Metals in the soil of urban cemeteries in Carazinho (South Brazil) in view of the increase in deaths from COVID-19: projects for cemeteries to mitigate environmental impacts

Environment, Development and Sustainability - The increasing mortality of COVID-19 can aggravate soil contamination by metals, harmful to the health of the population, requiring new projects for...     

Enhancing Diatom Growth by Using Zeolites to Change Seawater Composition (4 pp)

- Aims and Scope. The purpose of this study was to test whether two zeolites produced synthetically (products of zeolitic nature, PZN) could influence either the yield of a diatom culture or the chemical changes in the cultures. For this purpose, Phaeodactylum tricornutum was used as test organism in a culture medium of natural seawater enriched with N and P having negligible amounts of ammonia. Methods The PZN ZEBEN-06 and ZESTEC-56 were used in parallel experiments. The composition of trace metals and organic compounds with chelate activity in the culture media, were determined by anodic or cathodic stripping voltammetry. The impact of leaching silicon on the algal yield was evaluated by comparing the growth in the presence or absence of PZN, in seawater enriched or not-enriched with silicon. Results and Conclusions Both PZN significantly promoted the algal yield even in the absence of added silicon, a limiting nutrient for diatom growth. The PZN acted as a silicon buffer while providing a source of silicon required for growth. In addition, PZN released into the seawater small but significant amounts of the limiting micro-nutrient manganese (its concentration doubled during the experiments), while simultaneously removing relatively high quantities of zinc from the seawater. The presence of PZN inhibited the releasing of chelated compounds. These changes (sorption/desorption) caused by the PZN in the concentrations in the solutions used as culture media of P. tricornutum were probably responsible for the differences in both the diatom and exudation observed in the tested cultures.     

Design and assessment of a chamber to expose plants to simulated aerosol and rain

Increased reports of contaminants in atmospheric aerosols necessitate the development of exposure systems that can accurately simulate aerosols for research purposes. This study outlines the design, construction, cost, and performance of a simple plexiglass chamber equipped with nozzles for rain and aerosol generation. The chamber occupies approximately 152 cm x 125 cm (height x width) space and can be used to expose six large (625 cm2) plants or twelve smaller (144 cm2) ones. The total cost of the materials used in construction, including nozzles, was less than 700 dollars. Repeated analysis of the quantity and particle size distribution of the simulated aerosol and rain showed them to be highly predictable. By adjusting the volume and/or concentration of the spray, and the position of plants within the chamber, particle sizes typical of environmental aerosols (< or = 20 microm) and rains (0.7 to 1.2 mm) could be applied to experimental plants. This sample, economical system will allow for precise simulations of important aerosols and rain events in the study of their impingement on plants.     

Interspecific competition between native Eurasian red squirrels and alien grey squirrels: does resource partitioning occur?

In heterogeneous environments, differential niche selection by two competing species will result in niche partitioning so that individuals of each species can maximise their fitness under different sets of environmental variables. Thus, niche partitioning is considered essential to allow co-existence of ecologically related species. To assess whether niche partitioning was occurring between native red squirrels and alien grey squirrels living together in a 13-ha high-quality mixed deciduous woodland in north Italy, we investigated temporal and spatial patterns in their activity and foraging behaviour between 1996 and 1998. We used live trapping and radio-tracking to study numbers, distribution and behaviour of squirrels. Daily and seasonal temporal activity patterns, and activity on the ground and in the trees, were similar in the two species. However, grey squirrels were more tree specialists and had a narrower tree-species niche width than red squirrels, in particular making greater use of oak. Other studies of red and grey squirrels in allopatry show that the two species differ in the extent they utilise oak. Overall, tree-species niche overlap was about 70%. Grey squirrels had larger home ranges than red squirrels. Home ranges and core areas of both species were larger in males than females. Also, intraspecific home range and core-area overlap patterns were similar to those found in allopatric populations of these species. Overall, there was no evidence that the use of space of one species was affected by the other. Our results show that there was no niche partitioning of activity or foraging behaviour in time or space during the study. This suggests that, at moderate grey-squirrel densities, red squirrels are unable to avoid competition with grey squirrels, and that competition for food and/or space will occur when these resources become limiting.     

Watershed integrated management: A decision-support model on Sete Cidades Lake (Azores)

The Sete Cidades Lake (437 ha) is located in a volcanic crater of São Miguel Island (Azores). The watershed is 1923 ha, and 25% of it is covered with water. Extreme logging and the use of fertilizers in the cattle grazing areas have caused sedimentation and eutrophication of the main water body (Carlson Trophic State Index TSI = 40–50 mesoeutrophy). To deal with the issue, a linear programming model was created to generate efficient land-use scenarios for different amounts of phosphorus release. The model was calibrated for the present situation and then simulated to obtain 29 scenarios. It allowed us to derive parameters for each scenario. Then a multiobjective program was used to derive an acceptable weight for each indicator. The dominant solutions were discovered and discussed with different stakeholders.     

Influence of fly ash on soil physical properties and turfgrass establishment

A field study (1993-96) assessed the benefits of applying unusually high rates of coal fly ash as a soil amendment to enhance water retention of soils without adversely affecting growth and marketability of the turf species, centipedegrass [Eremochloa ophiuroides (Munro) Hack.]. A Latin Square plot design was employed that included 0 (control, no ash applied), 280, 560, and 1120 Mg ha-1 application rates of unweathered precipitator fly ash. The fly ash was spread evenly over each plot area, rototilled, and allowed to weather under natural conditions for 8 mo before seeding. High levels of soluble salts, indicated by the electrical conductivity (EC) of soil extracts, in tandem with an apparent phytotoxic effect from boron (B), apparently inhibited initial plant establishment as shown by substantially lower germination counts in treated soil. However, plant height and rooting depth were not adversely affected, as were the dry matter (DM) yields throughout the study period. Ash treatment did not significantly influence water infiltration rate, bulk density, or temperature of the soil, but substantially improved water-holding capacity (WHC) and plant-available water (PAW). Enhanced water retention capacity improved the cohesion and handling property of harvested sod.     

Analysis of the bacterial community composition in acidic well water used for drinking in Guinea-Bissau, West Africa

Potable water is a resource out of reach for millions worldwide,and the available water may be chemically and microbiologically compromised. This is particularly acute in Africa,where water-networks may be non-existent or restricted to a small fraction of the urban population,as in the case of Guinea-Bissau,West Africa. This study was carried out seasonally in Bolama(11°N),where unprotected hand-dug wells with acidic water are the sole source of water for the population. We inspected the free-living bacterial community dynamics by automated rRNA intergenic spacer analyses,quantitative polymerase chain reaction and cloning approaches.The results revealed a clear seasonal shift in bacterial assemblage composition and microbial abundance within the same sampling site. Temperature,pH and turbidity,together with the infiltration and percolation of surface water,which takes place in the wet season,seemed to be the driving factors in the shaping and selection of the bacterial community and deterioration of water quality. Analysis of 16 S rDNA sequences revealed several potential pathogenic bacteria and uncultured bacteria associated with water and sediments,corroborating the importance of a culture-independent approach in drinking water monitoring.     

A data envelopment analysis approach to choose transport modes based on eco-efficiency

The main purpose of this paper is to use data envelopment analysis (DEA) as a support tool to establish a relative eco-efficiency measure for the different bioethanol transportation modes and to prioritize these different modes according to these figures. From a review of previous studies, we selected a set of attributes to be considered in DEA, and then experts were consulted about the importance of these attributes for this type of analysis in Brazil. To quantify the attributes, we established indicators and submitted them to DEA to evaluate the relative eco-efficiency to each available transportation mode for the case studied. The use of DEA established the guidelines to improve the transportation modes that were not considered 100?% relatively eco-efficient. These improvements could be achieved considering the percentage, reduction or growth for each of the attributes in the selected transportation mode. The proposed approach can help the Brazilian government to develop a plan to improve the bioethanol transportation infrastructure and can be used to propel short-term improvements in the highway transport of bioethanol, which could be useful given the Brazilian transportation context.