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The potential of constructed wetlands (CWs) as a low technology for wastewater treatment is timely but there is a need to understand the route of pathogenic bacteria (Listeria monocytogenes and Salmonella spp.) and indicator organisms (Enterobacteriaceae and Escherichia coli) present in wastewater within those systems and to what extent they can compromise the further use of the plants (enabling in-house ornamental use) and water reuse (irrigation purposes). In the present study the fate of potential pathogenic bacteria within a CW, with ornamental plants, and an outlet pond established in a tourism house for wastewater treatment was assessed. The fate of pathogenic bacteria in lettuce, both plant tissues and soil, subject to irrigation with water contaminated either with L. monocytogenes or E. coli (indicator organism) was investigated. The uptake of indicator organisms by the CW ornamental plants was low and there was a decrease, from the CW wastewater inlet to the outlet, of up to 3 log for Enterobacteriaceae and up to 2 log for E. coli. Concerning Salmonella spp. no detection was registered in the water, plant tissues or substrate within the CW. On the other hand, several L. monocytogenes isolates were retrieved from water, root and substrate samples, found to have a high susceptibility to a battery of antibiotics. The irrigation of lettuce with water containing pathogenic bacteria (L. monocytogenes) and indicator organisms (E. coli) must be considered with caution since both bacteria were detected in the soil growing media and internalization of L. monocytogenes in roots was observed. These issues are poorly investigated and to our knowledge not addressed in the sphere of CWs. © 2017 Elsevier C.S.C. Calheiros (SFRH/BPD/63204/2009 and SFRH/BPD/109711/2015), V. Ferreira (SFRH/BPD/72617/2010) and R. Magalh?es (SFRH/BD/71704/2010) thank the grants from Funda??o para a Ci?ncia e Tecnologia (FCT, Portugal), Fundo Social Europeu and Fundos Nacionais do MEC through the program QREN ? POPH ? Tipologia 4.1?Forma??o Avan?ada. This work was supported by National Funds from FCT ? Funda??o para a Ci?ncia e a Tecnologia through project UID/Multi/50016/2013. The authors are thankful for the collaboration of Pa?o de Calheiros.

Wastewater reclamation contributes to the preservation of conventional water resources and thus helps to ensure appropriate human development for future generations. Wastewater reclamation can be achieved through several technologies. One of the most common technologies is the tertiary treatment of urban municipal wastewater, which is often based on membrane technologies. Reverse osmosis is an effective separation technology for removing dissolved salts and low molecular weight organic compounds. However, membranes suffer from fouling, which directly reduces technical, environmental and economic feasibility of the process and hence of the reclamation plant. One of the strategies helpful to reduce fouling is the optimisation of the membranes’ cleaning and maintenance. The aim of this work is to test the impact of the membrane cleaning protocol design on the recovery of the original properties of a reverse osmosis membrane used for several years in a wastewater reclamation plant in Spain. Furthermore, the work is focused on the validation of the adequacy of the most-common indicators used for assessing membranes’ cleaning efficiency.

This study explores the capability of Sulfate Radical-based Advanced Oxidation Processes (SR-AOPs) for the simultaneous disinfection and decontamination of urban wastewater. Sulfate and hydroxyl radicals in solution were generated activating peroxymonosulfate (PMS) under UV-C irradiation at pilot plant scale. The efficiency of the process was assessed toward the removal of three CECs (Trimethoprim (TMP), Sulfamethoxazole (SMX), and Diclofenac (DCF)) and three bacteria (Escherichia coli, Enterococcus spp., and Pseudomonas spp.) in actual urban wastewater (UWW), obtaining the optimal value of PMS at 0.5 mmol/L. Under such experimental conditions, bacterial concentration ≤ 10 CFU/100 mL was reached after 15 min of UV-C treatment (0.03 kJ/L of accumulative UV-C radiation) for natural occurring bacteria, no bacterial regrowth was observed after 24 and 48 h, and 80% removal of total CECs was achieved after 12 min (0.03 kJ/L), with a release of sulfate ions far from the limit established in wastewater discharge. Moreover, the inactivation of Ampicillin (AMP), Ciprofloxacin (CPX), and Trimethoprim (TMP) antibiotic-resistant bacteria (ARB) and reduction of target genes (ARGs) were successfully achieved. Finally, a harmful effect toward the receiving aquatic environment was not observed according to Aliivibrio fischeri toxicity tests, while a slightly toxic effect toward plant growth (phytotoxicity tests) was detected. As a conclusion, a cost analysis demonstrated that the process could be feasible and a promising alternative to successfully address wastewater reuse challenges.

[EN] This revision work focuses on the recent advances in the separation of microcontaminants from urban wastewaters, using ultrafiltration and Nanofiltration membranes. Conventional systems show advantages such as low pressure and fouling, competitive energetic- and maintenance costs compared to reverse osmosis, and higher rejection rates of organic microcontaminants compared to membrane distillation. However, these rejection rates strongly depend on temperature, flow, and pressure, as well as surface charge and concentration, challenging the adequate treatment of more complex matrices. Recent advances in material science strongly improved the implementation possibilities of different membrane types. In conventional industrial processes and especially in wastewater treatment, offering not only cost reducing solutions for urban wastewaters, but also more efficiency for the remediation of a high variety of industrial wastewaters. Moreover, membrane separation systems show great potential and applicability for added value substance recovery from wastewaters for the agricultural, chemical and consumer industry, for more sustainable natural resources use. Finally, perspectives on promising technologies for the implementation and combination of different membrane separation methods in treatment trains, such as advanced oxidation processes, are given, also aiming for zero-liquid discharge, to prevent microcontaminants and valuable resources from passing through conventional methods and focusing on closing the water cycle., This paper is part of a project that has received funding from the European Union's Horizon 2020 research and innovation program under the Marie Sk¿odowska-Curie grant agreement No 765860. The authors wish to thank the Spanish Ministry of Science, Innovation and Universities (MCIU), AEI and FEDER for funding under the CalypSol Project (Reference: RTI2018-097997-B-C32 and RTI2018-097997-B-C31). Furthermore, Dennis Deemter would like to give his thanks to the personnel at the Plataforma Solar de Almería.