The invention discloses an in-situ passive sampling device based on physical and chemical and bio-coupling monitoring and use thereof, the device comprises a foam plastic tray on the water surface, a supporting connection device under the water surface, a fish farming device and a sampling device. The invention comprises three passive samplers and a fish farming device, wherein the fish farming device can ensure the survival environment of the fish in the long-term test, maintain the fish survival rate, and apply the device to the safety evaluation of water quality of the centralized drinking water source.

A chemical oxygen demand (COD) of a sample including water is determined. At least two test specimens are obtained. Each of the test specimens include a mixture of the sample and a standard solution including potassium hydrogen phthalate (KHP) in a known concentration. Each of the specimens include a same amount of the sample. Each of the specimens include different amounts of the standard solution. Each of the specimens is diluted with water. A COD of each of the specimens is measured. A COD of the sample is determined based on the measured CODs of the specimens.

A decision support system and method can be used to control a water treatment or distribution system. The decision support system collects data from multiple water system operators and analyses the data for a selected water system according to one or more rules or algorithms. The system returns data, optionally including alerts or predictions, to the system operator. Optionally, the decision support system uses machine learning applied to (i) historical data from a selected water system and/or (ii) data from other water systems to modify the rules or algorithms used to analyze current data from a selected water system. In some embodiments, the data collected includes microbial population data such as ATP data, optionally including derivatives of microbial population data; microbial speciation information; or, metagenomic data.

The present disclosure generally relates to a system for monitoring and/or controlling the delivery of one or more organic carbon compounds to a wastewater treatment system. The system comprises a bio-electrochemical sensor to monitor metabolic activity of a population of exo-electrogenic bacteria and provide an electrical output corresponding with the metabolic activity, the bio-electrochemical sensor comprising an electrode pair and a power source to deliver a voltage across the electrode pair, and an electrical output analyzer to analyze the electrical output and correlate the electrical output with a value representing the amount of the one or more organic carbon compounds in the wastewater treatment system. A method and sensor for monitoring and/or controlling the delivery of one or more organic carbon compounds to a wastewater treatment system are also provided.

Methods for identifying animals that are genetically superior, drugs, nutritional strategies, or physiological manipulations that improve feed efficiency or productivity of animals, e.g., selecting animals that are genetically superior for feed efficiency or productivity based on metabolic rates of particular tissues, wherein metabolic rates of certain tissues such as skeletal muscle are inversely proportional to feed efficiency, while metabolic rates of other tissues such as mammary gland are directly proportional to milk production. Thus, animals with low skeletal muscle metabolic rates are generally more feed efficient, e.g., gain more weight per unit of food. The methods herein may be used to improve the genetics, nutrition, and handling or animals more efficiently produced animal products, e.g., meat production, milk, production, egg production, wool production, etc. The methods herein may also be used to determine estimated breeding values of animals for feed efficiency, growth, or production.

A chemical oxygen demand (COD) of a sample including water is determined. At least two test specimens are obtained. Each of the test specimens include a mixture of the sample and a standard solution including potassium hydrogen phthalate (KHP) in a known concentration. Each of the specimens include a same amount of the sample. Each of the specimens include different amounts of the standard solution. Each of the specimens is diluted with water. A COD of each of the specimens is measured. A COD of the sample is determined based on the measured CODs of the specimens.

A computer-implemented method includes controlling an instrument to measure a fluorescence emission spectrum of a sample including a first peak emission wavelength and at least a second peak emission wavelength, emitted in response to an excitation wavelength and controlling the instrument to measure an absorbance obtained at the excitation wavelength of the sample. The method may include determining, using the computer, a ratio of the measurements at either the second peak emission wavelength, or a sum of measurements at a plurality of peak emission wavelengths including at least the first peak emission wavelength and the second peak emission wavelength, to the first peak emission wavelength, and calculating, using the computer, a value for a quality parameter based on a combination of at least the ratio and the absorbance measurement. The method may include controlling an associated process based on the quality parameter.

The present disclosure discloses a manufacturing method of an optical fiber chemical ratiometric sensor measurement system for measuring underwater dissolved oxygen concentration. The manufacturing method includes the steps of firstly, preparing a carrier substrate to obtain a solution A; then, preparing an oxygen sensitive dye to obtain a solution B; preparing a reference dye to obtain a solution C; mixing the solution A, the solution B and the solution C according to a ratio of 2:1:1 to obtain a composite sensitive dye; depositing the composite sensitive dye on one end face of a sensing optical fiber to prepare a fiber optic probe; establishing the optical fiber chemical ratiometric sensor measurement system, receiving the optical signal by a spectrometer as a fluorescence spectrum, and finally saving and processing fluorescence spectral data by computer software.

The invention discloses an in-situ passive sampling device based on physical and chemical and bio-coupling monitoring and use thereof, the device comprises a foam plastic tray on the water surface, a supporting connection device under the water surface, a fish farming device and a sampling device. The invention comprises three passive samplers and a fish fat ling device, wherein the fish farming device can ensure the survival environment of the fish in the long-term test, maintain the fish survival rate, and apply the device to the safety evaluation of water quality of the centralized drinking water source.

An embodiment provides a method for measuring dissolved oxygen of an aqueous sample, including: introducing an aqueous sample into a measurement device comprising at least two dissolved oxygen sensors, wherein at least one of the at least two dissolved sensors comprises a trend sensor and at least another of the at least two dissolved sensors comprises a reference sensor; measuring a first value of dissolved oxygen using the trend sensor, wherein the trend sensor samples at a trend frequency; measuring a second value of dissolved oxygen from a reference sensor, wherein the reference sensor samples at a reference frequency, the reference frequency being less than the trend frequency; and correcting the first value of dissolved oxygen based upon the second value of dissolved oxygen. Other aspects are described and claimed.