The present disclosure discloses a method for determining optimal preservation temperature of the anaerobic ammonia oxidation biofilm in wastewater treatment, and belongs to the technical field of environmental engineering. The method of the present disclosure characterizes the ratio of living cells, early apoptotic cells, late apoptotic cells and dead cells in the anaerobic ammonia oxidation biofilm by flow cytometry, and the optimum storage temperature can be measured within a few hours. The method of the present disclosure performs correlation analysis on the characteristic indexes of the anaerobic ammonia oxidation biofilm activity recovery process to verify the reliability of the data. By using the method of the present disclosure, the step of recovering the biofilm activity can be omitted, the removal rates of ammonia nitrogen and total nitrogen were over 90% and 85%, respectively.

Methods of determining the presence or absence of fluorocarbon(s) on a substrate using X-ray Photoelectron Spectroscopy (XPS). A method may be used to determine the presence or absence of per- or polyfluoroalkyl substances PFASs. A method may use a porous polymer substrate. A method may use solid-phase extraction (SPE). A method may be used to determine the presence or absence of fluorocarbons in an aqueous sample. An aqueous sample may be a groundwater sample, wastewater sample, potable water sample, drinking water sample, or surface water sample. The limit of detection of fluorine in a method may be 0.05% F or less (for XPS analysis) and/or 20 ng or less on a substrate.

In-situ fluorimeters and methods and systems for collecting and analyzing sensor data to predict water source contamination are provided. In one embodiment, a method is provided that includes receiving sensor data regarding a water source. Changepoints may then be calculated within the sensor data and the sensor data may be split into intervals at the changepoints. A machine learning model may then be used to classify the intervals and a predicted contamination event for the water source may be identified based on the classified intervals. In another embodiment, an in-situ fluorimeter is provided. The in-situ fluorimeter comprises one or more UV LEDs centered around a pre-set excitation wavelength (e.g., a TLF excitation wavelength), a bandpass filter, a lens, a photodiode system, a machine learning platform; and an alarm triggered by contamination events, wherein the alarm is calibrated through the machine learning system.

Cell counting device A cell counting device and a method of using a cell counting device are disclosed. The cell counting device comprises a chamber for receiving a sample, at least one light source to emit light towards a section of the chamber. The section of the chamber comprises a sub-sample of the sample. The cell counting device also comprises a light detector to receive a light emitted from the section of the chamber and to generate an electronic signal associated with the received light, and a controller. The controller is configured to estimate the number of photoactive cells in the sample by calculating the distribution of variable fluorescence [F.sub.v] values of a predetermined number of sub-samples about the mean F.sub.v value.

A sample may be prepared and then analyzed using a liquid chromatography with tandem mass spectrometry system to determine presence and concentration of herbicide(s) present in the sample. In some examples, the method involves providing a sample containing one or more herbicides and adding a base to the sample. The base may increase the pH of the sample to ≥12, thereby hydrolyzing esters of the one or more herbicides. The method may further involve, subsequent to hydrolyzing the esters of the one or more herbicides, adding an acid to the sample so as to lower the pH of the sample to ≤3. Once prepared, the sample can be injected into a liquid chromatography instrument to separate the herbicide molecules from other molecules present in the sample before being ionized and characterized by mass-to-charge ratio and relative abundance using one or more mass spectrometers.

A drinking water supply system includes a drinking water line system, a plurality of drinking water withdrawal points connected to the drinking water line system, at least one sensor which is designed to determine measuring values, and a central control device which is designed to receive and evaluate the measuring values determined by the at least one sensor. The system also includes a presence detector designed to determine information about the presence of a person, or an acoustic sensor designed to measure measuring values for the volume. The central control device is designed to control the drinking water supply system as a function of the information about the presence of a person or as a function of the measured values for the volume. A method for controlling such a drinking water supply system and a computer program that causes the method to be carried out are also provided.

The present disclosure refers to a method and a system of sudden water pollutant source detection by forward-inverse coupling, including: building an one-dimensional forward water quality simulation model of a river way according to acquired mechanical parameters and water quality parameters; according to the one-dimensional forward water quality simulation model of the river way, measuring and calculating each monitoring index by using an inverse optimization source-detection model; by constructing the one-dimensional forward water quality simulation model of the river way, using the inverse optimization source-detection model for measurement and calculation; and performing the Bayesian updating, in order to realize multi-information fusion. The present disclosure may reasonably control and use different observation information, and combine the redundancy or complementarity of multi-sourced information in space or in time to obtain consistent interpretation of the measured object, thus overcoming the uncertainty of the water environment, improving the accuracy of water pollutant source detection.

A method for analyzing a fluid of a pool by a floating system. The method may include sensing, by a sensor of the floating system, at least one out of (a) a wind parameter related to a wind that impinges on the floating system and (b) a movement of the floating system; wherein the floating system further comprises a top portion comprises at least one float, a submerged portion that comprises comprises a fluid analysis instrument, a power source, a controller, and a propulsion unit; determining, by the controller, an impact of the wind on the floating system based on the at least one out of the wind parameter and the movement of the floating system; controlling, by the controller, a movement of the floating system based, at least in part, on the impact of the wind; and analyzing, by the fluid analysis instrument, at one or more analysis points, the fluid of the pool to provide one or more fluid analysis results.

Materials for binding per- and polyfluoroalkyl substances (PFAS) are disclosed. A fluidic device comprising the materials for detection and quantification of PFAS in a sample is disclosed. The fluidic device may be configured for multiplexed analyses. Also disclosed are methods for sorbing and remediating PFAS in a sample. The sample may be groundwater containing, or suspected of containing, one or more PFAS.

A method for characterising a solution S.sub.0 comprising a plurality of solutes, which comprises at least the steps consisting in: subjecting the solution S.sub.0 to a sequence of N successive rows of liquid-liquid extractions, this sequence leading to a total of [2.sup.(N+1)−1] different phases, 2.sup.N phases of which are issued from the last row N of partitions; acquiring experimental data by measuring an extensive and conservative quantity X in the 2.sup.N phases issued from the last row N of partitions of said sequence; and subjecting the experimental data to mathematical processing allowing to determine the distribution of the solutes of the solution S.sub.0, which contribute to the values of the quantity X obtained experimentally, according to various hydrophilicity/lipophilicity values.