Pilot-scale study on the removal of pharmaceuticals by LECA based SSF-constructed wetlands

In recent years, the occurrence and fate of pharmaceutically active compounds (PhACs) in the aquatic environment has been recognized as one of the emerging issues in environmental chemistry. Some compounds are just resistant to degradation in the sewage treatment plants (STPs) while others, although suffering partial degradation, still end up in receiving water bodies due to the large inputs received in STPs [1]. Clofibric acid (a metabolite from a series of widely used blood lipids lowering agents), ibuprofen (an anti-inflamatory non-prescription drug) and carbamazepine (an anticonvulsant and mood stabilizing drug) are some of the most frequently found PhACs in environmental monitoring studies [1]. Wastewater treatment by sub-surface flow constructed wetland systems (SSF-CWs) is a low-cost technology that has shown some capacity for removal of several organic xenobiotic pollutants, but fewer studies exist on pharmaceuticals behavior. The aim of the present work was to evaluate the efficiency of a pilot SSF-CW assembled with the plants cattail (Typha spp.) and a clay material (LECA 2/4) as support matrix, for the removal of three pharmaceuticals, namely ibuprofen (IB), carbamazepine (CB) and clofibric acid (CA), from contaminated wastewaters. Four beds were planted with pre-grown cattails (density of 80 plants/m2) and four were left unplanted to be used as controls. Experiments were conducted both in batch and in continuous mode with a flooding rate of 100%. Pharmaceutical concentrations were quantified by HPLC with UV detection at 210 nm (CB), 222 nm (IB) and 230 nm (CA). Solid phase extraction was used for sample pre-concentration whenever the measured pharmaceutical concentrations fell under the limit of quantification of the analytical method. The physico-chemical characterization of the support matrix material, LECA, involved the determination of properties such as pH, point of zero charge, electrical conductivity, apparent porosity, bulk density and hydraulic conductivity. In order to shed some light on the tolerance mechanisms developed by Typha spp. in the presence of these pharmaceuticals, biochemical and physiological parameters were evaluated. Typha spp. showed good tolerance to the presence of CA, CB and IB concentrations of 1 mg L-1, which is a value much higher than those usually reported in wastewaters. LECA alone was able to remove about 90% of the initial amounts of CB and IB in solution, and 50% of CA. IB was very susceptible to microbial degradation and up to 80% of the initial concentration could be removed by the microbial population present in the wastewater used. Overall, the CWS shows a higher removal performance for CA, CB and IB than any of its individual components (plants, support matrix, microorganisms) considered separately. CA proved to be the most resilient compound, which comes in agreement with other published data. However, this system enabled the removal of substantially higher amounts of CA than has previously been reported in other studies. The use of systems of this kind for the removal of pharmaceuticals from wastewaters seems like a promising alternative to the less efficient processes of conventional wastewater treatment

Influence of mordants in the colour of natural dyes: theoretical predictions and experimental results

Arraiolos tapestries are probably one of the richest artistic Portuguese expressions in terms of textile production and a cultural heritage that urges to preserve. The richness of colours displayed by some of the Arraiolos tapestries denotes the likely use of a wide variety of dyes. The different light-fastness of dyes combined with the use of different types of mordants can also explain the appearance of pale shades and fading in some tapestries due to different molecule interactions with the support fibres. The work we present is part of a major project (experimental and theoretical) that envisages the identification of the dyes and mordants used throughout the ages in the production of Arraiolos tapestries and the establishment of the major factors (like mordant, humidity and light) that are responsible for the colour and fading of the natural dyes as well as for the degradation of the fibres. It is well known that the colour of a dye depends on the type of mordant used, due to the formation of metal complexes that cause a change in the molecular orbitals energies and hence a shift in UV/Vis absorption bands. The electronic structure and transitions in the visible spectra of some dyes and mordants identified on Arraiolos rugs were predicted by the ZINDO-INDO/S semi-empirical molecular orbital method [1,2] in order to identify the origin of the colours and characterize the influence of metal coordination on colour modifications. The molecular geometry of each dye-mordant complex was optimized at DFT level using the Gaussian03 package [3] and a simulation of the UV/Vis absorption spectrum was calculated using ZINDO. Another important outcome of this study was the determination of the chromophore properties of fragment molecules produced by the dyes degradation processes that enabled the evaluation of the colour changes of the dyes and subsequent fading. Wool fibres were dyed with previously identified natural dyes and mordants and the colour parameters and the spectra were determined using a UV-Vis portable spectrometer. These parameters were compared with the results from the theoretical predictions

Using clay materials to remove pharmaceuticals from waters

Pharmaceutical active compounds (PhACs) have an important role in the treatment and prevention of disease in both human and animals. Ingested drugs are only partially absorbed by the organisms and studies have shown that the excreted compounds are only partially removed in the sewage treatment plants (STPs) [1]. Contaminated effluents are being released from the STPs and trace amounts of PhACs have been detected in wastewaters, surface and groundwaters worldwide [1]. Acidic pharmaceuticals like diclofenac, ibuprofen and clofibric acid are some of the most frequently detected compounds [1]. The concentrations detected are low (ng/L - μg/L) but, due to the very nature of these compounds, studies have shown damaging effects on the aquatic ecosystems [1]. Several different processed natural materials can be used as filter media in water and wastewater treatment systems. Some of these materials can additionally present functions which extend beyond the simple process of filtration. Their surface areas can constitute a support for microbial population growth in biofilters as well as support matrix for the development of macrophytes in sub-surface flow constructed wetland systems (SSF-CWS) [2] which are increasingly being used in sewage tertiary treatment. The efficiency of these biological systems in the removal of xenobiotics can be significantly enhanced by a greater capability of the support matrix to retain contaminants by sorption phenomena, ionic exchange or other physico-chemical processes [2]. The aim of the present work was to evaluate the efficiency of two different materials namely, Light Expanded Clay Aggregates [LECA] (in two different particle sizes) and sand, for the removal from water of three acidic PhACs, clofibric acid, diclofenac and ibuprofen. In addition, relationships were established between the compounds removal efficiencies and the physico-chemical properties of each material. A series of batch essays were carried out to study the sorption capacities of the different materials for the 3 chemical compounds. The influence of some experimental conditions, such as the contact time, the initial PhACs concentrations (1 mg/L up to 50 mg/L) and LECA particle size, were investigated. The media were sterilized before use in order to minimize any microbial development on the matrix and experiments were conducted in the dark to avoid any photocatalytic degradation reactions. The mineralogical composition of the materials was determined by X-ray diffraction and some physico-chemical properties were characterized. Samples of the contaminants’ aqueous solutions were collected over a range of contact times with the support matrix and the remaining concentrations in solution were determined by UV/Vis spectrophotometry. The results show that LECA has a good sorption capacity for acidic compounds. In contrast, sand does not exhibit any sorption capacity for any of the compounds tested. Not surprisingly, LECA with smaller particle sizes show higher efficiencies that larger grade LECA, due to a larger available surface area. However, the use of these smaller particle media at upper scales may present problems with hydraulic conductivities. From the results obtained, it can be concluded that expanded clay presents important advantages as a CWS support matrix or as a filter medium, because it has a good sorption capacity, a pH buffer capacity and an excellent control of hydraulic permeability. On the other hand, sand does not exhibit any sorption capacity that might enhance the performance of filters and CWS in the treatment of water contaminated with this type of contaminants

Removal of pharmaceuticals in constructed wetlands using Typha and LECA. A pilot-scale study.

An ever-increasing number of xenobiotic compounds are getting detected in environmental samples worldwide. Serious concern about the contamination of water resources and drinking water supplies has aroused from the prevalence of pharmaceutical residues in the aquatic ecosystems. Some pharmaceuticals such as ibuprofen, carbamazepine and clofibric acid are frequently detected in waters [1]. These compounds are generally quantified at low concentrations (at the ng/L or mg/L range) but, due to their persistence in the environment and to potentially cumulative effects in the organisms, studies have shown that these compounds can have some damaging effects on the aquatic ecosystems [1]. Several xenobiotic organic compounds have already been removed from contaminated waters using constructed wetlands (CW) where the processes occurring in natural wetlands can be optimized in engineered man-made ecosystems, specifically designed for wastewater treatment. Among several physico-chemical phenomena, sorption by the support matrix plays an important role in the contaminant removal mechanisms. It is important to select a matrix with a high sorption capacity, which will depend on the physico-chemical properties of the material chosen. Previous studies have shown that expanded clay (LECA) is capable to remove, by sorption, this type of substances from water [2]. CWs also take advantage of the ability of plants to adsorb, uptake and concentrate pollutants, as well as to release root exudates that enhance compound biotransformation and degradation. Wetland species such as the cattail (Typha spp.) have already been tested and found suitable for the removal of several organic compounds from wastewaters, being commonly used in CWs [3]. The aim of the present work was to evaluate the efficiency of a subsurface flow constructed wetland assembled with the plants Typha spp. and LECA as support matrix, for the removal of three pharmaceuticals, namely ibuprofen, carbamazepine and clofibric acid, from contaminated waters

Sorption behavior of granular matrices for application in pharmaceutical removal by SSF constructed wetlands

In recent years, the occurrence and fate of pharmaceutically active compounds (PhACs) in the aquatic environment has been recognized as one of the emerging issues in environmental chemistry. Clofibric acid, ibuprofen and carbamazepine are some of the most frequently found PhACs in environmental monitoring studies. Some xenobiotics have already been successfully removed from contaminated waters using constructed wetlands (CW). Depuration of wastewaters in CWs is achieved by the concerted action between plant rhizomes, microorganisms and matrix component. CWs efficiency can be significantly improved by careful selection of the matrix, plants and microorganism used. Among several physico-chemical phenomena, sorption by the matrix plays an important role in the PhACs removal mechanism. It is important to select a matrix with a high sorption capacity, which depends on the physico-chemical properties of the material chosen. Previous studies carried out by the authors showed that expanded clay (LECA) presents a high sorptive affinity by clofibric acid [1]. The aim of the present work was to evaluate the capacity of LECA to remove other PhACs, namely ibuprofen and carbamazepine, and compare the results obtained with these pharmaceuticals with those obtained previously with clofibric acid. In addition, other materials were tested for the removal of clofibric acid and the results were compared with those obtained with LECA. The ultimate objective of this work will be to optimize the performance of this component in the overall performance of a constructed wetlands system designed for the removal of PhACs from wastewaters

Removing pharmaceutical residues from contaminated wastewaters using expanded clay aggregates

Pharmaceutical compounds (PhCs) are ingested in large quantities by humans in treatment and prevention of disease, but they are only partially absorbed by the organisms being excreted together with their metabolites. The sewage treatment plants (STP) are only able to partially remove some of these compounds and, despite the low concentrations present in the wastewaters (ng-μg/L), these xenobiotics can still pose a serious threat to the aquatic environments. Sub-surface flow constructed wetland systems (SSF-CWS) are biological systems used in wastewater treatment, and clay materials can be used as support matrices for these systems. Clay materials act not only as filters but they also can potentially remove organic pollutants due to its sorption properties. In this study a processed clay material, light expanded clay aggregates (LECA), was tested for their sorption capacity towards three widespread water polluting pharmaceuticals, namely clofibric acid (CA), ibuprofen (IB) and carbamazepine (CB). Sorption assays were done with aqueous solutions of the individual compounds and with their mixture at different concentrations from 1.0 to 50.0 mg L-1. The sorptive properties of LECA were also investigated using wastewater spiked with a mixture of the three compounds at the same concentrations tested for the aqueous solutions. Reversed phase HPLC with UV-Vis detection at 210, 222 and 227 nm for CB, IB and CA respectively was used to measure the compounds concentrations. For the single-compound solutions the HPLC analyses were performed in isocratic mode with a mobile phase composed by 75:25 acetonitrile:water with 0.1% (v/v) phosphoric acid. For the solutions containing the three compounds, the separation was performed using the same elution solvents and a gradient program. The total run time was 8 minutes, the flow rate was 1.0 mL min-1 and the injection volume was 20 µL. Calibration curves were constructed for standard solutions of CB, IB and CA individually, as well as solutions containing the three mixed compounds. The average areas of the compounds’ peaks were plotted against the standards concentrations resulting in linear correlations with R2 equal to or higher than 0.999 in every calibration curve. Whenever the measured concentrations were below the method’s LOQs of 0.27 mg L-1, 0.39 mg L-1 and 0.13 mg L-1 for CB, IB and CA respectively, the samples were pre-concentrated on LiChrolut® RP-18. All data were analyzed by the analysis of variance method (ANOVA, single factor) at different significance levels. Results for the individual compounds in aqueous solutions have shown that LECA presents higher removal rates for IB and CB (44 – 92% and 60 – 95% respectively) whereas for CA the removal rates are moderate but still significant (30– 58%). In any case, and for all the studied compounds, the % removal decreased with the increasing load, the lower % removal still correspond to increasing absolute amounts sorbed. When the three compounds are put simultaneously in contact with LECA there are evidences of competitive sorption among the studied compounds, with CB being the less affected compound of the three. When all the compounds were dissolved in wastewater, there was a slight loss of removal efficiency, probably due to an increased solubility in the aqueous media owing to the organic matter present in the wastewater or to competitive sorption effects. Considering the hydraulic and physico-chemical properties of LECA which make this material suitable for constructed wetlands applications, its sorption properties evidenced in this work make it especially interesting for applications aiming at the removal of this kind of pollutants from wastewaters

Production and characterization of recombinant frutalin expressed in the yeast Pichia Pastoris

CNPq, CAPES, FUNCAP, FCT, ALBAN, UMINHO, UFC, UNIFO

Design and Optimization of Microbial Fuel Cells and Evaluation of a New Air-Breathing Cathode Based on Carbon Felt Modified with a Hydrogel—Ion Jelly®

Funding Information: This research was funded by Fundação para a Ciência e a Tecnologia projects DSAIPA/DS/0117/2020, UIDB/04565/2020, and UIDP/04565/2020, by the Associate Laboratory Institute for Health and Bioeconomy—i4HB project LA/P/0140/2020. This work was supported by the Associate Laboratory for Green Chemistry—LAQV financed by national funds from FCT/MCTES (UIDB/50006/2020). We also thank Fundação para a Ciência e Tecnologia (FCT) for funding (SFRH/BD/77568/2011 (R.N.L.C.); SFRH/BPD/80293/2011 (R.M.A.)). C.M.C. acknowledges FCT for the Ciência 2008 Program; S.V.R. acknowledges the financial support from FCT (Portuguese Foundation for Science and Technology) for a postdoctoral research grant (FRH/BPD/33864/2009). This work was supported by the Associate Laboratory for Green Chemistry—LAQV, financed by national funds from FCT/MCTES (UIDB/50006/2020 and UIDP/50006/2020); the Institute for Bioengineering and Biosciences—iBB, financed by FCT (UID/BIO/04565/2013); and from Programa Operacional Regional de Lisboa 2020 (Project N. 007317). Publisher Copyright: © 2023 by the authors.The increased demand for alternative sustainable energy sources has boosted research in the field of fuel cells (FC). Among these, microbial fuel cells (MFC), based on microbial anodes and different types of cathodes, have been the subject of renewed interest due to their ability to simultaneously perform wastewater treatment and bioelectricity generation. Several different MFCs have been proposed in this work using different conditions and configurations, namely cathode materials, membranes, external resistances, and microbial composition, among other factors. This work reports the design and optimization of MFC performance and evaluates a hydrogel (Ion Jelly®) modified air-breathing cathode, with and without an immobilized laccase enzyme. This MFC configuration was also compared with other MFC configuration performances, namely abiotic and biocathodes, concerning wastewater treatment and electricity generation. Similar efficiencies in COD reduction, voltage (375 mV), PD (48 mW/m2), CD (130 mA/m2), and OCP (534 mV) were obtained. The results point out the important role of Ion Jelly® in improving the MFC air-breathing cathode performance as it has the advantage that its electroconductivity properties can be designed before modifying the cathode electrodes. The biofilm on MFC anodic electrodes presented a lower microbial diversity than the wastewater treatment effluent used as inocula, and inclusively Geobacteracea was also identified due to the high microbial selective niches constituted by MFC systems.publishersversionpublishe