Volume 4, Issue 1, June 2020, Page: 8-13
Thermodynamic Modelling of Nitric Acid and Selected Metal Nitrate Systems on Sampled Fish Pond Waters of Kisii University
Gilbert Nyachae Moturi, Department of Chemistry, School of Pure and Applied Sciences, Kisii University, Kisii, Kenya
Evans Okemwa Kenanda, Department of Research and Extension, School of Pure and Applied Sciences, Kisii University, Kisii, Kenya
Received: Jul. 13, 2020;       Accepted: Aug. 5, 2020;       Published: Aug. 25, 2020
DOI: 10.11648/j.ajaic.20200401.12      View  87      Downloads  20
Abstract
Surface waters consist of a complex mixture of ions and solutes which interact in a complex manner under different thermodynamic conditions. This study explored thermodynamic behavior of nitric acid/nitrous acid- selected nitrate-water systems on some fish ponds using Mixed-Solvent Electrolyte, MSE, which was applied to calculate phase equilibria, speciation, and their effect on dissolved oxygen, dissolved nitrogen and concentration of nitrates in the pond waters. In particular, solubilities and chemical speciation we analyzed for various nitrogen-containing systems. The model reproduced the speciation, solubility, and Vapor–Liquid Equilibrium (VLE) data in the nitric acid + water system at ground temperature and pressure and was therefore used to predict the effects of chemical speciation, temperature, and concentrations of various acid, base, and salt components on the formation of competing solid phases over wide ranges of temperature and concentration in water. The water samples were obtained directly from four University fish ponds labeled as Migingo, Mfangano, Ringiti and Remba Islands. A sample of water was collected from each pond. The four samples were then analyzed of their concentrations of dissolved oxygen (DO), total nitrogen (TN), nitrates and nitrites, pH and electrical conductivity. The results were used to validate the model. The findings established that there is an inverse relationship between the amount of nitrates in water and the levels of dissolved oxygen. The higher the amount of nitrates the lower the amount of DO in the pond water. A pressure of about 1 atmosphere and temperature range 20-27°C favor most particle interactions resulting in higher levels of concentration of NO3- ions in pond water. This research also established that variation of water temp should not exceed ±5 within the day for optimal concentrations of competing particles in solution. The systems that were analyzed in this work include the HNO3/HNO2/NO2+ water mixtures in the full composition range that covers xHNO3 from 0 to 1 and, more generally, xNO2 from 0 to 1. Further, a model was established for the nitrate salt systems, involving the Li+, Na+, Ca2+, and Mg2+ cations, encountered in the fish pond waters. Rather than focusing on particular processes, the current work provided a comprehensive treatment on the basis of the available experimental thermodynamic data for such systems. These results provided a thermodynamic foundation to explain natural variations in salt concentrations and predict mineral equilibria in the pond waters. Validation of the model was achieved through VLE, pH, solubilities and conductivity measurements.
Keywords
Coefficient, Molality, Phase, Mixed-Solvent Electrolyte, Dissolved Oxygen, Total Nitrogen
To cite this article
Gilbert Nyachae Moturi, Evans Okemwa Kenanda, Thermodynamic Modelling of Nitric Acid and Selected Metal Nitrate Systems on Sampled Fish Pond Waters of Kisii University, American Journal of Applied and Industrial Chemistry. Vol. 4, No. 1, 2020, pp. 8-13. doi: 10.11648/j.ajaic.20200401.12
Copyright
Copyright © 2020 Authors retain the copyright of this article.
This article is an open access article distributed under the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Reference
[1]
Emiliano Brini, Christopher J. Fennell, Marivi Fernandez-Serra, Barbara Hribar-Lee, Miha Lukšič, and Ken A. Dill Chemical Reviews 2017 117 (19), 12385-12414 DOI: 10.1021/acs.chemrev.7b00259.
[2]
IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "heavy ater". doi: 10.1351/goldbook.H02758.
[3]
Chris J. Pickard. When is H2O not water? J. Chem. Phys. 127, 244503 2007); https://doi.org/10.1063/1.2812268.
[4]
Saifuddin Ahmed, Nicolas Ferrando, Jean-Charles de Hemptinne, Jean-Pierre Simonin, Olivier Bernard, Olivier Baudouin. Modeling of mixed-solvent electrolyte systems Fluid Phase Equilibria • December 2017.
[5]
Lin. C. J, Pehkonen S. O. (2011). Environmental Chemistry and Toxicology of Mercury, pp. 111-153.
[6]
Sommar, Bergan and Hall:Oxidation of Elemental Mercury in the Atmosphere; contraints imposed by global Scale Modeling. Journal of Atmospheric Chemistry October 2001. Volume 40, issue 2, pp191-212.
[7]
Lalonde, M, Janssens, H., Stark, W., Frohman, M. A. (2004) (Phospholipase D, a novel lipid modifying component of Drosphila phototransduction. A Dros. Res. conf. 45: 488B.
[8]
Bittrich D. R., S. P. Chadwick, C. L. Babiarz, H. Manolopoulos, A. P. Rutter, J. J. Schauer1, D. E. Armstrong, J. Collett, P. Herckes. Speciation of Mercury (II) and Methylmercury in Cloud and Fog Water. Aerosol and Air Quality Research, 11: 161–169, 2011.
[9]
Francesca Spataro & Antonietta Ianniello (2014). Sources of atmospheric nitrous acid: State of the science, current research needs, and future prospects. Journal of the Air & Waste Management Association. 64: 11, 1232-1250, DOI: 10.1080/10962247.2014.952846.
[10]
Nielsen O, Friis T, Kjaerulff S. (1996), The Schizosaccharomyces pombe map1 gene encodes an SRF/MCM1-related protein required for P-cell specific gene expression. Mol Gen Genet 253 (3): 387-92.
[11]
Wallace et. al., 2015.
[12]
S. A. Piontkovski, H. M. H. Al-Gheilani, B. Jupp, Y. V. B. Sarma, and A. R. Al-Azri. The Relationship between Algal Blooms, Fish Kill Incidents, and Oxygen Depletions along the Omani Coast. International Journal of Oceans and Oceanography ISSN 0973-2667 Volume 6, Number 2 (2012), pp. 145-177.
[13]
Ehiagbonare, J. and Ogunrinde, E. (2010). Water Quality Characteristics for Aquaculture uses in Abeokuta North Local Government area, Ogun State, Nigeria.
[14]
Clesceri L. S, Greenberg A. E, & Eaton A. D. (1998). Standard Methods for the Examination of Water and Wastewater (20 ed.). Washington, DC. American Public Health Association (APHA).
[15]
Winkler, L. W. (2006). Determination of Dissolved Oxygen by Winkler Titration Method. 12.097 Environmental Chemistry of Boston Harbor-IAP 2006.
[16]
Azimi. G, Papangelaki V. G (2010) The solubility of gypsum and anhydrite in simulated laterite pressure acid leach solutions up to 250°C. Hydrometallurgy 102: 1–13.
[17]
Zemaitis J. F., Clark, D. M., Rafal M. and Scrivner,. (1986). Handbook of Aqueous Electrolyte Thermodynamics. New York: DIPPR, ALChE.
[18]
Gruszkiewicz, M. S., Palmer, D. A., Springer, R. D., Wang, P. M., and Anderko, A. (2007). Solution Chem (Vol. 36).
[19]
Pitzer, K. (1991). Activity Coefficients in Electrolyte Solutions, 2nd ed. Boca Raton: CRC Press.
[20]
Kaj Thomsen, The extended UNIQUAC model. Aqueous Solutions, (2004) 1-12.
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