The measurement of glutaraldehyde-based biocides in seawater without the use of a derivatization agent. The measurement of glutaraldehyde-based biocides in seawater may be performed without additional components to reduce background interferences. The concentration of a glutaraldehyde-based biocides in a seawater sample is determined using reversed phase liquid chromatography and a gradient mobile phase of acetonitrile and deionized water. Systems for determining the concentration of glutaraldehyde-based biocide in a seawater injection system are also provided.

The measurement of glutaraldehyde-based biocides in seawater without the use of a derivatization agent. The measurement of glutaraldehyde-based biocides in seawater may be performed without additional components to reduce background interferences. The concentration of a glutaraldehyde-based biocides in a seawater sample is determined using reversed phase liquid chromatography and a gradient mobile phase of acetonitrile and deionized water. Systems for determining the concentration of glutaraldehyde-based biocide in a seawater injection system are also provided.

A carbon nanotube (CNT) ion-selective field effect transistor (IS-FET) integrated device is used to detect nitrate ion in water. The device is operated as an IS-FET sensor, holding the measured potential between the drain electrode and an external reference electrode constant with a potentiometric circuit. Transduction occurs by changes in the effective CNT film gate potential with changes in the phase boundary potential of an ion-selective membrane (ISM) film. Moreover, the nitrate ISM film makes the device highly selective towards nitrate sensing. This printable IS-FET nitrate sensor enables real-time and high-resolution measurements and recording of nitrate ion in water at low cost.

A carbon nanotube (CNT) ion-selective field effect transistor (IS-FET) integrated device is used to detect nitrate ion in water. The device is operated as an IS-FET sensor, holding the measured potential between the drain electrode and an external reference electrode constant with a potentiometric circuit. Transduction occurs by changes in the effective CNT film gate potential with changes in the phase boundary potential of an ion-selective membrane (ISM) film. Moreover, the nitrate ISM film makes the device highly selective towards nitrate sensing. This printable IS-FET nitrate sensor enables real-time and high-resolution measurements and recording of nitrate ion in water at low cost.

The invention relates to a method for maintaining an equilibrium of a physico-chemical parameter of a medium, and for recovering the equilibrium in case of loss of the latter. More precisely the method makes it possible to estimate the relevance of a corrective action on the medium in order to recover an equilibrium. The method is implemented by the processing unit of a system for regulating the medium. The invention applies in a non-limiting manner to the regulation of the equilibrium of the bathing water of a swimming pool.

The invention relates to a method for maintaining an equilibrium of a physico-chemical parameter of a medium, and for recovering the equilibrium in case of loss of the latter. More precisely the method makes it possible to estimate the relevance of a corrective action on the medium in order to recover an equilibrium. The method is implemented by the processing unit of a system for regulating the medium. The invention applies in a non-limiting manner to the regulation of the equilibrium of the bathing water of a swimming pool.

The present application relates to a method for improving analytical efficiency and cost effectiveness of oxygen isotope analysis of an aqueous sample. In particular, the present application relates to a method of determining an oxygen isotope composition of an aqueous sample by (a) equilibrating the aqueous sample with CO.sub.2 gas wherein the aqueous sample comprises an effective amount of carbonic anhydrase (CA) enzyme; and (b) measuring the oxygen isotope composition of the CO.sub.2 at equilibrium, wherein the oxygen isotope composition of the CO.sub.2 corresponds to the oxygen isotope composition of the aqueous sample.

The present application relates to a method for improving analytical efficiency and cost effectiveness of oxygen isotope analysis of an aqueous sample. In particular, the present application relates to a method of determining an oxygen isotope composition of an aqueous sample by (a) equilibrating the aqueous sample with CO.sub.2 gas wherein the aqueous sample comprises an effective amount of carbonic anhydrase (CA) enzyme; and (b) measuring the oxygen isotope composition of the CO.sub.2 at equilibrium, wherein the oxygen isotope composition of the CO.sub.2 corresponds to the oxygen isotope composition of the aqueous sample.

A system and method for the detection and elimination of microorganisms in a water flow is provided. The method includes arranging at least one light emission element at a water flow point, arranging of at least one light capture element at the water flow point, detecting the presence of the microorganism through the first light emission event and eliminating the microorganism through the realization of a second light emission event. A detection module is also provided which can be positioned at a water flow point.

Provided are a system for monitoring a hydroxyl radical scavenging index in water using a real-time multi-fluorescence analyzer and a parallel factor analysis apparatus and a method therefor, wherein the system monitors the hydroxyl radical scavenging index in water using the real-time multi-fluorescence analyzer and the parallel factor analysis apparatus, whereby it is possible to monitor the characteristics of an organic material in target water through a continuous flow analysis method without using an existing indicator material, rhodamine B. In addition, in a water treatment system having an advanced oxidation process (AOP) applied thereto in which ozone, ultraviolet rays, hydrogen peroxide, and the like are combined, it is possible to simply calculate the hydroxyl radical scavenging index in the target water through an organic material characteristic index for each component obtained by classifying the characteristic structure of the organic material in water using real-time fluorescence analysis by means of a parallel factor (PARAFAC) model. Accordingly, the amount of chemical injection and the amount of ultraviolet irradiation, which are process control variables, can be controlled, and under given operating variable conditions, the removal rate of a target material in water is predicted, whereby the system can also be used as a diagnostic tool for process evaluation in the advanced oxidation process. Furthermore, the system can provide operational convenience that enables process control while reducing the amount of power consumed in the advanced oxidation process even though the type of target material and the water quality characteristics of raw water change.