Influence of Organic Ammonium Derivatives on the Equilibria Between of NH4+, NO2- and NO3- Ions in River Waters

The braking effect of the ammonium derivatives on the natural aquatic environment varies dramatically with the number and nature of organic radical substitutions at nitrogen atom, particularly with their structure, composition and genesis. The most common discrepancy in their toxic effect are showing the natural and synthetic amines. For instance, the values of the maximum allowable concentration (MAC) of the derivatives of the natural origin for drinking water exceed the MAC of the synthetic ones by two orders. On the other hand, it has been found out that 1- naphtylamine (1-NA) inhibitory effect is associated to its toxicity. The Diethylamine (DEA) braking impact on the nitrification process is effectively lower than that of the toxicity. Our experiments show that the carbon-radicals of organic amines act as reducing agents. It is found that DEA decomposition leads to a high NH4+ ions (approx. 3.8 mg/L ammonium nitrogen) concentration in river water samples. By laboratory simulations two types of fixations by microbial organisms have been established: 1) absorption-desorption, the hydromicrobiotic reaction to ammonium (HMBRA) at the instantaneous increase of the concentration of ammonium ion in the river water (so-called shock/stress effect); 2) nitrogen fixation stimulated by a certain concentration (0.05mg/L) of a 1-NA and other amines.

Ionothermal Synthesis of Triclinic SAPO-34 Zeolites

A triclinic SAPO-34 molecular sieve was synthesized ionothermally. The as-synthesized products were characterized by powder X-ray diffraction (XRD), scanning electron microscope (SEM), nuclear magnetic resonance (NMR), fourier infrared spectrometer (FT-IR) and thermogravimetric (TG) analyses. The formation mechanism of the hierarchical porous triclinic SAPO-34 zeolites and the factors affecting the morphology of the SAPO-34 molecular sieve were investigated. The results show that the formation mechanism of the hierarchical pores is in accordance with Ostwald ripening theory, and the accumulation of grains constitutes the existence of mesopores and macropores. The crystallization temperature, ionic liquid type, and organic amines can effectively change the morphology and crystallinity of the SAPO-34 molecular sieve. The crystallization temperature, ionic liquid and template have great influence on the (111) crystal plane, thus affecting the morphology of the molecular sieve. Moreover, it can be proven through NMR and TG analyses that ionic liquids and organic amines can be used as structure directing agents together.

Optimization of Surface Properties of Plasma Electrolytic Oxidation Coating by Organic Additives: A Review

Plasma electrolytic oxidation (PEO) is an effective surface modification method for producing ceramic oxide layers on metals and their alloys. Although inorganic electrolytes are widely used in PEO, the organic additives have received considerable interest in the last decade due to their roles in improving the final voltage and controlling spark discharging, which lead to significant improvements in the performance of the obtained coatings. Therefore, this review summarized recent progress in the impacts of organic additives on the electrical response and the plasma discharges behavior during the PEO process. The detailed influence of organic additives, namely alcohols, organic acids, organic amines, organic acid salts, carbohydrate compounds, and surfactants on the corrosion behavior of PEO coatings is outlined. Finally, the future aspects and challenges that limit the industrial applications of PEO coating made in organic electrolytes are also highlighted.