Release kinetics of multi-nutrients from volcanic rock mining by-products: evidences for their use as a soil remineralizer

Great quantities of stone by-products are stored alongside different exploiting mines in south Brazil, which are becoming an unsustainable environmental issue. Powder materials of andesite and dacite rocks were obtained from two mining companies of Southern Brazil. The particle size classification of the materials was determined by sieving. The X-ray diffraction (XRD) technique was used to identify the mineral phases of the by-products and X-ray fluorescence (XRF) was applied to determine their chemical compositions. The concentrations of calcium (Ca), potassium (K), magnesium (Mg), phosphorus (P) and silicon (Si) released by the by-products were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Dissolution rates of andesite and dacite rocks were measured in Milli-Q water, and in solutions of 0.1 mol L−1 citric acid, and Milli-Q water acidified with 0.5 mol L−1 acetic acid, as a function of reaction times at 24–96 h (short-term), and at 96–5760 h (long-term). The solutions were agitated continuously on a mechanical rotatory shaker at room temperature. The parabolic diffusion, simplified Elovich, and power function models were applied at both time slots of solid-solution reaction. The results indicated that the relationships of quantity of released multi-nutrients were well described by power equation: ln qt = ln a + b ln t. Dissolution rates were obtained based on the release of Ca, K, Mg, P and Si at a steady state under far from equilibrium conditions. Dissolution rates of both by-products were not affected, within the experimental uncertainty, by Milli-Q water. Although the by-products dissolution rates were unaffected by Milli-Q water, its rates are increased along the time. The dissolution of the by-products minerals was significantly affected by the pH of the solutions. The multi-elements release by both by-products in 0.1 mol L−1 citric acid solution was significantly larger than another solutions, indicating that exchangeable cations were readily available in citric acid solution. The results obtained from power function model in two reaction time intervals can contribute to estimate the multi-nutrients-supplying power of by-products to soil. The present study provides both to solving an environmental issue associated with Brazilian rock exploitation and to create an alternative for soil fertilization and a more sustainable agriculture

Possibilities of using silicate rock powder: an overview

This study evaluates the on use of crushed rocks (remineralizers) to increase soil fertility levels and which contributed to increase agricultural productivity, recovery of degraded areas, decontamination of water, and carbon sequestration. The use of these geological materials is part of the assumptions of rock technology and, indirectly, facilitates the achievement of sustainable development goals related to soil management, climate change, and the preservation of water resources. Research over the past 50 years on silicate rocks focused on soil fertility management and agricultural productivity. More recently, the combined use with microorganisms and organic correctives have shown positive results to mitigate soil degradation; to expand carbon sequestration and storage; and to contribute to the adsorption of contaminants from water and soil. In this article we show results obtained in several countries and we show that this technology can contribute to the sustainability of agriculture, as well as to reverse global warming. Although mineral nutrients are released more slowly from these types of inputs, they remain in the soil for a longer time, stimulating the soil biota. In addition, they are a technology to soluble synthetic fertilizers replace, since the few nutrients derived from such inputs not consumed by plants are lost by leaching, contaminating groundwater and water resources. In addition, conventional methods rely heavily on chemical pesticides which cause damage to soil's microfauna (responsible for the decomposition of organic matter and nutrient cycling) and the loss of organic carbon (in the form of dioxide), which is quickly dispersed in the atmosphere. Silicate rock powders are applied in natura, have long-lasting residual effects and reduce greenhouse gas emissions

Possibilities of using silicate rock powder: An overview

This study evaluates the on use of crushed rocks (remineralizers) to increase soil fertility levels and which contributed to increase agricultural productivity, recovery of degraded areas, decontamination of water, and carbon sequestration. The use of these geological materials is part of the assumptions of rock technology and, indirectly, facilitates the achievement of sustainable development goals related to soil management, climate change, and the preservation of water resources. Research over the past 50 years on silicate rocks focused on soil fertility management and agricultural productivity. More recently, the combined use with microorganisms and organic correctives have shown positive results to mitigate soil degradation; to expand carbon sequestration and storage; and to contribute to the adsorption of contaminants from water and soil. In this article we show results obtained in several countries and we show that this technology can contribute to the sustainability of agriculture, as well as to reverse global warming. Although mineral nutrients are released more slowly from these types of inputs, they remain in the soil for a longer time, stimulating the soil biota. In addition, they are a technology to soluble synthetic fertilizers replace, since the few nutrients derived from such inputs not consumed by plants are lost by leaching, contaminating groundwater and water resources. In addition, conventional methods rely heavily on chemical pesticides which cause damage to soil's microfauna (responsible for the decomposition of organic matter and nutrient cycling) and the loss of organic carbon (in the form of dioxide), which is quickly dispersed in the atmosphere. Silicate rock powders are applied in natura, have long-lasting residual effects and reduce greenhouse gas emissions

Manual de Prácticas de Laboratorio de Tratamiento y Gestión del Suelo II

Este manual de laboratorio, en su segunda edición, reúne métodos clásicos utilizados en la caracterización química de suelos, incluidos los métodos nacionales e internacionales utilizados en Colombia. Se trata de una guía imprescindible para el conocimiento práctico de los estudiantes de la asignatura de Tratamiento y Gestión del Suelo de la Universidad de la Costa. La asignatura de Tratamiento y Gestión del Suelo para estudiantes de Ingeniería Ambiental considera los componentes teóricos y prácticos. Los componentes prácticos incluyen ocho experimentos de laboratorio, cuyas temáticas permitirán a los estudiantes aplicar los conocimientos adquiridos en las clases teóricas

Sustainable release of macronutrients to black oat and maize crops from organically-altered dacite rock powder

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 m3 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

Estado del arte del proyecto

Esta investigación determinará el potencial energético del biogás generado a partir de la digestión anaerobia de residuos pecuarios: pollinaza, porquinaza y bovinaza; en el Departamento del Atlántico. Se caracterizarán las fuentes: granjas, empresas pecuarias, y se hará una identificación y selección de las fuentes con potencial de aprovechamiento energético mediante un análisis multicriterio. Luego, se llevará a cabo una caracterización cuantitativa y cualitativa del potencial aprovechable de biogás y por último se establecerán escenarios posibles de aprovechamiento energético del biogás como fuente no convencional de energía renovabl

Application of Andesite Rock as a Clean Source of Fertilizer for Eucalyptus Crop: Evidence of Sustainability

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

Understanding the mobility of potential nutrients in rock mining by-products: An opportunity for more sustainable agriculture and mining

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

Artisanal ceramic factories using wood combustion: A nanoparticles and human health study

The ceramics industry, resulting from developments of modern compounds, is a segment of great influence in worldwide sustainability. Artisanal ceramic factories based on wood combustion have significant risks for the creation and discharge of atmosphere nanoparticles (NPs) and ultra-fine particles (UFPs). At present, there is insufficient recognition on the influence of engineered-NPs on the atmosphere and health. Real improvements are indispensable to diminish contact with NPs. The present study demonstrates the main NPs and UFPS present in an area of intense artisanal wood-combustion ceramic manufacturing. Particulate matter was sampled for morphological, chemical, and geochemical studies by sophisticated electron microbeam microscopy, X-Ray Diffraction, and Raman spectroscopy. From NPs configuration (10 nm) were produced around the studied artisanal ceramic factories. This study presents an indication of the recent information on population and work-related contact to NPs in the artisanal ceramic factories and their influence on health

Evaluation of Soil Re-mineralizer from By-Product of Volcanic Rock Mining: Experimental Proof Using Black Oats and Maize Crops

This study was focused on physical, petrographical, mineralogical, and chemical characterization of a volcanic-rock mining by-product (dacite rock), as well as on greenhouse experiment with black oats and maize crops to evaluate the potential use of the by-product as soil re-mineralizer. The by-product sample was obtained from a quarry in the Nova Prata mining district in southern Brazil. The particle size distribution of the by-product and soil was determined by sieving. Dacite rock petrographic description was performed on a polished thin section by optical microscopy. The soil and dacite rock mineralogical phases were identified by X-ray diffraction. The by-product and soil chemical composition was determined by X-ray fluorescence. Inductively coupled plasma mass spectrometry was performed to determine potentially toxic elements, As, Cd, Hg and Pb in by-product. Additional chemical compositions of the by-product and soil were analyzed using a scanning electron microscope equipped with an energy dispersive X-ray detector. Black oats and, sequentially maize, crops were cultivated in a typical Hapludox soil treated with the by-product in a greenhouse. Five by-product doses (0, 906, 1813, 3625, and 7251 kg ha−1) were added into pots containing soil, each with seven replications. Responses to treatments were evaluated from dry matter production, nutritional status of the crops, and in the changes in soil properties after 70 days of each cultivation. The results showed that the by-product is composed of plagioclase, K-feldspar, quartz, clinopyroxene, smectites, and opaque minerals with apatite as accessory mineral. The addition of 3625 and 7251 kg ha−1 doses of the by-product substantially increased the dry matter yield in maize leaves. The Ca uptake by maize leaves cultivated in soil with 7251 kg ha−1 dose of the by-product was significantly higher in soil with other doses, and all by-product doses promoted high concentrations of Mg and Ca. The accumulated amounts of Ca, K, Mg and P indicated that they were enough to supply maize nutritional needs. Improvements in soil properties, such as high levels of Ca, K and P and low levels of exchangeable Al and Al saturation were observed. The results of the study suggest that the by-product can be used as soil re-mineralizer. The dacite rock by-product studied here has potential to be an environmental solution to soil fertilization problem because it does not require chemical processing and can be used as it is mined