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Germination, development, and production of directly seeded agricultural products may be impacted by a variety of abiotic stresses. Silica nanoparticle seed priming has the ability to reduce the impact of external stressors. Stress brought on by salt has now become a barrier to wheat (Triticum turgidum) farming success. The goal of the current research was to clarify the effectiveness of seed priming with silica nanoparticles in reducing salt-induced stress in wheat plants. In this research, silica nanoparticle at three distinct concentrations—300, 600 and 900 ppm—was used for seed priming either alone or in combination with sodium chloride (2.3 and 4.6 ds/m). The application of silica nanoparticles considerably improved seedling development while salinity stress greatly decreased germination percent and seedling growth. Seed priming significantly increased shoot length (11.53%), root length (22.76%), seedling length (17.57%), shoot weight (35.56%), root weight (19.14%), germination stress tolerance index (91.55%), shoot length stress tolerance index (11.58%), root length stress tolerance index (22.6%), shoot weight stress tolerance index (35.54%) and root weight stress tolerance index (18.12%) under high saline treatment (4.6 ds/m). The significance of nano-silica in reducing the detrimental effects of salt stress on wheat seed growth is highlighted by the current investigation. The results showed that silica nanoparticle seed priming could enhance seedling early development under salt stress. [ABSTRACT FROM AUTHOR]

Livestock and chicken manures generated in 2017 in Al-Mafraq governorate (North of Jordan) were estimated to be around 250 × 103 tons and expected to increase in the coming years. Therefore, the accumulation of animal manures will continue to pose a significant threat to public health by direct or indirect exposure. In this work, manures of cow, sheep/goats, and chicken and poultry litter were tested for their chemical composition and thermal characteristics, and then the potential of these manures as valuable renewable energy resources were examined. The proximate and ultimate analyses of these wastes were evaluated along with their heating values. Representative samples of different animal manures, chicken feather, and poultry litter were also subjected to a pyrolysis process. Poultry litter had the highest heating value (19.48 MJ/kg) among the tested samples, followed by chicken feathers (18.95 MJ/kg) and sheep/goat (10.92 MJ/kg). Cow manure had the lowest heat value (8.68 MJ/kg). Based on the elemental analysis, poultry waste had the highest contents of carbon and hydrogen, while cow manure had the lowest. Positive correlations were found between the levels of hydrogen and carbon of the selected wastes and their heat values. Poultry litter had a high nitrogen content and a low C:N ratio, whereas cow manure had the lowest nitrogen content and the highest C:N ratio. Poultry manure and litter had a higher volatile matter and a lower ash content than sheep/goat and cow manures. Chicken manure was the best among the tested samples in terms of bio-oil production (36 wt%) followed by poultry litter and sheep/goat manures, while cow manure was the lowest. Poultry litter was found to be the best source for biogas production. It is anticipated that 48.7 million m3 of biogas can be produced annually from the available animal waste resources in this governorate, and this amount of biogas can be converted into energy of about 10.1 × 106 GJ. This amount of energy can satisfy the energy demand of at least 5% of the population in the Al-Mafraq governorate. In conclusion, the study recommended that converting animal solid manures to energy would be a promising waste management option or strategy to be applied in this governorate as well as in Jordan. [ABSTRACT FROM AUTHOR]

This contribution reports a thermodynamic assessment for the bromination of electric arc furnace dust (EAFD) by-products sourced from thermal degradation of tetrabromobisphenol A (TBBA); i.e., the most widely deployed brominated flame retardant. Upon TBBA's pyrolysis, HBr is released in conjunction with several volatile organic compounds leaving a solid carbonaceous residue. EAFD contains appreciable quantities of zinc, iron, and lead oxides. These oxides can react with HBr to form volatile metal bromides when the EAFD is added to the TBBA as a bromination agent. The selective bromination of zinc and lead contained in EAFD was thermodynamically evaluated under both oxidative and inert pyrolytic conditions while considering the effects of several variables. These factors span temperature, loads of TBBA, the presence of oxidizing agent, and the effect of the presence of other common EAFD's constituents such as sodium, potassium, calcium, silicon, and sulfur. It was found that a 100% extraction (based on thermodynamic feasibility) of both zinc and lead can be achieved for a mixture containing 60% EAFD and 40% TBBA (contaminated with minor amounts of iron) when pyrolyzed under inert conditions. However, when a thermal treatment is performed in the presence of oxygen, complete thermodynamic-based recovery of zinc and lead recoveries can be achieved at a lower temperature with no iron content. Removal of sodium and potassium chloride from EAFD prior to pyrolysis by washing, under oxidizing condition, can also result in a profound selectivity in zinc and lead bromination. The behavior of other elements during bromination process was also discussed. [ABSTRACT FROM AUTHOR]

This work reports a thermodynamic assessment of EAFD chlorination products stem from thermal decomposition products of PVC. Upon PVC pyrolysis, HCl gas is liberated in conjunction with several volatile organic matters leaving solid carbonaceous residue. EAFD contains appreciable quantities of zinc, iron and lead oxides. These react with HCl to form metal chlorides, if EAFD is added to the PVC as a dechlorination agent. Selective chlorination of zinc and lead present in EAFD leaving iron in its oxide form is of an apparent commercial value. Detailed thermodynamic analysis of EAFD chlorination by HCl was performed considering the effects of several variables. These include temperature, amount of chlorination agent, presence of oxidizing agent and the effect of presence of other EAFD constituents such as sodium, potassium, calcium, silicon and sulfur. It was found that 100% recovery of both zinc and lead can be achieved for mixture containing 50% EAFD and 50% PVC when pyrolyzed under inert conditions, but contaminated with at least 20% of the iron chloride. However, when thermal treatment is performed in the presence of oxygen, the 100% zinc and lead recoveries were achieved at lower temperature with a minimal iron contamination (< 2.6%). Removal of sodium and potassium chloride from EAFD prior to pyrolysis by washing, under oxidizing condition, has also resulted in great selectivity in zinc and lead chlorination. The behavior of other elements during chlorination process was also discussed. The results obtained shall be instrumental in efforts aiming to achieve optimum recycling operations for both categories of pollutants. [ABSTRACT FROM AUTHOR]

The pyrolysis of Tetrabromobisphenol A (TBBPA) mixed with electric arc furnace dust (EAFD) was studied using thermogravimetric analysis (TGA) and theoretically analyzed using thermodynamic equilibrium calculations. Mixtures of both materials with varying TBBPA loads (1:1 and 1:3) were prepared and pyrolyzed in a nitrogen atmosphere under dynamic heating conditions at heating rates of 5 and 10 °C/min. The mixtures degraded through several steps, including decomposition of TBBPA yielding mainly HBr, bromination of metal oxides, followed by their evaporation in the sequence of CuBr, ZnBr, PbBr, FeBr, MnBr, KBr, NaBr, CaBr, and MgBr, and finally reduction of the remaining metal oxides by the char formed from decomposition of TBBPA. Thermodynamic calculations suggest the possibility of selective bromination of zinc and lead followed by their evaporation, leaving iron in its oxide form, while the char formed may serve as a reduction agent for iron oxides into metallic iron. However, at higher TBBPA volumes, iron bromide forms, which can also be evaporated at a temperature higher than those of ZnBr and PbBr. Results from this work provide practical insight into selective recovery of valuable metals from EAFD while at the same time recycling the hazardous bromine content in TBBPA. [ABSTRACT FROM AUTHOR]

The reaction of aniline with hydrogen atom is investigated herein using the hybrid meta-DFT functional of BB1 K. Hydrogen atom is found to preferentially add at an ortho position. However, the fate of the o-(CHNH)H adduct is found to be solely the deactivation of the initial addition channel. The rate constant for the abstraction channel (CHNH + H → CHNH + H) is fitted by the expression 1.10 × 10 exp(−4,200/ T) cm molecule s. Our calculated rate constant for the abstraction channel agrees very well with the available experimental measurements. Satisfactory agreement is found between calculated and experimental measurements for the displacement channel (CHNH + H → CH + NH). Our detailed analysis for the corresponding displacements in toluene and phenol suggests that the three systems exhibit similar behavior with regard to the relative importance of abstraction and displacement channels. [ABSTRACT FROM AUTHOR]

The leachability of bottom medical waste ash from a Jordanian incinerator was studied in this work. The ash was characterized in terms of particle size distribution, chemical and mineralogical composition followed by leaching of several size fractions at different conditions (leaching time, temperature, initial pH, particle size, and solid liquid ratio). The major elements found in the ash were Ca, Si, Al, Cl, Na, Fe, Ti, S, Mg, Ba, and K, while the main mineral phases found in the ash were calcite, halite, sylvite, anhydrite, hematite, hydrochlorborite, cristobalite, melanterite, and chlormayenite. Leaching data indicates that as leaching time and S/L increased, the concentration of metals increased in the leachate. The highest leaching level was at a S/L ratio of 60 mg/ml. As the particles sizes decreased, the concentration of the majority of metals studied increased. Meanwhile, the effect of particle size on other metals was not regular due to the fact that sieving resulted in more concentrated metals in certain particle size fractions. Leachability results also indicate that variation in the initial pH has a slight effect on the degree of leaching. The concentration of some metal ions increased with temperature, while others increased initially but subsequently decreased. The extracted quantities of all the heavy metals were less than the limits set by EPA. [ABSTRACT FROM AUTHOR]

Electric arc furnace dust (EAFD) is a toxic waste which is mainly rich in iron oxide, zinc, and lead. Hydrometallurgical extraction of zinc from Jordanian EAFD in alkaline medium was investigated; NaOH, NaHCO3, and Na2CO3 were used as leaching agents. The pH values for the prepared solutions were 8.3, 8.2, and 12.55 for NaHCO3, Na2CO3, and NaOH, respectively. The effect of NaOH concentration (1, 3, 5, 7, and 9 M), contact time (5 min to 3 h), temperature (20, 40, and 60), and solid-to-liquid ratio (SLR; 20, 40, 80, and 120 mg/ml) on the leachability of zinc from EAFD were tested. The initial EAFD and the resulting leach residues were characterized using X-ray diffraction (XRD) and X-ray fluorescence (XRF). EAFD contained 25.9% Zn, 18.0% Fe, and 3.2% Pb. A maximum zinc recovery of 92.9% was achieved using 6 M NaOH at 60 °C with solid loading of 20 g/L and 3 h leaching time. NaHCO3 and Na2CO3 were not efficient leaching agents for Zn extraction since the recoveries were only 2.6 and 4.5%, respectively. Zn and Pb were depleted in the residues with an E-factor of 0.5-0.6 and 0.1-0.25, respectively. Iron was enriched in the residues; the E-factor was around 2. The EAFD contained mainly zincite, franklinite, and magnetite. After 3 h leaching, only traces of zincite exist in the residues, while sylvite and halite were completely dissolved. [ABSTRACT FROM AUTHOR]