In-line chemical analysis of wastewater: present and future trends

Bonastre, Alberto; Ors, R.; Capella, J.V.; Fabra, María José; Peris, Miguel

doi:10.1016/j.trac.2004.09.008

Cited by 43 publications

(21 citation statements)

References 26 publications

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“…However, current off-line methods used for water quality monitoring require laboratory equipment such as atomic spectrometers, fluorometers, and high-performance liquid chromatography. Consequently, these methods are not suitable for use in real-time monitoring due to the long turnaround times needed for laboratory analysis (Bonastre et al, 2005;Curini et al, 2001). Therefore, to protect the environment and human health, rapid, cheap, and versatile on-site monitoring is necessary to monitor water contamination.…”

Section: Introductionmentioning

confidence: 99%

An Automated Water Nitrate Monitoring System based on Ion-Selective Electrodes

Cho¹,

Kim²,

Jung³

et al. 2016

Journal of Biosystems Engineering

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Purpose: In-situ water quality monitoring based on ion-selective electrodes (ISEs) is a promising technique because ISEs can be used directly in the medium to be tested, have a compact size, and are inexpensive. However, signal drift can be a major concern with on-line management systems because continuous immersion of the ISEs in water causes electrode degradation, affecting the stability, repeatability, and selectivity over time. In this study, a computer-based nitrate monitoring system including automatic electrode rinsing and calibration was developed to measure the nitrate concentration in water samples in real-time. Methods: The capabilities of two different types of poly(vinyl chloride) membrane-based ISEs, an electrode with a liquid filling and a carbon paste-based solid state electrode, were used in the monitoring system and evaluated on their sensitivities, selectivities, and durabilities. A feasibility test for the continuous detection of nitrate ions in water using the developed system was conducted using water samples obtained from various water sources. Results: Both prepared ISEs were capable of detecting low concentrations of nitrate in solution, i.e., 0.7 mg/L NO3-N. Furthermore, the electrodes have the same order of selectivity for nitrate:, and maintain their sensitivity by > 40 mV/decade over a period of 90 days. Conclusions: The use of an automated ISE-based nitrate measurement system that includes automatic electrode rinsing and two-point normalization proved to be feasible in measuring NO3-N in water samples obtained from different water sources. A one-to-one relationship between the levels of NO3-N measured with the ISEs and standard analytical instruments was obtained.

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Section: Introductionmentioning

confidence: 99%

An Automated Water Nitrate Monitoring System based on Ion-Selective Electrodes

Cho¹,

Kim²,

Jung³

et al. 2016

Journal of Biosystems Engineering

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“…Some examples of continuous monitoring using ultraviolet visible (UV-vis) absorption and electronic nose sensors have demonstrated the feasibility of these techniques in the WWTP application; however, general failures to apply them in WWTPs are mainly because they need to have constant contact with wastewater or polluted air, resulting in instrument errors, frequent cleaning and recalibration [1].…”

Section: Introductionmentioning

confidence: 99%

A unified protocol for sensor calibration and verification in applications of WWTPs and sewer systems monitoring

Xin¹,

Bertrand-Krajewski²

2012

Water Pollution XI

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PREPARED, Enabling Change, is an EU-funded Collaborative Project under the Seventh Framework Programme (FP7). The project aims to gather urban utilities in Europe and worldwide to develop an advanced strategy in meeting the upcoming challenges for water supply and wastewater treatment brought by climate change. This work aims to increase technological capacity and improve performance of traditional water supply and wastewater treatment systems via better use of sensors. For newly developed multivariate sensors, calibration procedures are quite different from manufacturer to manufacturer. Manual operation during calibration and verification is commonly practised in this field due to complexity of the calibration procedure and occurrence of unpredictable events. In addition, many of the sensor manufacturers have not developed detailed instructions for sensor calibration. Therefore, a calibration and verification protocol is needed to guide and unify practice in this area where diversified practice is commonly observed. In this work, a unified protocol for sensor calibration and verification was developed and applied. Two sensor products, an optical sensor and an electronic nose sensor, are discussed as examples for calibration procedures, regression methods and verification methods of calibration in the application of wastewater treatment plant monitoring.

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“…However, despite these advances, the search of appropriate instrumentation for real time control (RTC) at WWTPs remains a very actual issue. As one of the weak links in ICA, sensors, and in particular in-situ sensors for nutrients, have an increasing potential (Jeppsson et al 2002;Bonastre et al 2005).…”

Section: Introductionmentioning

confidence: 99%

Potential of in-situ sensors with ion-selective electrodes for aeration control at wastewater treatment plants

Kaelin

Rieger

Eugster

et al. 2008

Water Science and Technology

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A pilot-scale activated sludge wastewater treatment plant (WWTP) operated with nitrification and pre-denitrification was monitored with a set of on-line sensors for over 3 years. Wet-chemistry ex-situ analyzers, UV and UV-Visible in-situ sensors and in-situ sensors based on ion-selective electrodes (ISE) were used. New ISE sensors for ammonium, nitrate and nitrite, adapted to water and wastewater matrices, have been released in recent years, With adequate quality control they proved to be highly accurate and reliable in WWTP influents and activated sludge (AS) reactors even at the end of the biological treatment zone, working at low ammonium concentrations (1-2 mgN/l). The ammonium measurement was used to test several feed-forward and feed-back aeration control strategies. The first aim was to keep inorganic nitrogen compounds, i.e. ammonium, nitrate and particularly nitrite, as low as possible in the effluent, and within Swiss national standards (<2.0 mgNH(4)-N/l, <0.3 mgNO(2)-N/l, 24 h average). All the strategies were successful at keeping ammonium low and subsequently at gaining denitrification capacity to significantly reduce the total nitrogen discharge. Some control strategies however generated temporary peaks of ammonium or even accumulation of nitrite.

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In-line chemical analysis of wastewater: present and future trends

Cited by 43 publications

References 26 publications

An Automated Water Nitrate Monitoring System based on Ion-Selective Electrodes

An Automated Water Nitrate Monitoring System based on Ion-Selective Electrodes

A unified protocol for sensor calibration and verification in applications of WWTPs and sewer systems monitoring

Potential of in-situ sensors with ion-selective electrodes for aeration control at wastewater treatment plants

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