Abstract: A method is provided for measuring an electrolytically-active species concentration in an aqueous or non-aqueous solution for use in providing control of the concentration of the species in a source solution thereof based on the measurements. In the method, a sample containing an electrolytically-active species is added into a measurement cell that has a working electrode and an auxiliary electrode, and a constant current is applied to the measurement cell while the working and auxiliary electrodes are in contact with the sample with monitoring of voltage difference across the electrodes until a change in the voltage difference is detected. A feedback signal is generated based on a parameter of the change in the voltage difference that is directly proportional to the amount of the electrolytically-active species in the sample, which can be used for process control. An apparatus is also described.

Abstract: A method of controlling an exothermic or endothermic chemical reaction is provided. The method involves measuring a temperature of a first reactant flowing at a first flow rate, contacting the first reactant with a second reactant flowing at a second flow rate to form a reaction product, measuring the temperature of the reaction product, and determining the temperature difference between the temperature of the first reactant and the temperature of the reaction product. The method can further involve adjusting the flow rate of at least one of the first reactant and the second reactant, or shutting down flow, based on the temperature difference. An apparatus to carry out the method is also provided. The method and apparatus can be useful in controlling many different reactions, including the reaction of sodium hypochlorite and ammonia to form monochloramine.

Abstract: The present invention provides a method of treating an aqueous system for biocide control, by adding an acidified solution that includes monoalkyldithiocarbamate salt and alkyl isothiocyanate to an aqueous system. A biocide feed system is also provided that is configured to generate a reproducible level of alkyl isothiocyanate. The method and system provide effective levels of alkyl isothiocyanate for rapid biocidal activity, along with levels of monoalkyldithiocarbamate salt which can decompose to form additional alkyl isothiocyanate and provide longer-term biocidal activity.

Abstract: A method of controlling an exothermic or endothermic chemical reaction is provided. The method involves measuring a temperature of a first reactant flowing at a first flow rate, contacting the first reactant with a second reactant flowing at a second flow rate to form a reaction product, measuring the temperature of the reaction product, and determining the temperature difference between the temperature of the first reactant and the temperature of the reaction product. The method can further involve adjusting the flow rate of at least one of the first reactant and the second reactant, or shutting down flow, based on the temperature difference. An apparatus to carry out the method is also provided. The method and apparatus can be useful in controlling many different reactions, including the reaction of sodium hypochlorite and ammonia to form monochloramine.

Abstract: The present invention provides a method of treating an aqueous system for biocide control, by adding an acidified solution that includes monoalkyldithiocarbamate salt and alkyl isothiocyanate to an aqueous system. A biocide feed system is also provided that is configured to generate a reproducible level of alkyl isothiocyanate. The method and system provide effective levels of alkyl isothiocyanate for rapid biocidal activity, along with levels of monoalkyldithiocarbamate salt which can decompose to form additional alkyl isothiocyanate and provide longer-term biocidal activity.

Abstract: A method is provided for measuring an electrolytically-active species concentration in an aqueous or non-aqueous solution for use in providing control of the concentration of the species in a source solution thereof based on the measurements. In the method, a sample containing an electrolytically-active species is added into a measurement cell that has a working electrode and an auxiliary electrode, and a constant current is applied to the measurement cell while the working and auxiliary electrodes are in contact with the sample with monitoring of voltage difference across the electrodes until a change in the voltage difference is detected. A feedback signal is generated based on a parameter of the change in the voltage difference that is directly proportional to the amount of the electrolytically-active species in the sample, which can be used for process control. An apparatus is also described.