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Applications of Nanomaterials in Agriculture and Their Safety Aspect
Published in Devarajan Thangadurai, Saher Islam, Jeyabalan Sangeetha, Natália Cruz-Martins, Biogenic Nanomaterials, 2023
Leo Bey Fen, Ahmad Hazri Abd. Rashid, Nurul Izza Nordin, M.A. Motalib Hossain, Syed Muhammad Kamal Uddin, Mohd. Rafie Johan, Devarajan Thangadurai
In the food sector, engineered nanomaterials (ENMs) are used as food additives to improve food stability during processing and storage, enhance characteristics of product, or increase the efficacy and bioavailability of nutrients in the food. Among ENMs-based food additives, synthetic amorphous silica (SAS) is the most common type. SAS is generally used as clarifying agent for beverages, while as an anti-caking and free-flow agent in several food products in powdered form (E551) (Dekkers et al., 2011). Besides SAS, several formulated anti-caking agents have been utilized in food items, including calcium silicate, dicalcium phosphate, sodium ferrocyanide, sodium aluminosilicate, and microcrystalline cellulose. However, there is a lack of concrete evidence whether such materials are (partly) available at the nanoscale (Peters et al., 2016).
Microcircuitry and Remote Monitoring
Published in Martha J. Boss, Dennis W. Day, Air Sampling and Industrial Hygiene Engineering, 2020
Those compounds that are readily oxidized by chlorination are cyanides of SodiumPotassiumCadmiumZinc The copper cyanide complex is also considered amenable to chlorination, although longer reaction times are required (also for silver and gold cyanide complexes). The nickel cyanide complex is more resistant to chlorination than the copper complex, yet it can be considered as amenable to chlorination under extreme oxidizing conditions. Iron complexes (most commonly the sodium ferrocyanide salt) are not readily oxidizable by chlorine.
Resources and Processing
Published in C. K. Gupta, Extractive Metallurgy of Molybdenum, 2017
Nearly all the molybdenum production in Peru is derived from porphyry copper ores. In this context, the Toquipala porphyry copper deposit can be cited as a leading example. An estimate places the ore reserves here at about 700 million tonnes. These deposits form a wholly owned subsidiary of Southern Copper Corp. The ore is a low-grade porphyry containing 1.2% copper and 0.018% molybdenum. The ore is conventionally crushed and ground and then concentrated by flotation, recovering a 31% copper concentrate containing 0.3% molybdenum. After thickening to 60% solids, this concentrate is adjusted for a pH of 8 and floated in a rougher molybdenum flotation circuit at 30% solids. The reagents, sodium ferrocyanide and sodium perchlorate, are used as copper depressors, and the concentrate is refloated a number of times until a molybdenite concentrate with an assay of 87% MoS2 and 1.2% copper is obtained. Rougher bulk flotation is implemented with sodium isopropyl xanthate (Z-11) and pine oil at pH 11.5. The copper recovery is 88% and that of molybdenum 60%. There are, however, additional losses that are incurred in cleaner flotation and molybdenum separation, and because of this the overall molybdenum recovery comes to only about 37%. The last stages of copper depression are carried out by using sodium cyanide.
Reversible photochromic photocatalyst Bi2O3/TiO2/Al2O3 with enhanced visible photoactivity: application toward UDMH degradation in wastewater
Published in Journal of Environmental Science and Health, Part A, 2020
The cylindrical catalyst sinks at the bottom of the solution, which has less light scattering and is rapidly blackened by light to enhance the absorption of light. The catalyst particles (2.0 g was more suitable for the photocatalytic vessels, as shown in Table A1) were added into 40 mL of UDMH solution with an initial concentration of 100–120 mg L–1 (pH = 7.0–7.1). Prior to irradiation, dark experiments (adsorption) were carried out for 30 min to reach the adsorption equilibrium of UDMH with the catalyst. The solution containers were sealed with plastic wrap to avoid the concentration change caused by solution evaporation during irradiation. Traces of UDMH can react with amino ferrocyanide sodium to form a red complex in a weakly acidic aqueous solution, and the color depth of the red complex is proportional to the content of UDMH. Thus, the concentration of UDMH was determined by amino sodium ferrocyanide spectrophotometry at 500 nm.[13] Finally, in order to further evaluate the mineralization effect of the optimized catalyst on wastewater, the detection of TOC was carried out, expressed as [32,33] The catalysts were washed with ethanol and dried for the repeat test of stability before the photodegradation experiment.
Continuous flow hygroscopicity-resolved relaxed eddy accumulation (Hy-Res REA) method of measuring size-resolved sodium chloride particle fluxes
Published in Aerosol Science and Technology, 2018
N. Meskhidze, T. M. Royalty, B. N. Phillips, K. W. Dawson, M. D. Petters, R. Reed, J. P. Weinstein, D. A. Hook, R. W. Wiener
Sodium chloride particles were generated by bubble bursting inside the wind tunnel using two 40 L aquariums. Each aquarium was filled with tap water and ∼2.8 kg of Morton coarse salt (NaCl with small amounts of anticaking agent – hydrous form of sodium ferrocyanide, ) purchased in a grocery store. Every 2 days, ∼1 L water and ∼100 g of salt was added to the aquariums. Each aquarium had a dedicated pump, and air was bubbled through twelve (six in parallel for each aquarium), fine-porosity wooden frits, positioned over a depth range ∼10 cm below the air–water interface. It is well known that factors such as water temperature, salinity (Mårtensson et al. 2003; Lewis and Schwartz 2004), bubble generation techniques (Stokes et al. 2013), and the purity of the solution (Modini et al. 2013) are likely to affect the nascent NaCl particle production. However, over 15 min of the flux averaging time, the changes to the system were minor, and, therefore, had no measureable effect on the outcome of the study. Salt purity and water purity (tap water) had only a weak influence on the aerosol properties. Particle size distributions (PSDs) inside the wind tunnel were determined by using the SMPS method (Wang and Flagan 1990). The SMPS consisted of TSI 3081 long column mobility analyzer (TSI Inc., Shoreview, MN, USA) that was operated at a 5:1 sheath to sample flow ratio. Detailed operating procedures are described further below.
Copper ferrocyanide chemically immobilized onto a polyvinylidene fluoride hollow-fibre membrane surface for the removal of aqueous cesium
Published in Environmental Technology, 2022
The PVDF hollow-fibre membrane to be used as support was purchased from Energy & Environment Co., Ltd. (Korea). Ethanol (94%), sodium hydroxide (NaOH, 1 N), acrylic acid (99%), potassium nitrate (KNO3, 99%), and sodium nitrate (NaNO3, 99%) were purchased from Duksan Chemicals Co. (Korea). Ammonium cerium(IV) sulfate dihydrate ((NH4)4Ce(SO4)4·2H2O, 94%), ethylenediamine (EDA, 99%), copper(II) chloride dihydrate (CuCl2·2H2O, 99%), sodium ferrocyanide decahydrate (C6FeN6Na4·10H2O, 99%), and cesium nitrate (CsNO3, 99%) were obtained from Merck (Germany). All chemicals were used as received without further purification.