Non-dispersive infrared (NDIR) sensor for real-time nitrate monitoring in wastewater treatment

Roodenko, Katy; Hinojos, David; Hodges, Kimari L.; Veyan, Jean-François; Chabal, Yves J.; Clark, Kenneth E.; Katzir, Abraham

doi:10.1117/12.2506550

Cited by 4 publications

(4 citation statements)

References 9 publications

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“…The sensitivity of the nitrate S-ISEs without PTFE dropped from −52 to 0 mV/dec after 10 days in wastewater, meaning that it had reached its life span and needed replacement. In addition, PTFE-loaded S-ISEs outperformed the commercial nitrate sensors, which could only last for 30 min in wastewater, and similarly are better than the specifications for other types of nitrate sensors such as nondispersive infrared (NDIR) nitrate sensors, imprinted polymer impedimetric nitrate sensors, and selective enzymatic nitrate sensors. ,, We hypothesize that there are two main reasons for the particularly superior performance of the PTFE-loaded S-ISEs. First, the PTFE mixed with the PTFE-loaded S-ISE membrane polymer matrix greatly enhances the antifouling capability by modifying the sensor surface charge and the surface topography .…”

Section: Resultsmentioning

confidence: 94%

“…Some progress has been made to alleviate electrode reading drift by adding an intermediate ion-to-electron layer, such as multiwalled carbon nanotubes (MWCNTs) or electropolymerized poly(3,4-ethylenedioxythiophene) (PEDOT), between the electrode (solid contact) and the S-ISE membrane polymer matrix. , However, the top ISE membrane layer exposed to the bulk wastewater solution suffers from fouling as a result of the adhesion of organic/inorganic compounds and/or particles and thus acutely shortens useful life spans on the order of just a few hours or days for wastewater monitoring . To enhance the durability of water sensors, nondispersive infrared (NDIR) nitrate sensors have been developed where organic/inorganic matter is periodically removed by cleaning, but this cleaning poses an obvious obstacle for long-term and continuous monitoring. To intrinsically alleviate bacterial attachment instead, the hydrophilicity of sensor surfaces could be enhanced.…”

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confidence: 99%

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Toward Long-Term Accurate and Continuous Monitoring of Nitrate in Wastewater Using Poly(tetrafluoroethylene) (PTFE)–Solid-State Ion-Selective Electrodes (S-ISEs)

et al. 2020

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Long-term accurate and continuous monitoring of nitrate (NO3 –) concentration in wastewater and groundwater is critical for determining treatment efficiency and tracking contaminant transport. Current nitrate monitoring technologies, including colorimetric, chromatographic, biometric, and electrochemical sensors, are not feasible for continuous monitoring. This study addressed this challenge by modifying NO3 – solid-state ion-selective electrodes (S-ISEs) with poly(tetrafluoroethylene) (PTFE, (C2F4) n ). The PTFE-loaded S-ISE membrane polymer matrix reduces water layer formation between the membrane and electrode/solid contact, while paradoxically, the even more hydrophobic PTFE-loaded S-ISE membrane prevents bacterial attachment despite the opposite approach of hydrophilic modifications in other antifouling sensor designs. Specifically, an optimal ratio of 5% PTFE in the S-ISE polymer matrix was determined by a series of characterization tests in real wastewater. Five percent of PTFE alleviated biofouling to the sensor surface by enhancing the negative charge (−4.5 to −45.8 mV) and lowering surface roughness (R a: 0.56 ± 0.02 nm). It simultaneously mitigated water layer formation between the membrane and electrode by increasing hydrophobicity (contact angle: 104°) and membrane adhesion and thus minimized the reading (mV) drift in the baseline sensitivity (“data drifting”). Long-term accuracy and durability of 5% PTFE-loaded NO3 – S-ISEs were well demonstrated in real wastewater over 20 days, an improvement over commercial sensor longevity.

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Section: Resultsmentioning

confidence: 94%

mentioning

confidence: 99%

Toward Long-Term Accurate and Continuous Monitoring of Nitrate in Wastewater Using Poly(tetrafluoroethylene) (PTFE)–Solid-State Ion-Selective Electrodes (S-ISEs)

et al. 2020

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“…There are various methods to improve the performance of NDIR sensors. For example, Max-IR Labs utilizes the NDIR technique together with fiber-optic evanescent wave spectroscopy (FEWS) for ammonia detection [47]. The IR radiation is transmitted through a silver-halide (AgClxBr1-x) optical waveguide without cladding and the detection performed by means of the evanescent field ( Figure 5).…”

Section: Optical Methodsmentioning

confidence: 99%

Ammonia Gas Sensors: Comparison of Solid-State and Optical Methods

et al. 2020

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High precision and fast measurement of gas concentrations is important for both understanding and monitoring various phenomena, from industrial and environmental to medical and scientific applications. This article deals with the recent progress in ammonia detection using in-situ solid-state and optical methods. Due to the continuous progress in material engineering and optoelectronic technologies, these methods are among the most perceptive because of their advantages in a specific application. We present the basics of each technique, their performance limits, and the possibility of further development. The practical implementations of representative examples are described in detail. Finally, we present a performance comparison of selected practical application, accumulating data reported over the preceding decade, and conclude from this comparison.

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“…The nondestructive optical sensing methods have applications in detection and measurement of compounds as well as atmospheric gases. , One optical absorption method is the nondispersive infrared (NDIR) technique, which detects gas in air or contaminants in water . As a gas sensor, the advantage of high selectivity is provided through a unique absorption wavelength of the target gas .…”

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confidence: 99%

Chamberless NDIR CO₂ Sensor Robust against Environmental Fluctuations

Vafaei

Amini

2021

ACS Sens.

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Accuracy of CO 2 measurement is affected by ambient air fluctuations, making the compensation of such variations in drift-like sensor response essential for concentration level assessment. Here, a series of experiments were carried out with a chamberless approach in a nondispersive infrared (NDIR) gas sensor to examine the combined effect of environmental temperature and relative humidity fluctuations on sensor responses at different concentrations of CO 2 . To eliminate the drift-like terms caused by environmental fluctuations, the behavior of the sensor was modeled to include ambient temperature, relative humidity, the measured responses as the inputs, and the concentration level as the output. The sensor was fabricated by a light source with an embedded parabolic reflector, a thermopile detector, and two reflective walls that are exposed to the applicable range of CO 2 gas. The predicted concentration level was determined by analyzing the system and acquiring a heuristic function based on an ensemble regression model. The created model's reliability and sensor's performance were evaluated by the test and validation data, and the respective accuracies of 99.83 and 98.90% demonstrated the model effectiveness. The chamberless structure of the sensor provides reduction in diffusion time, improves the linearity of responses accompanied by eliminating drift-like variation of responses in varying ambient conditions, and prepares the sensor for industrial applications.

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Non-dispersive infrared (NDIR) sensor for real-time nitrate monitoring in wastewater treatment

Cited by 4 publications

References 9 publications

Toward Long-Term Accurate and Continuous Monitoring of Nitrate in Wastewater Using Poly(tetrafluoroethylene) (PTFE)–Solid-State Ion-Selective Electrodes (S-ISEs)

Toward Long-Term Accurate and Continuous Monitoring of Nitrate in Wastewater Using Poly(tetrafluoroethylene) (PTFE)–Solid-State Ion-Selective Electrodes (S-ISEs)

Ammonia Gas Sensors: Comparison of Solid-State and Optical Methods

Chamberless NDIR CO₂ Sensor Robust against Environmental Fluctuations

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Non-dispersive infrared (NDIR) sensor for real-time nitrate monitoring in wastewater treatment

Cited by 4 publications

References 9 publications

Toward Long-Term Accurate and Continuous Monitoring of Nitrate in Wastewater Using Poly(tetrafluoroethylene) (PTFE)–Solid-State Ion-Selective Electrodes (S-ISEs)

Toward Long-Term Accurate and Continuous Monitoring of Nitrate in Wastewater Using Poly(tetrafluoroethylene) (PTFE)–Solid-State Ion-Selective Electrodes (S-ISEs)

Ammonia Gas Sensors: Comparison of Solid-State and Optical Methods

Chamberless NDIR CO2 Sensor Robust against Environmental Fluctuations

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Product

Resources

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Chamberless NDIR CO₂ Sensor Robust against Environmental Fluctuations