Search

The present paper presents the rutting evaluation of different asphalt mixtures in use in the state of Rio Grande do Sul, Brazil's southernmost-region, through the uniaxial repeated load test and the monitoring of mixtures performance in field, culminating in a criteria proposal for the parameter Flow Number depending on traffic. For this, five distinct asphalt binders were studied, five grain size distributions, three warm mixtures and 21 hot mixes, with different mineralogical types of aggregates, and 15 monitored test sites distributed geographically throughout the state. The results indicated that the binder modifications were the most influential characteristics in the asphalt mixtures rutting. Also, it was verified that the Flow Number criteria proposed so far in the country present significant differences. In this way, a new criterion was suggested, and it is possible to infer a good applicability for asphalt concretes, except for warm mixes and those with rubber binder. [ABSTRACT FROM AUTHOR]

Recycling post-consumer packaging of high and linear/low-density polyethylene (HDPE, LDPE/LLDPE) and polypropylene (PP) (most representative in any plastic waste stream) is a viable alternative. However, these packages must be washed first, especially those with a high content of contaminants (such as yogurt—HDPE and margarine—PP). Therefore, this study aimed to develop a complete pre-treatment of polymeric wastes (HDPE, LDPE/LLDPE, PP) involving the steps of quantification, characterization, washing (pre-wash/ washing/rinsing), treatment of the generated effluent and the reuse of treated water in a closed circuit. Afterward, the qualification of recyclable material selectors was performed with associations/cooperatives of recyclable material in the Rio Grande do Sul, South region of Brazil. The results indicated that the subdivision in prewash/washing/rinsing utilizing sulfonic acid (1.16% v/v), lauryl (sodium lauryl ether sulfate) (0.53% v/v) and soda (0.31% v/v) was suitable for obtaining clean polymeric waste. Treatment of effluent using aluminum sulfate (4 g L−1) as a coagulant, followed by filtration, was efficient with removal values greater than 90%. These characteristics of treated water allowed its reutilization water of a safe way in closed circuit in the process of washing of the polymeric wastes. Finally, a total of sixty-four selectors of recyclable materials were trained and the theoretical–practical training was quite satisfactory for more than 95% of selectors. Therefore, it can be concluded that the great importance to transmitting the knowledge to society generated in this studies and thus provides best conditions for the development of these selectors of recyclable materials. [ABSTRACT FROM AUTHOR]

The present study verified the potential of volcanic rock powder residues originating from the extraction of semi-precious rocks in the state of Rio Grande do Sul, Brazil, as precursors or adsorbents for dyes and metallic ion removal from water. In this way, it is possible to add value and give an adequate destination to this waste. Volcanic rock powder residues from Ametista do Sul (AME) and Nova Prata (NP) were the starting materials. These were used naturally or submitted to the alkaline activation process at 60 °C and alkaline fusion at 550 °C. The analysis of the starting samples by X-ray fluorescence (XRF) revealed that they are mainly composed of aluminum, calcium, iron, and silicon oxides, which corroborates the presence of numerous crystalline phases observed in the X-ray diffraction spectra (XRD). Moreover, by XRD analysis of the synthesized samples, alkaline fusion proved to be more efficient in the dissolution of crystalline phases and consequently in the formation of the amorphous phase (more reactive). Furthermore, the adsorption tests with acid green and acid red dyes and Ag+, Co2+, and Cu2+ ions indicated the viability of using residual volcanic rock powder as raw material for the production of adsorbents functionalized with sodium hydroxide, being that the samples synthesized by alkaline fusion showed better results of removal and adsorption capacity for all the contaminants used in the study. [ABSTRACT FROM AUTHOR]

From the territorial perspective of development, in the territory of the Fourth Colony of Italian immigration, located in the center of the state of Rio Grande do Sul / Brazil has been investing in tourism to leverage its development in line with other productive activities. As a strategy, tourism has been used to compose the commercialization and dissemination narratives of the specific natural and cultural resources found in the territory itself. Despite the public incentive to develop the activity, the creation of tourist routes and itineraries did not meet the expectations of local entrepreneurs. In this aspect, the main objective was to analyze the aspects that inhibited the process of tourism development in the territory. Methodologically, the study has a qualitative cut and the information was collected through primary and secondary sources. As a result, the study found that despite government support, local actors were not included in the tourism development process and the fragility of social capital prevented many tourism activities from succeeding over the years. However, tourism has resumed its growth process driven by local actors who jointly prepare and at the same time experience recreational activities, rural trails and paths, festivities and gastronomic events. [ABSTRACT FROM AUTHOR]

• The higher the clay content was, the higher was the amplitude of the mineral bands. • VIS–NIR–SWIR spectroscopy successfully identified the mineral composition of soils. • The separation of samples by textural class facilitated mineralogical identification. The physical and chemical attributes of soils are strongly influenced by the nature of the minerals they contain and their concentration. Thus, soil texture is directly dependent on the content in clayey minerals, which influences a number of characteristics such as water dynamics. Although the mineralogical composition of soil is usually determined by X-ray diffraction spectroscopy, this technique is expensive and time-consuming, and uses toxic materials, all of which makes it impractical for obtaining large data sets. Also, available methods for acquiring, interpreting and examining visible–near infrared–shortwave infrared (VIS–NIR–SWIR) spectra are largely ineffective with tropical soils. The aim of this work was to ascertain whether VIS–NIR–SWIR reflectance spectroscopy (350–2500 nm) is useful for identifying minerals in subtropical soils as classified by textural class. For this purpose, soil samples were collected at 66 points at three different soil depths (0–20, 20–40 and 40–60 cm) over a study area located in the State of Rio Grande do Sul (Brazil). The soil texture were determined with the pipette method, and soil spectra were recorded on a FieldSpec Pro VIS-NIR-SWIR laboratory spectrophotometer. Soil minerals were identified, and their proportions determined, from the second-derivative of the Kubelka–Munk (KM) function for the spectra. Five main minerals were thus identified from their spectral signatures, namely: hematite, goethite, kaolinite, chlorite and illite. Identification of the minerals was facilitated by classifying the samples according to texture. The higher the clay content was, the higher was the spectral amplitude of the minerals identified. Those textural classes with the highest clay contents exhibited the greatest proportions of iron oxides and of clay minerals such as kaolinite. These relationships allowed more comprehensive analysis of the soils and expeditious characterization of the study area in terms of texture and mineralogy with a view to facilitating decision-making agricultural support policies. [ABSTRACT FROM AUTHOR]

Urban cemeteries on a global scale raise concerns due to their potential to concentrate differing levels of hazardous pollutants in their native soils due to the unnatural concentration of burials in a limited space. It is paramount for sustainability that designers of future cemeteries take this into account in order to minimize the deposition and movement of these contaminants within the soil profile. The objective of this manuscript is to identify the levels of certain hazardous element contamination, specifically heavy metals, in the soil of horizontal urban cemeteries that do not utilize herbicides for weed control. In this, solutions were sought for the construction of future urban cemeteries capable of mitigating further contamination of the environment by the increase in interments. The soils of three urban cemeteries (A, B and C) in the Brazilian city of Carazinho, in Rio Grande do Sul State, were sampled with 5 monitoring points in the internal area and 5 points in the external area of the cemeteries. At each point, 3 replications were performed at two depths (0–20 and 20–40 cm), totaling 180 samples in all, to determine the concentration of the following metals: copper (Cu), zinc (Zn), iron (Fe), manganese (Mn), lead (Pb), and chromium (Cr) (g kg−1). In addition, online interviews with 15 architects who design cemeteries were conducted. Architectural design solutions to mitigate environmental contamination were modeled utilizing the Building Information Modeling system (BIM). The results showed an excess of Cu in the soil of cemeteries A, B and C, surpassing the standards allowed by Brazilian federal regulations. A total of 80% of the interviewed architects expressed their preference for the vertical cemetery, with gas and effluent treatment systems to mitigate environmental impacts. • Urban cemeteries are sources of environmental contamination. • Case studies point to the presence of excess metals in the soil of urban cemeteries. • Excess of copper (Cu) in the soil of cemeteries A, B and C. • The construction of new urban cemeteries must include architectural elements to minimize contamination of the environment. • Ideal cemetery projects with sustainability. [ABSTRACT FROM AUTHOR]

• The combination of soil depths led to a more accurate prediction of soil texture. • The MIR region has developed more robust models for predicting clay and sand content. • MIR region has more highlighted and intense peaks related to soils. • The most important bands for texture prediction were related to mineralogy. The demand for quality and low-cost soil information is growing due to the demands of land use planning and precision agriculture. Soil texture is one of the key soil properties, as it determines other vital soil characteristics such as soil structure, water and thermal regime, diversity of living organisms, plant growth, as well as the soil quality in general. It is usually not constant over an area, varying in space and with soil depth. Routine soil texture analysis is, however, time consuming and expensive. Because of this, the success of proximal soil sensing techniques in estimate soil properties using the VIS-NIR-SWIR and MIR regions is increasing. Advantages of soil spectroscopy include time efficiency, economic convenience, non-destructive application and freeing of chemical agents involved. Therefore, the objectives of this study were: (a) to explore the potential of clay, sand and silt prediction using reflectance spectroscopy; (b) assess the performance of predictive models in different spectral regions, i.e. VIS-NIR-SWIR and MIR; (c) assess the effect of different soil depths on predictive models; and finally (d) explain the differences in prediction accuracy in the means of the input data structure. Soil samples were collected at three depths (0–20, 20–40 and 40–60 cm) at 70 sampling sites over a study area located in the State of Rio Grande do Sul (Brazil). The content of soil texture was determined by Pipette method, and soil spectra were obtained with FieldSpec Pro (VIS-NIR-SWIR) and by Alpha Sample Compartment RT (MIR). Cubist regression algorithm was applied to train predictive models in three separate modeling modes differing in spectral region: (i) VIS-NIR-SWIR, (ii) MIR and (iii) VIS-NIR-SWIR plus MIR. The results showed that the combination of all three soil depths led to a more accurate prediction of soil texture compared to subdivided soil depths. This was explained by variability of the data, which was larger for the total dataset than for the depth-specific data. Consequently, we suggested that no precise comparison between different studies can be made without a proper description of the input data. For all-depths models, the MIR calibration obtained the best accuracy, which was explained due to more information comprised in the MIR region against the VIS-NIR-SWIR. The bands that were more important in predicting soil texture in MIR are related to mineralogy, specifically to kaolinite. This study demonstrated that the MIR spectroscopy technique is capable to complement the standard soil particle size analysis, specially where a large number of soil samples need to be treated in a short period of time. [ABSTRACT FROM AUTHOR]