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Influence of nitrates salts on chosen properties of ceramic brick
Published in Claudio Modena, F. da Porto, M.R. Valluzzi, Brick and Block Masonry, 2016
rosion exposure. The spectra at the values of 1767, 1358, 833 cm-1 were related to the presence of nitrate groups, which confirms the observations in the scanning microscope. On the other hand, spectra at the values of 3414 and 1632 cm-1 came from molecular water of crystallization. Taking into account the hygroscopic character of magnesium nitrate, it may be assumed that this is molecular water built into the structure of this salt to form the Mg(nO3)2*6H2O hydrate. The spectra coming from water of crystallization are very narrow, which gives ground for thinking that the hydrated structures are characterised by a large degree of order. However, these forms are not visible in the xRD tests. On the other hand, the spectrum at the value of 3235 cm-1 came from hydroxyl groups. This gives ground for thinking that amorphous magnesium hydrogen carbonate formed in the brick. According to (Shand 2006) formation of magnesium nitrate hexahydrate with the formula Mg(nO3)2*4 Mg(OH)2 is also possible.
The use of recovered struvite and ammonium nitrate in fertigation in a horticultural rotation: agronomic and microbiological assessment
Published in Environmental Technology, 2022
Mar Carreras-Sempere, Carmen Biel, Marc Viñas, Miriam Guivernau, Rafaela Caceres
To assess the effectiveness of the recovered products as raw materials for fertilizer blends, three fertigation treatments were applied throughout a crop rotation trial to compare the agronomic performance of the crops and their environmental effects. The treatments consisted of supplying three different NS, differing on the P and N sources and the N-NO3−:N-NH4+ ratio: (i) struvite (STR) treatment, with 100% and 17 ± 4% of P and N-recovered source, respectively; (ii) struvite and ammonium nitrate (SAN) treatment, with 100% and 39 ± 11% of P and N-recovered source, respectively; and (iii) control (CON) treatment, using solely synthetic mineral fertilizers. The recovered nutrients were the P and N from ground struvite and the N-NH4+ from liquid AN. The reference P fertilizer used in the CON nutrient solution was monopotassium phosphate (KH2PO4). Other commercial fertilizers were used to complete the nutrients needed for the cNS and to diminish the pH: potassium nitrate, potassium sulphate, calcium nitrate, magnesium nitrate, micronutrients, and nitric acid (respectively). The fertigation system was established with 2 tanks per treatment, containing the mentioned cNS to be released into passing irrigation water through venturi system with automatic control of irrigation (Dosatron, France). The concentration of the different compounds that made up the cNS for each treatment and crop is shown in Table 5S.
Study on the thermal decomposition mechanism of Mg(NO3)2·6H2O from the perspective of resource utilization of magnesium slag
Published in Environmental Technology, 2022
Meng-hui Zhang, Liang Zhao, Han-lu Xu, Wen-chang Wu, Hui Dong
As a strategic metal, nickel has been widely used in military, civil, chemical, electromagnetic and other fields because of its outstanding advantages such as high boiling point and melting point, strong corrosion resistance and oxidation resistance [1,2]. The nitric acid leaching process of laterite nickel ore is one of the important methods to obtain nickel [3–5]. In this process, however, the acquisition of Ni is accompanied by the accumulation of magnesium slag magnesium nitrate hydrate (Mg(NO3)2·6H2O). The accumulation of magnesium slag not only increases the burden on the environment but also causes the waste of magnesium resources. Thus, how to efficiently recycle magnesium slag Mg(NO3)2·6H2O is the key to the environmentally benign development of the laterite nickel ore nitric acid leaching process.
Valorization of resources from end-of-life lithium-ion batteries: A review
Published in Critical Reviews in Environmental Science and Technology, 2022
Francine Duarte Castro, Mentore Vaccari, Laura Cutaia
The graphite residue can also be used as an adsorbent for pollutant removal from aqueous media. Natarajan and Bajaj (2016) converted graphite from spent LIBs into graphite oxide using a modified Hummers’ method (Hummers & Offeman, 1958). Both graphite and graphite oxide were, then, used to adsorb anionic CR and cationic MB dyes from an aqueous solution (25 mg l−1 of dye). The adsorption efficiencies of graphite toward CR and MB were 76% and 92%, respectively, while graphite oxide was able to remove 100% of CR and MB (4 h adsorption). Zhang et al. (2016) tested surface modifications to enhance the performance of graphite anode extracted from LIBs as an adsorbent. Mg-enriched engineered carbons were synthesized using nitric acid oxidization and magnesium nitrate. The produced material exhibited high efficiency in phosphate removal (up to 95%) for Mg content >30%, while the non-doped material removed less than 10% of the contaminants. Zhao et al. (2017) developed MnO2-modified graphite sorbents from spent LIBs and used the product to adsorb water contaminated with Pb(II), Cd(II) and Ag(I), achieving removal efficiencies of 99.9%, 79.7%, and 99.8% under optimized conditions, respectively.