Determination of nitrate in municipal waste water by UV spectroscopy

Karlsson, Mikael; Karlberg, Bo; Olsson, Ralf J. O.

doi:10.1016/0003-2670(95)00179-4

Cited by 65 publications

(44 citation statements)

References 10 publications

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“…Several inorganic ions also absorb in this range of the ultraviolet spectrum [1,[9][10][11], but most are found at such low concentrations in normal ocean waters so as not to interfere, with the exception of bromide [3,11,12]. One instrument, the In Situ Ultraviolet Spectrophotometer (ISUS), was developed at the Monterey Bay Research Institute [11] and became commercially available in 2003 (Satlantic Inc., Halifax NS).…”

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confidence: 99%

Correcting Nitrate Profiles Measured by the In Situ Ultraviolet Spectrophotometer in Arctic Ocean Waters

Christensen¹,

Melling²

2009

TOOCEAJ

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Abstract:A recently commercialized sensor, the In Situ Ultraviolet Spectrophotometer (ISUS), can determine seawater nitrate concentrations rapidly. Procedures for incorporating ISUS data within routine conductivity, temperature, and depth (CTD) profiling studies have not been described. Using a CTD system with an ISUS, vertical hydrographic profiles with nutrient concentrations were determined at 42 sites across the shelf break on the Beaufort Sea, Alaska. Key data processing steps included elimination of redundant nitrate values, shifting the ISUS data so as to be simultaneous with the CTD data, and correcting the ISUS output voltages for warm-up drift. After regressing the corrected ISUS output voltages against nitrate concentrations determined on bottle samples, the ISUS-estimated nitrate concentrations reproduced the bottle results within +/-0.28 μM. The highly detailed ISUS profiles showed mesoscale intrusions of low nutrient water on the upper continental slope and strong nutrient upwelling near the shelf break.Keywords: Nitrate Concentration, Ultraviolet Spectrophotometer, CTD Observations, CTD Processing, Arctic Ocean, Beaufort Sea.With the recognition that the nitrate ion has a strong absorption peak in the lower ultraviolet spectrum below 230 nm [1][2][3], several separate approaches were developed which offered the potential for measurement of high-resolution nitrate distributions in near-surface waters of the oceans [4][5][6][7][8][9]. Several inorganic ions also absorb in this range of the ultraviolet spectrum [1, 9-11], but most are found at such low concentrations in normal ocean waters so as not to interfere, with the exception of bromide [3,11,12]. One instrument, the In Situ Ultraviolet Spectrophotometer (ISUS), was developed at the Monterey Bay Research Institute [11] and became commercially available in 2003 (Satlantic Inc., Halifax NS). The ISUS illuminates a volume of natural seawater in a cell of fixed width (10 mm) and the absorption spectra is measured thrice. The instrument's microprocessor pools the resulting spectra, fits ideal nitrate and bromide absorbance spectra to the observed seawater spectra, and then calculates both these concentrations. Since bromide is conservative with salinity [13,14], the bromide concentration is reported as a salinity. To correct for apparent absorbance due to dark current, every tenth spectrum is a dark scan in which the ultraviolet illumination is blocked. For the instrument used in our study (serial number 003), the manufacturer reported the usable nitrate range, accuracy, and precision to be 0.5-200 μM, +/-2 μM, and +/-0.05 μM. Based on conductivity, temperature, depth (CTD) and ISUS data collected in the Beaufort Sea north of Alaska, we developed the processing procedures for the ISUS data collected during routine CTD vertical profiling. Specifically, our routines eliminated redundant measurement values, corrected for time-delay and for the warm-up drift found in the ISUS data. The results were compared and normalized to measured nitrate concentrati...

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confidence: 99%

Correcting Nitrate Profiles Measured by the In Situ Ultraviolet Spectrophotometer in Arctic Ocean Waters

Christensen¹,

Melling²

2009

TOOCEAJ

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“…This method is based in the setting of a material for the ionic interchange deposit in PVC membranes. The measurement range of this method is high, but it is very sensitive to interference, especially by chlorine ions, which implies the necessity of a frequent calibration process (Karlsson et al 1995).…”

Section: Measurement Techniques For Nitrates Concentration Estimationmentioning

confidence: 99%

“…Spectrometry has been commonly applied to the identification or determination of the concentration of contaminants in water (Thomas et al 1990a,b;Beemster & Kahle 1995;Karlsson et al 1995;Holm et al 1997;Gross et al 1999;Johnson & Coletti 2002). Specifically, several methods to measure the nitrates/nitrites content of water have been proposed using ultraviolet spectrophotometry: In Gross et al (1999) a method based on the light absorption at 220 nm produced by the presence of nitrates in water is proposed.…”

Section: Measurement Techniques For Nitrates Concentration Estimationmentioning

confidence: 99%

“…In Karlsson et al (1995) the nitrate concentration analysis was performed using UV spectroscopy, measuring from 180 to 820 nm, and using a method of partial adjusting using mean squares. The authors applied this method to obtain good quality measures of nitrate concentrations in the water of Stockholm's zone.…”

Section: Measurement Techniques For Nitrates Concentration Estimationmentioning

confidence: 99%

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Nitrates/nitrites concentration estimation in wastewater samples using transmittance curve models optimized by evolutionary computation techniques

López-Espí

Salcedo‐Sanz

Pérez-Bellido

et al. 2010

Journal of Hydroinformatics

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This paper presents an application of evolutionary computation algorithms in the estimation of the concentration of nitrates/nitrites in water. Specifically, we start from the measured transmittance curves of a water sample and a model of the curve consisting of a mixture of polynomial, Fermi and Gaussian functions. An evolutionary programming algorithm is then used to obtain the optimal parameters of the model which minimize the distance between the measured and the modeled transmittance curves. This process allows us to separate the modeled transmittance curve into several components, one of them associated with the nitrate/nitrite concentration. We can extract the nitrate/nitrite concentration of the water sample using this component of the transmittance model. We test our proposal on several laboratory samples and on three real samples measured in different locations around Madrid, Spain.

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“…Spectroscopic methods such as ultraviolet, [13][14][15][16][17][18][19][20][21] atomic absorption, 22 infrared, 23 Raman, 24 mass 25,26 and molecular absorption 27 have been used. Polarography is often employed 1,3,28,29 and this and other electrochemical methods are used in conjunction with other regimes such as high performance liquid chromatography.…”

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confidence: 99%

The Detection of Nitrate Using in-situ Copper Nanoparticle Deposition at a Boron Doped Diamond Electrode

et al. 2005

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Determination of nitrate in municipal waste water by UV spectroscopy

Cited by 65 publications

References 10 publications

Correcting Nitrate Profiles Measured by the In Situ Ultraviolet Spectrophotometer in Arctic Ocean Waters

Correcting Nitrate Profiles Measured by the In Situ Ultraviolet Spectrophotometer in Arctic Ocean Waters

Nitrates/nitrites concentration estimation in wastewater samples using transmittance curve models optimized by evolutionary computation techniques

The Detection of Nitrate Using in-situ Copper Nanoparticle Deposition at a Boron Doped Diamond Electrode

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