Volatile organic compounds, VOCs, are air pollutants widely produced by biogenic and anthropogenic sources. This work quantitatively studied the presence of these gases in the internal and external ...environments of schools, comparing one in an urban area (La Salle School, Canoas, RS) and another in a rural area (Santa Cassia Farm School, Nova Santa Rita, RS). The aim of this study was to compare if this environmental differences (location) influence their gases concentration. Monitoring campaigns were conducted for 6 months, occurring every 2 weeks in both schools during class hours, 1 day indoors and 1 day outdoors. The results showed higher concentrations of total volatile organic compounds in the urban school external environment compared with the same rural school environment and, in the comparison between environments, the internal environments of the two schools obtained higher VOC concentrations than the external ones, except in November and December at the urban school.
A mina Ipixuna extrai caulim sedimentar e produz matéria-prima final para a indústria do papel. O minério varia devido a presença de minerais contaminantes. Whiteness, yellowness e composição química ...são parâmetros importantes no processamento mineral. Visualmente, minério com cor vermelha ou amarela é descartado, e com cor clara é aproveitado. Nesta pesquisa, as análises com espectrofotometria, estereomicroscopia e mineralogia com amostras de minério mostraram que a mineralogia contaminante é um indicador importante na tomada de decisão sobre o beneficiamento. Verificou-se que blocos com cor amarela e com alto teor de ferro, podem gerar produto final com qualidade para o papel, quando o principal mineral contaminante é a goethita, removida na separação magnética e branqueamento no químico.
Global demineralization of agricultural soils due to unsustainable use of highly soluble fertilizers and intensive exploitation is an issue of increasing concern. Methods of remineralization include ...the application of volcanic rock by-product, such as vesicular andesite on mineral-deficient fields. The present work analyzed the petrography, mineralogy, and chemistry of volcanic rock by-product (vesicular andesite rock), as well as on-field experiment with eucalyptus. The petrographic description was performed on a polished thin section by optical microscopy. The mineralogical phases were identified with X-ray diffraction. The by-product chemical composition was determined by X-ray fluorescence and inductively coupled plasma mass spectrometry for potentially toxic elements. Additional chemical compositions were analyzed using a scanning electron microscope equipped with a dispersive X-ray detector. A nine-month field experiment was carried out to evaluate the agronomic performance of Eucalyptus saligna Smith cultivated in an Ultisol. Four different doses (treatment T1 = control, treatment T2 = nitrogen, phosphorous, and potassium fertilizer 100%, treatment T3 = by-product 100%, and treatment T4 = by-product 50% and nitrogen, phosphorous and potassium fertilizer 50%), were applied on soil. Responses to treatments were evaluated from height and diameter at breast height at three, six, and nine months after eucalyptus planting. The total phosphorous and potassium content in soil was measured at three and six months after eucalyptus planting. The results showed that the by-product is composed of plagioclase, potassium feldspar, zeolite, smectite, and opaque minerals with apatite as an accessory mineral. The primary oxides found in by-product via X-ray fluorescence were silicon, aluminum, iron, calcium, sodium and with lower concentration, the potassium and phosphorus. In all evaluated parameters, it was verified that T2 and T4 treatments significantly enhanced the available soil phosphorous, and the eucalyptus height, with maximum gains (79% and 62% of phosphorous, and 20% and 23% of height) at nine months after eucalyptus plantation. The maximum gains of eucalyptus diameter at breast height were similar (23% and 24%) at six months after plantation. Soil available potassium was significantly enhanced in T3, T4 and T2 treatments at nine months after planting, with maximum gains of 71%, 55% and 53%. The work indicated an improvement in the phosphorus and potassium levels in soils, and in eucalyptus crop growth by adding by-product, being a partial nitrogen, phosphorous, and potassium fertilizer substitution strategy. The use of these geological materials is presented as an alternative to increase agricultural productivity and reduce the environmental impacts caused by excessive use of highly soluble fertilizers.
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•Volcanic rock mining by-product has a significant potential to replace highly soluble fertilizers.•Eucalyptus growth was better with a by-product mixed with soluble fertilizers than with soluble fertilizers alone.•Vesicular andesite rock present minerals and nutrients usefully for plants.
•Rejects rocks as mechanisms of remineralization and rejuvenation of degraded soils.•The pulverized volcanic rock can provide the macro and micronutrients for the plants.•Volcanic rocks have the ...highest possibility of supplying nutrients to the soil.
This study is related to the chemical and mineralogical characterizations and to the availability of mineral nutrients in four fresh samples of fine material generated in crushing mills of volcanic rocks of the Serra Geral Formation in northeastern state of Rio Grande do Sul (RS), Brazil. The objective of the study is to estimate the agronomic potential of rocks, after pulverization, to its application as a fertilizer for the soil by means of the incorporation of rock, using a technique known as stonemeal. The analytical techniques were used: X-ray diffraction (XRD), X-ray fluorescence (XRF), mass spectrometry with inductively coupled plasma (ICP-MS), and leaching tests by extraction with citric acid solution diluted to 2%. The results indicated the potential of providing nutrients to the soil, corroborating the results of other studies based on the technique stonemeal. The following characteristics were identified in the samples: presence of calcium and magnesium as carbonates; high alkalinity; good availability of phosphorus; potassium average availability; and of the presence of micronutrients such as zinc, boron, copper, iron, and manganese.
This study was developed to evaluate the chemical and mineralogical properties of acid volcanic rock waste from mining activities by measuring the availability of macronutrients and micronutrients in ...Milli-Q water, and in acidic solutions to evaluate the potential use of this type of waste as natural soil fertilizers. The sample used in this work was obtained from a company of the mining district of Nova Prata, Rio Grande do Sul State, southern Brazil. Petrographic studies using conventional optical microscopy and scanning electron microscope allowed to define the mineral composition of in powder wastes as being comprised mainly by pyroxene, feldspar, and variable contents of amorphous glass in matrix. The primary oxides detected in the samples by X-ray Fluorescence were calcium oxide, silicon dioxide, aluminium oxide, iron oxide, and with concentration minor potassium oxide, and phosphorus oxide. Several important nutrients were transferred into the acidic solutions, indicating the significant potential and feasibility of these wastes to be effectively used as natural fertilizers. This study is of great relevance to the sector of mining and to agriculture in the region because it can create an alternative disposal treatment for tailings, and improve the environmental sustainability of local farms, thereby avoiding excessive chemical fertilizer consumption.
•Volcanic rock powder has a promising potential of soil natural fertilizer.•Stonemeal can give proper destination for the waste of mining in the global context.•This technique may contribute to the sustainable development.
The increase in demand for highly soluble fertilizers brings a global sustainability concern. Alternative sources for traditional fertilization are therefore needed. Rock powder use has been proposed ...as an alternative approach to soil remineralization. However, research on the agricultural potential of minerals and rocks as alternative sources of nutrients is limited to changes in soil chemical attributes or effects on crop yield. In this work, we report an experimental study addressing the dissolution of two silicate rock-derived powders (andesite and dacite) that were produced during mining activities in Southern Brazil. The rock powders were exposed to Milli-Q water at pH (7.4–8.8) range, in solutions of 0.1 mol L−1 citric acid at pH range 2.1–3.3, and Milli-Q water acidified with 0.5 mol l−1 acetic acid (pH 5–5.8), in a continuous mechanical rotatory shaker at room temperature. Dissolution kinetics were determined as a function of reaction times at 24 to 5760 h, and solution pH. Based on this kinetics, dissolution rates were determined for the individual powders and compared to expected values for aluminosilicates. Based on this comparison, it was shown that the application of andesite and dacite rock-derived powder to replace high soluble fertilizers is feasible due to high dissolution rates of their minerals. The average andesite dissolution rates in Milli-Q water, in citric acid solution, and in Milli-Q water acidified with acetic acid were 2.1 × 10−5, 1.92 × 10−1 and 6.3 × 10−4 mmol cm−2 s−1, respectively for Ca, being 183%, 22.6%, and 69.2% higher than for the dacite rock. This make andesite rock a potential substitute for carbonate-based liming. In contrast, the average dacite dissolution rates in Milli-Q water, in citric acid solution, and in Milli-Q water acidified with acetic acid were 1.05 × 10–5, 7.22 × 10−5, and 3.72 × 10−5 mmol cm−2 s−1, respectively for K, being 72.0%, 61.4%, and 73.6% higher than the andesite rock. This highlights its potential use as a K source for agriculture to replace highly soluble K-fertilizers.
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•The dissolution experiments of by-products were performed with different extraction solutions.•Volcanic rock by-product as a source of multi-nutrients.•Three mathematical models were used to describe and estimate the behavior of multi-nutrients release from by-products.
The interest in Unmanned Aerial Vehicle (UAV) has been increased very fast. Recent advances in computer technology, software and sophisticated sensors are the main reasons for the increase of this ...technology. Nowadays, Brazil and other countries work for the development of UAV in different markets, highlighting the precision agriculture and urban mapping. The objective of the this research is to study the technical feasibility of the use of planialtimetric data obtained from digital aerial photographs taken by on board cameras in small UAV for the generation of digital terrain model (DTM) that it is able to give support for the calculation of volume in mine caves. The experiment was done at INCOPEL quarry, in Estância Velha, where it was installed control targets for aerial restitution of the picture and sample targets on the seven workbenches of the quarry. Thus, comparative studies were done between orthometric elevations measured with GNSS RTK technique and the ones that were measured in the Photogrammetry Software PhotoScan. It was also checked the correlation between the experiment variables. It was found that the scale found in the experiment satisfies the National Commission of Cartography (CONCAR) standard, regarding the technical specifications of vector geospatial data and serves the purpose of calculating volumes in open-pit mine. O interesse em veículos aéreos não tripulados (VANT) tem crescido rapidamente. Os avanços recentes na tecnologia computacional, desenvolvimento de software e sensores sofisticados são os principais motivos do aumento desta tecnologia. Atualmente, o Brasil e outros países trabalham para o desenvolvimento de VANT em diferentes mercados, destacando-se a agricultura de precisão e o mapeamento urbano. O objetivo desta pesquisa é estudar a viabilidade técnica do uso de dados planialtimétricos obtidos a partir de fotografias aéreas digitais tomadas por câmeras a bordo de pequenos VANTs para a geração de modelo digital do terreno (MDT) que seja capaz de dar suporte para o cálculo de volume em cavas de minas. O experimento foi realizado na pedreira da INCOPEL, em Estância Velha, onde foram instalados alvos de controle para a restituição aérea da imagem e alvos amostrais nas sete bancadas da pedreira. Estudos comparativos foram realizados comparando as elevações ortométricas medidas com a técnica GNSS RTK com as medidas no Photogrammetry Software PhotoScan. Também foi avaliada a correlação entre as variáveis experimentais. Constatou-se que a escala encontrada no experimento satisfaz a norma da Comissão Nacional de Cartografia (CONCAR), no que diz respeito às especificações técnicas de dados geoespaciais vetoriais e atende a finalidade de cálculo de volumes em cavas de minas.
Abstract
Sustainable agriculture plays an important role in agricultural productivity, in which it seeks to reduce dependence on conventional synthetic fertilizers (imported from Europe) and promote ...the use of alternative, low-cost and environmentally friendly sources. An experiment was carried out in the municipality of Santa Maria, Rio Grande do Sul, Brazil, with the objective of evaluating the efficiency and agronomic viability of using a mineral product (amygdaloid basalt powder) as an agricultural input on tomato productivity Solanum lycopersicum. The experimental design used was randomized blocks with six treatments and four replications, at doses 0 (treatment 1 - control), 1.0 ton ha-1 of rock dust (treatment 2), 2.5-ton ha-1 of rock dust (treatment 3), 3.5-ton ha-1 of rock dust (treatment 4), 4.5-ton ha-1 of rock dust (treatment 5), and recommended fertilization for tomato 5-20-20 NPK (treatment 6 - standard). The treatments were applied in December 2018 and the transplant took place in February 2019. According to the conditions under which the experiment was submitted and analyzing the results obtained, it can be inferred that the application of 1-ton ha-1 of amygdaloidal basalt in the soil increased parameters such as root length, stem diameter, green and dry mass of shoots and roots, number of flowers/plants, number of fruits/plant and productivity in tomato Solanum lycopersicum. It is a viable, sustainable, and low-cost strategy that contributes to the achievement of the Sustainable Development Goal (SDG 2) and can be replicated in Brazil and worldwide.
The concept of remineralizing soils with the application of rock in the form of bran or powder is not new, but the term remineralizer is new. It was defined by Brazilian Law Nº. 12,890 / 2013, which ...included it in Law Nº. 6894 / 1980 (Law of Fertilizers). In 2016 the Ministry of Agriculture, Livestock and Supply (MAPA) published normative instructions dealing with the parameters of geochemical quality and the research of applicability and agronomic efficiency necessary to register the remineralizing product. This legal and normative process follows the increase in studies of characterization and application of dacite rock by-product as a sustainable environmental and economic alternative to soil fertilization in several regions of Brazil and also worldwide, since this legislation is the first to address the use of rock meal as soil fertilizers. The study brings the results of research on material from silicate rock (acidic volcanic rock - dacite) mined in an aggregate production quarry in Nova Prata, RS, Brazil. The methodology used in the study were: i) the geochemical characterization of samples of comminuted material, covering chemical, mineralogical and leaching analysis; and ii) statistical research of feasibility and agronomic efficiency application in soybean crop (Glycine max (L)).
The dacite rock by-product had a Sum of Bases content (CaO + MgO + K2O) of approximately 9%, within a tolerance of 10% to less. K2O values were above 1% and free silica content well below the maximum limit of 25%. The analyzes of toxic elements content were below that established by NI Nº 5/2016 which are: As < 15 ppm, Cd < 10 ppm, Hg < 0.1 ppm and Pb < 200 ppm.
The laboratory tests of chemical leaching in a 24 h period showed the availability of fertilizing elements even under conditions of minimal ionic strength (deionized water). The elements with the highest concentration in solution were Si, Ca, P, Mg and K. The high availability of Si stands out, which characterizes the silicate remineralizer.
The agronomical test unit consisted of 4 different areas, which one divided into plots 4.0 m wide and 21.0 m long, totaling 84 m2 per area, and 336 m2 in the study (84 × 4). The experimental design used was a randomized block with 7 treatments and each plot was subdivided into 3 subplots, corresponding to the application times, counted in days before sowing (DBS), for: 50 DBS, 20 DBS and 0 DBS
From the study it is observed that the product remineralizer having different elements according to their prescribed limit and quality which could be used as substitute of limestone or others.
The experiment conducted for the 50 days before sowing (50 DBS) showed a statistically significant difference between treatments for the parameters 3 grains per pod, 1000-grain weight (g) and productivity (kg ha-1). The application carried out 20 days before sowing (20 DBS) showed a statistically significant difference between treatments for the parameters number of pods per plant, 3 grains per pod and 1 grain per pod, grains per pod, 1000-grain weight (g) and productivity (kg ha-1). For the application carried out on the day of sowing (0 DBS), a statistically significant difference was observed between treatments for the parameters number of pods per plant, grains per pod, 1000-grain weight (g) and productivity (kg ha-1)
When compared to the main productivity numbers of soybean in Brazil, which were 3.379 kg, the suggested treatment increased the production about 18% for 0 DBS and 16% for 20 DBS.
At 20 DBS the difference between the treatments in the dose of 3 ton ha-1 and the Control was 1023 kg ha-1 and the difference with the standard treatment Limestone in the dose of 3 ton ha-1 was 831 kg ha-1. In the application at the time of sowing (0 DBS) the difference between the treatments in the dose of 3 ton ha-1 and the Control was 1153 kg ha-1 and with the standard treatment Limestone in the dose of 3 ton ha-1 was 875 kg ha-1. In conclusion, the best time of application found was 0 days before sowing at the rate of 3 ton ha-1 followed by 20 DBS.
However, the application of fertilizers in the same day of sowing, for commercial crops is not recommended by the governmental agencies, due to the fact that all staff and machineries are used to sow the soybean, making very difficult to apply the dacite rock by-product in the same day, so the final recommendation of this study was to apply the soil fertilizer as close as possible to 0 DBS, not exceeding 20 DBS.
The results of the study recommend that the dacite rock by-product can be used as soil fertilizer. The by-product studied here has potential to be an environmental solution to soil fertilization problem because it does not involve chemical processing and can be used in its natural form and also can solve the problem of by-products deposited outside the mines, increasing the consumption of highly soluble fertilizers.
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•Dacite rock powder is a technology for the replacement of conventional fertilizers.•By-products of dacite is a sustainable source to soil fertilization in the worldwide.•Application of dacite rock by-product increased the productivity of soybean crops.
By-products from the dairy industry and mining activities represent a great environmental overload, which justify research for value-added reuse of these by-products (dairy sludge and dacite rock ...powder). Dairy sludge is generated at a rate of about 0.2–10 l per liter of processed milk, and dacite powder, from rock mining extraction and processing, is generated for about 52,400 m
3
per year in Nova Prata city, Southern Brazil. For both by-products, the compositions of calcium (Ca), magnesium (Mg), potassium (K) and phosphorous (P), arsenic (As), cadmium (Cd), chromium (Cr), mercury (Hg), and lead (Pb) were determined by using appropriate analytical techniques. A greenhouse experiment was conducted to determine release of macronutrients, such as Ca, K, Mg, and P, from by-products to support black oat (
Avena strigosa
) and maize nutrition. Twelve by-products doses were blended with a typic Hapludox soil and were applied to pots with five replications each. Black oat (first cultivation) and, sequentially, maize (second cultivation) were cultivated for 70 days each. Ameliorations in soil chemical attributes, leaf dry matter yield, and plant nutritional status were evaluated at the end of each cultivation. There was a significant (
p
< 0.05) increase in all parameters evaluated in a dose of 7251 kg ha
−1
of dacite rock powder and 20,594 kg ha
−1
of dairy sludge. Compared to the control treatments, both crops grew well better on all mixtures. The presence of potentially toxic elements in both by-products was irrelevant, indicating that effective blending of dacite rock powder along with dairy sludge could be a potential source of Ca, K, Mg, and P in agriculture without posing a risk of contamination to the environment.
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