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1
Guimarães, Miguel J. M., Welson L. Simões, José N. Tabosa, José E. dos Santos, and Lilia Willadino. "Cultivation of forage sorghum varieties irrigated with saline effluent from fish-farming under semiarid conditions." Revista Brasileira de Engenharia Agrícola e Ambiental 20, no. 5 (May 2016): 461–65. http://dx.doi.org/10.1590/1807-1929/agriambi.v20n5p461-465.
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ABSTRACT This study aimed to evaluate the cultivation of forage sorghum subjected to different leaching fractions with saline effluent from fish-farming under semiarid conditions. The experiment was set in a randomized block design, with four blocks, in split plots, composed of four leaching fractions (0; 5; 10 and 15%) and three forage sorghum varieties ('Volumax', 'F305' and 'Sudão'). Irrigation was performed using saline effluent from fish farming with electrical conductivity of 2.5 dS m-1. The analyzed variables were: plant height; stem diameter; width, length and number of leaves; fresh and dry matter yield, and relative contents of potassium and sodium in the shoots. Forage sorghum under saline effluent irrigation and leaching fraction of 15% shows a yield increase of 25%, in comparison to sorghum without the leaching fraction. The variety 'Volumax' was more sensitive to salinity than the others, since it showed lower shoot growth and low values of leaf area, fresh matter and dry matter.
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Krzanowski, James E., T. Taylor Eighmy, Bradley S. Crannell, and J. Dykstra Eusden. "An analytical electron microscopy investigation of municipal solid waste incineration bottom ash." Journal of Materials Research 13, no. 1 (January 1998): 28–36. http://dx.doi.org/10.1557/jmr.1998.0005.
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Incinerator bottom ash samples have been characterized using analytical electron microscopy (AEM) techniques, including electron diffraction, energy dispersive spectroscopy, and electron energy loss spectroscopy. The samples were first separated by magnetic properties and density. Three resulting fractions were examined: the magnetic, high-density (MHD) fraction, the nonmagnetic/high-density (NMHD) fraction, and the nonmagnetic, low-density (NMLD) fraction. Examination of these samples revealed a variety of submicron microstructural features. For the MHD fraction, metal oxides, iron silicates, aluminum silicates, and calcium phosphate compounds were found in addition to amorphous material. The NMHD fraction contained elements similar to the MHD fraction but had more amorphous material; crystalline silicates were less common. Compounds such as MgO and chloroapatite were also found. The NMLD fraction contained SiO2 and numerous metal oxides. The results of some of these analyses were used to model leaching behavior of the ash. Based on the AEM results, three mineral phases were chosen as candidates for aqueous geochemical thermodynamic equilibrium modeling of pH-dependent leaching: chromite, chloroapatite, and zincite. In two of these three cases (chromite, chloroapatite), the selected mineral phase provided excellent agreement with the experimentally observed leaching behavior. AEM was shown to be a useful tool for elucidating mineralogy of complex environmental samples.
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Ku, Catherine S. M., and David R. Hershey. "255 LEACHING FRACTION, FERTIGATION RATE AND PHOSPHORUS LEACHING FROM POTTED GERANIUM." HortScience 29, no. 5 (May 1994): 466c—466. http://dx.doi.org/10.21273/hortsci.29.5.466c.
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Single-pinched `Yours Truly' geranium (Pelargonium × hortorum) were greenhouse grown in 15-cm diameter pots. They received constant liquid fertigation with a modified Hoagland solution #1 at 0.25, 0.5, 1.0, and 1.5 strength. The 1.0 strength Hoagland solution contained 210 mg/L NO3-N and 31 mg/L P. Leaching fractions (LFs) were 0, 0.2 and 0.4. The total P applied via fertigation ranged from 33 mg at 0 LF and 0.25x Hoagland to 407 mg at 0.4 LF and 1.5x Hoagland. The leachate P concentration ranged from <5 mg/L to -60 mg/L. The P concentration in the recently matured leaves was in the acceptable range for all treatments. We were able to recover 90 to 99% of the applied P by analyzing the shoots, soilless medium, and leachate. Only 4% of the recovered P was in the leachate for plants receiving 0.5x Hoagland and a 0.2 LF. However, these plants were equal in yield to plants receiving higher fertigation rates and higher LFs.
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Seniūnaitė, Jurgita, and Saulius Vasarevičius. "Fresh Bottom Ash Characteristics Dependence on Fractional Composition." Mokslas - Lietuvos ateitis 9, no. 4 (September 11, 2017): 363–70. http://dx.doi.org/10.3846/mla.2017.1064.
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Waste incineration process generates two main by-products streams: fly ash and bottom ash. Bottom ash is composed of a variety of oxides, heavy metals and salts. Chemical materials distributed unevenly in different fractions of bottom ash. This study investigates the heavy metals (Pb, Cd) content dependence of bottom ash and fraction composition. Studies were performed with five different fractions (0–2 mm; 2–5.6 mm; 5.6–11.2 mm; 11.2–22,4 mm; 22.4–40 mm) of fresh bottom ash. After a one-step leaching test (distilled water was used as a solvent), was determinate, that highest concentrations of the lead (Pb) (from 0.141 to 0.146 mg/l) are leached from the smallest (0–2 mm 2–5.6 mm) bottom ash fractions particles. Heavy metals concentration in these fractions eluates respectively was 2.83 and 2.91 times higher than the limit value of leaching. The highest concentration of cadmium (4.214 mg/l) was determinate in 0–2 mm fraction bottom ash eluate. concentration of cadmium was 1.40 times higher than the limit value of leaching. It can be concluded that 0–2 mm; 2–5.6 mm fraction bottom ash can’t be used in civil engineering, without pre-treatment (eg. washing or aging).
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Simões, Welson L., Anderson R. de Oliveira, Alessandra M. Salviano, Jucicléia S. da Silva, Marcelo Calgaro, and Miguel J. M. Guimarães. "Efficient irrigation management in sugarcane cultivation in saline soil." Revista Brasileira de Engenharia Agrícola e Ambiental 25, no. 9 (September 2021): 626–32. http://dx.doi.org/10.1590/1807-1929/agriambi.v25n9p626-632.
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ABSTRACT The objective of this study was to evaluate the influence of leaching fraction on the biometric and production characteristics and technological quality of the juice of sugarcane varieties grown in saline soil in the Brazilian semiarid region. The experimental design was in randomized blocks, with three repetitions, in a 2 × 3 × 3 factorial scheme, corresponding to two sugarcane cultivation cycles: plant cane and ratoon cane; three sugarcane varieties: RB72454, SP943206 and VAT90212; and, three leaching fractions of irrigation water: 0; 9.1; and 16.6%. Number of living leaves, number of internodes, leaf area, stem diameter, plant height, number of tillers, yield, total soluble solids content (°Brix), percentage of industrial fiber, juice purity, juice Pol%, cane Pol% and total recoverable sugar were evaluated. At the end of the two crop cycles, water use efficiency was determined. The varieties SP943206 and VAT90212 showed higher yield under leaching fraction of irrigation water of 9.1% in both cycles, and higher water use efficiency values were observed for the variety VAT90212. Application of leaching fractions to reduce soil salinity does not promote changes in the technological quality of the sugarcane varieties RB72454, SP943206 and VAT90212.
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NOAMAN, MAHER N., and EL-SAYED EL-HADDAD. "Effects of irrigation water salinity and leaching fraction on the growth of six halophyte species." Journal of Agricultural Science 135, no. 3 (November 2000): 279–85. http://dx.doi.org/10.1017/s0021859699008333.
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A pot experiment was carried out at Nahshala Farm, about 50 km from Al-Ain, UAE, during the 1998/99 growing seasons, using six halophytes: Spartina sp., Distichlis palmeri, Paspalum vaginatum, Juncus roemerianus, Salicornia bigelovii and Batis maritima, under two levels of leaching fraction, 0·25 and 0·50 and three levels of irrigation salinity, 10, 20 and 40 g/l. The objectives of the experiment were twofold: (1) to find out the optimum and threshold of saline water irrigation to keep salinity level down as much as possible in the soil using the leaching fraction technique; and (2) to study the response (growth and biomass production) of some halophytes to different levels of salinity. The experiment was conducted in triplicate with a split-plot design arranged in a randomized complete block. Results indicate that these halophyte species can be grown productively at a leaching fraction between 0·25 and 0·50 when salinity of the irrigation water is less than 20 g/l. At higher salinities, Salicornia bigelovii can grow and yield satisfactorily under these conditions, while the other species may require more frequent irrigation at higher leaching fractions. Some of these tested halophytes may be able to revegetate the salt-affected lands and be a potential source of forage in these harsh habitats. This study supports the idea of seawater agriculture by demonstrating the possibility of using some high salt-tolerant halophytes at relatively higher leaching fraction in order to maintain satisfactory yield production of such halophytes.
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Barreiro Fidalgo, Alexandre, Olivia Roth, Anders Puranen, Lena Z. Evins, Kastriot Spahiu, and Charlotta Askeljung. "Powder Leaching Study for Grain Boundary Inventory of Two High Burnup Fuels." MRS Advances 4, no. 17-18 (2019): 981–86. http://dx.doi.org/10.1557/adv.2018.683.
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ABSTRACTIn the context of safety assessment, the fraction of inventory that is expected to rapidly dissolve when water contacts the spent fuel is called the Instant Release Fraction (IRF). Conceptually, this fraction consists of radionuclides outside of the uranium dioxide matrix and therefore the fraction can be further divided into the radionuclides in the fuel/cladding gap and radionuclides in the grain boundaries. The relative importance of these two fractions is investigated here for two Swedish high burnup fuels through simultaneous grinding and leaching fuel fragments in simplified groundwater for a short period of time. The hypothesis is that this will expose grain boundaries to leaching solution and provide an estimate of the release of the grain boundary inventory upon contact with water. The studied fragments were used in previous leaching experiments and thus pre-washed to remove any pre-oxidized phases. The results showed a significant release of iodine, cesium and rubidium and to a lower extent molybdenum and technetium. The fraction of inventory in the aqueous phase of actinides and lanthanides was 1-2 orders of magnitude lower than for the elements associated to the IRF. Both fuels displayed a very similar behavior and no correlation as a function of burnup or fission gas release was found.
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Lira, Raquele M. de, Leandro C. Gordin, Ênio F. de F. e. Silva, Gerônimo F. da Silva, Daniel da C. Dantas, and José E. F. de Morais. "Leaching of cations in soil cultivated with sugarcane subjected to saline irrigation and leaching fractions." Revista Brasileira de Engenharia Agrícola e Ambiental 22, no. 9 (September 2018): 616–21. http://dx.doi.org/10.1590/1807-1929/agriambi.v22n9p616-621.
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ABSTRACT The objective of this study was to evaluate the concentration of cations in the leachate of soil cultivated with sugarcane irrigated with brackish water. An experiment was carried out in drainage lysimeters at the Federal Rural University of Pernambuco, at the Recife campus. The experimental design was completely randomized in a 5 x 2 factorial scheme, with four replicates, corresponding to five levels of electrical conductivity of the irrigation water (ECw) (0.5, 2.0, 3.5, 5.0 and 6.5 dS m-1) and two leaching fractions (LF1 = 0 and LF2 = 0.17) corresponding to water depths equivalent to 100 and 120% of crop evapotranspiration (ETc), by which the irrigations were managed. Electrical conductivity of the drained water was daily monitored and Na, K, Ca and Mg concentrations in the drainage water were determined at 129, 214, 286 and 324 days after planting (DAP). There were higher salt concentrations in the leachates when leaching fraction LF1 = 0 was used. The use of the 0.17 leaching fraction led to greater dissolution of the salts and may have caused a higher uptake of the essential cations by the crop. Sodium was the most quantitatively leached cation at all collection dates.
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Grismer, M. E. "Leaching fraction, soil salinity, and drainage efficiency." California Agriculture 44, no. 6 (November 1990): 24–26. http://dx.doi.org/10.3733/ca.v044n06p24.
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Zhang, Yanhao, Haohan Zhang, Zhibin Zhang, Chengying Liu, Cuizhen Sun, Wen Zhang, and Taha Marhaba. "pH Effect on Heavy Metal Release from a Polluted Sediment." Journal of Chemistry 2018 (August 23, 2018): 1–7. http://dx.doi.org/10.1155/2018/7597640.
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The performance of Cd, Ni, and Cu release from river sediment at different pH was investigated by a leaching test using deionised water and river water as leachants. Visual MINTEQ geochemical software was used to model the experimental results to predict heavy metal release from sediments. The distribution and speciation of heavy metals in the sediments after leaching test were analyzed by Tessier sequential extraction. Leaching test results showed that the release amounts of Cd, Ni, and Cu are in the range of 10.2–27.3 mg·kg−1, 80.5–140.1 mg·kg−1, and 6.1–30.8 mg·kg−1, respectively, with deionised water as leachant at different pH. As far as the river water was used as the leaching solution in the test, the results show similar metal leaching contents and tendencies to that of the deionised water as leaching solution. The results of Tessier sequential extraction indicate that Cd of residual fraction easily forms obvious precipitate under the acidic condition, especially in the range of pH 0–4 with the residual of Cd over 50% of the total Cd in the sediment. The exchangeable content of Ni decreases with the increase of pH under the range of 0–5. The Fe-Mn oxide fraction of Cu in the sediments changes significantly from pH 0 to pH 9. Based on the effect of pH on the leaching of Cd, Ni, and Cu from the polluted sediment in the tests, more accurate information could be obtained to assess the risk related to metal release from sediments once it is exposed to the changed acid/alkali water conditions.
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Lira, Raquele M. de, Ênio F. de F. e. Silva, Gerônimo F. da Silva, Diego H. S. de Souza, Elvira M. R. Pedrosa, and Leandro C. Gordin. "Content, extraction and export of nutrients in sugarcane under salinity and leaching fraction." Revista Brasileira de Engenharia Agrícola e Ambiental 23, no. 6 (June 2019): 432–38. http://dx.doi.org/10.1590/1807-1929/agriambi.v23n6p432-438.
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ABSTRACT The objective of this study was to evaluate the contents of macronutrients and also chlorine and sodium in the diagnostic leaf, and the extraction and export of macronutrients in sugarcane irrigated with saline water and leaching fractions. The experiment was conducted in a complete randomized design in a 5 x 2 factorial scheme with four replications, corresponding to five levels of water salinity (0.5, 2.0, 3.5, 5.0 and 6.5 dS m-1) and two leaching fractions (L1 = 0 and L2 = 0.17). The treatments were applied 60 days after planting. At 280 days after planting, diagnostic leaves were collected and used to evaluate the nutritional status and the contents of Cl and Na. At 360 days after planting, the sugarcane was harvested and its stalks were separated into tops and leaves. Exposure to water of increasing salinity linearly reduced the N, P, K and Mg contents of the diagnostic leaves and increased their Ca, Cl and Na contents. This effect was minimized by the application of the 0.17 leaching fraction. The extraction of nutrients followed the order K > Ca > N > Mg > S > P. The salinity of the irrigation water had a negative effect on the nutritional status of the plant and on its extraction and export of nutrients; the application of the 0.17 leaching fraction improved the results, except for Ca and S.
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Peng, Yige, and Anthony K. Lau. "Improving the Quality of Crop Residues by the Reduction of Ash Content and Inorganic Constituents." Journal of Biobased Materials and Bioenergy 14, no. 2 (April 1, 2020): 209–19. http://dx.doi.org/10.1166/jbmb.2020.1950.
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In this study, the mechanical size fractionation technique and the water leaching technique were applied in sequence to reduce the ash content of crop residues to target value of 6% db (dry basis) following the applicable standard. Results showed that the finest fraction of ground crop residues (< 0.25 mm) had much higher ash content than the coarser fractions, thus demonstrating that size fractionation can reduce the need for leaching as ash removal technique, and it was most effective for corn stover. For a water-to-biomass ratio (w/w) of 30, the final ash contents of the biomass materials involved in all experimental treatments were effectively reduced to below the target value. Canola straw had the highest ash removal efficiency and element removal efficiency as compared to wheat straw and corn stover. Even though the leaching condition (12 h, 25 °C) was adequate for effective ash reduction, SiO2 removal efficiency could be significantly improved when the leaching temperature was raised from 25 °C to 45 °C. A preliminary cost analysis indicated that biomass pretreatment by mechanical size fraction followed by water leaching as needed would lead to a 30% increase in the total production cost (TPC) of agro-pellets, and this is significantly lower than the increase in TPC by 66% if the pretreatment is done by water leaching only of the ground crop residues.
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Simões, Welson L., Jony E. Yuri, Miguel J. M. Guimarães, José E. dos Santos, and Emanoel F. J. Araújo. "Beet cultivation with saline effluent from fish farming." Revista Brasileira de Engenharia Agrícola e Ambiental 20, no. 1 (January 2016): 62–66. http://dx.doi.org/10.1590/1807-1929/agriambi.v20n1p62-66.
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ABSTRACT This study aimed to evaluate the distribution of salts along the soil profile, the biometric parameters and the yield of beet cultivars under different leaching fractions using saline effluent from fish farming, under the conditions of the Sub-middle São Francisco Valley. An experiment was conducted at the Caatinga Experimental Field of the Embrapa Semi-Arid, in 2013. The treatments were arranged in split plots composed of four leaching fractions (0, 5, 10 and 15%) in the plots, with saline effluent from fish farming, and three table beet cultivars in the subplots: Scarlet Super, Early Wonder 200 and Fortuna. The analysed parameters were: salt distribution along the soil profile, number of leaves, length and width of leaves and petioles, total and commercial yields. The application of leaching fractions of 10 and 15% promoted better salt distribution along the soil profile. The beet cultivar Fortuna showed the highest commercial yield for a lower leaching fraction.
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Serga, Vera, Aleksej Zarkov, Ervins Blumbergs, Andrei Shishkin, Janis Baronins, Edgars Elsts, and Vladimir Pankratov. "Leaching of Gold and Copper from Printed Circuit Boards under the Alternating Current Action in Hydrochloric Acid Electrolytes." Metals 12, no. 11 (November 15, 2022): 1953. http://dx.doi.org/10.3390/met12111953.
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Modern technologies for recycling electronic waste (e-waste) have high economic efficiency and environmental safety requirements. Among the existing technologies, hydrometallurgy is considered to be the most promising technology for e-waste recycling. Increasing attention paid to the chlorination method is associated with the complex recycling of low-grade ores containing noble metals and the raw materials of secondary polymetallic. In this paper, we propose a new scheme for leaching metals from computer printed circuit boards (PCBs) pre-crushed in a disintegrator: The processes of chlorine production and hydrochlorination are implemented in one reactor under the action of an alternating current (AC) of industrial frequency (50 Hz). Three fine fractions of raw material powders with particle size d < 90 µm, d = 90–180 µm, and d = 180–350 µm were used as research objects and the finest fraction of the raw material (d < 90 µm) was studied in more detail. It was found that complete leaching of gold is achieved from fractions of raw materials with a particle size d = 90–180 µm and d = 180–350 µm, containing 277 ppm and 67 ppm of the gold, respectively, at an experiment duration (tex) of 2 h, a current density (i) of 0.66 A·cm−2, and a solid/liquid (S/L) ratio of 8.6 g·L−1. Under the same conditions of the electrochemical leaching process from the fraction of raw materials with a particle size of d < 90 µm and a gold content of 824 ppm, the degree of metal leaching is 80.5%. At the same time, with an increase in particle size in the raw material fractions from d < 90 µm to d = 180–350 µm and a copper content in the raw material from 1.40% to 6.13%, an increase in the degree of its leaching from 81.6% to 95.2%, respectively, is observed. In the framework of the preliminary study presented in this work, for the finest raw material fraction with d < 90 μm the highest gold leaching degree (86.3%) was achieved under the following experimental conditions: tex= 4 h, CHCl = 6 M, i = 0.88 A·cm–2, S/L ratio—8.6 g·L–1 and the highest copper leaching degree (94.2%) was achieved under the following experimental conditions: tex = 2 h, CHCl = 6 M, i = 0.64 A·cm–2, and S/L ratio—2.9 g·L–1.
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Morais, José E. F. de, Ênio F. de F. e. Silva, Larissa G. L. de Andrade, Sirleide M. de Menezes, Weliston de O. Cutrim, Daniel da C. Dantas, Geronimo F. da Silva, and Mário M. Rolim. "Nutritional status, Na+ and Cl- concentrations, and yield of sugarcane irrigated with brackish waters." Revista Brasileira de Engenharia Agrícola e Ambiental 26, no. 11 (November 2022): 863–74. http://dx.doi.org/10.1590/1807-1929/agriambi.v26n11p863-874.
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ABSTRACT Salinization reduces the osmotic potential of soil solutions and promotes the accumulation of toxic ions (Na+ and Cl-) in plants, causing nutritional imbalance and yield reductions. Thus, the objective of the present study was to evaluate foliar concentrations of nutrients and Na+ and stalk yields in sugarcane RB92579 under different electrical conductivities of irrigation water and leaching fractions (LF). The experiment was conducted in drainage lysimeters in a 5 × 2 factorial scheme with five electrical conductivities of irrigation water - ECw (0.5, 2.0, 4.0, 6.0, and 8.0 dS m-1) without (LF1 = 0) or with a leaching fraction (LF2 = 0.17), and four replicates. Increased ECw decreased the concentrations of N, P, K, Mg, S, Fe, Mn, Cu, and Zn and increased those of Ca, Cl, and Na, reducing the biomass production in two cycles (plant-cane and first ratoon). The use of a leaching fraction of 0.17 mitigated the deleterious effects of salinity on nutrient concentration and yield.
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Million, Jeff, and Tom Yeager. "Monitoring Leaching Fraction for Irrigation Scheduling in Container Nurseries." EDIS 2016, no. 2 (April 11, 2016): 4. http://dx.doi.org/10.32473/edis-ep529-2015.
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Scheduling irrigation in container nurseries can be a daunting task for producers. There is a great risk of under- or over-watering. The leaching fraction (LF) test is a valuable tool for measuring the volume of container drainage collected during irrigation relative to the volume of water entering the container. With this test, producers can adjust their irrigation to maintain a low percentage of leaching. This 4-page fact sheet explains how to perform the test, gives example calculations, and provides some suggestions on how to utilize LF testing when managing irrigation. Written by Jeff Million and Tom Yeager, and published by the Environmental Horticulture Department, December 2015. ENH1268/EP529: Monitoring Leaching Fraction for Irrigation Scheduling in Container Nurseries (ufl.edu)
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Al-Busaidi, Ahmed, Jaaman Rabeea, Mushtaque Ahmed, and Salim Al-Rawahy. "Estimating Leaching Requirements for Barley Growth under Saline Irrigation." Journal of Agricultural and Marine Sciences [JAMS] 17 (January 1, 2012): 1. http://dx.doi.org/10.24200/jams.vol17iss0pp1-8.
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The utilization of marginal water resources for agriculture is receiving considerable attention. The lands irrigated with saline water are required to reduce salt accumulations through leaching and/or drainage practices. A field experiment was carried out to investigate the effect of saline irrigation and leaching fraction on barley (Hordeum vulgare L.) growth. For this purpose highly saline water was diluted to the salinity levels of 3, 6 and 9 dS m-1 and applied by drip irrigation at 0.0, 0.15, 0.20 and 0.25 leaching fractions (LF). The results of the experiment showed that both quantity and quality of water regulated salts distribution within the soil in the following manner: a) the salts were found higher near or immediate below the soil surface; b) an enhanced LF carried more salts down the soil horizon but there was no significant difference in plant yield between different treatments of leaching fractions. Salinity of water significantly impaired barley growth. The good drainage of sandy soil enhanced the leaching process and minimized the differences between leaching fractions. The increment in saline treatments (3, 6 and 9 dS m-1) added more salts and stressed plant growth. However, the conjunctive use of marginal water at proportional LF could be effective in enhancing the yield potential of crops in water-scarce areas.
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Lin, Yan, Hongjuan Sun, Tongjiang Peng, Dingran Zhao, and Xiyue Zhang. "The Leaching Kinetics of Iron from Titanium Gypsum in a Citric Acid Medium and Obtain Materials by Leaching Liquid." Molecules 28, no. 3 (January 18, 2023): 952. http://dx.doi.org/10.3390/molecules28030952.
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In this study, the effect of citric acid on iron leaching from titanium gypsum (TiG) was systematically investigated. The conditions for the leaching of valuable metals were optimized while varying such parameters as the leaching time, citric acid mass fraction, leaching temperature, and the liquid–solid ratio. It was found that under the conditions of a citric acid mass fraction of 10%, at a 80 °C leaching temperature, a leaching duration of 80–90 min and a liquid–solid ratio of 8, the whiteness of titanium gypsum (TiG) increased from 8.1 to 36.5, and the leaching efficiencies of iron reached 84.37%. The kinetic analysis indicated that the leaching process of iron from TiG was controlled by the reaction product layer from 0–20 min, while the leaching process of iron from TiG was controlled by internal diffusion from 20–90 min. The apparent activation energy of the leaching reactions was 33.91 kJ/mol and 16.59 kJ/mol, respectively. High-value-added calcium oxalate and ferrous oxalate were prepared from the calcium and iron in the filtrate of the oxalic acid extraction. The leaching liquid could be recycled, which will provide a new way to utilize titanium gypsum.
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Cheng, Jun Hua, Jian Zhang, and Di Jiang Wen. "Comparison of Leaching Characteristics of Lead in Waste CRTs." Advanced Materials Research 177 (December 2010): 470–74. http://dx.doi.org/10.4028/www.scientific.net/amr.177.470.
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This study investigates four extraction methods (water extraction, toxicity characteristics leaching procedure (TCLP), modified TCLP with pH control and sequential chemical extraction (SCE)), each representing different liquid-to-solid (L/S) ratios, pH controls, and types of leachant and their effects on the leaching concentration of Pb in cathode ray tubes (CRTs).The results indicated that for extraction with distilled water,the lead leaching concentration (mg/L) decreased with L/S ratio in the range of 2-100. The results also showed that the leaching concentration was strongly pH-dependent in the TCLP and modified TCLP tests. In modified TCLP tests,in the case of pHs lower than 6.3,the leaching concentrations of Pb decreased with an increase in pH. Due to the nature of amphoteric elements, in the case of pHs higher than 7, the Pb leaching concentration increased with increasing pH. In SCE tests, the Pb speciation approached the extractable carbonate bound fraction. Both amounts of Pb leached from the SCE and modified TCLP tests were much higher than those for the regular TCLP and water extraction tests. The initial particle size of samples have great effect on the leachability of Pb from waste CRTs.
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Amin, M. G. Mostofa, Anita Forslund, Xuan Thanh Bui, René K. Juhler, Søren O. Petersen, and Mette Lægdsmand. "Persistence and Leaching Potential of Microorganisms and Mineral N in Animal Manure Applied to Intact Soil Columns." Applied and Environmental Microbiology 79, no. 2 (November 2, 2012): 535–42. http://dx.doi.org/10.1128/aem.02506-12.
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ABSTRACTPathogens may reach agricultural soils through application of animal manure and thereby pose a risk of contaminating crops as well as surface and groundwater. Treatment and handling of manure for improved nutrient and odor management may also influence the amount and fate of manure-borne pathogens in the soil. A study was conducted to investigate the leaching potentials of a phage (Salmonella entericaserovar Typhimurium bacteriophage 28B) and two bacteria,Escherichia coliandEnterococcusspecies, in a liquid fraction of raw pig slurry obtained by solid-liquid separation of this slurry and in this liquid fraction after ozonation, when applied to intact soil columns by subsurface injection. We also compared leaching potentials of surface-applied and subsurface-injected raw slurry. The columns were exposed to irrigation events (3.5-h period at 10 mm h−1) after 1, 2, 3, and 4 weeks of incubation with collection of leachate. By the end of incubation, the distribution and survival of microorganisms in the soil of each treatment and in nonirrigated columns with injected raw slurry or liquid fraction were determined.E. coliin the leachates was quantified by both plate counts and quantitative PCR (qPCR) to assess the proportions of culturable and nonculturable (viable and nonviable) cells. Solid-liquid separation of slurry increased the redistribution in soil of contaminants in the liquid fraction compared to raw slurry, and the percent recovery ofE. coliandEnterococcusspecies was higher for the liquid fraction than for raw slurry after the four leaching events. The liquid fraction also resulted in more leaching of all contaminants exceptEnterococcusspecies than did raw slurry. Ozonation reducedE. colileaching only. Injection enhanced the leaching potential of the microorganisms investigated compared to surface application, probably because of a better survival with subsurface injection and a shorter leaching path.
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Cambissa, Paulo Bumba Chiumbua, Geocleber Gomes de Sousa, José Marcelo da Silva Guilherme Guilherme, Geovana Ferreira Goes, Bruna Barboza Gadelha, and Bubacar Baldé. "Salt stress and leaching fraction in cowpea culture." Revista Brasileira de Agricultura Irrigada 16 (August 31, 2022): 121–30. http://dx.doi.org/10.7127/rbai.v1601305.
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Schosseler, Jil, Anna Trentmann, Bernd Friedrich, Klaus Hahn, and Hermann Wotruba. "Kinetic Investigation of Silver Recycling by Leaching from Mechanical Pre-Treated Oxygen-Depolarized Cathodes Containing PTFE and Nickel." Metals 9, no. 2 (February 5, 2019): 187. http://dx.doi.org/10.3390/met9020187.
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This paper focuses on the recycling of silver from spent oxygen-depolarized cathodes through an innovative combination of pre-treatment methods and leaching. A silver- and polytetrafluorethylene (PTFE)-rich fraction was produced by cryogenic milling, screening, and magnetic separation. In order to understand the kinetic leaching mechanism, the silver-rich fraction was leached by different concentrations of nitric acid and hydrogen peroxide. Results showed that nickel influences the silver leaching. This leads to complex reaction systems, which cannot be described by the Arrhenius law.
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CARVALHO, JOSÉ FRANCISCO DE, ÊNIO FARIAS DE FRANÇA E. SILVA, GERÔNIMO FERREIRA DA SILVA, MÁRIO MONTEIRO ROLIM, and ELVIRA MARIA REGIS PEDROSA. "PRODUCTION COMPONENTS OF Vigna unguiculata (L. Walp) IRRIGATED WITH BRACKISH WATER UNDER DIFFERENT LEACHING FRACTIONS." Revista Caatinga 29, no. 4 (December 2016): 966–75. http://dx.doi.org/10.1590/1983-21252016v29n422rc.
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ABSTRACT The objective of this work was to evaluate the production components of cowpea (Vigna unguiculata L. Walp) subjected to irrigation with brackish water and different leaching fractions. The experiment was conducted in a lysimeter system of the Department of Agricultural Engineering of the Federal Rural University of Pernambuco, Recife campus. The treatments, consisting of two water salinity levels (ECw) (1.2 and 3.3 dS m-1) and five leaching fractions (0, 5, 10, 15 and 20%), were evaluated using a completely randomized design in a 2x5 factorial arrangement with four replications. The variables evaluated were: number of pods per plant, 100-grain weight, number of grains per pod, grain and shoot dry weight, grain yield and harvest index. The soil salinity increased with increasing salinity of the water used for irrigation, and reduced with increasing leaching fraction. The salinity of the water used for irrigation influenced only the variables number of pods per plant and grain yield. The estimated leaching fractions of 9.1% and 9.6% inhibited the damage caused by salinity on the number of pods per plant and grain yield, respectively. Therefore, the production of V. unguiculata irrigated with brackish water, leaching salts from the plant root environment, is possible under the conditions evaluated.
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Cypher, Quinn, Wesley C. Wright, Xiaocun Sun, Lauren Fessler, and Amy Fulcher. "Automated Leaching Fraction-based Irrigation System Reduces Leaching, Conserves Water, and Supports Crop Growth in a Commercial Nursery." Applied Engineering in Agriculture 38, no. 5 (2022): 807–16. http://dx.doi.org/10.13031/aea.15082.
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HighlightsAn automated irrigation system based on a novel leachate sensor was built to schedule and deliver irrigation to a container nursery.The sensor network was designed to achieve a 0.15 leaching fraction; it maintained an actual average leaching fraction of 0.17.Water use and container effluent were reduced by 60% and 96%, respectively, without reducing crop growth. Abstract.With the aim of reducing irrigation water use, an irrigation and leachate measurement and control system was developed and evaluated to automatically schedule and actuate irrigation in a commercial nursery. Leachate and irrigation sensors were built using a tipping bucket mechanism and used to calculate the daily leaching fraction (LF) = volume leached/volume applied. For the experimental daily irrigation schedule, the previous day’s LF was used to calculate irrigation run time for the current day using a scaled multiplier, where the change in irrigation run time was proportional to the difference between the calculated LF and the target LF, 0.15. The control zone was irrigated for two hours every other day simulating the commercial nursery’s standard schedule. The irrigation control system worked as designed and correctly imposed the irrigation treatments, including correctly delaying in response to rain and actuating based on a programmed minimum runtime, when necessary. Season-long water use was 60% less for the leachate-based irrigation schedule compared to the grower’s standard irrigation schedule (p = 0.0028). The average daily LFs were 0.17 and 0.73 for the LF-based irrigation and control, respectively (p < 0.0001). Compared to the grower’s standard practice the time averaged irrigation application rate was 3.3-fold less and time averaged leaching rate was 12.1-fold less for the LF-based irrigation schedule. Substrate volumetric water content was not correlated with LF and thus was not a good predictor of leaching fraction. Growth metrics were not impacted by irrigation treatment (p = 0.1429), indicating plants received sufficient water in the LF-based irrigation system. This novel system was able to actuate and adjust irrigation run-time based on daily leaching fraction without being influenced by the lag between irrigation and leaching and had an average leaching fraction within 0.02 of the target LF. Reducing water use with this LF-based schedule has the potential to reduce agrichemical-laden nursery effluent and increase nursery irrigation capacity, i.e., their ability to expand production on the current water supply. Keywords: Container effluent, ET-based irrigation, Irrigation schedule, Leachate, Precision irrigation, Sensor-based irrigation.
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Fibrianty, Fibrianty, Eko Hanudin, and Azwar Ma’as. "Leaching Characteristics of Udipsamment Ameliored by Mineral Soil and Adhesive Polymer." JOURNAL OF TROPICAL SOILS 27, no. 1 (January 17, 2022): 17. http://dx.doi.org/10.5400/jts.2022.v27i1.17-25.
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Udipsamment is characterized by sand fraction > 95%, loose, and very high leaching. This study aimed to determine the effect of mineral soil ameliorants and adhesive polymers on the character of nutrient leaching in Udipsamment. The leaching study in lysimeters used a completely randomized design with three replications. The treatments consist of bagasse (B), mineral soil included Inceptisol (I) and Vertisol (V), and adhesive polymers included tapioca 1% and 2% (T1 and T2), tapioca dregs 1% and 2 % (A1 and A2), Polyvinylalcohol 0.1% and 0.2% (P1 and P2). Combination of treatments are IB, VB, IBT1, IBT2, VBT1, VBT2, IBA1, IBA2, VBA1 , VBA2 , IBP1, I BP2, VBP1, and VBP2. Observations were made before and after leaching. The research showed that VBT2 increases moisture-holding capacity. Amelioration improved the ability of Udipsamment to hold nutrients, after leaching for six months, there was a decrease in organic C, total N, and available P compared to before leaching. Amelioration increased the soil CEC, even up to the sixth month leaching, the soil CEC showed a higher value than before leaching. The amount of clay fraction was relatively uniform between the surface and the bottom of the lysimeter, indicating that the adhesive polymer successfully bonding the clay-sand particles and prevented clay leaching.
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Cabrera, Raul I., Richard Y. Evans, and J. L. Paul. "NITROGEN LEACHING LOSSES FROM CONTAINER-GROWN ROSES." HortScience 27, no. 6 (June 1992): 583a—583. http://dx.doi.org/10.21273/hortsci.27.6.583a.
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Nitrogen leaching losses of 21, 40 and 49% were measured from container-grown `Royalty' roses irrigated for one year with nutrient solutions containing 77, 154 and 231 mg N/l. There were no significant differences in number of flowers per plant or dry matter per plant. The N present in the harvested flowers accounted for 43, 27 and 17% of the N applied for the 77, 154 and 231 mg N/l treatments, respectively. Plants receiving 154 mg N/l at leaching fractions of 0.1, 0.25 and 0.5 had corresponding N leaching losses of 22, 38 and 56%. In this experiment, however, the 0.5 leaching fraction produced yields significantly higher than those of the 0.1 and 0.25 treatments. The N recovered in the harvested flowers accounted for 28, 25 and 19% of that applied to the 0.1, 0.25 and 0.5 treatments, respectively. The results of these studies suggest that modifications in current irrigation and fertilization practices of greenhouse roses would result in a considerable reduction of N leaching losses and enhance N fertilizer use efficiency, without loss of cut flower yield and quality.
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Zhang, Lei, Hangchao Chen, Jinhe Pan, Zhiping Wen, Shulan Shi, Xin Long, and Changchun Zhou. "The Effect of Physical Separation and Calcination on Enrichment and Recovery of Critical Elements from Coal Gangue." Minerals 12, no. 11 (October 28, 2022): 1371. http://dx.doi.org/10.3390/min12111371.
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Critical metallic elements in coal gangue have great utilization potential, especially due to the current shortage of these metals. This paper focused on examining the feasibility of physical separation (screening and float-sink tests) and calcination treatment for the enrichment of critical elements (Li, Ga, and rare earth elements plus yttrium (REY)) from coal gangue. The impacts of these enrichment methods on the acid leaching recovery of these elements were then studied. Screening tests indicated that Li and Ga were enriched in >0.125 mm size fraction and the content of REY was highest in <75 μm size fraction. Float-sink tests showed that high-density fractions were enriched in Li and Ga, and low-density fractions were enriched in REY. Physical separation cannot significantly improve the leaching rate of Li, Ga, and REY. Notably, Li, Ga, and REY were enriched significantly, and their acid leaching recoveries were increased by 54~68% after calcination under 400 °C. Sequential chemical extraction tests showed that the majority of insoluble Li, Ga, and REY was converted into soluble forms at the above temperature, which is attributed to the formation of amorphous metakaolinite and the decomposition of organic matter. Based on the results, a conceptually combined flowsheet was proposed for the extraction of Li and Ga from coal gangue.
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Fjendbo, Simon, Klaartje De Weerdt, Henrik Erndahl Sørensen, and Mette Rica Geiker. "When and How Should Chloride Profiles be Calibrated for Paste Fraction?" Nordic Concrete Research 66, no. 1 (July 1, 2022): 1–18. http://dx.doi.org/10.2478/ncr-2021-0021.
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Abstract Due to stochastic and systematic variations in the paste fraction, data for total chloride content are occasionally calibrated using parallelly measured calcium content as a measure of the actual paste fraction − assuming non-calcareous aggregates and no calcium leaching. Data from concrete exposed at the marine Fehmarn Belt Exposure Site questions the latter assumption. In the outer zone experiencing calcium leaching (ten mm after ten years), errors will be introduced by calcium calibration. To account for the wall effect, calcium profiles from cores taken before exposure might be used to correct for the systematically higher paste fraction at cast surfaces.
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Li, Deying, and Lulu Wang. "Hydraulic Conductivity of Rootzones Affected by Different Leaching Fraction and Salinity Component of Leaching Solution." ats 10, no. 1 (2013): 0. http://dx.doi.org/10.2134/ats-2013-0009bc.
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Ku, Catherine, and David Hershey. "Fertigation rate, leaching fraction, and growth of potted poinsettia." Journal of Plant Nutrition 19, no. 12 (December 1996): 1639–52. http://dx.doi.org/10.1080/01904169609365227.
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Deng, Yan, Xue Duan Liu, Hong Wei Liu, Hui Dan Jiang, Liang Feng Xu, Yun Hua Xiao, Xiao Dong Hao, Hua Qun Yin, and Yi Li Liang. "Bioleaching of Cadmium from Contaminated Paddy Fields by Consortium of Autotrophic and Indigenous Cadmium-Tolerant Bacteria." Solid State Phenomena 262 (August 2017): 617–21. http://dx.doi.org/10.4028/www.scientific.net/ssp.262.617.
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It has been a major issue for urgent solution in China as a result of a series of poisoning cases caused by cadmium. Yet there is no effective methods for removal of cadmium from the paddy soils. Microbial leaching process as an effective approach is currently applied to remediate the contaminated soils. In this study, bioleaching of cadmium from contaminated paddy soils by consortium of autotrophic and indigenous cadmium-tolerant bacteria was applied. The bioleaching results showed that the leaching rate of cadmium was from 74.93% to 92.76%. The distribution of the Cd fractions had a significant change before and after bioleaching with the organic fraction and residues fraction mainly remained. Moreover, the microbial community analysis showed that the Acidithiobacillus and Acidiphilium became the dominant genus in the bioleaching process. The combination of bioleaching with acidophilic chemolithotrophic microorganisms and the cadmium-resistant bacteria provides a potential process for bioremediation of metal-contaminated soils.
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Schotanus, D., M. J. van der Ploeg, and S. E. A. T. M. van der Zee. "Spatial distribution of solute leaching with snowmelt and irrigation: measurements and simulations." Hydrology and Earth System Sciences 17, no. 4 (April 22, 2013): 1547–60. http://dx.doi.org/10.5194/hess-17-1547-2013.
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Abstract. Transport of a tracer and a degradable solute in a heterogeneous soil was measured in the field, and simulated with several transient and steady state infiltration rates. Leaching surfaces were used to investigate the solute leaching in space and time simultaneously. In the simulations, a random field for the scaling factor in the retention curve was used for the heterogeneous soil, which was based on the spatial distribution of drainage in an experiment with a multi-compartment sampler. As a criterion to compare the results from simulations and observations, the sorted and cumulative total drainage in a cell was used. The effect of the ratio of the infiltration rate over the degradation rate on leaching of degradable solutes was investigated. Furthermore, the spatial distribution of the leaching of degradable and non-degradable solutes was compared. The infiltration rate determines the amount of leaching of the degradable solute. This can be partly explained by a decreasing travel time with an increasing infiltration rate. The spatial distribution of the leaching also depends on the infiltration rate. When the infiltration rate is high compared to the degradation rate, the leaching of the degradable solute is similar as for the tracer. The fraction of the pore space of the soil that contributes to solute leaching increases with an increasing infiltration rate. This fraction is similar for a tracer and a degradable solute. With increasing depth, the leaching becomes more homogeneous, as a result of dispersion. The spatial distribution of the solute leaching is different under different transient infiltration rates, therefore, also the amount of leaching is different. With independent stream tube approaches, this effect would be ignored.
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Schotanus, D., M. J. van der Ploeg, and S. E. A. T. M. van der Zee. "Spatial distribution of solute leaching with snowmelt and irrigation: measurements and simulations." Hydrology and Earth System Sciences Discussions 9, no. 12 (December 4, 2012): 13451–90. http://dx.doi.org/10.5194/hessd-9-13451-2012.
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Abstract. Transport of a tracer and a degradable solute in a heterogeneous soil was measured in the field, and simulated with several transient and steady state infiltration rates. Leaching surfaces were used to investigate the solute leaching in space and time simultaneously. In the simulations, a random field for the scaling factor in the retention curve was used for the heterogeneous soil, which was based on the spatial distribution of drainage in an experiment with a multi-compartment sampler. As a criterion to compare the results from simulations and observations, the sorted and cumulative total drainage in a cell was used. The effect of the ratio of the infiltration rate over the degradation rate on leaching of degradable solutes was investigated. Furthermore, the spatial distribution of the leaching of degradable and non-degradable solutes was compared. The infiltration rate determines the amount of leaching of the degradable solute. This can be partly explained by a decreasing travel time with an increasing infiltration rate. The spatial distribution of the leaching also depends on the infiltration rate. When the infiltration rate is high compared to the degradation rate, the leaching of the degradable solute is similar as for the tracer. The fraction of the soil that contributes to solute leaching increases with an increasing infiltration rate. This fraction is similar for a tracer and a degradable solute. With increasing depth, the leaching becomes more homogeneous, as a result of dispersion. The spatial distribution of the solute leaching is different under different transient infiltration rates, therefore also the amount of leaching is different. With independent stream tube approaches, this effect would be ignored.
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Alam, Mohammed Z., Calvin Chong, Jennifer Llewellyn, and Glen P. Lumis. "Evaluating Fertilization and Water Practices to Minimize NO3-N Leachate from Container-grown Forsythia." HortScience 44, no. 7 (December 2009): 1833–37. http://dx.doi.org/10.21273/hortsci.44.7.1833.
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To minimize fertilizer and water use, and NO3-N runoff from container culture, growth, and nutrient status of forsythia (Forsythia ×intermedia Zab. ‘Spring Glory’) in No. 2 containers were compared in response to a controlled-release fertilizer (CRF; Nutricote 18-6-8 100-day at rates of 2, 4, and 6 kg·m−3) and placements (incorporation and topdress) under three irrigation strategies [drip-irrigated low (25% or less) leaching fraction (DrLoLF), hand-sprinkled low leaching fraction (HsLoLF), and hand-sprinkled high (50% or less) leaching fraction (HsHiLF)]. In a coexperiment under drip irrigation only, forsythia response was also examined under incorporation, topdress, and dibble fertilizer placements with the same CRF rates applied as single or split dose. Dibble fertilizer placement was superior to both incorporation and topdress in this order. Maximum growth of forsythia occurred at rates of 4.7 kg·m−3 with dibble. With incorporation and topdress, maximum growth was not achieved even at the 6 kg·m−3 maximum rate tested. Forsythia grew better with incorporated than with topdressed CRF with the DrLoLF treatment. The response was reverse with HsHiLF or showed no differences with HsLoLF. Under drip irrigation, greater concentrations of NO3-N generally leached from incorporation and dibbled containers in this order than from topdress. Less nitrate was leached from the topdressed containers because less was released from the CRF prills. At the 6 kg·m−3 CRF rate, total cumulative NO3-N leachings were 76, 85, and 22 kg·ha−1 (45 × 45-cm container spacing) for dibbling, incorporation, and topdress, respectively, under drip irrigation. Split application of CRF greatly reduced NO3-N in leachate, although plant growth also was reduced as a result of less availability of and uptake of nutrients under this strategy.
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Brogowski, Zygmunt, and Józef Chojnicki. "Sorption properties of granulometric fractions in Haplic Cambisol developed from boulder loam." Soil Science Annual 70, no. 2 (June 1, 2019): 147–57. http://dx.doi.org/10.2478/ssa-2019-0013.
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Abstract The aim of the paper was to investigate the sorption properties of granulometric fractions separated from the genetic horizons of arable Haplic Cambisol developed from boulder loams of the Middle-Polish (Riss) Glaciation, Wartanian Stadial (central Poland). Separation of granulometric fractions was made with application of the Atterberg method without the use of centrifuging and dispersing agents. The cation exchange capacity average value in cmol(+)kg−1 and % contribution in particular fractions reached: 1–0.1 mm – 2.1 (1.6%), 0.1–0.05 mm – 5.5 (4.0%), 0.05–0.02 mm – 8.5 (6.1%), 0.02–0.01 mm – 13.0 (10.1%), 0.01–0.005 mm – 16.1 (12.8%), 0.005–0.002 mm – 28.6 (20.5%) and fraction <0.002 mm – 48.7 (44.9%). Leaching of the total exchangeable bases was the largest in the 0.1–0.05 mm fraction and decreased successively with decreasing grain diameter. Sorption properties of the tested soil determine its high agricultural value and buffer properties. The cation exchange capacity of the recognised granulometric fractions successively increased with decrease of their diameter while leaching process intensity in individual fractions decreased gradually as their dimensions decreased. Calcium was the most leached cation, followed by magnesium and sodium, whereas potassium was not leached at all. Significant increase of the cation exchange capacity in fractions from carbonate horizons was mostly caused by the increased contribution of calcium, which could be released from carbonates during extraction of bases.
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Jovanović, Gvozden, Mladen Bugarčić, Nela Petronijević, Srecko R. Stopic, Bernd Friedrich, Branislav Marković, Srđan Stanković, and Miroslav Sokić. "A Multifocal Study Investigation of Pyrolyzed Printed Circuit Board Leaching." Metals 12, no. 12 (November 25, 2022): 2021. http://dx.doi.org/10.3390/met12122021.
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Electric waste from numerous devices that are put out of use every day has some form of printed circuit board that contains precious and valuable metals in their components. In order to extract these metals, the printed circuit boards were crushed and pyrolyzed into powder. The fine pyrolyzed printed circuit board (PPCB) powder was separated into fractions, and the fine metallic fraction was used as a raw material for metal leaching extraction. In order to better understand how various metal species react in leaching media, several leaching agents were used (sulfuric acid, nitric acid, glycine, and acid mine drainage-AMD) alone, and with the addition of hydrogen peroxide. Additionally, the influence of the S/L ratio and leaching temperature were investigated in sulfuric acid leaching solutions, as this is the one most widely used. In one case, the reactor was heated in a thermal bath, while in the other, it was heated in an ultrasonic bath. Lastly, several experiments were conducted with a (consecutive) two-pronged leaching approach, with and without applied pretreatment. The aim of this paper is to give a multifocal and detailed approach to how metals such as Al, Cu, Co, Zn, Sn, and Ca behave when extracted from fine PPCB powder. However, some attention is given to Nd, Pd, Pb, and Ba as well. One of the main findings is that regardless of the pretreatment or the sequence of leaching media applied, consecutive two-pronged leaching cannot be used for selective metal extraction. However, AMD was found to be suitable for selective leaching with very limited applications.
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Lira, Raquele M. de, Ênio F. de F. e. Silva, Djalma E. Simões Neto, José A. Santos Júnior, Breno L. de C. Lima, and Jucicléia S. da Silva. "Growth and yield of sugarcane irrigated with brackish water and leaching fractions." Revista Brasileira de Engenharia Agrícola e Ambiental 22, no. 3 (March 2018): 170–75. http://dx.doi.org/10.1590/1807-1929/agriambi.v22n3p170-175.
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ABSTRACT The objective was to evaluate the growth and yield of sugarcane irrigated with brackish water and leaching fractions. A completely randomized experimental design was used, in a 5 x 2 factorial scheme, with four replicates. The treatments consisted of five irrigation water salinity levels (0.5, 2.0, 3.5, 5.0 and 6.5 dS m-1) and two leaching fractions (0 and 0.17), corresponding to 100 and 120% of the crop evapotranspiration. The irrigation management was performed daily. Irrigation water salinity levels were obtained by adding NaCl and CaCl2 to the public-supply water, in order to obtain a molar ratio between Na:Ca of 1:1. The following measurements were taken: height and stem diameter; number of tillers; number of leaves and leaf area with monthly frequency between 60 and 300 days after planting (DAP). It was concluded that irrigation water salinity negatively influenced the variables of growth and yield in the sugarcane, and the leaching fraction of 0.17 was capable of reducing the deleterious effects of the salts on the plants.
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Prieto-Espinoza, Maria, Bernd Susset, and Peter Grathwohl. "Long-Term Leaching Behavior of Organic and Inorganic Pollutants after Wet Processing of Solid Waste Materials." Materials 15, no. 3 (January 23, 2022): 858. http://dx.doi.org/10.3390/ma15030858.
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The recycling of mineral materials is a sustainable and economical approach for reducing solid waste and saving primary resources. However, their reuse may pose potential risks of groundwater contamination, which may result from the leaching of organic and inorganic substances into water that percolates the solid waste. In this study, column leaching tests were used to investigate the short- and long-term leaching behavior of “salts”, “metals”, and organic pollutants such as PAHs and herbicides from different grain size fractions of construction & demolition waste (CDW) and railway ballast (RB) after a novel treatment process. Specifically, silt, sand and gravel fractions obtained after a sequential crushing, sieving, and washing process (“wet-processing”) of very heterogeneous input materials are compared with respect to residual contamination, potentially limiting their recycling. Concentrations in solid fractions and aqueous leachate were evaluated according to threshold values for groundwater protection to identify relevant substances and to classify materials obtained for recycling purposes according to limit values. For that, the upcoming German recycling degree was applied for the first time. Very good agreement was observed between short and extensive column tests, demonstrating that concentrations at L/S 2 ratios are suitable for quality control of recycling materials. Different solutes showed a characteristic leaching behavior such as the rapid decrease in “salts”, e.g., SO42− and Cl−, from all solid fractions, and a slower decrease in metals and PAHs in the sand and silt fractions. Only the gravel fraction, however, showed concentrations of potential pollutants low enough for an unlimited re-use as recycling material in open technical applications. Sand fractions may only be re-used as recycling material in isolated or semi-isolated scenarios. Leaching from heterogeneous input materials proved harder to predict for all compounds. Overall, column leaching tests proved useful for (i) initial characterization of the mineral recycling materials, and (ii) continuous internal (factory control) and external quality control within the upcoming German recycling decree. Results from such studies may be used to optimize the treatment of mixed solid waste since they provide rapid insight in residual pollution of material fractions and their leaching behavior.
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Hroncová, Emília, Juraj Ladomerský, Anna Ďuricová, and Jozef Puskajler. "Monitoring the Acid Neutralisation Capacity and Options for Leaching Iron from Waste Mud from the Production of Al2O3." Advanced Materials Research 1001 (August 2014): 94–102. http://dx.doi.org/10.4028/www.scientific.net/amr.1001.94.
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Red and brown mud is created in the processing of bauxite into Al2O3. The chemical composition of red and brown mud depends upon the method of processing bauxite on a mud landfill, and the time and availability of mud leaching by rain. Samples of red mud from landfill in Žiarska Kotlina had pH values of 9.46 ± 0.11 and brown mud had 10.2 ± 0.15. We studied the development of changes in pH and concentrations of Fe (spectrometrically with AAS) in eluates during the leaching of red and brown mud samples. Results show that there is no release of Fe during brown mud elution. When using 0.025 and 0.05 M H2SO4 for elution, the pH decreased slightly from 10.2 ± 0.15 to 2.4 ± 0.05. Elution of 0.1 M H2SO4 shows that pH decreased to a value of 2.2 ± 0.05 by the 40th fraction and then it fell to a value of 1.77 ± 0.04 in the 100th fraction. The greatest amount of iron was released in the 8th and 55th fraction at a pH of 2 – 4 which could be observed by the change in colour of eluates. The progress of the release of iron was similar for both kinds of mud. Then we determined the neutralisation capacities of various fractions of mud in H2SO4, NaOH and H2O leachates by titration. It was discovered that the reaction of the alkaline proportions of red mud with the agent is greatest with fine granularity but for red mud, it does not change depending upon the size of the grain. The release of acid proportions depended upon time not upon texture. When leaching with water, the leached alkaline compounds from brown mud are mainly from the finest particles, and in the case of red mud, it was the opposite, from the largest particle fraction.
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Liu, Binlong, Michael Finkel, and Peter Grathwohl. "Mass Transfer Principles in Column Percolation Tests: Initial Conditions and Tailing in Heterogeneous Materials." Materials 14, no. 16 (August 20, 2021): 4708. http://dx.doi.org/10.3390/ma14164708.
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Initial conditions (pre-equilibrium or after the first flooding of the column), mass transfer mechanisms and sample composition (heterogeneity) have a strong impact on leaching of less and strongly sorbing compounds in column percolation tests. Mechanistic models as used in this study provide the necessary insight to understand the complexity of column leaching tests especially when heterogeneous samples are concerned. By means of numerical experiments, we illustrate the initial concentration distribution inside the column after the first flooding and how this impacts leaching concentrations. Steep concentration gradients close to the outlet of the column have to be expected for small distribution coefficients (Kd<1 L kg−1) and longitudinal dispersion leads to smaller initial concentrations than expected under equilibrium conditions. In order to elucidate the impact of different mass transfer mechanisms, film diffusion across an external aqueous boundary layer (first order kinetics, FD) and intraparticle pore diffusion (IPD) are considered. The results show that IPD results in slow desorption kinetics due to retarded transport within the tortuous intragranular pores. Non-linear sorption has not much of an effect if compared to Kd values calculated for the appropriate concentration range (e.g., the initial equilibrium concentration). Sample heterogeneity in terms of grain size and different fractions of sorptive particles in the sample have a strong impact on leaching curves. A small fraction (<1%) of strongly sorbing particles (high Kd) carrying the contaminant may lead to very slow desorption rates (because of less surface area)—especially if mass release is limited by IPD—and thus non-equilibrium. In contrast, mixtures of less sorbing fine material (“labile” contamination with low Kd), with a small fraction of coarse particles carrying the contaminant leads to leaching close to or at equilibrium showing a step-wise concentration decline in the column effluent.
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Wang, Xiaodong, Jian Li, Robbie G. McDonald, Arie van Riessen, and Robert D. Hart. "X-ray diffraction line profile analysis of acid-resistant goethite in Western Australian nickel laterite ore." Journal of Applied Crystallography 48, no. 3 (May 9, 2015): 814–26. http://dx.doi.org/10.1107/s1600576715006275.
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The goethite peaks in synchrotron and laboratory X-ray powder diffraction (XRPD) patterns of an acid-resistant nickel laterite ore sample from a site in Western Australia exhibit a `super-Lorentzian' shape. The method for extracting the coherently scattering domain size distribution published by Leoni & Scardi [J. Appl. Cryst.(2004),37, 629–634] is adapted to fit the asymmetric goethite peak profiles, allowing the refinement of lattice parameters for multiple goethite structural models while maintaining their relationships. The anisotropic peak broadening due to the acicular shape of the goethite crystals is addressed using spherical harmonics predefined from an XRPD pattern of a synthetic goethite sample. A bimodal coherently scattering domain size distribution of goethite crystals is predicted from the goethite profile fitting and agrees with previous transmission electron microscopy findings that two goethite populations with different domain sizes and metal substitutions exist in the ore sample. The small goethite size fraction dissolved slowly during atmospheric acid leaching, while the large goethite fraction barely dissolved. Caustic pre-treatment by KOH digestion significantly enhanced the acid-leaching performance of the small goethite fraction, but had no effect on the large goethite fraction. This study demonstrates that quantitative phase analysis on designated goethite size fractions can successfully fit the super-Lorentzian shaped line profiles of natural goethite crystals with a confirmed bimodal domain size distribution.
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Niemiera, Alexander X., and Carol E. Leda. "Nitrogen Leaching from Osmocote-Fertilized Pine Bark at Leaching Fractions of 0 to 0.4." Journal of Environmental Horticulture 11, no. 2 (June 1, 1993): 75–77. http://dx.doi.org/10.24266/0738-2898-11.2.75.
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Abstract Pine bark-filled PVC columns with 1 g Osmocote (14N-6.3P-11.6K)(14-14-14) per column were irrigated five days a week for 12 weeks with a leaching fraction (LF) of 0, 0.2, or 0.4. Every two weeks cumulative N content of collected leachate and medium solution N concentration (pour-through method) were determined. The total amount of N leached from bark at 0.4 LF was 61% greater than at 0.2 LF. Medium solution NO3-N concentrations of 0 LF were four to eight times greater than at 0.4 LF for all sampling dates. After 84 days, there was no difference in amount of N remaining in Osmocote prills for the LF treatments.
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Tonhauzer, Kristína, Peter Tonhauzer, Janka Szemesová, and Bernard Šiška. "Estimation of N2O Emissions from Agricultural Soils and Determination of Nitrogen Leakage." Atmosphere 11, no. 6 (May 26, 2020): 552. http://dx.doi.org/10.3390/atmos11060552.
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Leaching of nitrogen from the soil is a natural but unfavorable effect that generates N2O emissions. Exact quantification of nitrogen leakage is a challenging process. Intensive leakage occurs mainly when the soil is without vegetation and under specific climatic conditions. This paper aims to quantify the amount of nitrogen leakage from arable land and grassland, and to estimate N2O emissions in 2017. Estimating the country-specific fraction of leached nitrogen (FracLEACH) is important for the emission balance from this source. Emissions are underestimated when the fraction is low; on the contrary, a high fraction causes overestimation. The internationally recognized fraction is 30%, according to the 2006 Intergovernmental Panel on Climate Control (IPCC) Guidelines. This factor represents the fraction of nitrogen losses compared to total nitrogen inputs and sources. In this study, we analyzed the effects of climatic conditions on agricultural soils in Slovakia to evaluate the area of nitrogen loss through leaching.
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Dudley, Lynn M., Alon Ben-Gal, and Uri Shani. "Influence of Plant, Soil, and Water on the Leaching Fraction." Vadose Zone Journal 7, no. 2 (May 2008): 420–25. http://dx.doi.org/10.2136/vzj2007.0103.
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GUIMARÃES, MIGUEL JULIO MACHADO, WELSON LIMA SIMÕES, TEREZINHA DE JESUS RANGEL CAMARA, CLÁUDIA ULISSES DE CARVALHO SILVA, and LILIA GOMES WILLADINO. "ANTIOXIDANT DEFENSES OF IRRIGATED FORAGE SORGHUM WITH SALINE AQUACULTURE EFFLUENT." Revista Caatinga 31, no. 1 (March 2018): 135–42. http://dx.doi.org/10.1590/1983-21252018v31n116rc.
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ABSTRACT The objective of this work was to evaluate the biomass production and antioxidant enzymatic system activity of irrigated forage sorghum with saline aquaculture effluent under different leaching fractions. The experiment was conducted in the Caatinga Experimental Field of the Embrapa Semiarido, in Petrolina, State of Pernambuco, Brazil. The experimental design was a complete randomized block in a split-plot arrangement with four replications, consisting of three forage sorghum varieties (Volumax, F305 and Sudan) and four leaching fractions (0, 5, 10 and 15%). The vegetal materials were collected when the plants were at the soft-dough stage. The biomass production and activity of the enzymes superoxide dismutase, catalase and ascorbate peroxidase were evaluated. Irrigation with saline aquaculture effluent with leaching fraction of 15% results in low salinity level in the root zone and higher biomass production of forage sorghum Sudan and F305, in semiarid conditions. The antioxidant system was activated in the three sorghum varieties to prevent accumulation of reactive oxygen species, with the synchrony between the enzymes superoxide dismutase and catalase resulting in a better productive response of the varieties Sudan and F305.
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Troeglazova, Anna V. "PROBABILITY-DETERMINED DESIGN PLANNING FOR DECOMPOSITION OF SILICON-CONTAINING SAMPLES." Interexpo GEO-Siberia 8, no. 2 (July 8, 2020): 49–55. http://dx.doi.org/10.33764/2618-981x-2020-8-2-49-55.
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An alternative method of acid leaching of silicon-containing metallurgical samples using ultrasonic vibrations is proposed in order to extract Si quantitatively from the solid phase into the solution. The effect of ultrasonic vibration, leaching temperature, phase contact time, weight of the sample, particle size, fraction of hydrofluoric acid in the reaction mixture was investigated. The results of laboratory studies showed that acid leaching assisted by ultrasonic vibrations is an efficient, safe and economically profitable way of sample preparation of silicon-containing metallurgical samples.
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Prior, LD, AM Grieve, PG Slavich, and BR Cullis. "Sodium chloride and soil texture interactions in irrigated field grown sultana grapevines. III. Soil and root system effects." Australian Journal of Agricultural Research 43, no. 5 (1992): 1085. http://dx.doi.org/10.1071/ar9921085.
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Five salinity treatments, ranging between 0.37 and 3.47 dS m-1, were applied through a trickle irrigation system to own-rooted sultana grapevines for six years. The changes in soil salinity levels and the relationship between soil salinity and yield were studied, and a simplified salt balance model was developed to calculate leaching fractions. Soil salinity was strongly influenced by soil texture as well as by salt treatment, because leaching fractions were lower in heavier soils; they averaged 23% in the lightest soils and 10% in the heaviest. Leaching fractions also increased with salt treatment, from 7% in the 0.37 dS m-1 treatment to 24% in the 3.47 dS m-1 treatment. This was probably because water use by salinized vines was lower. Yield was correlated with mean soil salinity, ECe, but the relationship was not as good as with plant salinity levels. The fitted model accounted for between 52 and 62% of the variance. It was concluded that soil salinity levels at the end of winter should be maintained below 1.0 dS m-1 in order to keep yield losses below 10%. For own-rooted sultana grapevines in Sunraysia, this requires a leaching fraction of about 8%. Rootzone depth and root density were lower in the heavier soils, and were decreased by salt treatment. The deleterious effects of salt treatment on clay dispersion and soil hydraulic conductivity were also greater in the heavier soils. Soil properties must therefore be considered when predicting the effects of saline water on crop productivity, especially in the long term.
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Zhang, Lunchao, Jikai Zhou, Xu He, and Chen Chen. "XRD-Rietveld Method for Evaluating the Leaching Characteristics of Hardened Cement Paste in Flowing Water." Advances in Civil Engineering 2020 (August 18, 2020): 1–12. http://dx.doi.org/10.1155/2020/6715271.
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In order to study the leaching characteristics of hardened cement paste by flowing environmental water, indoor simulated leaching tests of Portland cement paste were carried out at different flow velocities with home-made flow field device and tap water as the erosion medium. By means of mechanical properties tests, X-ray diffraction (XRD), and Rietveld full-spectrum quantitative analysis of specimens after leaching at different ages, the change rules of the flexural strength, main phase composition, and mass fraction of the specimens after leaching were obtained. The results show that, within 90 days, the flow rate in the test has no obvious effect on the leaching of hardened cement paste. With the increase in age, the leaching of hardened cement paste gets more obvious. Rietveld full-spectrum quantitative analysis shows that the leaching of hardened cement paste changes with the relative content of CaCO3 and Ca(OH)2. The higher the relative content of CaCO3 is, the better compaction and leaching resistance the paste has. The leaching resistance of hardened cement paste is also related to the gradient of Ca(OH)2. The smaller the gradient is, the better the leaching resistance is. The Rietveld full-spectrum quantitative analysis method can be used as a method to evaluate the leaching effect of hardened cement paste.
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Herre, A., C. Siebe, and M. Kaupenjohann. "Effect of irrigation water quality on organic matter, Cd and Cu mobility in soils of central Mexico." Water Science and Technology 50, no. 2 (July 1, 2004): 277–84. http://dx.doi.org/10.2166/wst.2004.0142.
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Untreated wastewater has been used for irrigation since 1912 at the Irrigation District 03, Central Mexico. Accumulated heavy metals are dominantly bound to the organic soil fraction. In a field study we evaluated the effect of wastewater irrigation on the quality of soil organic matter and the amount of water extractable Cu and Cd. In a column experiment we tested if water treatment affects the leaching of both metals and dissolved organic carbon (DOC) out of soils that have been irrigated for more than 90 years with untreated wastewater. The field study shows that long term irrigation increases the mineralizable carbon fraction and the DOC concentrations. The water extractable Cu and Cd concentrations also increase and correlate with DOC. In the column leachates the Cu concentrations also correlate with DOC, the Cd concentrations correlate with the sum of cations, chloride and DOC concentrations. Water treatment reduced Cd leaching, but it did have no substantial effect on Cu leaching.
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Zhang, Hai Ying, Guo Liang Yuan, and Guo Xian Ma. "Analysis of Heavy Metal Leaching in Fly Ash from One Shanghai Municipal Solid Waste Incineration (MSWI) Plant." Advanced Materials Research 531 (June 2012): 292–95. http://dx.doi.org/10.4028/www.scientific.net/amr.531.292.
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The characteristics and leaching behavior of heavy metals in fly ash, sampled from one MSWI (municipal solid waste incineration) plant in Shanghai China, were investigated. The results indicated that the main elements of fly ash were Fe, K, Na, Cl, Si, Ca, Al, and the total fraction of heavy metals was in the range of 0.8 % - 2.0%. Hence, MSWI fly ash was considered to be one kind of hazardous waste due to its potential environmental risk. Leaching toxicity was performed on fly ash samples from the MSWI plant in Shanghai China. Leaching toxicity of the heavy metals by the ALT (available leaching toxicity) procedure exceeded that by the HVEP (horizontal vibration extraction procedure) standard. Leaching concentrations of Ni, Zn, Cd and Pb exceeded the limit of hazardous waste identification standard. Hence, fly ash is a hazardous waste.