Thermodynamics of the dissociation of ammonium ion in seawater from 5 to 40�C

Activity coefficients in sea water using monte carlo simulations. General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal Take down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. AbstractA new approach to the estimation of activity coefficients in sea water has been established using statistical mechanics. The distribution of particles (ions and nonelectrolytes) are simulated with a Monte Carlo method combined with a particle insertion technique that allows calculation of the activity coefficients. The simulations are based on the primitive model of electrolytes and accounts for both short-and long-ranged forces, but does not suffer from the approximations used in the classical theory. Excellent agreement have been found with experimental data and calculations based on the Pitzer model. D

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“…This has been done earlier by Clegg and Whitfield (1995) using the Pitzer formalism. Experimental data are available from Khoo et al (1977).…”

Section: Equilibrium Constantsmentioning

confidence: 99%

Activity coefficients in sea water using Monte Carlo simulations

2003

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“…Moreover, pK a is affected by ionic strength, I, of the solution as expressed in Equation (2) [24]. The ionic strength of stored urine was estimated to be 0.6 mol·L −1 according to Siegrist et al [19].…”

Section: Resultsmentioning

confidence: 99%

“…Of course, the determined pK a values are rather estimates than exact data, because firstly, the ionic strength of the stored urine was estimated and secondly, the temperature range for which Equation (2) was established is between 5˚C and 40˚C [24]. Nevertheless, these pK a values were utilized to calculate FAN by means of Equation (3) from TAN concentrations and pH data displayed in The calculated FAN concentrations in the stored urine at different times are shown in Figure 3(a).…”

Section: Resultsmentioning

confidence: 99%

Pretreating Stored Human Urine for Solar Evaporation by Low-Technology Ammonia Stripping

Gulyas¹,

Zhang²,

Otterpohl³

2014

JEP

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In order to avoid the loss of ammonia during solar drying of stored urine, low-tech stripping is suggested as a pretreatment process for ammonia recovery. The mass transfer of ammonia from stored urine with an initial pH of about 9 was tested in a simple closed vessel operated at 72˚C, 74˚C and 85˚C. The specific urine/gas interface was 16.97 m −1 . For ammonia absorption, a beaker with sulfuric acid was positioned in the gas phase of the container. After keeping the stored urine for 73 h at 85˚C, the concentration of free ammonia (NH3) was reduced by more than 99%, and the pH of the stored urine decreased to 6.4 due to ammonia volatilization. Total ammonia ( 3 NH + + 4 NH ) concentration was reduced by only 83% in the same period. At lower temperatures, the process was slower. Required treatment time can be reduced when specific gas/liquid interface is increased. Because it is known that water can be heated in solar boxes to temperatures above 90˚C, this simple stripping apparatus is feasible to be operated with solar energy in remote areas with suitable climatic conditions where no electric power is available. As the area demand for solar "low-tech stripping" is less than 1 m 2 per capita, this process can be looked at as a suitable pretreatment of stored urine prior to solar evaporation.

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“…Oxygen measured with a 3 Star Oxymeter (Thermo Scientific ® ), pH measured with a HI-98160 pH meter (Hanna ® ) and carbon dioxide (CO 2 ), total ammonia nitrogen (TAN), nitrite (NO 2 ) and nitrate (NO 3 ) measured with LaMotte ® kits, were recorded daily (early morning) and un-ionized ammonia nitrogen (N-NH 3 ) calculated using the method by Khoo et al (1977). Temperature was recorded continuously using Tidbit temperature sensors, data loggers HOBO ® , registering temperature values every 30 min, the data was downloaded using software HOBO ware Pro 2.7.2.…”

Section: Facilities Ras and Water Qualitymentioning

confidence: 99%

Broodstock management of the fine flounder Paralichthys adspersus (Steindachner, 1867) using recirculating aquaculture systems

Carrera

Cota

Montes

et al. 2013

lajar

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ABSTRACT. The present study describes the methodology used at IMARPE for the capture, acclimation and management of P. adspersus broodstock using recirculating aquaculture systems (RAS). RAS improved the water quality and maintained the environmental parameters during the acclimation period, temperature (17.2±1ºC), oxygen (8.1±0.7 mg L -1 ), pH (7.3±0.2), ammonia (0.004±0.003 mg L -1 ), nitrite (0.52±0.2 mg L -1 ) and nitrate (3.45±2.6 mg L -1 ). Fish began to be fed normally from day 15 post-capture, once or twice a day using live fish (Odonthestes regia regia, Mugil cephalus), crustacean (Emerita analoga), fresh food (Engraulis ringens and Dosidicus gigas) and artificial feed. A significant loss in the weight of the fish was registered during the first days of captivity, followed by a continuous increase in both sexes. The specific growth rate was positive from the third month of captivity, being the relative growth rate 24.5% and 16.2% in August 2010 in males and females, respectively. Different internal and external parasites were detected in the fish, being Entobdella sp. and Philometra sp. the prevailing parasites observed during samplings. Keywords: Paralichthys adspersus, reproduction, recirculating aquaculture system, broodstock management, culture, Peru. Manejo de reproductores del lenguado Paralichthys adspersus (Steindachner, 1867)usando sistemas de recirculación en acuicultura RESUMEN. El presente trabajo, describe la metodología desarrollada en IMARPE para la captura, aclimatación y acondicionamiento de ejemplares adultos de P. adspersus en sistemas de recirculación (SRA), con la finalidad de formar un stock de reproductores. El SRA permitió manejar parámetros medioambientales estables durante el periodo de acondicionamiento, como: temperatura del agua (17,2±1ºC), oxígeno disuelto (8,1±0,7 mg L -1 ), pH (7,3±0,2), amonio (0,004±0,003 mg L -1 ), nitrito (0,52±0,2 mg L -1 ) y nitrato (3,45±2,6 mg L -1 ). Se dio inicio a la alimentación el día 15 post-captura, utilizando alimento vivo (Odonthestes regia regia, Mugil cephalus), crustáceos (Emerita analoga), alimento fresco (Engraulis ringens y Dosidicus gigas) y artificial semihúmedo. Durante los primeros días de acondicionamiento los peces mostraron una disminución en el peso, hasta su adaptación a las condiciones de cultivo, luego de lo cual se produjo un incremento continuo en ambos sexos. La tasa específica de crecimiento fue positiva a partir del tercer mes y la tasa de crecimiento relativo mostró que en agosto 2010, el peso promedio se incrementó 24,5% en machos y 16,2% en hembras. Se realizó un análisis patológico a los ejemplares capturados y se observó la presencia de diferentes parásitos internos y externos, entre ellos predominaron Entobdella sp. y Philometra sp. Latin American Journal of Aquatic ResearchPalabras clave: Paralichthys adspersus, reproducción, sistema de recirculación en acuicultura, manejo de reproductores, cultivo, Perú.

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Thermodynamics of the dissociation of ammonium ion in seawater from 5 to 40�C

Cited by 74 publications

References 15 publications

Activity coefficients in sea water using Monte Carlo simulations

Activity coefficients in sea water using Monte Carlo simulations

Pretreating Stored Human Urine for Solar Evaporation by Low-Technology Ammonia Stripping

Broodstock management of the fine flounder Paralichthys adspersus (Steindachner, 1867) using recirculating aquaculture systems

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