While cyanide is rarely an issue in municipal wastewater processes, it does have a useful role in some industrial applications. Now engineers responsible for those processes can employ the S80-T80 Cyanide Analyzer Monitoring System from Electro-Chemical Devices to ensure cyanide levels in wastewater effluent are compliant with local, state and federal regulations.

While cyanide is toxic, it is widely used by a variety of industries, including the manufacture of nylon and plastics, the case hardening of steel, metal plating, the separation of gold and silver from ores and the scrubbing of stack gases from blast furnaces. According to the U.S. EPA, the lethal oral doses of cyanide compounds generally range from 50 to 200 mg. In addition, short-term exposure to cyanide above the maximum contaminant level can cause rapid breathing, tremors and other neurological effects. Long-term exposure can cause weight loss, thyroid effects and nerve damage. The EPA’s National Primary Drinking Water Regulations are legally enforceable primary standards and treatment techniques that apply to public water systems. These regulations limit the level of cyanide contaminants in drinking water to 0.2 mg/L.

The S80-T80 Cyanide Analyzer Monitoring System includes an S80 Pion Cyanide Sensor and a dual-channel T80 Transmitter, which help ensure effluent is treated to U.S. EPA regulatory requirements prior to discharge. Its ion electrode is a combination electrode with a silver cyanide/silver sulfide solid-state pressed crystal sensing element and a double junction reference electrode. The ion selective electrode cartridge develops a millivolt potential proportional to the concentration of free CN ions in the measured solution. The typical output is 54mV to 60mV per decade of change in concentration. 

The speed of sensor response varies from a few seconds in concentrated solutions up to a few minutes in the lower ppm ranges. The ion sensors are used with the Model T80 Transmitter with its dual channel mix and match capabilities. This analyzer measures cyanide from 0.2 to 260 ppm and auto-ranges the display between the ppb and ppm scales.

S80 sensors come in immersion or insertion packages that are designed with a 0.75-inch MNPT compression fitting as the process connection. This design employs a variable insertion length to accommodate installation in pipe tees, flow cells or through tank walls. The retractable configuration is designed with a 1-inch MNPT ball valve, a 1-x-0.75 inch reducer and a 0.75-inch MNPT compression fitting to provide the process connection. 800-729-1333; www.ecdi.com