Drug-Related Problems in Elderly Patients Attended to by Emergency Services.

The progressive aging and comorbidities of the population have led to an increase in the number of patients with polypharmacy attended to in the emergency department. Drug-related problems (DRPs) have become a major cause of admission to these units, as well as a high rate of short-term readmissions. Anticoagulants, antibiotics, antidiabetics, and opioids have been shown to be the most common drugs involved in this issue. Inappropriate polypharmacy has been pointed out as one of the major causes of these emergency visits. Different ways of conducting chronic medication reviews at discharge, primary care coordination, and phone contact with patients at discharge have been shown to reduce new hospitalizations and new emergency room visits due to DRPs, and they are key elements for improving the quality of care provided by emergency services.

Sono-Enzymatically Embedded Antibacterial Silver-Lignin Nanoparticles on Cork Filter Material for Water Disinfection.

Providing clean drinking water is a great challenge worldwide, especially for low-income countries where the access to safe water is limited. During the last decade, new biotechnological approaches have been explored to improve water management. Among them, the use of antimicrobial nanoparticles for designing innovative centralized and decentralized (point-of-use) water treatment systems for microbial decontamination has received considerable attention. Herein, antimicrobial lignin capped silver nanoparticles (AgLNP) were embedded on residual cork pieces using high-intensity ultrasound coupled with laccase-mediated grafting to obtain biofunctionalized nanomaterial. The developed AgLNP-coated cork proved to be highly efficient to drastically reduce the number of viable Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus in liquid medium. Additionally, the coated-cork was characterized using FTIR-ATR spectroscopy and SEM imaging, and further used as a filter bed in a point-of-use device for water disinfection. The constructed water filtering system significantly reduced the amount of viable E. coli and resistant Bacillus cereus spores from filtered water operating at increasing residence times of 1, 4, 6, 16, 24, and 48 h. Therefore, the presented results prove that the obtained cork-based antimicrobial nanocomposite material could be used as a filtering medium for the development of water filtration system to control pathogen dissemination.

Evaluation of substrate clogging in a full-scale horizontal subsurface flow treatment wetland using electrical resistivity tomography with an optimized electrode configuration.

This study investigated the spatial distribution of clogging matter in a full-scale horizontal subsurface flow treatment wetland (HSSF TW) based on an electrical resistivity tomography (ERT) method, comparing the performance of two different electrode configurations (i.e., Schlumberger and Wenner arrays). The results indicated that during the draining phase, the substrate apparent resistivities of the full-scale HSSF TWs were negatively correlated with the clogging matter fraction (v/v), and a functional relationship between the two parameters was established using a first-order k-C* model. The detected clogging matter fraction (v/v) based on the Schlumberger array showed higher accuracy (linear slope = 0.900, R-squared = 0.902) than the Wenner array (linear slope = 0.685, R-squared = 0.685). Most of the severe substrate clogging in the full-scale HSSF TW occurred within a 10-m flow distance, and the distribution of the clogging matter showed different characteristics at different substrate depths. From a cross section positioned 1 m from the inlet, the average clogging matter fraction (v/v) at a 0-0.30 m depth (23.1 ± 14.9%) was significantly higher than that at a 0.30-0.80 m depth (5.0 ± 2.1%). The clogging matter at a 5-m flow distance was evenly distributed at different substrate depths. Only a few localized clogging zones were observed in the cross section at a 10-m flow distance. This study provided an accurate and feasible method for investigating the volume fraction of clogging matters containing different organic contents and demonstrates the spatial heterogeneity of clogging matter in HSSF TWs.

Building Resilient Cities: Climate Change and Health Interlinkages in the Planning of Public Spaces.

Greenhouse gases emissions resulting from the combustion of fossil fuels are worsening air quality and affecting the climate system. While climate change impacts on meteorological variables affects air quality by altering the concentration and distribution of pollutants, air pollution significantly influences the climate, leading to negative impacts on human health. Due to the combination of high temperatures, air pollution, and high population density, cities are particularly vulnerable to climate change impacts. The planning and design of public spaces aimed at climate change mitigation and adaptation can result in multiple co-benefits for human health, while reducing social inequalities. To address the major research gaps in the communication between health and planning experts, and the lack of capacity among public sectors and policy makers, it is necessary to promote capacity building and knowledge sharing between the planning and health sectors. The purpose of this article is to develop preliminary recommendations for a process that allows a comprehensive assessment of the interlinkages between climate and health, social, environmental, and economic vulnerabilities, and the quality of the urban spaces, to support local governments, policymakers, and education institutions in making informed decisions for public spaces. The methods applied were a literature review and interviews with experts.

Effect of intermittent induced aeration on nitrogen removal and denitrifying-bacterial community structure in Cork and gravel vertical flow pilot-scale treatment wetlands.

In this work, we have evaluated the impact of intermittent induced aeration in total nitrogen (TN), ammonia (NH4-N) and nitrate-nitrogen (NO3-N) removal in four pilot-scale vertical flow constructed wetlands (VFCW) (two aerated two non-aerated) using cork by-product or gravel as the filter material and planted with Phragmites australis. Both aerated and non-aerated systems achieved high COD and BOD5 elimination rates (≥ 90%) at the end of the 5-month test period. However, the aerated systems presented maximal COD and BOD5 removal from the third month of operation onwards since air supply favored the oxidative bioprocesses occurring within the wetlands. Cork and gravel aerated VFCW also proved to be more efficient (p < 0.05) in NO3-N removal than the non-aerated systems and this upgraded performance was correlated with a significant higher relative abundance of the nirS gene. The aerated systems also showed a slightly improved NH4-N removal. Noticeably, cork VFCW showed higher TN removal mean values (∼35%) than gravel wetlands (27-28%) regardless aeration. Moreover, cork VFCW showed higher relative abundance of the nosZ gene. Our results demonstrated a better nitrogen elimination for the aerated cork pilot-scale VFCW, and this behavior was correlated with a higher abundance of both nirS and nosZ, two of the key functional genes involved in nitrogen metabolism.

Cohort Multicenter Study on the Role of Medications in Parenteral Nutrition-Related Alteration of Liver Function Tests in Adults.

BACKGROUND: Our objective was to assess in non-critically-ill adult inpatients receiving parenteral nutrition (PN) the risk of developing liver function test (LFT) alterations when receiving concomitant possibly hepatotoxic medications or others reported to improve LFTs during PN. METHODS: A multicenter retrospective analysis of prospectively collected data was performed on patients receiving PN. Two groups were recruited: group LALT (patients with any LFT alterations during PN), and group NOLALT (patients without such alterations). Exclusion criteria were previous sepsis, shock, renal failure, hyperglycemia, LFT alteration, or biliopancreatic surgical procedures. Medications were classified into 2 categories: medications reported to improve LFTs during PN (n = 8) and possibly hepatotoxic medications (n = 54), including a subgroup of possibly highly hepatotoxic medications (n = 30). RESULTS: The study included 200 patients, 136 (68.0%) in the LALT group. The groups differed in the number of patients requiring surgical intervention ≤7 days before PN (LALT, 94 [69.1%]; NOLALT, 29 [45.3%]; P < .002) and those receiving possibly hepatotoxic medications (LALT, 126 [92.6%]; NOLALT, 45 [70.3%]; P < .001). Variables in the final Cox regression model were possibly hepatotoxic medications, odds ratio (OR) 3.310 (1.678-6.530); surgical intervention prior to PN, OR 1.861 (1.277-2.711); baseline triglyceridemia, OR 1.005 (1.001-1.009); and creatinine, OR 1.861 (1.043-3.323). CONCLUSIONS: Patients who received PN and concomitantly possibly hepatotoxic medications had a 3-fold risk of developing LFT alterations. Medications reported to improve LFTs had no effect. The use of possibly hepatotoxic medications during PN was associated with LFT alterations.

Enhancement of rhizocompetence in pathogenic bacteria removal of a constructed wetland system.

The main goal of the present study was to enhance the rhizobacterium potential in a horizontal subsurface flow constructed wetland system planted with Phragmites australis, through environmentally friendly biological approaches. The bioinoculation of antagonist bacteria has been used to promote higher rhizosphere competence and improve pathogenic bacteria removal from wastewater. The experiment was performed both with single and sequential bioinoculation. The results showed that strain PFH1 played an active role in pathogenic bacteria removal, remarkably improving inactivation kinetics of the pathogenic tested bacterium Salmonella typhi in the plant rhizosphere. The single bioinoculation of selected bacteria into the rhizosphere of P. australis improved the kinetics of S. typhi inactivation by approximately 1 U-Log10 (N/N0) (N is the number of viable cultured bacteria at time t, N0 is the number of viable and cultivable bacteria at time t0) compared to the control. By a series of multi-bioinoculations, the enhancement of pathogenic bacteria reduction compared to the inhibition rate in the pilot-scale control was of 2 U-Log10(N/N0). These findings suggested that this strain represents a promising candidate to enhance water purification in constructed wetlands.

Microbial nitrate removal efficiency in groundwater polluted from agricultural activities with hybrid cork treatment wetlands.

Agricultural practices have raised the level of nutrients reaching aquifers. In Europe, nitrate pollution is considered as one of the main threats for the quality of groundwater in agricultural areas. Treatment wetlands (TWs), also known as Constructed Wetlands, are used for groundwater treatment in areas with an important concentration of nitrogen compounds; total nitrogen removal depends on the type and operation scheme. Cork by-product from the industry has shown clear adsorbent properties to remove organic pollutants. The work is focused on the characterization of microbial communities involved in the nitrate­nitrogen removal process in groundwater polluted from agricultural activities. The experimental design allowed the comparison of nitrate removal efficiency depending on the filter media material, cork by-product or gravel, used in two hybrid TWs (a vertical flow cell followed by a horizontal subsurface flow cell), installed in areas close to two irrigated agricultural plots at the Lleida plain area (Spain). Both physicochemical and microbial results were consistent and confirm the nitrate removal efficiency using cork as a filter media. A significant (p = 0.0025) higher removal in Bellvís TW using cork compared with the Vilanova de la Barca gravel system was observed, achieving a removal rate from 80 to 99% compared to the 5-46%, respectively. Regarding the community composition of the two different TWs, microorganisms were mainly related to the phylum Proteobacteria, and included members found to be key players in the nitrogen cycle, such as ammonia and nitrite oxidizers, as well as denitrifiers. Also, the group Bacteroidetes turns to be another abundant phylum from our bacterial dataset, whose members are suggested to be strongly involved in denitrification processes. Some groups showed to prevail depending on the type of media (cork or gravel); Firmicutes and Delta and Epsilonproteobacteria had a significant higher abundance in the TW with cork, while Acidobacteria and Planctomyces were prevalent in gravel. Therefore, cork could be an alternative material used by treatment wetlands to minimize the impact in the environment caused by nitrogen pollution in groundwater bodies.

Cork as a sustainable carbon source for nature-based solutions treating hydroponic wastewaters - Preliminary batch studies.

Reusing by-products is an important strategy to ensure the preservation of natural capital and climate change mitigation. This study aimed at evaluating the potential of cork granulates, a by-product of winery industry, as an organic carbon (OC) source for the treatment of hydroponic wastewaters. First, chemical characterization was performed and discussed. Secondly, batch studies were performed using synthetic hydroponic wastewater to understand the role of particle size (PS), pH and contact time (CT) on the release of OC. The suberin is the major compound, representing >50%. It was noticed that a variance on the content of suberin across species, within the same species and depending on the extraction part (belly, cork and back) could be expected. >60% of the sample is composed by carbon while <1% was nitrogen (high C:N ratio), indicating a low risk of releasing organic nitrogen. The statistical results suggested that the main effect of PS on the release of OC is greater than both, CT and pH. The chemical release of OC gets slower with time, being this effect greater as the PS increase. Moreover, estimations showed that using the 4 mm PS, the amount of water treated would be twice the amount if the 8 mm PS had been used. The PS seems to play an important role at design nature-based solutions (NBS) focused on denitrification. The surface response methodology indicates a significant negative interaction between CT and PS suggesting that the mathematical model could be used for further optimization studies. The reuse of organic by-products as filter media seems to be an economic and environmentally friendly alternative to enhance denitrification in NBS, while preserving natural capital. However, further real scale and long-term experiments are needed to validate cork's potential as an "internal" OC source for NBS.

Monitoring levels of viable Helicobacter pylori in surface water by qPCR in Northeast Spain.

Helicobacter pylori infection is a risk factor for chronic active gastritis, peptic ulcers, gastric carcinoma and lymphoma. Although the infection may be acquired through different transmission routes, the presence and viability of H. pylori in water sources are not well known. Therefore, the aim of our study was to analyse the viability of H. pylori cells in urban surface waters collected at the Vallparadís public park in Terrassa, Barcelona, Spain. The water samples were analysed by viability quantitative polymerase chain reaction (qPCR) using propidium monoazide and specific primers for the H. pylori vacuolating cytotoxin (vacA gene). Viable H. pylori were found in 91.3% of the samples analysed, with an average concentration of 3.46 ± 1.06 log cell 100 mL-1. Our work proves a quick and simple procedure for evaluating viable H. pylori cells in environmental samples by qPCR. Furthermore, the results provide evidence that urban surface waters may contain considerable levels of viable H. pylori cells, thus indicating they are a potential source of infection, which represents a public health concern.

Ionic coupling of hyaluronic acid with ethyl N-lauroyl l-arginate (LAE): Structure, properties and biocide activity of complexes.

Ethyl αN-lauroyl l-arginate hydrochloride (LAE) was coupled with hyaluronic acid (HyA) to form ionic complexes with LAE to HyA ratios of 1:1 and 1:2. The complexes were extensively characterized by FTIR and NMR spectroscopies and their thermal properties evaluated by thermogravimetry and calorimetry. Thin films prepared from these complexes by casting displayed a smectic-like structure based on an ordered arrangement of LAE and HyA layers with a nanometric periodicity of 3.8-3.9 nm. Films immersed in water at pH 7.4 and 5.5 dissociated to deliver free LAE to the environment and reaching the equilibrium in few hours. The biocide activity of these films against both Gram-positive and Gram-negative bacteria was preliminary assessed by the liquid medium method, and shown to be notable in both cases. The antibacterial property of the complexes was found to increase with the content of LAE and to be particularly efficient against Gram-negative S. enterica bacteria.

Amphiphilic ionic complexes of hyaluronic acid with organophosphonium compounds and their antimicrobial activity.

Amphiphilic ionic complexes of hyaluronic acid and alkyltrimethylphosphonium soaps with alkyl chains containing even numbers of carbons from 12 to 22 have been produced. The complexes have a nearly stoichiometric composition, are non-water soluble, and are stable to heat up to temperatures above 200 °C. These complexes are amphiphilic and able to adopt a biphasic structure with the paraffinic and polysaccharide phases ordered arranged with a periodicity ranging between 3 and 5 nm depending on n. The paraffinic phase in complexes with n ≥ 18 was crystallized and showed melting at temperatures between 58 and 70 °C depending on the n value. The complexes decomposed upon incubation in water under physiological conditions, and undergone extensive biodegradation by the action of hyaluronidases. Biocide assays carried out in both solid and liquid media demonstrated a high antimicrobial activity of the complexes against Gram-positive S. aureus but moderate against Gram-negative E. coli and C. albicans fungi.

Multicenter study of parenteral nutrition in non-critically ill elderly patients compared to younger patients - Study IAIOS-PN (Incidence and Assessment of Iatrogenesis in Older Subjects receiving Parenteral Nutrition).

OBJECTIVE: this study assessed the incidence of hyperglycemia, hypertriglyceridemia, and liver function test (LFT) alterations among patients older and younger than 65 years receiving parenteral nutrition (PN). A secondary objective was to compare the incidence of any of these three events. MATERIAL AND METHODS: inclusion criteria were non-critically ill adult inpatients receiving PN for ≥ 7 days in 15 hospitals in Spain. Exclusion criteria were hyperglycemia, hypertriglyceridemia, LFT alterations, sepsis, shock, pancreatic/hepatobiliary surgery, renal failure, diabetes mellitus (DM) type 1, insulin-treated DM type 2, acute DM complications, or obesity prior to PN. Patients were classified into groups YOUNG (aged 35-64) and OLD (aged 65-95). RESULTS: this study recruited 200 patients. Group YOUNG included 63 (31.5%) patients and OLD, 137 (68.5%). Hyperglycemia appeared in 37 (18.5%) patients, eight (12.7%) in group YOUNG and 29 (21.2%) in group OLD (p = 0.174). Hypertriglyceridemia appeared in only one (0.7%) patient. LFT alterations appeared in 141 (70.5%) patients, 44 (69.8%) in group YOUNG and 97 (70.8%) in group OLD (p = 1.000). The model for hyperglycemia included DM type 2, previous surgical procedure, and use of hyperglycemia-inducing medications. The model for LFT alteration included previous surgical procedure, amount of lipids and amino acids, medications causing LFT alterations and a trend for age group. The model for any event included surgical procedure, DM type 2, and medications causing alterations. CONCLUSION: patients of ≥ 65 years receiving PN had similar incidences of hyperglycemia, hypertriglyceridemia, and LFT alterations as younger patients. Additionally, older patients had trends toward lower LFT alterations.

Multicenter study of parenteral nutrition in non-critically ill elderly patients compared to younger patients - Study IAIOS-PN (Incidence and Assessment of Iatrogenesis in Older Subjects receiving Parenteral Nutrition) / Estudio multicéntrico de nutrición parenteral en pacientes ancianos no críticos comparados con pacientes más jóvenes - Estudio IAIOS-PN (Incidencia y Valoración de Yatrogenia en Sujetos Ancianos que reciben Nutrición Parenteral)

Objective: this study assessed the incidence of hyperglycemia, hypertriglyceridemia, and liver function test (LFT) alterations among patients older and younger than 65 years receiving parenteral nutrition (PN). A secondary objective was to compare the incidence of any of these three events. Material and methods: inclusion criteria were non-critically ill adult inpatients receiving PN for ≥ 7 days in 15 hospitals in Spain. Exclusion criteria were hyperglycemia, hypertriglyceridemia, LFT alterations, sepsis, shock, pancreatic/hepatobiliary surgery, renal failure, diabetes mellitus (DM) type 1, insulin-treated DM type 2, acute DM complications, or obesity prior to PN. Patients were classified into groups YOUNG (aged 35-64) and OLD (aged 65-95). Results: this study recruited 200 patients. Group YOUNG included 63 (31.5%) patients and OLD, 137 (68.5%). Hyperglycemia appeared in 37 (18.5%) patients, eight (12.7%) in group YOUNG and 29 (21.2%) in group OLD (p = 0.174). Hypertriglyceridemia appeared in only one (0.7%) patient. LFT alterations appeared in 141 (70.5%) patients, 44 (69.8%) in group YOUNG and 97 (70.8%) in group OLD (p = 1.000). The model for hyperglycemia included DM type 2, previous surgical procedure, and use of hyperglycemia-inducing medications. The model for LFT alteration included previous surgical procedure, amount of lipids and amino acids, medications causing LFT alterations and a trend for age group. The model for any event included surgical procedure, DM type 2, and medications causing alterations. Conclusion: patients of ≥ 65 years receiving PN had similar incidences of hyperglycemia, hypertriglyceridemia, and LFT alterations as younger patients. Additionally, older patients had trends toward lower LFT alterations

Objetivo: valorar la incidencia de hiperglicemia, hipertrigliceridemia y alteraciones de los parámetros bioquímicos hepáticos (PBH) en pacientes mayores de 65 años frente a pacientes más jóvenes con nutrición parenteral (NP). El objetivo secundario fue comparar la incidencia de cualquiera de los tres eventos. Material y métodos: se incluyeron adultos no críticos hospitalizados que recibieron NP durante siete días o más en 15 hospitales españoles. Se excluyeron pacientes con hiperglicemia, hipertrigliceridemia, alteración de los PBH, sepsis, shock, cirugía biliopancreática, insuficiencia renal, diabetes tipo 1 o tipo 2 insulinodependiente, complicaciones diabéticas agudas y obesidad previas a la NP. Los pacientes se clasificaron en dos grupos: YOUNG (35-64 años) y OLD (65-95 años). Resultados: se incluyeron 200 pacientes; 63 (31,5%) en el grupo YOUNG y 137 (68,5%) en el OLD. Se detectó hiperglicemia en 37 (18,5%) pacientes, ocho (12,7%) en el grupo YOUNG y 29 (21,2%) en el OLD (p = 0,174). Solo hubo un caso (0,7%) de hipertrigliceridemia. Alteraciones de PBH aparecieron en 141 (70,5%) pacientes, 44 (69,8%) en el grupo YOUNG y 97 (70,8%) en el OLD (p = 1,000). El modelo para hiperglicemia incluyó como variables diabetes tipo 2, cirugía previa y el uso de medicamentos hiperglucemiantes. El modelo para alteración de PBH incluyó cirugía previa, dosis de lípidos y aminoácidos y medicaciones hepatotóxicas. Hubo una tendencia a menor alteración por la edad. El modelo global para cualquier evento incluyó cirugía previa, diabetes tipo 2 y medicaciones que causen las alteraciones estudiadas. Conclusión: los pacientes de 65 años o más que recibieron NP tuvieron incidencias similares de hiperglicemia, hipertrigliceridemia y alteración de PBH a las de los pacientes más jóvenes. Hubo una tendencia a menor alteración de PBH en los pacientes mayores

Decision support system for management of reactive nitrogen flows in wastewater system.

The change in nitrogen balance causes many environmental and socioeconomic impacts. In relation to food production and nitrogen release in wastewater systems, wastewater and sludge discharge and mineral fertilizer use intensify nitrogen imbalance of a region. The replacement of mineral fertilizer by nitrogen from treated wastewater, biosolids, and treated urine is a promising alternative. This work presents a model to support decision taking for the management of reactive nitrogen flows in wastewater systems based on system dynamics. Six scenarios were simulated for nitrogen flows in wastewater systems and related components.

Antibacterial Films Made of Ionic Complexes of Poly(γ-glutamic acid) and Ethyl Lauroyl Arginate.

The biocide agent LAE (ethyl αN-lauroyl l-arginate chloride) was coupled with poly(γ-glutamic acid) (PGGA) to form stable ionic complexes with LAE:PGGA ratios of 1 and 0.5. The nanostructure adopted by these complexes and its response to thermal changes were examined in detail by Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) using synchrotron radiation in real time. A layered biphasic structure with LAE filling the space between the polypeptidic sheets was adopted in these complexes. The complexes were stable up to above 250 °C, non-water soluble, and were able to form consistent transparent films. The release of LAE from the complexes upon incubation in aqueous buffer was examined and found to depend on both pH and complex composition. The antibacterial activity of films made of these complexes against Gram-positive (L. monocytogenes and S. aureus) and Gram-negative (E. coli and S. enterica) bacteria was preliminary evaluated and was found to be very high against the formers and only moderate against the later. The bactericide activity displayed by the LAE·PGGA complexes was directly related with the amount of LAE that was released from the film to the environment.

An antimicrobial stewardship program reduces antimicrobial therapy duration and hospital stay in surgical wards / Un programa de uso de antimicrobianos reduce la duración de la terapia antimicrobiana y la estancia hospitalaria en salas de cirugía

We report a quasi-experimental study of the implementation of an antimicrobial stewardship program in two surgical wards, with a pre-intervention period with just assessment of prescription and an intervention period with a prospective audit on antibiotic prescription model. There was a significant reduction of length of stay and the total days of antimicrobial administration. There were no differences in mortality between groups. The antimicrobial stewardship program led to the early detection of inappropriate empirical antibiotic treatment and was associated with a significant reduction in length of stay and the total duration of antimicrobial therapy (AU)

Presentamos un estudio cuasi-experimental de la aplicación de un programa de uso de terapia antimicrobiana en dos salas quirúrgicas, con un período de pre-intervención en que se realizó evaluación de la prescripción y un período de intervención con una auditoría prospectiva sobre la prescripción antibiótica siguiendo un modelo de recomendación. Hubo una reducción significativa de la estancia media y del total de días de tratamiento antibiótico. No hubo diferencias en la mortalidad entre los grupos. El programa de uso de terapia antimicrobiana condujo a la detección precoz de tratamiento antibiótico empírico inadecuado y se asoció con una reducción significativa de la estancia media y la duración total de la terapia antimicrobiana (AU)

Enzymatic functionalization of cork surface with antimicrobial hybrid biopolymer/silver nanoparticles.

Laccase-assisted assembling of hybrid biopolymer-silver nanoparticles and cork matrices into an antimicrobial material with potential for water remediation is herein described. Amino-functional biopolymers were first used as doping agents to stabilize concentrated colloidal dispersions of silver nanoparticles (AgNP), additionally providing the particles with functionalities for covalent immobilization onto cork to impart a durable antibacterial effect. The solvent-free AgNP synthesis by chemical reduction was carried out in the presence of chitosan (CS) or 6-deoxy-6-(ω-aminoethyl) aminocellulose (AC), leading to simultaneous AgNP biofunctionalization. This approach resulted in concentrated hybrid NP dispersion stable to aggregation and with hydrodynamic radius of particles of about 250 nm. Moreover, laccase enabled coupling between the phenolic groups in cork and amino moieties in the biopolymer-doped AgNP for permanent modification of the material. The antibacterial efficiency of the functionalized cork matrices, aimed as adsorbents for wastewater treatment, was evaluated against Escherichia coli and Staphylococcus aureus during 5 days in conditions mimicking those in constructed wetlands. Both intrinsically antimicrobial CS and AC contributed to the bactericidal effect of the enzymatically grafted on cork AgNP. In contrast, unmodified AgNP were easily washed off from the material, confirming that the biopolymers potentiated a durable antibacterial functionalization of the cork matrices.

Key design factors affecting microbial community composition and pathogenic organism removal in horizontal subsurface flow constructed wetlands.

Constructed wetlands constitute an interesting option for wastewater reuse since high concentrations of contaminants and pathogenic microorganisms can be removed with these natural treatment systems. In this work, the role of key design factors which could affect microbial removal and wetland performance, such as granular media, water depth and season effect was evaluated in a pilot system consisting of eight parallel horizontal subsurface flow (HSSF) constructed wetlands treating urban wastewater from Les Franqueses del Vallès (Barcelona, Spain). Gravel biofilm as well as influent and effluent water samples of these systems were taken in order to detect the presence of bacterial indicators such as total coliforms (TC), Escherichia coli, fecal enterococci (FE), Clostridium perfringens, and other microbial groups such as Pseudomonas and Aeromonas. The overall microbial inactivation ratio ranged between 1.4 and 2.9 log-units for heterotrophic plate counts (HPC), from 1.2 to 2.2 log units for total coliforms (TC) and from 1.4 to 2.3 log units for E. coli. The presence of fine granulometry strongly influenced the removal of all the bacterial groups analyzed. This effect was significant for TC (p=0.009), E. coli (p=0.004), and FE (p=0.012). Shallow HSSF constructed wetlands were more effective for removing Clostridium spores (p=0.039), and were also more efficient for removing TC (p=0.011) and E. coli (p=0.013) when fine granulometry was used. On the other hand, changes in the total bacterial community from gravel biofilm were examined by using denaturing gradient gel electrophoresis (DGGE) and sequencing of polymerase chain reaction (PCR)-amplified fragments of the 16S rRNA gene recovered from DGGE bands. Cluster analysis of the DGGE banding pattern from the different wetlands showed that microbial assemblages separated according to water depth, and sequences of different phylogenetic groups, such as Alpha, Beta and Delta-Proteobacteria, Nitrospirae, Bacteroidetes, Acidobacteria, Firmicutes, Synergistetes and Deferribacteres could be retrieved from DGGE bands.