Potential nitrification and denitrification on different surfaces in a constructed treatment wetland

Improved understanding of the importance of different surfaces in supporting attached nitrifying and denitrifying bacteria is essential if we are to optimize the N removal capacity of treatment wetlands. The aim of this study was therefore to examine the nitrifying and denitrifying capacity of different surfaces in a constructed treatment wetland and to assess the relative importance of these surfaces for overall N removal in the wetland. Intact sediment cores, old pine and spruce twigs, shoots of Eurasian watermilfoil (Myriophyllum spicatum L.), and filamentous macro-algae were collected in July and November 1999 in two basins of the wetland system. One of the basins had been constructed on land that contained lots of wood debris, particularly twigs of coniferous trees. Potential nitrification was measured using the isotope-dilution technique, and potential denitrification was determined using the acetylene-inhibition technique in laboratory microcosm incubations. Nitrification rates were highest on the twigs. These rates were three and 100 times higher than in the sediment and on Eurasian watermilfoil, respectively. Potential denitrification rates were highest in the sediment. These rates were three times higher than on the twigs and 40 times higher than on Eurasian watermilfoil. The distribution of denitrifying bacteria was most likely due to the availability of organic material, with higher denitrification rates in the sediment than on surfaces in the water column. Our results indicate that denitrification, and particularly nitrification, in treatment wetlands could be significantly increased by addition of surfaces such as twigs.     

Carbon taxation as a means to incentivize forest and fire management

Environment, Development and Sustainability - Wildland fires are increasingly becoming a major concern for many European countries, affecting ecosystems and societies, and they are expected to...     

Biodegradation of azo dyes by the yeast Candida zeylanoides in batch aerated cultures

A number of simple azo dyes was degraded in liquid aerated batch cultures by a strain of the yeast Candida zeylanoides. The standard decolorization medium contained glucose as a carbon and energy source, and its pH was either controlled to 5.0-5.2, or allowed to decrease to 3.2-2.8, in the course of microorganism growth. The extent of colour removal in the culture medium was assessed through the decrease in dye absorbance of the supernatants. The extent of colour removal ranged from 44 to 90%, after 7 days, for 5 out of 6 dyes studied in shaked cultures, without pH control, and from 46 to 67%, after 22 hours, for 6 out of 8 dyes in batch experiments, at controlled pH.     

Study of atmospheric ozone formation by means of a neural network-based model

The occurrence of high ozone levels in the atmosphere of urban areas has become a serious pollution problem in a number of large cities in the world. Although mathematical models have been proposed for predicting ozone concentrations as a function of a number of gas components, sometimes there are uncertainties due to lack of the combined effects of meteorological factors and the complex chemical reaction system involved. The application of neural network models, based on measured values of air pollutants and meteorological factors at different locations within the S?o Paulo Metropolitan Area, combine chemical and meteorological information. This has shown to be a promising tool for predicting ozone concentration. Simulations carried out with the model indicate the sensitivity of ozone in relation to different air pollution and weather conditions. Predictions using this model have shown good agreement with measured values of ozone concentrations.     

Environmental noise in hospitals: a systematic review

Environmental noise has been growing in recent years, causing numerous health problems. Highly sensitive environments such as hospitals deserve special attention, since noise can aggravate patients’ health issues and impair the performance of healthcare professionals. This work consists of a systematic review of scientific articles describing environmental noise measurements taken in hospitals between the years 2015 and 2020. The researchers started with a consultation of three databases, namely, Scopus, Web of Science, and ScienceDirect. The results indicate that for the most part, these studies are published in journals in the fields of medicine, engineering, environmental sciences, acoustics, and nursing and that most of their authors work in the fields of architecture, engineering, medicine, and nursing. These studies, which are concentrated in Europe, the Americas, and Asia, use as reference values sound levels recommended by the World Health Organization. L_eq measured in hospital environments showed daytime values ranging from 37 to 88.6 dB (A) and nighttime values of 38.7 to 68.8 dB (A). L_eq values for outdoor noise were 74.3 and 56.6 dB (A) for daytime and nighttime, respectively. The measurements were taken mainly inside hospitals, prioritizing more sensitive departments such as intensive care units. There is a potential for growth in work carried out in this area, but research should also include discussions about guidelines for improvement measures aimed at reducing noise in hospitals.

Graphical abstract

     

Quantitative PCR Detection and Characterisation of Human Adenovirus,Rotavirus and Hepatitis A Virus in Discharged Effluents of Two Wastewater Treatment Facilities in the Eastern Cape,South Africa

The occurrence of enteric viruses in reclaimed wastewater, their removal by efficient treatment processes and the public health hazards associated with their release into the environments are of great significance in environmental microbiology. In this study, TaqMan-based real-time polymerase chain reaction (qPCR) was used to assess the prevalence of human adenovirus (HAdV), rotavirus (RV) and hepatitis A virus (HAV) in the final effluents of two wastewater treatment plants in the Eastern Cape Province, South Africa, over a twelve-month sampling period. The correlation between the concentrations of viruses in the effluents samples and faecal coliform (FC) densities were assessed as to validate the use of FC as microbiological indicator in water quality assessment. HAdV was detected in 62.5 % (30/48) of the samples with concentrations ranging between 8.4 × 10¹ and 1.0 × 10⁵ genome copies/L while HAV and RV were only detected at concentrations below the set detection limits. FCs densities ranged from 1 to 2.7 × 10⁴ CFU/100 ml. Adenovirus species HAdV-B (serotype 2) and HAdV-F (serotype 41) were detected in 86.7 % (26/30) and 6.7 % (2/30) of the HAdV-positive samples, respectively. No consistent seasonal trend was observed in HAdV concentrations, however, increased concentrations of HAdV were generally observed in the winter months. Also, there was no correlation between the occurrence of HAdV and FC at both the treatment plants. The persistent occurrence of HAdV in the discharged treated effluents points to the potential public health risk through the release of HAdV into the receiving watersheds, and the possibility of their transmission to human population.     

Modelling of coastal vulnerability in the stretch between the beaches of Porto de Mós and Falésia, Algarve (Portugal)

Coastal systems are characterized by high geophysical and biophysical sensitivity as being their massive occupation a serious issue concerning their self-regulation. Worldwide coastal areas are exposed to problems such as coastal erosion, degradation and destruction of marine habitats, pollution and rising sea level. Thus, it is crucial to design models of coastal vulnerability assessment to ensure a better management of coastal areas. This study characterizes the vulnerability of the coastal stretch between the beaches of Porto de Mós and Falésia in the Algarve, corresponding to 52?km of the south coast of Portugal. The expansion of urban areas was modelled using a Cellular Automata (CA) based approach. Results show that 65% of the coastal stretch has high and very high vulnerability caused by both physical and human factors. Results further indicate that urban growth may interfere with the natural evolution of the coastal geomorphology. The scenario of urban expansion for the year 2015 highlights the need to develop effective urban planning processes to ensure a correct balance between the geophysical resilience of coastal systems and the promotion of the coastal sector as a strategic asset for the regional and national economy.     

Data depth for the uniform distribution

Given a set $X$ of $k$ points and a point $z$ in the $n$ -dimensional euclidean space, the Tukey depth of $z$ with respect to $X$ , is defined as $m/k$ , where $m$ is the minimum integer such that $z$ is not in the convex hull of some set of $k-m$ points of $X$ . If $z$ belongs to the closed region $B$ delimited by an ellipsoid, define the continuous depth of $z$ with respect to $B$ as the quotient $V(z)/\text{ Vol }(B)$ , where $V(z)$ is the minimum volume of the intersection of $B$ with the halfspaces defined by any hyperplane passing through $z$ , and $\text{ Vol }(B)$ is the volume of $B$ . We consider $z$ a random variable and prove that, if $z$ is uniformly distributed in $B$ , the continuous depth of $z$ with respect to $B$ has expected value $1/2^{n+1}$ . This result implies that if $z$ and $X$ are uniformly distributed in $B$ , the expected value of Tukey depth of $z$ with respect to $X$ converges to $1/2^{n+1}$ as the number of points $k$ goes to infinity. These findings have applications in ecology, namely within the niche theory, where it is useful to explore and characterize the distribution of points inside species niche.     

Bacterial communities of the marine sponges Hymeniacidon heliophila and Polymastia janeirensis and their environment in Rio de Janeiro, Brazil

In this study we performed a survey of the bacterial communities associated with the Western Atlantic demosponges Hymeniacidon heliophila and Polymastia janeirensis, based on 16S rRNA sequencing and transmission electron microscopy (TEM). We compared diversity and composition of the sponge-associated bacteria to those of environmental bacteria, represented by free-living bacterioplankton and by bacteria attached to organic particulate matter in superficial sediments. Partial bacterial 16S rRNA sequences from seawater, sediment, and sponges were retrieved by PCR, cloning, and sequencing. Sequences were subjected to rarefaction analyses, phylogenetic tree construction, and LIBSHUFF quantitative statistics to verify coverage and similarity between libraries. Community structure of the free-living bacterioplankton was phylogenetically different from that of the sponge-associated bacterial assemblages. On the other hand, some sediment-attached bacteria were also found in the sponge bacterial community, indicating that sponges may incorporate bacteria together with sediment particles. Rare and few prokaryotic morphotypes were found in TEM analyses of sponge mesohyl matrix of both species. Molecular data indicate that bacterial richness and diversity decreases from bacterioplankton, to particulate organic sediment, and to H. heliophila and P. janeirensis. Sponges from Rio de Janeiro harbor a pool of novel and exclusive sponge-associated bacterial taxa. Sponge-associated bacterial communities are composed of both taxons shared by many sponge groups and by species-specific bacteria.     

Occurrence and behaviour of pharmaceutical compounds in a Portuguese wastewater treatment plant: Removal efficiency through conventional treatment processes

Wastewater treatments can eliminate or remove a substantial amount of pharmaceutical active compounds (PhACs), but there may still be significant concentrations of them in effluents discharged into surface water bodies. Beirolas wastewater treatment plant (WWTP) is located in the Lisbon area and makes its effluent discharges into Tagus estuary (Portugal). The main objective of this study is to quantify a group of 32 PhACs in the different treatments used in this WWTP. Twelve sampling campaigns of wastewater belonging to the different treatments were made in 2013–2014 in order to study their removal efficiency. The wastewaters were analysed by solid phase extraction (SPE) and ultra-performance liquid chromatography coupled with tandem mass detection (UPLC–MS/MS). The anti-diabetics were the most frequently found in wastewater influent (WWI) and wastewater effluent (WWE) (208 and 1.7 μg/L, respectively), followed by analgesics/antipyretics (135 μg/L and < LOQ, respectively), psychostimulants (113 and 0.49 μg/L, respectively), non-steroidal anti-inflammatory drugs (33 and 2.6 μg/L, respectively), antibiotics (5.2 and 1.8 μg/L, respectively), antilipidemics (1.6 and 0.24 μg/L, respectively), anticonvulsants (1.5 and 0.63 μg/L, respectively) and beta blockers (1.3 and 0.51 μg/L, respectively). A snapshot of the ability of each treatment step to remove these target PhACs is provided, and it was found that global efficiency is strongly dependent on the efficiency of secondary treatment. Seasonal occurrence and removal efficiency was also monitored, and they did not show a significant seasonal trend.