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The occurrence of emerging micropollutants (pharmaceuticals, pesticides, personal care products, industrial compounds, etc.) in the environment is considered a major threat to human health and aquatic ecosystems. These micropollutants enter the environment through anthropogenic actions and have been identified in surface, ground, waste, and even in drinking water, in quantities ranging from ng L−1 to µg L−1. Currently, the pollution of the global water cycle with persistent organic pollutants remains one of the major challenges of the twenty-first century. Most of these organic substances are only partially removed by conventional wastewater treatment plants. Particularly, considerable amounts of pharmaceuticals are used in human and veterinary medicine, which are not efficiently removed during conventional wastewater treatments and subsequently continuously enter freshwater systems and even agricultural crops. Accordingly, we have evaluated the effectivity of TiO2 as a photocatalyst in tandem with Na2S2O8 as an oxidant for the treatment of a wastewater effluent polluted with pharmaceutical (atenolol, carbamazepine, clarithromycin, erythromycin, irbesartan, and ketoprofen) residues. Results show that the use of solar heterogeneous photocatalysis by means of band-gap semiconductor materials, especially TiO2 in combination with a strong oxidant such as Na2S2O8, significantly enhances their disappearance from the wastewater effluent. However, the selected pharmaceuticals show a slow degradation in wastewater effluent compared to pure water indicating that the occurrence of dissolved salts and organic carbon in wastewater effluent noticeably slows down the efficiency of the treatment. A single first-order model satisfactorily explains the photocatalytic degradation of the compounds studied for both, pure and wastewater. In the case of wastewater effluent, the highest DT50 values were observed for macrolides (13 and 16 min for erythromycin and clarithromycin, respectively), while the other compounds studied showed DT50 values below 10 min. This methodology has a notorious interest in some areas of the Mediterranean basin with water shortage, such as SE of Spain, where more than 3000 h of sunlight per year are recovered. [ABSTRACT FROM AUTHOR]

Reusing reclaimed water for crop irrigation can mitigate water scarcity in agriculture; however, contaminants such as pharmaceuticals and pesticides in wastewater pose risks. This study investigated the impact of a coupled bio-solar photocatalytic treatment on the reclamation of water polluted with seven pharmaceuticals and seven pesticides for irrigation of two tomato crop cycles. Pollutant residues were removed using natural sunlight and TiO 2 /Na 2 S 2 O 8 in a pilot plant located in Murcia, Spain. Efficient removal (> 96 %) of all target pollutants was achieved in the effluent after coupled treatment. Reclaimed water was then used to irrigate the tomato crops, and several yield and quality parameters were analysed to evaluate the effects on the harvested tomatoes. No significant differences were observed in the total yield, number and mean fruit weight, size, pericarp firmness, external colour, and nutritional data between the crops irrigated with reclaimed, control, and polluted water. However, differences in the degree of ripeness were observed. None of the investigated pollutants was detected above the limit of quantification in tomato samples irrigated with reclaimed water, except for venlafaxine (0.028 µg kg -1 ) in the second crop cycle. When the crop was irrigated with polluted water, different pollutant residues were detected in soil (10) and tomato (4) samples. The results suggest that coupled bio-solar photocatalytic treatment is an effective method for reclaiming water polluted with pharmaceutical and pesticide residues, and the reclaimed water can be safely used for tomato irrigation without compromising crop yield and quality., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

The author comments on the potential of advanced technological innovations in the sustainable treatment and reuse of water resources in Spain. The topics discussed include the three technological methods in achieving sustainable drinking water and wastewater treatment, the challenges encountered by the government in securing quality and adequate water resources and the technologies used in decreasing the consumption of energy.

The system ozone and hydrogen peroxide was used to reclaim wastewater from the secondary clarifier from a Sewage Treatment Plant (STP) of Alcalá de Henares (Madrid-Spain). The assays were performed by bubbling a gas mixture of oxygen and ozone, with ∼24 g Nm-3 of ozone concentration, through a volume of wastewater samples for 20 minutes at 25°C . The removal of dissolved micropollutants such as Pharmaceutical and Personal Care Products (PPCPs) and Organic Carbon (TOC) was enhanced by adding periodic pulses of hydrogen peroxide while keeping pH above 8.0 throughout the runs. Removal efficiency ratios in the range of 7-26 mg O3/mg TOC and 0.24 mg O3/ng micropollutants at 5 minutes of ozonation were assessed as reference data to reclaim wastewater from STP. The relation between the extent of TOC removed and ozone doses used was related by a second-order kinetic model in which the time-integrated ozone-hydrogen peroxide concentration was included. [ABSTRACT FROM AUTHOR]

This study analyzes the performances of 2 methods of oxidation based on ozone, namely ozonation and ozone combined with hydrogen peroxide (O3/H2O2), on two biotreated municipal wastewater effluents. The main parameters monitored to evaluate the effectiveness of the processes were Chemical Oxygen Demand (COD), Dissolved Organic Carbon (DOC) and Biochemical Oxygen Demand (BOD5). Ozonation and O3/H2O2 treatment removed 44% and 48%, respectively, of the COD, after 90 min, of the secondary effluent of Calafell wastewater treatment plant (Spain). On the secondary effluent from the Grasse wastewater treatment plant (France), these same treatments (O3; O3/H2O2) achieved, respectively, a degradation of 52% and 100% of the COD after 60 min. The transferred ozone dose (TOD) during Calafell and Grasse effluents' ozonation were 122 mg·L-1 and 77 mg·L-1 after 90 min, respectively. A low removal of DOC was monitored during both O3 or O3/H2O2 treatments applied to Calafell wastewater, respectively 12% and 14%. Better DOC reductions were obtained on the water of Grasse treated with O3 or O3/H2O2, respectively, 48% and 60%. In addition, ammonia nitrogen was oxidized to nitrate nitrogen thus giving rise to an over ozone consumption. And finally, both processes proceeded with an increase of pH values. These results highlight the strong dependency of O3 or O3/H2O2 treatment effectiveness in terms of dissolved organic matter (DOM) removal and ozone consumption on wastewater composition (organic and inorganic substances). [ABSTRACT FROM AUTHOR]

Abstract: Landfill, a matured and economically appealing technology, is the ultimate approach for the management of municipal solid wastes. However, the inevitable generation of leachate from landfill requires further treatment. Among the various leachate treatment technologies available, advanced oxidation processes (AOPs) are among powerful methods to deal with the refractory organic constituents, and the Fenton reagent has evolved as one promising AOPs for the treatment of leachates. Particularly, the combination of UV-radiation with Fenton''s reagent has been reported to be a method that allows both the photo-regeneration of Fe2+ and photo-decarboxylation of ferric carboxylates. In this study, Fenton and photo-Fenton processes were fine tuned for the treatment of leachates from the Colmenar Viejo (Madrid, Spain) Landfill. Results showed that it is possible to define a set of conditions under which the same COD and TOC removals (≈70%) could be achieved with both the conventional and photo-Fenton processes. But Fenton process generated an important quantity of iron sludge, which will require further disposal, when performed under optimal COD removal conditions. Furthermore conventional Fenton process was able to achieve slightly over an 80% COD removal from a “young” leachate, while for “old” and ”mixed” leachates was close to a 70%. The main advantage showed by the photo-assisted Fenton treatment of landfill leachate was that it consumed 32 times less iron and produced 25 times less sludge volume yielding the same COD removal results than a conventional Fenton treatment. [Copyright &y& Elsevier]

The increasing occurrence of cyanobacterial blooms worldwide represents an important threat for both the environment and public health. In this context, the development of risk analysis and management tools as well as sustainable and cost-effective treatment processes is essential. The research project TALGENTOX, funded by the Ibero-American Science and Technology Program for Development (CYTED-2019), aims to address this ambitious challenge in countries with different environmental and social conditions within the Ibero-American context. It is based on a multidisciplinary approach that combines ecology, water management and technology fields, and includes research groups from Chile, Colombia, Mexico, Peru and Spain. In this review, the occurrence of toxic cyanobacteria and cyanotoxins in freshwaters from these countries are summarized. The presence of cyanotoxins has been confirmed in all countries but the information is still scarce and further monitoring is required. In this regard, remote sensing or metagenomics are good alternatives at reasonable cost. The risk management of freshwaters from those countries considering the most frequent uses (consumption and recreation) has been also evaluated. Only Spain and Peru include cyanotoxins in its drinking water legislation (only MC-LR) and thus, there is a need for regulatory improvements. The development of preventive strategies like diminishing nutrient loads to aquatic systems is also required. In the same line, corrective measures are urgently needed especially in drinking waters. Advanced Oxidation Processes (AOPs) have the potential to play a major role in this scenario as they are effective for the elimination of most cyanotoxins classes. The research on the field of AOPs is herein summarized considering the cost-effectiveness, environmental character and technical applicability of such technologies. Fenton-based processes and photocatalysis using solar irradiation or LED light represent very promising alternatives given their high cost-efficiency. Further research should focus on developing stable long-term operation systems, addressing their scale-up., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Physicochemical characterization of olive mill wastewaters (OMW) was studied after a primary and secondary treatment was implemented in an olive oil factory in Jaén (Spain), comprising natural precipitation, Fenton-like reaction, flocculation-sedimentation and olive stone filtration in series. The application of membrane technology in improving the quality of the secondary-treated OMW (OMW/ST) was examined, to reduce the hazardous electroconductivity (EC) values (2-3 mS cm(-1)). Particle size distribution on OMW/ST shows supra-micron colloids and suspended solids as well as sub-micron particles with a mean size below 1.5 μm remaining in considerable concentration. The high organic pollutants percentage (31.7%) registered with an average diameter below 3 kDa is sensibly relevant for membrane fouling. Mesophilic aerobic bacteria growth warns of possible membrane biofouling formation. The saturation index indicates to work upon recovery factor below 90%. Finally, operating at a pressure equal to 15 bar ensured low fouling and high flux production on the selected NF membrane (69.9 L h(-1)m(-2)) and significant rejection efficiencies (55.5% and 88.5% for EC and COD). This permits obtaining an effluent with good quality according to the recommendations of the Food and Agricultural Association (FAO) with the goal of reusing the regenerated water for irrigation., (Copyright © 2014 Elsevier B.V. All rights reserved.)