The aim of this study is to compare the removal of organic micropollutants (OMPs) in wastewater by activated sludge (AS) and constructed wetlands (CWs). This analysis was carried out in a wastewater treatment plant (WWTP) of a rural community where they implemented two technologies in parallel: AS and a pilot plant of horizontal subsurface flow (HSSF) constructed wetlands. In this case, these systems were fed by the same influent and the removal efficiencies of 14 OMPs, including analgesics/anti-inflammatories, anticonvulsants, stimulants, antifungals, fragrances, plasticizers, and transformation products, were evaluated in each system. Regarding the presence of OMPs in the wastewater, the concentrations of these compounds in the influent ranged from 0.16 to 7.75 µg/L. In general, the removal efficiencies achieved by the AS system were between 10%–95% higher than those values reported by HSSFs with values above 80% for naproxen, ibuprofen, diclofenac, caffeine, triclosan, methyl dihydrojasmonate, bisphenol-A, 2-hydroxyl ibuprofen, and carboxy ibuprofen (p < 0.05). This behavior can be related to the aerobic conditions that promote the AS system with oxidation-reduction potential (ORP) and dissolved oxygen (DO) values above −281 mV and 0.24 mg/L, respectively. However, the removal of galaxolide was greater in HSSF system than in AS with significant difference of 70% (p < 0.05). Despite these results, this study reveals that comparing both technologies, AS had the best removal performance of these OMPs studied.

The main objective of this review is to evaluate the performance of constructed wetlands (CWs) used to reduce antibiotic-resistant genes (ARGs) during sewage treatment. To accomplish this objective, statistical and correlation analyses were performed using published data to determine the influence of operational and design parameters on ARG reduction in CWs. The effects of design and operational parameters, such as different CW configurations, seasonality, monoculture and polyculture, support medium, and hydraulic retention time (HRT), on ARG removals, were analyzed. A comparison of ARG reduction under different CW configurations showed that the hybrid configuration of surface flow (SF)–vertical subsurface flow (VSSF) achieved the highest reductions, with values of 1.55 ulog. In this case, aeration is considered an important factor to reduce ARGs in CWs, and it should be considered in future studies. However, statistical analyses showed that the ARG reductions under different CW configurations were not significant (p > 0.05). The same behavior was observed when the effects of operational factors on ARG reductions were analyzed (p > 0.05). The results of this study show that CWs are not optimal technologies to reduce ARGs in sewage. The combination of CWs with advanced wastewater technologies can be a solution for enhancing ARG reduction and reducing the spread of antibiotic resistance.

The main objective of this study is to evaluate the water quality of different rainwater harvesting (RWH) systems and the social acceptance of their reuse in young users as an exploratory approach. Three RWH systems were implemented, and the quality of harvested rainwater was evaluated focusing on physicochemical and in situ parameters. Social acceptance was studied in one of the RWH systems using an adapted technology acceptance model. An informative talk about the operation of RWH was given to the users, who were students from a rural primary school. Surveys were conducted before and after the talk to evaluate the impact of providing information to users. The social acceptance was studied in one of the RWH systems. The results indicated that the harvested rainwater from RWH systems was suitable for reuse in agriculture despite the increase in turbidity and chloride concentrations in the outlet tap. The concentration of turbidity, phosphate as phosphorus, chloride and nitrate ranged between 0.8 and 1.9 NTU, 0.01–0.2 mg/L, 2.8–5.0 mg/L and 0.3–0.9 mg/L, respectively. In the acceptance study, the survey results and correlation analyses showed that providing information to users is crucial for increasing the acceptance of RWH systems. Moreover, this study demonstrated that RWH systems are a viable alternative technology for reusing and supplying water in arid and semiarid areas.