Effect of Silicate, Carbonate, Calcium Lignosulphonate, and Silicic Acid Additives on Ammonium Nitrate Degradation

Ammonium nitrate is the most commonly used nitrogen fertilizer in the agriculture and plays an important role in the development of leaves and stems in plants. The storage and production of ammonium nitrate at the industrial scale can result in degradation and caking. Various solutions have been proposed, however, to date, an effective solution to the degradation problem has not been identified. The addition of silicic acid during the production of ammonium nitrate prevents the double salt formation caused by sulphuric acid additive, which is a process requirement. Silicic acid was combined with calcium carbonate in the dilution stage in order to increase the fracture strength of ammonium nitrate. With the addition of calcium lignosulphonate, the phase conversion of ammonium nitrate granules was completed more rapidly, and thus the problem of degradation was prevented. Thus, chemical and physical degradation of the ammonium nitrate structure were prevented during the 2-year storage period, which was adopted as the standard for the ammonium nitrate production process.

Enhancement in the rate of nitrate degradation on Au- and Ag-decorated TiO2 photocatalysts

The solar-driven reduction of nitrate to nitrogen has been studied in the presence of a formate hole scavenger, over a series of Au- and Ag-decorated TiO2 catalysts.

Magnetic In–Pd catalysts for nitrate degradation

Magnetic catalysts offer the possibility of rapidly eliminating nitrate oxyanions, a ubiquitous drinking water contaminant, without generating a secondary waste stream.

Denitrification characteristics of a newly isolated indigenous aerobic denitrifying bacterium under oligotrophic conditions

A novel indigenous bacterium, strain JM10, isolated from the oligotrophic Hei He reservoir was characterized and showed aerobic denitrification ability. JM10 was identified as Bacillus sp. by phylogenetic analysis of its 16S rRNA gene sequence. Strain JM10 displayed very high levels of activity in aerobic conditions, consuming over 94.3% NO3−-N (approximately 3.06 mg L−1) with a maximum reduction rate of 0.108 mg NO3−-N L−1 h−1. Full-factorial Box–Behnken design and response surface methodology were employed to investigate the optimal nitrate degradation conditions. The optimum conditions for nitrate degradation, at a rate of 0.140 mg L−1 h−1, were found to be an inoculum size of 16.3% v/v, initial pH of 7.6, C/N ratio of 7.4, and temperature of 27.4 °C, and the C/N ratio and temperature had the largest effect on the nitrate degradation rate. Strain JM10 was added into the water samples from Hei He reservoir and the total nitrogen and nitrate removal rates of the strain reached 66.5% and 100%, respectively. Therefore, our results demonstrate that the strain JM10 favored the bioremediation of the oligotrophic reservoir.

Effects of sodium silicate, calcium carbonate, and silicic acid on ammonium nitrate degradation, and analytical investigations of the degradation process on an industrial scale

Ammonium nitrate is an inorganic chemical that has numerous applications in different industries. However, various problems are associated with both the production and subsequent storage of ammonium nitrate, including caking, degradation, unwanted phase transition, and recrystallization. Although several methods have been developed to attempt to solve these problems, many of them fail to work in practice. In this study, different compounds including silicic acid and sodium silicate were added to slow the progress of or to prevent the degradation of ammonium nitrate. Multiple instrumental analyses such as ion chromatography and scanning electron microscopy were used to monitor the degradation process.

Perchlorate Removal in Biodegradable Polymers Bioreactor

This work evaluates the feasibility of the biodegradable polymers (BDPs) bioreactor concept for removal of perchlorate from groundwater; and the likely impacts of nitrate and pH were also examined. Batch experiments demonstrated clearly that ClO4- was eliminated from the aqueous phase readily under appropriate surface biofilm of enriched mixed consortium on PBS, a new kind of BDPs, with the PBS granules as the sole chemical and physical substrate for the microorganism. Simultaneous perchlorate and nitrate degradation were occurring with the PBS granules degradation to supply conbon source. The optimal pH of perchlorate reduction was at 6.7. Morphological observation indicated the microbes in biofilm decomposed PBS through metabolism and provided carbon source for themselve by releasing small organic molecules.

Effects of Calcium Lignosulfonate and Silicic Acid on Ammonium Nitrate Degradation

Ammonium nitrate salts are the most commonly used nitrogenous fertilizers in industry. However, storage of ammonium nitrate is problematic, since its initial properties can decline because of environmental factors, leading to large economic losses. In this study, in order to prevent the caking and degradation of ammonium nitrate, an alternative composition with additional calcium lignosulfonate and silicic acid was studied. The resulting fertilizer was analyzed by screening analysis, ion chromatography, and electron microscopy methods.