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 dichloroamine and trichloroamine 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.

An embodiment provides a method of forecasting water quality deterioration in a water distribution system, including: receiving, at an electronic device, a data set comprising measured values of a plurality of components within the water distribution system; determining, based upon algorithmic analysis of the measured values, a water quality index; and providing, based on the determined water quality index, a recommendation to mitigate water quality deterioration in the water distribution system. Other aspects are described and claimed.

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.

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.

An optical nitrate sensor features a signal processor or signal processing module configured to: receive signaling containing information about a measurement (M) of UV optical absorbance of nitrate dissolved in water of a UV light that is generated by a UV LED centered at 229 nm and that traverses a confined volume of the water within a prescribed region of a sensor body, and also about a reference sample (R) of a portion of the UV light not traversing the confined volume of the water; and determine corresponding signaling containing information about the concentration of nitrate dissolved in the water, based upon the signaling received.

A system and method for treating water containing at least one contaminant. The system and method include a water treatment module such as a reverse osmosis unit. An electrochemical contaminant detection system is positioned in the waste water stream of the water treatment module. The contaminant detection system includes a contaminant sensor and a water quality sensor module. The contaminant sensor measures the concentration of the contaminant in the waste water stream and the water quality sensor module measures one or more water quality parameters of the waste water stream. A processor uses an algorithm to determine the concentration of the contaminant in the feed water based on the measurements of the contaminant sensor and water quality sensor module.

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.

Disclosed is a measuring arrangement for measuring the total nitrogen bound (TN) in a measuring liquid, comprising: a radiation source emitting UV radiation; a radiation receiver configured to generate a signal that depends on the intensity of radiation impinging on the radiation receiver; a vessel having a first opening and a second opening opposite the first opening; a first window closing the first opening; and a second window closing the second opening. The first and second windows are transparent to the measuring radiation. The measuring radiation emitted by the radiation source propagates along a measuring path which extends from the radiation source through the first window, the vessel, and the second window to the radiation receiver. The measuring arrangement also includes a heating element in thermal contact with the vessel wall.

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.