The present disclosure relates to a microfluidic device for measuring one or more parameters in a fluid sample, which includes a sample microfluidic channel disposed on a solid substrate, a reagent microfluidic channel disposed on a solid substrate, a mixing microfluidic channel disposed on a solid substrate, and an optical reading window located downstream of the mixing microfluidic channel, through which a response indicative of the parameter(s) change can be measured optically. The present disclosure also relates to an apparatus for measuring one or more parameters in a fluid sample which includes the microfluidic device as well as a method for measuring one or more parameters in a fluid sample through the device or the apparatus.

A composition and an assay solution for the determination of dissolved borate concentration comprising a catechol dye, a solubilizing agent, and a buffer are described. The composition and assay solution may further comprise a solubilizing agent. The catechol dye acts as a chemical borate sensor. The chemical borate sensor changes its optical properties upon binding to borate. The multivalent cation chelator binds multivalent cations present in a sample being analyzed. The buffer prevents changes in pH. The solubilizing agent aids in solubilizing the catechol dye, multivalent cation chelator, and/or the buffer.

Apparatus and method for detecting a dissolved gaseous impurity in an aqueous environment, comprises a tube for isolating liquid surface, or a sampler for obtaining a liquid sample from the aqueous environment, a vacuum pump located to exert a vacuum, leaving the surface to evaporate into the vacuum; and a holding compartment for holding evaporated gas which may then be analyzed using electrochemical or spectroscopic methods. The apparatus is useful for detecting levels of ammonia in fish ponds or indeed any impurity that may be dissolved in the water.

A system for stereoscopic and real-time monitoring of an ocean methane profile includes a waterborne communication floating body, a gravity anchor, and a monitoring mechanism disposed therebetween, wherein the monitoring mechanism includes a submarine methane leakage intensity monitoring apparatus, a plurality of methane monitoring apparatus capable of synchronously monitoring methane content and a hydrodynamic environment, and a plastic-coated steel cable connected between the waterborne communication floating body and the gravity anchor; a data acquisition cabin is connected to the plastic-coated steel cable through a first communication module; and a first floating ball assembly is connected to the plastic-coated steel cable through a fixing rope. The submarine methane leakage intensity monitoring apparatus and the plurality of methane monitoring apparatus are disposed between the gravity anchor and the waterborne communication floating body at predetermined intervals.

Methods and devices for obtaining approximate property data from the aqueous liquid phase of a multiphase fluid produced from a well. The method includes introducing a discrete sample of the multiphase fluid to a separation vessel; mixing a demulsifier with the discrete sample of the multiphase fluid; allowing the multiphase fluid to separate into separate liquid phases; drawing a measured sample of the aqueous liquid phase from the separation vessel, and diluting it with a measured amount of fresh water; analyzing the diluted aqueous liquid phase sample in a water analysis unit to measure a property of the diluted aqueous liquid phase sample and obtain diluted aqueous liquid phase sample data; and calculating the approximate aqueous liquid phase property data using the diluted aqueous liquid phase sample data and accounting for the amount of fresh water used to dilute the measured sample of the aqueous liquid phase.

Various embodiments of the present disclosure are directed to carbon dioxide and/or hydrogen sulphide sampling and detection system and method for determination of the content of gaseous CO2 and/or H2S in a liquid, among other chemical compounds. In one embodiment, the detection system includes a membrane block having a liquid sample inlet port and a sample outlet port between which a sample flow path extends. The membrane block includes a first membrane unit and a second membrane unit. The first membrane unit includes a sample flow on the first side of a first permeable membrane element, and a carrier gas flow on the second side of the first permeable membrane element. The second membrane unit having a sample flow on the first side of a second permeable membrane element and a carrier gas flow on the second side of the second permeable membrane element.

A testing device (10) for testing the level of a selected chemical in central heating system water in a central heating system circuit comprises: a sample chamber (14) for holding a sample of central heating system water to be tested, the sample chamber (14) being connectable (12) to the central heating system circuit to allow fluid to pass between the central heating system circuit and the sample chamber (14); means (16) for controlling filling of the sample chamber (14) with central heating system water from the central heating system circuit, and emptying of the sample chamber (14); at least one valve (18) for isolating the sample of central heating system water from the heating circuit during testing; and optical testing apparatus including a light source (20) and a detector (22), for measuring an optical property of the sample of central heating system water isolated within the sample chamber (14) and thereby making a determination as to whether or not the level of the selected chemical in the water is greater than a predetermined threshold level.

A sample of water is tested for silica and phosphate content in a single apparatus. In the test method, a first sample of the water is colorimetrically analyzed in a reaction chamber using a “molybdenum blue” test in which silica and phosphate in the sample are complexed with a first reagent. The phosphate complexes are then optically inactivated by a second reagent and the color of the silica complexes is intensified with a third reagent. From this, the silica content is calculated. A further sample is colorimetrically analyzed without using the second reagent, so that a combined silica and phosphate content of the further sample is obtained. A value of the silica content is subtracted from the value of the combined silica and phosphate content, resulting in a phosphate content for the sample. The silica content and the phosphate content of the sample are reportable.

A grid-based source-tracing method and system for sewage outfalls and a storage medium are provided. The method specifically includes the steps of: dividing a river into multiple reaches; determining monitoring sites according to the divided reaches; acquiring on-line monitoring data of each of the monitoring sites, and calculating soft measurement data; determining a river reach with sewage outfalls according to upstream and downstream soft measurement data; and intensively arranging monitoring sites in the river reach with sewage outfalls to subdivide the river reach with sewage outfalls, thereby determining a position of a sewage outfall. The method divides the river into multiple reaches and performs the grid-based source-tracing for the sewage outfall of the river gradually. In real practice, with online conductivity and water level monitoring data, the method can effectively determine the river reach with sewage outfalls using soft measurement.

Apparatus and methods are provided for measuring phosphate in water. The methods can involve electrically pre-treating a potentiometric sensor and using the electrically pre-treated potentiometric sensor in a water sample to obtain a phosphate measurement. The potentiometric sensor includes a working electrode and a counter electrode. The working electrode includes a metal/metal oxide electrode having a detection surface. The electrical pre-treatment generates a metal phosphate on the detection surface of the metal/metal oxide electrode. The phosphate measurement results in a fresh layer of mixed oxide on the detection surface of the metal/metal oxide electrode. The electrically pre-treatment can be performed in situ in the water sample, allowing for field monitoring of water bodies. In some embodiments, the method can also involve cleaning the sensor prior to electrically pre-treating the sensor or after obtaining the phosphate measurement.