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Ammonia & Ammonium Sensors: Advanced Environmental Monitoring

By Hadeer Omar On Aug 24, 2025 507 0

Contents

1 Water Sensor for Ammonia and Ammonium

2 Why is Ammonia Detection Important?

3 Ammonia Sensor Operation Principles

4 Ammonia Sensor Types

4.1 1. An optical Ammonia Sensor

4.2 2. Metal Oxide Sensor:

4.3 3. Conductive Polymer Ammonia Sensor:

5 Applications

6 Conclusion

7 References:

Ammonia and ammonium play vital roles in both business and the environment; thus, their detection and monitoring are crucial. While ammonia is a vital raw material used in the manufacture of fertilizers, chemicals, and other industrial products, it is also poisonous, flammable, and environmentally harmful. Excess ammonia in water systems lowers water quality, damages aquatic life, and renders water unsafe for human use. As a result, dependable sensors for ammonia and ammonium detection are critical for environmental monitoring, industrial safety, and public health. This page delves into their detecting principles, sensor types, and practical applications across a variety of fields.

Water Sensor for Ammonia and Ammonium

An ion selective electrode (ISE) is used in the ammonium water sensor to measure the amount of charged ammonium ions present in water. The sensor can also determine the amount of ammonia present in the water by performing certain calculations.

Diffusion potential is the foundation of the ammonium ion selective electrode’s operation. Because of the selective membrane’s high ammonium ion selectivity, ammonium ions will preferentially flow through it and into the internal electrolyte when the ISE comes into contact with the solution to be measured. A potential difference, or diffusion potential, is created on both sides of the selective membrane as a result of the varying concentrations of ammonium ions. The concentration of ammonium ions in the solution to be measured and the electrode’s potential have a logarithmic relationship, and measuring the potential allows one to quantify the ammonium ion concentration.

Why is Ammonia Detection Important?

Ammonia is a crucial chemical raw material used in the chemical industry to produce nitric acid, soda ash, urea, and ammonium nitrogen fertilizer. However, ammonia is another gas that can easily pose a risk. Since ammonia is a flammable and explosive gas, an ammonia leak will not only injure people but also result in an explosion. Ammonia monitoring is crucial in the chemical industry.

Because ammonia degrades water quality, it is bad for aquatic life and unfit for human consumption. Aquatic habitats suffer because ammonia encourages nitrification, which reduces oxygen levels. Therefore, precise ammonia level detection and monitoring are essential for environmental protection and for fulfilling water quality standards set by international environmental authorities.

Ammonia Sensor Operation Principles

Electrochemical sensing uses direct contact between an ammonia and a sensitive electrode. The electrochemical process produces an electrical signal that can be used to gauge the ammonia concentration. uses materials that are sensitive to light and ammonia. This reaction alters the material’s optical properties, such as absorbance or fluorescence, and by measuring these changes, the amounts of ammonia can be ascertained. Colorimetric detection is based on chemical reactions that result in a color shift when ammonia is present. This colorimetric shift is quantitatively analyzed to determine the ammonia content.

Ammonia Sensor Types

A portable gas detector should be installed in areas where ammonia gas leaks easily due to its characteristics in order to detect leaks and prevent hazardous accidents caused by excessive leaks. Optical ammonia sensors, metal oxide sensors, and conductive polymer ammonia sensors are the three main types of sensors currently utilized for industrial ammonia monitoring.

1. An optical Ammonia Sensor

Optical interference sensors, ultraviolet absorption sensors, infrared absorption sensors, and optical fiber sensors are the primary categories of optical sensors. Ammonia detection relies on two primary optical principles. One method relies on the color of the reagent that reacts with ammonia or causes the indicator’s color to change; the other method uses light absorption by the gas to finish the sensing process and ascertain the gas concentration. Spectrophotometry can be used to analyze the gas to be tested once it has reacted and taken on color. In order to determine whether ammonia is present in the atmosphere, the pH test paper can change color due to the ammonia gas’s alkaline nature at a specific concentration. However, this test must make sure that the ammonia concentration is high and that the color change of the test paper cannot be sensitively assessed, which will result in a significant amount of error.

Ammonia levels in the environment can be determined using an optical sensor. This gas sensor has good selectivity and high sensitivity. The primary parts of the light absorption ammonia gas detection system are spectrographs and lasers. By emitting light through the air, the laser completes the detection of the ammonia content in the gas environment in terms of sensitivity and selectivity. The light that reaches the detector will have an effect on the spectrum of the various gas components in the air as well as the properties of each component. There are clear benefits.

2. Metal Oxide Sensor:

Among the developed gas-sensing materials, the metal oxide gas sensor has grown in importance. According to research, ammonia can be detected using metal oxides like titanium oxide, molybdenum trioxide, and tin oxide. The metal oxide sensor is a highly promising gas sensor with the following benefits: robustness, durability, affordability, ease of use, etc. The metal oxide sensor’s primary mechanism involves chemically adsorbing ammonia molecules to the metal oxide sensing layer. This alters the conductance of the metal oxide sensor, which in turn determines the ammonia gas concentration.

3. Conductive Polymer Ammonia Sensor:

Polypyrrole, polyaniline, and polythiophene are examples of conductive polymers that can be used to monitor ammonia. Conductive polymers can function as conductive sensors at room temperature, unlike metals and metal oxides. The oxidation-reduction reaction between ammonia gas and conductive polymer is the primary determinant of the sensing mechanism of conductive polymer for ammonia gas.

The sensitivity of a conductive polymer sensor exposed to ammonia gas for an extended period of time progressively increases due to the irreversibility of this reaction. cut down. The ammonia sensor operates through three different mechanisms: conductive polymer monitoring, metal oxide monitoring, and optical monitoring. A summary of the ammonia monitoring techniques is provided. The future miniaturization of ammonia gas monitoring sensors is still a trend for gas detection because of the growing awareness of environmental protection. As devices become smaller, it is also important to make sure that the sensors are inexpensive, easy to use, highly sensitive, and have good selectivity.

Applications

– Water quality analysis: Identifying the amount of ammonium ions in wastewater, groundwater, surface water, and other water bodies.

– Soil analysis: Calculating the amount of nitrogen and ammonium in the soil.

– Food analysis: Measuring the amount of ammonium in food.

– Biochemical research: to investigate how organisms use ammonium ions for metabolism.

– Industrial production: to track ammonium ion concentrations during industrial production.

Conclusion

In conclusion, identifying ammonium and ammonia in water systems is essential for maintaining public health, industrial safety, and environmental protection. Reliable monitoring is crucial because of their involvement in nutrient cycles, toxicity at high concentrations, and potential for explosive hazards. From ion-selective electrodes to optical and polymer-based technologies, ammonium sensors offer precise, real-time data for a variety of applications, including biochemistry, wastewater treatment, and agriculture. Safer procedures and sustainable ecosystem management are supported by the growing ability to monitor ammonia in complex and dynamic environments thanks to advancements in sensor technology, including improvements in sensitivity, selectivity, and miniaturization.