Technology for production of granular calcium-ammonium nitrate

The article presents the technology for production of granular calcium-ammonium nitrate, which is suitable for implementation into the existing production of complex mineral fertilizers. The paper considers the physicochemical foundations of manufacturing calcium-ammonium nitrate and provides the calculations of the equilibrium constants of the reactions occurring at the temperatures of 25–1700С. A new process flow diagram was proposed. It was shown that the production of calcium ammonium nitrate as a valuable agrochemical fertilizer is possible by mixing of 82–84% ammonium nitrate solution with solid carbonate raw materials with further granulation and drying in a drum granulator and dryer. The work determines the conditions for the interaction of reagents making it possible to reduce the losses of nitrogen. The density of aqueous suspensions of chalk and the rate of its precipitation are established. The obtained results allow improving an industrial plant based on the existing equipment for the production of complex mineral fertilizers. The technological parameters for the preparation of the product are optimized to meet the requirements of technical conditions. During commissioning and stabilization of the technological regime, a product was obtained containing 25.9–27.8% of total nitrogen, 15.6–16.8% of CaCO3, 0.01–0.64% of Ca(NO3)2, and 0.32–0.75% of H2O with the following particle size distribution: 95.3–96.3% of 1–5 mm particle size, and 3.7–4.8% of particle size of less than 1 mm with a granule hardness of 30 N per granule.

Ammonia volatilization from manure mixed with biochar

Ammonia (NH3) volatilization from ammonia-based fertilizer and animal manure reduces their nitrogen fertilizer value and is a source of environmental pollution. Mixing manure with biochar may lower NH3 volatilization from manure by adding H+, adsorbing mineral nitrogen (N), or increasing N immobilization in microbial biomass. The objective of this study was to determine whether wood-based biochar could lower NH3 volatilization from vented pails containing manure (liquid swine, dairy slurry, and solid poultry manure) or a urea ammonium nitrate solution (UAN). Two types of wood-based biochar (BlueLeaf and Dynamotive) were mixed with three types of manure and UAN fertilizer solution at 0, 2.5, 5, 10, and 25 % biochar by volume in vented pails. After 21 d storage in an outdoor shaded area, the greatest NH3 volatilization was from poultry manure, which had pH 9.4 on average and low water content regardless of the biochar source and application rate. There was less NH3 volatilization from UAN fertilizer solution when mixed with 25% (v/v) of Dynamotive biochar compared to NH3 volatilization from UAN fertilizer solution mixed with 0–10% (%) of Dynamotive biochar, probably because pH decreased from 7.0 to 6.4 after 21 d contact. Mixing wood-based biochar with manure had no impact on NH3 volatilization, suggesting that these biochar sources did not appreciably change the pH and N dynamics in stored manure after 21 d.

Degradation of Materials Based on Alkali-Activated Blast-Furnace Slag after Exposure to Aggressive Environments

The paper summarizes partial results of a study of degradation of materials based on alkali-activated blast-furnace slag (AAS) and comparative on cement CEM III/A 32.5 R after exposure to aggressive environments. It further specifies the possibilities for utilising destructive and non-destructive techniques to determine the progress of degradation and characterizes the degree of their correlation. After 28 days of ageing in a water environment, the produced test specimens (40×40×160 mm beams) were placed in aggressive media (ammonium nitrate solutions; sodium sulfate, rotating water) and after subsequent 28, 56 and 84 days of degradation were subjected to testing. Testing comprised both a destructive form (determination of compressive strength and flexural strength) and a selected non-destructive technique (Impact-echo method). The partial outputs were supplemented by the results acquired from monitoring weight changes. In addition, the development of Ultrasonic Pulse Velocity in relation to the progress of the degradation processes was also monitored. While the exposure of both test specimens to water and sodium sulfate did not result in any significant changes, the exposure to the ammonium nitrate solution exhibited rapid signs of degradation associated with a significant reduction in functional characteristics.

Effects of Urea-Ammonium Nitrate Solution on Yield, N2O Emission, and Nitrogen Efficiency of Summer Maize Under Integration of Water and Fertilizer

In order to clarify the effects of urea-ammonium nitrate solution (UAN) on the yield, nitrogen-use efficiency (NUE), and N2O emissions of summer maize under the condition of water and fertilizer integration, different types of nitrogen fertilizer were selected, namely, ordinary urea (urea) and UAN. Our results showed that the application of UAN was beneficial to improve the dry matter accumulation and the distribution of summer maize. Compared with urea treatment, the total nitrogen accumulation of UAN treatment was increased by 15.8%, and the harvest index was increased by 5.5%. The partial productivity, agronomic use efficiency, and recovery rate of nitrogen for UAN treatment were also increased by 9.1, 19.8, and 31.2%, respectively, compared to those of urea treatment. The soil nitrogen dependence rate treated with UAN was significantly decreased by 13.6%, compared to that of urea treatment. In addition, UAN was beneficial to reduce N2O emissions. The N2O warming potential (GWPN2O) and N2O greenhouse gas intensity (GHGIN2O) of urea treatment were 39.3 and 52.4% higher, compared to those of UAN treatment. The improvement of dry matter accumulation and distribution and nitrogen efficiency for UAN treatment were beneficial to increase the grain yield by 9.1%, compared to that of urea treatment. In conclusion, under the fertigation, the application of UAN favors higher yield and nitrogen uptake, with less soil nitrogen residue, higher NUE, and better environmental effect.

VNT4, a Derived Formulation of Glutacetine® Biostimulant, Improved Yield and N-Related Traits of Bread Wheat When Mixed with Urea-Ammonium-Nitrate Solution

Optimizing nitrogen use efficiency (NUE) could mitigate the adverse effects of nitrogen (N) fertilizers by limiting their environmental risks and raising agronomic performance. We studied the effects of VNT4, a derived formulation of Glutacetine® biostimulant, mixed with urea-ammonium-nitrate solution (UAN) on the growth, N-related traits and agronomic performance of winter wheat (Triticum aestivum L.). The experiment was performed under six contrasting field conditions over two years in Normandy (France), including a site where 15N labelling was undertaken. Taking into account all the sites, we report that VNT4 significantly improved grain yield (+359 kg ha−1), total grain N and NUE. VNT4 application improved growth during tillering and stem elongation (+10.7%), and N and 15N uptake between tillering and maturity (+7.3%N and +16.9%15N) leading to a higher N accumulation at maturity (+9.3%N). This N mainly originated from fertilizer (+19.4%15N) and was assimilated after the flag leaf stage in particular (+47.6%15N). These effects could be related to maintenance of physiological functions of flag leaves as suggested by the enhancement of their nutrient status (especially S, Zn and Mo). The adoption of VNT4 as a UAN additive is an efficient agronomic practice to enhance wheat productivity under an oceanic temperate climate.

Comparison of McMaster and Mini-FLOTAC effi ciency methods in diagnostics of Ascaris suum infection in young pigs

The coproovoscopic methods involving count chambers are widely used in the veterinary practice for diagnostics. These methods are important in assessments of the prevalence rates of nematode infections in pigs and for FECR tests. However, more basic data is needed on the efficiency of the commercial methods of diagnostics, tested at the different specific gravity of the flotation solutions. In a thorough analysis of publications of Ukrainian scientists, we have found that the data is sparse on the efficiency comparison of the modified McMaster’s and MiniFLOTAC methods. The aim of our study was to compare the efficiency of the commercial coproovoscopic techniques: the modified McMaster’s method (with sensitivity of 25 EPG), and MiniFLOTAC combined with Fill-FLOTAC (with sensitivity of 5 EPG) in testing for A. suum infection in piglets. Results of approbation of the mentioned methods are presented for the following saturated solutions: NaCl (SG=1.2), MgCl2 •6H2 O (SG =1.27) and NH4 NO3 (SG=1.28). Fecal samples were taken at own private farm, in Mlynok village of Onufriivka district, Kirovohrad region from 20 4 month old pigs with spontaneous A. suum infection. The laboratory assessments were performed in the Scientific Laboratory of Parasitology and Veterinary and Sanitary Expertise of the Poltava State Agrarian Academy. It is established that at high rates of A. suum infection in young pigs, McMaster’s method with the ammonium nitrate solution is more efficient compared to the Mini-FLOTAC method. In average, 5331.2 eggs of A. suum were determined per 1 g of feces using the former method, compared to 4567.5 EGP according to the Mini-FLOTAC technique (P < 0.001). The highest diagnostic efficiency of the modified McMasters method and the combination of Mini-FLOTAC and Fill-FLOTAC is seen when ammonium nitrate (NH4 NO3 ) solution of 1.28 SG is used (P < 0.001). Our results add new data on the efficiency of the commercial methods of diagnostics with varying specific gravity of the flotation solutions, for pigs infected with nematodes. Key words: EPG, pigs, nematode, ascariasis, diagnostics, efficiency.

ANALYSIS OF KINETIC CHARACTERISTICS OF BAROMEMBRANE AND ELECTROBARMEMBRANE SEPARATION OF AMMONIUM NITRATE SOLUTION

The paper presents a generalized analysis of literature data on the current-voltage, omics characteristics and electrical conductivity of membrane systems. Based on an analysis of the literature, it is noted that electrodialysis is a promising method for the separation of solutions for the production of ammonium nitrate. An analysis of literature revealed that the application of an external constant electric field to the membrane separation of solutions containing charge-transporting components (nitrate ions and ammonium ions) causes the directed transfer of cations and anions through the membranes. The studies revealed that with the baromembrane separation of the studied solutions with increasing transmembrane pressure, the specific output stream increases. This is due to an increase in the driving force of the process. For the OFAM-K anode membrane, with an increase in the current density, with the electrobaromembrane separation of the ammonium nitrate solution, the specific output stream decreases, which is associated with a change in the pH value of the acidified anode permeate. nd for the OPMN-P cathode membrane, the specific output stream increases with a change in the pH of the alkalized cathode permeate. A modified mathematical equation is proposed for theoretical calculation of the specific output stream and the retention coefficient of the OFAM-K and OPMN-P nanofiltration membranes. Experimental studies of membrane systems equipped with the anode OFAM-K and the near-cathode OPMN-P membranes from voltage and transmembrane pressure revealed that for the aqueous solution of ammonium nitrate there are two characteristic periods on the current-voltage, omics characteristics and electrical conductivity of the membrane system (the first period is beyond regime, dissociation of water (H+ and OH-) at the phase boundary with the advent of additional electric current carriers, the second is the degradation of the active layer of a semipermeable membrane). When studying the current-voltage characteristics of a membrane system equipped with an anode OFAM-K and a near-cathode OPMN-P membranes, when separating model and technological solutions, a decrease in the total omics resistance of the system is observed, which is associated with the solution throttling process.