There is provided a biofilm capacitance microbial electrochemical cell (MEC) sensor to measure organic carbon in water and wastewater rapidly and accurately, represented by the 5-day biochemical oxygen demand (BOD.sub.5). The MEC runs at charging (open circuit) and discharging (close circuit) conditions alternately to improve the sensitivity, response time and accuracy. The detectable BOD.sub.5 concentrations with the biofilm-capacitance MEC range from 5 to 250 mg/L (R.sup.2>0.9). The MEC sensor enables BOD.sub.5 measurements at every 2 minutes (1 minute charging and 1 minute discharging), indicating semi-continuous quantification of organic carbon in water and wastewater.

The invention provides an automated device for accessing the viability of a wide range of organisms based on the metabolic production of fluorescent products from non-fluorescent substrates. Also provide are methods for detecting contaminants in a fluid and measuring the viability of organisms in a fluid or liquid. Components of the invention include the incorporation of a reusable filter to concentrate the organisms, the back flush of the filter to collect the organisms for assay, and the addition of the substrate in a fluorescent detection chamber to detect the enzymatic activity produced by viable organisms to detect the presence of such organisms.

Method and system for detection and quantification of oxidizable organics in water. The method involves the partial electrolytic decomposition of the oxidizable organics in a short time frame, preferably less than five seconds, and does not involve the use of toxic reagents. The system includes an electrochemical sensor probe that, in turn, includes a boron-doped diamond microelectrode array. The system additionally includes an electronic transducer and a computing device. The system utilizes an analysis technique to convert sensor signal to a result that can be correlated with COD or BOD values obtained by standard methods. The method and system are particularly suitable for, but not limited to, use in monitoring of water quality at wastewater treatment plants. By employing the method before and after adding aerobic microorganisms to the sample, the method may be used to distinguish biologically oxidizable organics from total oxidizable organics.

The present disclosure generally relates to a system for monitoring and/or controlling one or more agents, such as cleaning agents, in a wastewater treatment system. The system comprises a bio-electrochemical sensor for monitoring metabolic activity of a population of exo-electrogenic bacteria and providing an electrical output corresponding with the metabolic activity, where the bio-electrochemical sensor comprises an electrode pair and a power source for delivering a voltage across the electrode pair, and an electrical output analyzer for analyzing the electrical output and correlating the electrical output with the one or more agents in the wastewater treatment system. a change in electrical output beyond a threshold indicates that an adjustment in the delivery of the one or more agents is needed. a method and sensor for monitoring and/or controlling a cleaning process in a wastewater treatment system are also provided. The system, method, and sensor disclosed herein are particularly useful for cleaning membranes incorporated in a wastewater treatment process.

The disclosure includes an apparatus for determining a measured value in a liquid medium, comprising at least a light transmitter, at least one light receiver assigned to the transmitter, a measuring chamber that can be filled with the medium, wherein an optical path runs through the measuring chamber from the transmitter to the receiver. The apparatus includes a dosing apparatus for dosing at least one reagent and/or the medium, and for inserting the dosed reagent and/or the medium into the measuring chamber. The dosing apparatus is designed as a tube, and the tube includes at least a first control point, wherein the volume in the tube from a starting point to a first control point defines the amount of reagent or medium to be inserted into the measuring chamber. The disclosure further includes the use of the apparatus and a method for dosing the reagent.

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.

The present disclosure provides a color chart and a test kit for estimating chemical oxygen demand of water. The color chart includes a blue component, an indigo component, an umber component, and an orange component. The test kit includes an oxidant, a reductant, an indicator, and the color chart. The present disclosure also provides a method for estimating chemical oxygen demand of water. The method includes providing a water sample; adding an oxidant to the water sample; heating the water sample; adding a reductant to the water sample; adding an indicator to the water sample, such that the water sample develops a color; and matching the color of the water sample with the color components of the color chart to estimate the chemical oxygen demand of the water sample.

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.

The disclosure includes an apparatus for determining a measured value in a liquid medium, comprising at least a light transmitter, at least one light receiver assigned to the transmitter, a measuring chamber that can be filled with the medium, wherein an optical path runs through the measuring chamber from the transmitter to the receiver. The apparatus includes a dosing apparatus for dosing at least one reagent and/or the medium, and for inserting the dosed reagent and/or the medium into the measuring chamber. The dosing apparatus is designed as a tube, and the tube includes at least a first control point, wherein the volume in the tube from a starting point to a first control point defines the amount of reagent or medium to be inserted into the measuring chamber. The disclosure further includes the use of the apparatus and a method for dosing the reagent.

Measurement arrangement for determining a constituent substance or quality parameter of water by thermal decomposition in a reaction module, delivery of the reaction product to a detector in a carrier gas flow, and evaluation of a detector signal for deriving a value of the constituent substance or quality parameter, wherein the reaction module is a vessel of vertical orientation during operation having an internal resistance heating or infrared heating, and has a head section into which the sample is introduced, a reaction zone, where the thermal decomposition is performed, as well as a foot section, from which the reaction product is output in the carrier gas flow, wherein the head section of the reaction module has an injection port for temporarily introducing an injection needle or permanently supporting a small supply tube, which injection port comprises an O-ring which is internally spring-loaded by a silicon padding or an inserted spring.