Thermo Scientific Orion 7070iX TRO Analyzer

Thermo Fisher Scientific has developed a total residual oxidant (TRO) analyser to address the needs of the wastewater industry, which calls for a robust, dependable instrument capable of measuring low ppb chlorine concentrations in effluent and treated wastewater in line with stringent regulatory requirements.

Operating on US Environmental Protection Agency-approved iodometric electrode technology, the Thermo Scientific Orion 7070iX TRO Analyzer has been designed to offer high sensitivity for low-level chlorine measurements down to 1 ppb with 1 ppb resolution. With this capability, the system provides users with the confidence that chlorine concentrations in water discharged into natural water sources do not exceed the safety threshold or pose a threat to marine life. For optimal application flexibility, the analyser also enables full range measurements up to 15 ppm.

Compared with the conventional DPD (N,N-Diethyl-1,4-Phenylenediamine Sulfate) colorimetric method, the iodometric electrode technology does not suffer from turbidity or colour interferences, which can have a negative impact on result accuracy and precision. Further, the analyser is capable of operating autonomously for long periods of time with minimal instrument drift (<5% for >180 days without calibration), eliminating the need for routine maintenance. At the same time, the system’s self-cleaning capability prevents chemical and biological fouling of the measurement cell and sensor, minimising downtime and facilitating continuous testing.

To maximise efficiency and productivity, the analyser can operate automatically on-demand in intermittent on-off mode, based on sample flow: once the flow starts, the unit’s pumps turn on and they shut down as soon as the flow stops. The product also provides real-time monitoring of TRO fluctuations, alerting users within just 120 s from the change, prompting timely corrective action.

The high sensitivity of the instrument allows users to have full control over their chlorination and dechlorination processes, while its compatibility with different water matrices, including sea water, industrial water and brackish ballast water, makes it suitable for a wide variety of applications.