A detection system and method for simultaneously determining the concentration of ammonium and nitrate/nitrite in samples such as surface water and wastewater. The detection system and method herein can further comprise a cleaning loop and a calibration loop and can be used in situ and over long periods of time without replacement or frequent maintenance and upkeep.

A calibration liquid (1) is used for calibrating a water quality measurement device (100). The water quality measurement device (100) includes a plurality of sensors to be brought into contact with a measurement target liquid so as to measure concentrations of a plurality of types of target components contained in the measurement target liquid, and measures the concentrations of the plurality of types of target components. The calibration liquid (1) includes a solution which contains the plurality of types of target components at respective concentrations determined for the target components, and the solution has a pH within a predetermined pH range.

An optical nitrate sensor features a signal processor or signal processing module configured to: receive signaling containing information about a concentration of nitrate dissolved in the water based upon a first UV optical absorbance of light centered at 229 nm, and also containing information about a dissolved organic matter (DOM) sensed in the water based upon a second UV optical absorbance of associated light centered in a range of 250 nm to 275 nm; and determine corresponding signaling containing information about a corrected concentration of nitrate dissolved in the water by compensating the concentration of nitrate for the DOM sensed in the water, based upon the signaling received.

A method for analyzing stable isotopes of particulate organic carbon (POC) and nitrogen in seawater using elemental analysis-isotope ratio mass spectrometry (EA-IRMS), including: using a glass fiber filter membrane to filter a collected water sample and then filter 100 ml of distilled water; subjecting a resulting membrane sample to acidification; and subjecting an acidified membrane sample to EA-IRMS analysis on a machine, where an oxygen addition time is set to 80 s and a combustion tube temperature is set to 700° C. for an elemental analyzer, and a trap current is set to 300 μA to 400 μA for an isotope ratio mass spectrometer. The method of the present disclosure can reduce a detection cost and improve the data accuracy and work efficiency.

A water quality measuring system includes a first introduction section for introducing rearing water as a sampling target, and a first adding section which adds an acid to the rearing water introduced by the first introduction section, and a nitrous acid sensor whose measurement target is nitrous acid and which measures the measurement target concentration of the rearing water to which the acid has been added by the first adding section. The water quality measuring system includes a second adding section which adds a base to the rearing water introduced by the first introduction section, and an ammonia sensor whose measurement target is ammonia and which measures the measurement target concentration of the rearing water to which the base has been added by the second adding section.

The present invention discloses an optical detection cell for detecting inorganic analytes in an aquatic environment. The optical detection cell comprises a microfluidic channel defining an optical detection path. First and second transparent windows are bonded at opposite locations on the microfluidic channel. The optical detection cell is provided with a UV-LED, and light detector respectively positioned proximally to the first and second transparent windows. The UV-LED configured to be driven by a constant electrical current having a value between 2.5 mA and 50.0 mA.

A method of determining a disinfectant composition of a municipal water supply from a water sample that includes: (a) obtaining a water sample from a water source at a sampling location; (b) adding a chlorine-containing material to the water sample in the presence of an oxidation reduction potential (ORP) measurement device; (c) generating a plurality of ORP measurements during addition of the chlorine-containing material to the water sample; (d) estimating a concentration of one or more of free ammonia, fully combined ammonia, monochloramine, or a mixture of dichloramine and trichloramine in the water sample in which the estimation is derived from the relationship between the added chlorine material and the plurality of ORP measurements; and (e) determining a disinfectant composition of the water source at the water sampling location from the concentration calculation. A method of determining free ammonia composition is also included.

The disclosure provides a method for evaluation of removal of nitrogen-containing organic matter from the wastewater. The method includes: 1) pretreating a wastewater sample from a wastewater treatment plant; enriching nitrogen-containing organic matter in the wastewater sample with a solid-phase extraction cartridge; separating the nitrogen-containing organic matter from a substrate and disruptors of the wastewater sample, and collecting the nitrogen-containing organic matter; 2) detecting and analyzing the nitrogen-containing organic matter collected in 1) with a Fourier-transform ion cyclotron resonance mass spectrometer, thereby obtaining mass spectra of the nitrogen-containing organic matter; 3) preprocessing peak data of the mass spectra of the nitrogen-containing organic matter in each wastewater sample; setting the nitrogen-containing organic matter corresponding to the peak data as a global variable; arranging wastewater samples into cross-sectional data according to wastewater treatment processes; creating an assessment matrix for evaluating removal of the nitrogen-containing organic matter.

In an embodiment, a sensor system and a method for monitoring properties of field soils and wastewater are described. In an embodiment, a sensor system comprises a cartridge system implemented in an integrated circuit. The cartridge system comprises a chemical sensor and a computer processor coupled to the chemical sensor. The chemical sensor is configured to receive a sample of a test material such as soil or wastewater. Based on the sample of the test material, the chemical sensor determines a measure of a property in the test material. The computer processor receives, from the chemical sensor, the measure of the property in the test material, and computes, based on, at least in part, the measure of the property in the test material, a concentration level of the property in the test material. Based on the concentration level of the property in the test material, the computer processor generates an output that includes the concentration level. In an embodiment, the concentration level of the property in the test material is provided to a computer-based controller that controls agricultural equipment executing an agricultural prescription in an agricultural field.

The disclosure provides a method for evaluation of removal of nitrogen-containing organic matter from the wastewater. The method includes: 1) pretreating a wastewater sample from a wastewater treatment plant; enriching nitrogen-containing organic matter in the wastewater sample with a solid-phase extraction cartridge; separating the nitrogen-containing organic matter from a substrate and disruptors of the wastewater sample, and collecting the nitrogen-containing organic matter; 2) detecting and analyzing the nitrogen-containing organic matter collected in 1) with a Fourier-transform ion cyclotron resonance mass spectrometer, thereby obtaining mass spectra of the nitrogen-containing organic matter; 3) preprocessing peak data of the mass spectra of the nitrogen-containing organic matter in each wastewater sample; setting the nitrogen-containing organic matter corresponding to the peak data as a global variable; arranging wastewater samples into cross-sectional data according to wastewater treatment processes; creating an assessment matrix for evaluating removal of the nitrogen-containing organic matter.