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Making ecosystem-based management operational. Deliverable 8.1, European Union’s Horizon 2020 Framework Programme for Research and Innovation grant agreement No. 642317
No full textDrinking-water access and health in refugee camps: An overview of the Saharawi case
No full textDrinking-water deprivation in terms of access, quantity and quality poses serious health hazards both in the short and long term. This is especially critical in refugee chronic situations that last for decades, such as the Saharawi refugee camps (> 40 years). Water access and water quantity improves health, as water is not only needed for direct consumption or cooking but also for hygiene, directly related to health. On the other hand, water quality avoids not only gastrointestinal diseases in the short term, but also other health issues that appear under a long term exposure. This chapter reviews the history of drinking water and health at the Saharawi refugee camps, showing how water access has improved over the years but still does not guarantee the minimum quantity of 20 l/person/day established by UNHCR. It also shows how water treatment using chlorination has reduced dramatically the diseases associated to microbiological contamination, and how the poor raw water quality that a percentage of the population is still consuming has produced long term health effects, such as the prevalence of fluorosis and goitre
Interaction between stress induced by competition, predation, and an insecticide on the response of aquatic invertebrates
No full textAssessment of the influence of key abiotic factors on the alternative microcystin degradation pathway(s) (mlr−): A detailed comparison with the mlr route (mlr+)
No full textCyanobacterial proliferation and toxin production in water bodies around the world have led to global concern about the control of these issues. Indigenous bacteria have been shown to degrade the cyanotoxin microcystin (MC) in natural environments. The mlr cluster has been widely used as a marker for microcystin biodegradation; however, recent studies have shown that alternative pathway(s) also contribute to the natural removal of MCs in the ecosystem. The main objective of this study is to provide initial insights concerning how key abiotic factors affect the rate of MC biodegradation via alternative pathway(s) and to provide a detailed comparison with the mlr+ pathway. Our results show that nutrient inputs and previous exposure to MCs trigger changes in the rate of MC degradation via alternative pathway(s), while temperature does not produce any significant change. Our results further indicate that the alternative pathway(s) may be less efficient at degrading MCs than the mlr+ pathway, suggesting the importance of microbial diversity in determining the half-life of MCs in the water column
Removal of nitrate by asymmetric capacitive deionization
No full textContamination of groundwater with nitrates is a major concern, especially for areas relying on this as a drinking water source. In this work, a capacitive deionization (CDI) system equipped with carbon electrodes coated with different metal oxides was studied to determine its ability to reduce nitrate concentrations. Results performed in a three-electrode cell were used as a proof of concept and demonstrated that coated electrodes had higher nitrate removal than that of uncoated electrodes, likely because of a reduction in hydrophobicity and an increase in surface area provided by the metal oxides. Moreover, tests using different electrolytes (NaNO3 and Ca(NO3)2) revealed similar nitrate removal values, although different electrosorption patterns were observed for Na+ and Ca2+. Furthermore, an operational mode based on a multistep approach showed that nitrates could be removed below regulatory limits while reducing the volume of waste brine. A larger, eight-cell flow CDI reactor was also tested. The results from this reactor showed that the cell potential, as well as the ion being removed from a multicomponent solution (Ca2+, Na+, Cl−, NO3−) influence electrosorption kinetics. Different adsorption mechanisms based on ion charge/size/electrode affinity are discussed, possibly leading to a methodology for preferentially removing certain ions by CDI technology
Interlaced CNT Electrodes for Bacterial Fouling Reduction of Microfiltration Membranes
No full textnterlaced carbon nanotube electrodes (ICE) were prepared by vacuum filtering a well-dispersed carbon nanotube-Nafion solution through a laser-cut acrylic stencil onto a commercial polyvinylidene fluoride (PVDF) micro filtration (MF) membrane. Dead-end filtration was carried out using 10(7) and 10(8) CFU mL(-1) Pseudomonas fluorescens to study the effects of the electrochemically active ICE on bacterial density and morphology, as well as to evaluate the bacterial fouling trend and backwash (BW) efficacy, respectively. Finally, a simplified COMSOL model of the ICE electric field was used to help elucidate the antifouling mechanism in solution. At 2 V DC and AC (total cell potential), the average bacterial log removal of the ICE-PVDF increased by similar to 1 log compared to the control PVDF (3.5-4 log). Bacterial surface density was affected by the presence and polarity of DC electric potential, being 87-90% lower on the ICE cathode and 59-93% lower on the ICE anode than that on the PVDF after filtration, and BW further reduced the density on the cathode significantly. The optimal operating conditions (2 V AC) reduced the fouling rate by 75% versus the control and achieved up to 96% fouling resistance recovery (FRR) during BW at 8 V AC using 155 mM NaCl. The antifouling performance should mainly be due to electrokinetic effects, and the electric field simulation by COMSOL model suggested electrophoresis and dielectrophoresis as likely mechanism
Drivers of change and pressures on aquatic ecosystems. ecosystems: AQUACROSS Deliverable 4.1
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A critical review on iodine presence in drinking water access at theSaharawi refugee camps (Tindouf, Algeria)
No full texttIodine content in drinking water at the Saharawi refugee camps was analysed to assess the controversy inthe origin of the prevalence of goitre among this population. A review on the iodine presence in drinkingwater reported in the literature was conducted, along with international standards and guidelines foriodine intake and iodine concentration in drinking water were also consulted. Chinese legislation wastaken as the reference standard to evaluate the iodine concentration in water as adequate (10–150 µg/L)or not (high iodine >150 µg/L and iodine excess goitre >300 µg/L). Water sampling was conducted in 2015and 2016 at the Saharawi camps (El Aiun, Awserd, Smara, Boujador and Dakhla) and at the institutionalcapital of Rabouni. The water supply in the camps is organized in three zones: El Aiun and Awserd whereeach ‘wilaya’ receives treated water 20 days and raw water another 20 days; Smara, Rabouni and Boujadorreceiving treated water continuously and Dakhla receiving raw water continuously. Results show thatSmara, Rabouni and Boujador have access to drinking water with adequate iodine levels, as it occursin Dakhla where raw water meets the Chinese standard, however in El Aiun and Awserd all populationshould have access to treated water given the current quality of the raw water supply. External supplies ofwater and animal milk could be also contributing to the high iodine intake. In conclusion, the contributionof drinking water as the main source of iodine to the urinary iodine concentration (UIC) and goitreprevalence among the Saharawi refugee population is not clear. Further studies should be conducted toassess the iodine content among all the nutritional sources of the population with a detailed study onthe daily intake of these foods and drinks, including UIC and goitre prevalence studies
