Disclosed are various embodiments for measuring ionic activity by quantifying total dissolved solids (TDS) concentration in wastewater. In some embodiments, ionic activity of wastewater is monitored by quantifying the total dissolved solids concentration, which can be used for determining the ammonia reduction progress through nitrification and the luxurious phosphorous uptake process reaction and/or the reaction progress of soluble phosphorous species and reactive ions, including one or more alkali and alkaline-earth species and/or soluble metals species, to form non-soluble ionic phosphorous precipitate during biological activated wastewater processes and digester biosolids treatment processes.

An automated descaling system can be integrated into a tankless water heater or can be a separate system that is attached to a tankless water heater. The automatic descaling system comprises a cleaning media chamber and a four way valve with a motor. The descaling system can be set on an automatic cleaning schedule.

A method of treating water in a water treatment system after a replacement of an ion exchange bed includes introducing water to be treated into the ion exchange bed of the water treatment system to produce treated water, calculating a current exchange daily average flow rate of water through the water treatment system, calculating a cumulative daily average flow rate of water through the water treatment system, and determining an estimated number of days remaining to exhaustion of the ion exchange bed based on the current exchange daily average flow rate and the cumulative daily average flow rate.

When the water quality of effluent water or intermediate water is measured, the effluent water or the intermediate water is allowed to flow from a pipe 40, 50, or 60 to a measurement column 84 via pipes 37, 80, 83, and the water quality is measured by a sensor 85. In a case where the water quality of raw water is measured, the effluent water and the raw water are introduced from pipes 40, 70 and mixed in a line mixer 38, and the water quality is measured by the sensor 85. After the measurement of the water quality, the effluent water (or fresh water) is allowed to flow, to clean the sensor 85 and the like, and the water quality of the effluent water (or fresh water) is measured to check the characteristics of the sensor 85.

A tankless water heater including a water inlet, a water outlet, a conductivity sensor, a temperature sensor, and a heating chamber connected to the water inlet and the water outlet wherein the heating chamber is configured to heat a flow of water received from the water inlet and output the flow of water to the water outlet. The water heating system can further include a controller communicably coupled to the conductivity sensor and the temperature sensor, where the controller calculates an adjusted conductivity of a flow of water through the water heater.

A coffee machine is disclosed having a water system intended to be connected to a water supply system, a filter unit disposed at the inlet of the water system, a pump, a tank disposed in the water system between the filter unit and the pump, a sensor unit disposed in the tank and suitable for measuring at least one quality parameter of the water contained in the tank, a monitoring unit electrically connected to the sensor unit to receive electrical signals that are indicative of the measured water quality parameters, transduce the electrical signals in numerical values and compare the numerical values of the measured parameters with preset threshold ranges, and a user interface operatively connected to the monitoring unit and having an alarm to indicate when a water parameter is out of the preset threshold range.

A method and apparatus for producing a biocide from a hypochlorite oxidant and an ammonium salt are provided. The method includes monitoring a control parameter to optimize the ratio between the hypochlorite oxidant and the ammonium salt. The control parameter may be oxidation-reduction potential, conductivity, induction or oxygen saturation.

A method of treating water in a water treatment system after a replacement of an ion exchange bed includes introducing water to be treated into the ion exchange bed of the water treatment system to produce treated water, calculating a current exchange daily average flow rate of water through the water treatment system, calculating a cumulative daily average flow rate of water through the water treatment system, and determining an estimated number of days remaining to exhaustion of the ion exchange bed based on the current exchange daily average flow rate and the cumulative daily average flow rate.

A method for operating a water softening plant includes an automatic blending device, an incoming flow of untreated water being divided into a first partial flow which is softened and a second partial flow which is not softened and then combined into a flow of blended water. The proportions of the two partial flows are adjusted by the automatic blending device such that a desired hardness DV results in the flow of blended water. The conductivity of the softened water and blended water are measured by conductivity sensors in their respective flows. The conductivity of the untreated water is calculated from the measured conductivity of the soft water, from the measured conductivity of the blended water and from the determined proportions of the partial flows. It is possible for the hardness of the blended water to be adjusted very reliably and with improved accuracy.

A method and apparatus for producing a biocide from a hypochlorite oxidant and an ammonium salt are provided. The method includes monitoring a control parameter to optimize the ratio between the hypochlorite oxidant and the ammonium salt. The control parameter may be oxidation-reduction potential, conductivity, induction or oxygen saturation.