addition of extra nutrient, the biomass produced was around 3.17 and 2.65 g/L respectively. The cells produced in the 2nd time reused medium without extra nutrient showed similar performance to the fresh mediumin lipid production (biomass 7.42±0.31 g/L, lipid yield 2.74±0.42 g/L and lipid content 36.90±4.36%) and removal efficiencies for organics and nutrients (chemical oxygen demand, total nitrogen and total phosphorus removal of 86.47±1.40%, 50.73±6.15% and 74.36±3.39% respectively) in non-sterile distillery and domestic mixed wastewater (1:1, v/v) after two-day cultivation. Around 30% reduction in the material cost for the medium preparation could be achieved by the spent medium reuse.

Nematodes as a factor for consideration in the wastewater treatment and water reuse process

AbstractNematodes play an important role in wastewater treatment systems by contributing to removal the biochemical oxygen demand concentration or fecal bacteria. The nematodes removal can be used to evaluate the degree of efficiency of wastewater treatment systems. For water reuse, current regulations set the criteria for biological quality that pose a risk to public health (E. coli, intestinal nematodes eggs, Legionella spp., etc.), regardless the control of certain organisms, such as plant-parasitic nematodes, that can cause diseases in crops and great economic losses in the agricultural sector. This study considers the effectiveness of the removal of total nematodes as method of measuring the efficiency of wastewater treatment systems. Additionally, the presence of plant-parasitic nematodes will be studied in the frame of water reuse. Finally, the biochemical oxygen demand, chemical oxygen demand, and total suspended solids were analyzed in order to evaluate the performance of treatment systems. It wa...

Conceptual Frame on Technological Perspective for Water Resources Management in the Mediterranean Region

The availability of fresh water supplies in most of the Mediterranean countries is falling short to meet the growing demand. This situation often creates conflicts among the various sectors and places much more pressure on the natural and ecosystems supporting such resources. Therefore, the challenge of water use and allocation is already a major political concern in the Basin and will most likely amplify in the coming years.