Environments, Volume 5, Issue 12 (December 2018) – 14 articles

The Espírito SantoBay is located in Espírito Santo state in the eastern part of Brazil. It is surrounded by the city of Vitória on one side and by the Atlantic Ocean on the other. Superficial sediments of Espírito Santo Bay were analyzed at 12 (western shallow silt sediments) + 8 (eastern sandy sediments and relatively deep sampling stations) = 20 uniformly distributed sampling points, where geochemical analysis was performed. Nineteen elements were analyzed: Mo, Cu, Pb, Zn, Ag, Ni, Mn, Fe, As, U, Th, Sr, Cd, Sb, Bi, V, Cr, Ba, and Al. This selection was made based on the most representative heavy metals present in this area and according to the results obtained from the geochemical analysis. Their concentrations were compared with metal contamination benchmarks such asscreening quick reference tables (SQuiRTs), effects rangelow (ERL), effects range median (ERM), threshold effects levels (TELs), probable effects levels (PELs), and apparent effects thresholds (AETs). The results indicated that there was no particular pollution condition able to alter the condition of any part of this water body. The authors conclude that the Espírito Santo Bay is only moderately polluted, and some elements are virtually absent. Full article

The promotion of the development of co-digestion power plants will be intensified in many European Union member states as the main target of the Union concerning energy generation is complete decarbonisation by 2050. This potential expansion prompts the need for optimal resources allocation according to several techno-economical parameters, highlighting energy costs, power infrastructures access, and social and environmental aspects and restrictions. In Spain, agricultural and livestock biogas production trough co-digestion power plants is still poorly deployed, although the EU Directive 2009/28/EU stipulates that energy from bio-fuels and bio-liquids should contribute to a reduction of at least 35% of greenhouse gas emissions in order to be taken into account, and many authors agree that biogas produced from energy crops and livestock waste fulfils this criterion. Moreover, biogas can be used to upgrade gas pipelines and may have other efficient thermal uses. In this paper, through a Geographical Information System approach, eight different co-digestion mixtures have been evaluated and the most profitable ones have been optimized for the Spanish Iberian Peninsula according to the geographical distribution of the resources. Furthermore, the best locations for co-digestion power plants siting have been calculated, minimizing transport costs and considering technical, environmental and social restrictions. In contrast with other studies, this proposed approach is focused on a holistic optimization. Results show that in Spain the most feasible co-digestion mixtures are based on slurry, glycerine and animal meals, and four areas arise with an outstanding energetic potential up to 208 MW exploitable in large electrical power plants, while 347 MW can be reserved for distributed generation based on this technology. Full article

Particulate matter studies have been conducted regularly in the capital city of Mongolia. In contrast, studies related to the source and general estimation of levels of sulfur dioxide (SO₂) over whole years are lacking. To explore the yearly trend in SO₂, whole-year data of air pollutants were obtained from the Air Pollution Reducing Department. The results showed that the annual average concentration of SO₂ was 32.43 µg/m³ at the Amgalan official monitoring station in 2017, which changed from 53 µg/m³ in 2016, representing a reduction of around 40%. The back-trajectory model and the National Oceanic and Atmospheric Administration (NOAA)’s hybrid single particle Lagrangian integrated trajectory model (HYPSLIT) were used to determine the source of SO₂. A total of 8760 backward trajectories were divided into eight groups. The results showed that 78.8% of the total trajectories in Ulaanbaatar came from an area inside Mongolia. The results showed that pollutants enter Ulaanbaatar mainly from the northwest and north during the winter season. There are industrial cities, such as Darkhan and Sukhbaatar, in North Mongolia. Air pollutants created in the industrial area traveled into Ulaanbaatar during the winter season. Full article

In the modern world, noise pollution continues to be a major problem that impairs people’s health, and road traffic is a primary contributor to noise emissions. This article describes an environmental impact study of the noise generated by the reconstruction of an urban section of a highway. Noise maps were calculated, and an environmental impact matrix was generated to determine the environmental impact of this reconstruction. The implementation of noise barriers was simulated based on these noise maps, and the effectiveness of the barriers was evaluated using Artificial Neural Networks (ANNs) combined with Design of Experiments (DoE). A functional variable significance analysis was then made for two parameters, namely, the coefficient of absorption of the barrier material and the barrier height. The aim was to determine the influence of these parameters on sound attenuation and on the formation of acoustic shadows. The results obtained from the ANNs and DoE were consistent in demonstrating that the absorption coefficient strongly influences the noise attenuation provided by noise barriers, while barrier height is correlated with the formation of larger areas of acoustic shadow. The environmental impact matrix also indicates that the existence of noise pollution has a negative effect on the environment, but that this impact can be reversed or minimized. The application of simulated noise barriers demonstrated that noise levels can be reduced to legally acceptable levels. Full article

Leisure noise is a continual source of complaints from residents of affected areas, and its management poses a difficult challenge for local authorities, especially in tourist destinations, such as Málaga. The city council of this city has set a goal of mitigating the noise produced by leisure activities. In 2015, it began mitigation actions, starting with the assessment of the noise through a temporal monitoring campaign in two specific areas of the city where leisure activities are prevalent. Beyond the objective assessment of the noise levels through measurements, the research team programmed several communication actions (a) to improve the trust, visibility, and reliability of the noise-monitoring process through press and social networks and (b) to gather the subjective response to noise from residents in the affected areas. The results obtained were very helpful to raise awareness among stakeholders and to support the planning and prioritization of further noise mitigation actions. Furthermore, the research team aimed to analyze the long-term noise indicators and the time-based patterns of noise in different areas, trying to establish conclusions that can be helpful for other areas of the city and testing the applicability of previous leisure noise models for the city of Málaga. The results showed that the noise levels in the leisure areas in Málaga are quite high at night (Ln over 60 dBA in almost every location), especially during weekend nights, where we observed locations with noise levels over 75–80 dBA until late hours of the night. We also made an analysis of the leisure noise models proposed in previous investigations and their performance in the case of Málaga. Full article

Health Services building stock is usually the top energy consumer in the Administrative sector, by a considerable margin. Therefore, energy consumption supervision, prediction, and improvement should be carried out for this group in a preferential manner. Most prior studies in this field have characterized the energy consumption of buildings based on complex simulations, which tend to be limited by modelisation restrictions and assumptions. In this paper, an improved method for the clusterization of buildings based on their electrical energy consumption is proposed and, then, reference profiles are determined by examining the variation of energy consumption over the typical yearly consumption period. The temporary variation has been analyzed by evaluating the temporary evolution of the area consumption index through data mining and statistical clusterization techniques. The proposed methodology has been applied to building stock of the Health Services in the Castilla y León region in Spain, based on three years of historical monthly electrical energy consumption data for over 250 buildings. This building stock consists of hospitals, health centers (with and without emergency services) and a miscellaneous set of administrative and residential buildings. Results reveal five distinct electrical consumption profiles that have been associated with five reference buildings, permitting significant improvement in the demand estimation as compared to merely using the classical energy consumption indicators. Full article

Matching demand profile and solar irradiance availability is necessary to meet space heating and domestic hot water needs by means of an air-source heat pump and photovoltaic system in a single-family house. Demand-side management, with smart control of the water storage set-point, is a simple but effective technique. Several studies in the literature pursue demand-side matching and self-consumption goals through system adjustments based on the model predictive control. This study proposes a rule-based control strategy, based on instantaneous photovoltaic (PV) power production, with the purpose of enhancing the self-consumption. This strategy exploits the building’s thermal capacitance as a virtual battery, and the thermal storage capacity of the system by running the heat pump to its limit when PV surplus power is available, and by eventually using an electric heater in order to reach higher temperatures. Results of annual dynamic simulations of a building and its heating system show that the proposed rule-based control strategy is able to reduce significantly the energy exchanges between the system and the grid. Despite the enlarged renewable energy share, economic analysis points out the pursuit of the self-consumption goal may lead to a diminution of the economic advantage in the Italian context (Italian weather data and the electric power pricing scheme). Full article

The study of land use/land cover (LULC) has become an increasingly important stage in the development of forest ecosystems strategies. Hence, the main goal of this study was to describe the vegetation change of Azrou Forest in the Middle Atlas, Morocco, between 1987 and 2017. To achieve this, a set of Landsat images, including one Multispectral Scanner (MSS) scene from 1987; one Enhanced Thematic Mapper Plus (ETM+) scene from 2000; two Thematic Mapper (TM) scenes from 1995 and 2011; and one Landsat 8 Operational Land Imager (OLI) scene from 2017; were acquired and processed. Ground-based survey data and the normalized difference vegetation index (NDVI) were used to identify and to improve the discrimination between LULC categories. Then, the maximum likelihood (ML) classification method was applied was applied, in order to produce land cover maps for each year. Three classes were considered by the classification of NDVI value: low-density vegetation; moderate-density vegetation, and high-density vegetation. Our study achieved classification accuracies of 66.8% (1987), 99.9% (1995), 99.8% (2000), 99.9% (2011), and 99.9% (2017). The results from the Landsat-based image analysis show that the area of low-density vegetation was decreased from 27.4% to 2.1% over the past 30 years. While, in 2017, the class of high-density vegetation was increased to 64.6% of the total area of study area. The results of this study show that the total forest cover remained stable. The present study highlights the importance of the image classification algorithms combined with NDVI index for better understanding the changes that have occurred in this forest. Therefore, the findings of this study could assist planners and decision-makers to guide, in a good manner, the sustainable land development of areas with similar backgrounds. Full article

The urgent need for the reduction of greenhouse gas (GHG) emissions requires efficient and integrated energy communities in order to decrease final energy demand and sustain energy transitions towards renewable energy sources (RES). This introduces a big research challenge for future energy systems design and optimization, given the multi-level and inter-sectorial dimensions of the problem. Buildings cover a central role in this context, because they represent the nexus between different energy carrier networks. The study of the management of multi-sector and multi-energy systems presents several challenges, such as the need to take into account uncertainties, to represent the heterogeneity of the energy demand and the scalability of the problem. This paper aims at outlining such a framework, and at showing the state-of-the-art nature of the above-mentioned challenges. Full article

Analysis of the hourly Canadian Prairie data for the past 60 years has transformed our quantitative understanding of land–atmosphere–cloud coupling. The key reason is that trained observers made hourly estimates of the opaque cloud fraction that obscures the sun, moon, or stars, following the same protocol for 60 years at all stations. These 24 daily estimates of opaque cloud data are of sufficient quality such that they can be calibrated against Baseline Surface Radiation Network data to yield the climatology of the daily short-wave, long-wave, and total cloud forcing (SWCF, LWCF and CF, respectively). This key radiative forcing has not been available previously for climate datasets. Net cloud radiative forcing changes sign from negative in the warm season, to positive in the cold season, when reflective snow reduces the negative SWCF below the positive LWCF. This in turn leads to a large climate discontinuity with snow cover, with a systematic cooling of 10 °C or more with snow cover. In addition, snow cover transforms the coupling between cloud cover and the diurnal range of temperature. In the warm season, maximum temperature increases with decreasing cloud, while minimum temperature barely changes; while in the cold season with snow cover, maximum temperature decreases with decreasing cloud, and minimum temperature decreases even more. In the warm season, the diurnal ranges of temperature, relative humidity, equivalent potential temperature, and the pressure height of the lifting condensation level are all tightly coupled to the opaque cloud cover. Given over 600 station-years of hourly data, we are able to extract, perhaps for the first time, the coupling between the cloud forcing and the warm season imbalance of the diurnal cycle, which changes monotonically from a warming and drying under clear skies to a cooling and moistening under cloudy skies with precipitation. Because we have the daily cloud radiative forcing, which is large, we are able to show that the memory of water storage anomalies, from precipitation and the snowpack, goes back many months. The spring climatology shows the memory of snowfall back through the entire winter, and the memory in summer, goes back to the months of snowmelt. Lagged precipitation anomalies modify the thermodynamic coupling of the diurnal cycle to the cloud forcing, and shift the diurnal cycle of the mixing ratio, which has a double peak. The seasonal extraction of the surface total water storage is a large damping of the interannual variability of precipitation anomalies in the growing season. The large land-use change from summer fallow to intensive cropping, which peaked in the early 1990s, has led to a coupled climate response that has cooled and moistened the growing season, lowering cloud-base, increasing equivalent potential temperature, and increasing precipitation. We show a simplified energy balance of the Prairies during the growing season, and its dependence on reflective cloud. Full article

H₂ permeation and separation properties of two Pd-based composite membranes were evaluated and compared at 400 °C and at a pressure range of 150 kPa to 600 kPa. One membrane was characterized by an approximately 8 μm-thick palladium (Pd)-gold (Au) layer deposited on an asymmetric microporous Al₂O₃ substrate; the other membrane consisted of an approximately 11 μm-thick pure palladium layer deposited on a yttria-stabilized zirconia (YSZ) support. At 400 °C and with a trans-membrane pressure of 50 kPa, the membranes showed a H₂ permeance of 8.42 × 10⁻⁴ mol/m²·s·Pa^0.5 and 2.54 × 10⁻⁵ mol/m²·s·Pa^0.7 for Pd-Au and Pd membranes, respectively. Pd-Au membrane showed infinite ideal selectivity to H₂ with respect to He and Ar at 400 °C and a trans-membrane pressure of 50 kPa, while the ideal selectivities for the Pd membrane under the same operating conditions were much lower. Furthermore, the permeation tests for ternary and quaternary mixtures of H₂, CO, CO₂, CH₄, and H₂O were conducted on the Pd/YSZ membrane. The H₂ permeating flux decreased at the conclusion of the permeation tests for all mixtures. This decline however, was not permanent, i.e., H₂ permeation was restored to its initial value after treating the membrane with H₂ for a maximum of 7 h. The effects of gas hourly space velocity (GHSV) and the steam-to-carbon (S/C) ratio on H₂ permeation were also investigated using simulated steam methane reforming mixtures. It was found that H₂ permeation is highest at the greatest GHSV, due to a decline in the concentration polarization effect. Variations in S/C ratio however, showed no significant effect on the H₂ permeation. The permeation characteristics for the Pd/YSZ membrane were also investigated at temperatures ranging from 350 to 400 °C. The pre-exponential factor and apparent activation energy were found to be 5.66 × 10⁻⁴ mol/m²·s·Pa^0.7 and 12.8 kJ/mol, respectively. Scanning Electron Microscope (SEM) and X-ray diffraction (XRD) analyses were performed on both pristine and used membranes, and no strong evidence of the formation of Pd-O or any other undesirable phases was observed. Full article

The application of seawater desalination technology using a reverse osmosis (RO) membrane has been expanding because it requires less energy compared with other distillation methods. Even in Middle Eastern countries where energy costs are lower such as Saudi Arabia, UAE, Qatar, and Kuwait, almost all desalination plants where only water production is required have adopted the RO method. However, large plants in excess of half mega-ton size are required, and Seawater Reverse Osmosis (SWRO) operation lacks reliability due to heavy biofouling and large amounts of briny discharge contaminated with chemicals. For reliable desalination systems with lower environmental impact, membrane-processing technology, including biotechnology (such as marine bacteria), has been examined as national research in Japan in the “Mega-ton Water System” project. We examined the influence of chlorination on marine bacteria using the fluorescence microscopic observation method and found that the effect of chlorination is limited. Chlorination sterilization triggers biofouling and sodium bisulfate (SBS) addition as a de-chlorinating agent also triggers biofouling, so a process with no chlorine or SBS addition would reduce biofouling. As polyamide SWRO membranes have low chlorine resistivity, such a process would enable longer membrane life in real plants. We used a biofouling monitoring technology, the Membrane Biofilm Formation Rate (mBFR), to design a process that involves no chlorine or SBS addition and verified it in the Arabian Gulf Sea, of Saudi Arabia, which is one of the most difficult and challenging seawaters in which to control biofouling. Furthermore, by minimizing the addition of a sterilizer, the desalination system became more environmentally friendly. Full article

A Home Energy Management System (HEMS) has no direct and immediate energy-saving effect. It gives insight into the resident’s behaviour regarding energy use. When this is linked to the appropriate feedback, the resident is in a position to change his or her behaviour. This should result in reduced gas and/or electricity consumption. The aim of our study is to contribute to the effective use of HEMSs by identifying types of homeowners in relation to the use of a HEMS. The research methods used were a literature review and the Q-method. A survey using the Q-method was conducted among 39 owners of single-family homes in various Rotterdam neighbourhoods. In order to find shared views among respondents, a principal component analysis (PCA) was performed. Five different types of homeowners could be distinguished: the optimists, the privacy-conscious, the technicians, the sceptics, and the indifferent. Their opinions vary as regards the added value of a HEMS, what characteristics a HEMS should have, how much confidence they have in the energy-saving effect of such systems, and their views on the privacy and safety associated with using a HEMS. The target group classification can be used as input for a way in which local stakeholders, e.g., a municipality, can offer HEMSs that are in line with the wishes of the homeowner. Full article