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- Evaluation of different substrates in constructed wetlands planted with Typha latifolia for the treatment of tannery wastewaterPublication . Calheiros, Cristina S. C.; Rangel, António O. S. S.; Castro, Paula M. L.
- Ecotechnologies as urban solutions for sustainable water managementPublication . Calheiros, Cristina S. C.; Monteiro, Cristina M.; Rangel, António O. S. S.; Castro, Paula M. L.
- Glyphosate in portuguese adults – a pilot studyPublication . Nova, Paulo; Calheiros, Cristina S.C.; Silva, MargaridaBackground: Glyphosate is a broad-spectrum biocide and the active ingredient in the most widely used herbicides worldwide. Since 2015, when the International Agency for Research on Cancer classified it as a Class 2A carcinogen, global interest in this chemical spiked particularly as regards exposure of the general population. Objective: An exploratory glyphosate exposure assessment was conducted among Portuguese adults. Methods: Self-selected participants provided first morning urine which was tested for glyphosate and its metabolite aminomethylphosphonic acid (AMPA) at two distinct periods of time, by two different laboratories using gas chromatography with tandem mass spectrometry (GC-MS-MS) and high performance liquid chromatography linked to triple quadrupole mass spectrometry (HPLC-MS/MS), respectively. Results: In the first round of testing 28% and 50% presented detectable levels of glyphosate and AMPA respectively, with median values of 0.25 and 0.16 μg/L. Systematically available internal dose values were 8.20E- 06 mg/Kg (glyphosate) and 5.04-05 mg/Kg (AMPA). In the second round 73% and 97% presented detectable levels of glyphosate and AMPA respectively with median values of 0.13 and 0.10 μg/L. Systematically available internal dose values were 4.00E-06 mg/Kg (glyphosate) and 3.00E-06 mg/Kg (AMPA). Conclusions: Glyphosate exposure was detected among Portuguese adults, with percentages of glyphosate and AMPA contaminated urine in both rounds of testing and above values from previous studies in other European countries. Systematically available internal doses values were below EFSA’s risk assessment values (ADI or AOEL), and as such, the concentration values measured in this study are not per se a human health problem. Even though there were study limitations, it is the first assessment in Portugal and contributes to the overall knowledge map of glyphosate exposure in Europe.
- Phytoremediation as a biotechnological tool for environmental restorationPublication . Marques, Ana P. G. C.; Rangel, António O. S. S.; Calheiros, Cristina S. C.; Oliveira, Rui S.; Franco, Albina R.; Vosatka, Miroslav; Dodd, John C.
- Diverse Arbuscular Mycorrhizal Fungi (AMF) communities colonize plants inhabiting a constructed wetland for wastewater treatmentPublication . Calheiros, Cristina S. C.; Pereira, Sofia I. A.; Franco, Albina R.; Castro, Paula M. L.Constructed wetlands (CWs) are biological wastewater treatment systems that comprise several components where plants and associated organisms play an important role in water depuration. Microbial studies emphasize bacterial dynamics, whereas studies of arbuscular mycorrhizal fungi (AMF) are scarce and the functional role of AMF in aquatic and wetland plants is poorly understood. The aim of this study was to analyze the AMF communities colonizing the roots of Canna indica, Canna flaccida, and Watsonia borbonica inhabiting a CW treating wastewater of a tourism unit. The dynamics of the AMF communities were evaluated by Denaturing Gradient Gel Electrophoresis (DGGE) of 18S rRNA gene amplification products along cold (C) and hot (H) seasons for three consecutive years. DGGE profiles allowed the estimation of AMF species richness (S), and Shannon-Wienner (H) and Pielou (J) indexes, for the different plant species, showing differences between species and along the years. Excised bands from DGGE were analyzed and identified through sequencing for arbuscular mycorrhiza, revealing the presence of AMF strains closely related to Glomus sp., Rhizophagus sp. and Acaulospora sp. genera. Concomitant water quality analyses showed that the system was effective in organic and nutrient removal during the sampling period. Findings from this study suggest that AMF diversity found in the CW is influenced by the water constituents, season, and plant species.
- Constructed Wetlands for freshwater and saline aquaculture wastewater treatment: a microcosm experiencePublication . Jesus, J. M.; Borges, M. T.; Calheiros, Cristina S. C.; Castro, Paula M. L.The aquaculture industry discharges large volumes of nutrient rich wastewater, contributing to eutrophication events. Recent culture intensification methodologies such as recirculation (RAS) and shallow raceway (SRS) systems discharge wastewater with even higher nutrient concentrations, though at lower volumes (Rana et al., 2005). Hence, efluent treatment options are of vital importance. Constructed wetlands (CWs) are a possible but underexplored treatment solution even for high salinity situations (Lymbery et al., 2006) consisting of planted shallow channels, relying upon biological, physical and chemical processes to treat wastewater (EPA, 2000). Therefore, this study aims to extend the knowledge on the possible use of CWs for aquaculture wastewater treatment, either fresh or saline. To fulfill this goal, several microcosms were created simulating subsurface systems with HRT = 7 days and planted with Typha latifolia. Substrate used was expanded clay 8 – 12.5 mm Ø. Macrophyte survival, growth, and nutrient removal (phosphate, nitrite, nitrate and ammonia) were assessed over a period of 4 weeks. Freshwater (simulated) and saline (real) fish farm effluents (recirculation SRS, 2.4% salinity) were tested. Results showed that plants adapted better to freshwater conditions exhibiting higher growth rate. Plants at 2.4% salinity did not growth in height after 2 weeks, but survival remained high.The microcosm wetland system was able to treat the effluent by removing 61%, 78% and 98% of NH4, NO2 and PO4, respectively, in fresh water, and 94%; 78%, 34% and 100% of NH4, NO2, NO3 and PO4, respectively, in saline wastewater. An improvement of removal with time was observed, suggesting the existence of a system adaptation period. The microcosm treatment was able to reduce nutrient concentrations to legally acceptable values. Hence, constructed wetlands can be an adequate solution for aquaculture efffluent treatment. Further studies are necessary, however, to achieve a better adaptation of the plant used to salinity.
- Polishing domestic wastewater on a subsurface flow constructed wetland: organic matter removal and microbial monitoringPublication . Mina, I. Aguiar-Pinto; Costa, M.; Matos, A.; Calheiros, C. Sousa Coutinho; Castro, P. M. L.Microbial monitoring of constructed wetlands (CWs) treating domestic wastewater is generally scarce, despite the need of more knowledge about its biocenosis. The sanitation quality of a wastewater treated in a CW is a crucial aspect, mainly when the receiving water body is used as a swimming and/or recreation area. The present study was carried out in a horizontal subsurface flow CW planted with Phragmites australis receiving pre-treated domestic wastewater (mean flow 50 m3 day−1), from a population of about 300 inhabitants. The monitoring programme undertaken during the first year operation, revealed removal efficiencies of 61% BOD5, 44% COD, and 65% TSS for inlet water with ca. 90 mg L−1 BOD5, 157 mg L−1 COD, and 17 mg L−1 TSS. Total Coliform (TC) and Faecal Coliform (FC) bacteria were removed from wastewater (mean inlet values of 5 × 106 CFU 100 mL−1 TC and of 9 × 105CFU 100 mL−1 FC), with efficiencies of 92 and 97%, respectively. The dynamics of microbial communities established in the system assessed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), had revealed a high bacterial diversity within the system, with no relevant differences in composition at the CW inlet and outlet but exhibiting temporal differences in bacterial communities.
- Aromatic plants for water treatment in Green roofs technologyPublication . Monteiro, Cristina M.; Calheiros, Cristina; Castro P. M. L, Paula M. L
- Toxicity assessment of high salinity tannery wastewater for the treatment in constructed wetlands.Publication . Silva, Gabriela; Calheiros, Cristina S.C.; Quitério, Paula V.B.; Crispim, Luís F.C.; Brixc, Hans; Moura, Sandra G.C.; Castro, Paula M.L.
- Evaluation of different substrates to support the growth of Typha latifolia in constructed wetlands treating tannery wastewater over long-term operationPublication . Calheiros, Cristina S. C.; Rangel, António O. S. S.; Castro, Paula M. L.The aim of this study was to investigate the performance of horizontal subsurface flow constructed wetlands planted with Typha latifolia treating tannery wastewater under long-term operation. Two expanded clay aggregates (Filtralite® MR3–8-FMR and Filtralite® NR3–8-FNR) and a fine gravel-FG were used as substrate for the constructed wetland units plus one unit with FMR was left as an unvegetated control. The systems were subject to three hydraulic loadings, 18,8 and 6cm d⁻¹, and to periods of interruption in the feed. The relationship between the substrate, plant development and removal efficiency, especially of organic matter, was investigated. Organic loadings up to 1800 kg BOD5 ha⁻¹ d⁻¹ and 3849 kg COD ha⁻¹ d⁻¹ were applied leading to mass removals of up to 652 kg BOD₅ ha⁻¹ d⁻¹ and 1869 kg COD ha⁻¹ d⁻¹, respectively. The three different substrates were adequate for the establishment of T. latifolia, although the clay aggregates allowed for higher plant propagation levels. The units with FNR and FMR achieved significantly higher COD and BOD₅ removal when compared to the FG and to the unplanted units. The systems proved to be tolerant to high organic loadings and to interruptions in feed suggesting this technology as a viable option for the biological treatment of tannery wastewater.