A method of measuring nitrate concentration in an aqueous sample includes mixing the aqueous sample with a water-soluble thioether chosen to reduce nitrate in the aqueous sample to nitrite in the presence of a water soluble catalyst, and a water soluble reagent system adapted to interact with nitrite to generate a color; measuring color generation, and correlating the color generation to nitrate concentration.

Techniques for determining a mineralogy of a portion of a drainage basin include identifying topography data associated with a drainage basin comprising at least one body of water; identifying weather data associated with the drainage basin; identifying first sensor data associated with a first water sensor installed in the drainage basin; identifying second sensor data associated with a second water sensor that is located downstream of the first water sensor in the drainage basin; providing the first sensor data, second sensor data, topography data, and weather data as input to a machine learning algorithm; and determining, by the machine learning algorithm, a mineralogy of a portion of the drainage basin.

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 system and method to measure the amount of a gas dissolved in a fluid is described. The fluid is transferred to an equilibrator and pH is adjusted so that the equilibrium between the gas and its ions in the fluid is displaced towards more gas, so that the measurement may be carried out when there is proportionally more gas in the fluid.

A sensor for measuring a concentration of a particular ion, molecule or atom in a fluid includes a sample handling portion for providing at least some of the fluid, a first photo-detection device, and a first light source. The first photo-detection device is configured to measure a power of light incident thereon, and the first light source includes a solid-state light emitting device. The first light source is configured to emit light having a wavelength less than 240 nanometers incident on the fluid provided by the sample handling portion, and the first photo-detection device is configured to receive light having passed through the fluid.

The present disclosure provides a method and system for predicting effluent ammonia nitrogen (NH.sub.4N) and an electronic device. The method includes: obtaining data to be tested; and inputting the data to be tested into a trained deep echo state network, to obtain predicted NH.sub.4N concentration. A method for establishing the deep echo state network includes: establishing an original network, where the original network includes a plurality of input variables and reservoirs, and a principal component analysis (PCA) mapping layer is added between adjacent ones of the reservoirs; initializing the original network to obtain an initialized network; performing parameter optimization on the initialized network by a matrix generation method of singular value decomposition and a competitive swarm optimizer (CSO) algorithm, to obtain an optimized network; and training and testing the optimized network, to obtain the trained deep echo state network.

A method of measuring nitrate concentration in an aqueous sample includes mixing the aqueous sample with a water-soluble thioether chosen to reduce nitrate in the aqueous sample to nitrite in the presence of a water soluble catalyst, and a water soluble reagent system adapted to interact with nitrite to generate a color; measuring color generation, and correlating the color generation to nitrate concentration.

Disclosed are an intelligent simulation device for bottom sediment pollution process and control as well as an experimental method. The device includes an experimental flume to which a water inlet tank and a water return tank are connected; a wave-making system, an illumination system, a dosing system and an aeration system; an environmental condition parameter online monitor capable of determining water environmental parameters online; an online water quality index analyzer for monitoring water quality indexes in real time; a water automatic sampling device for automatically collecting water samples in a single or cycle mode; an offline analyzer capable of determining water quality indexes of the collected water samples or physical-chemical indexes of sediments; and an automatic control module for automatically controlling various devices. Further disclosed is an experimental method based on the intelligent simulation device for bottom sediment pollution process and control.

Biosensor systems for detecting levels of nitrogen-containing molecules are provided. Further provided are biosensor system components and various detection platforms, methods, and kits.

Target water quality parameters may be estimated based on measurements of surrogate water quality parameters, which may be easier to measure than the target parameters. Systems and methods in accordance with aspects of the present teachings may include determining correlations between surrogate parameters and a target parameter using a training sample of data, and using the correlations to estimate values of the target parameter corresponding to out-of-sample measurements of the surrogate parameters. In some examples, determining the correlation between the surrogate parameters and the target parameter includes developing a nonlinear surrogate model that can be described as an almost piecewise linear model.