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On-line Toxicity Analyzer

The EZ Series Toxicity analyzer is able to detect and measure wastewater streams that present an acute or chronic toxicity to the biomass of a treatment plant. This allows operators to take corrective measures to protect the viability of the waste water treatment plant, e.g. by storing the toxic water in a buffer tank. With a response time of 15 minutes, toxic compounds present in the wastewater can be detected in an early stage by the Toxicity analyzer. The on-line analyzer thus functions as an early warning system and, indirectly, as a continuous assessment of a healthy respiration rate of the biomass.

The measurements are carried out on real sludge freshly sampled from the customer’s waste water treatment plant (WWTP), by means of self-cleaning sampling-filtration systems (option). This unique approach to respirometry has the following advantages:

  • Dynamic changes in biomass viability are taken into account
  • Measurement at same pH as the WWTP
  • Measurement at same temperature as the WWTP

The second generation on-line Toxicity analyzer has been downscaled to a compact, light-weight unit with improved analytical performance and significantly reduced consumption, yet retaining all the benefits of the single DO sensor design, and the continuous use of sludge sampled from the WWTP:

  • Built-in automatic cleaning and calibration
  • Shorter pathways for waste water and sludge
  • Transparent door allows instant 180° visual inspection
  • Reduced environmental footprint (60% weight reduction)

The Toxicity analyzer is also known as the Hach EZ7900 Series and available worldwide through your local Hach team.


Please visit the Hach.com website to download the detailed datasheet.

Parameters: Toxicity

Product type: Online water analyzers

Measuring technology: Respirometry

Type of application process: Wastewater treatment

Industries: Food & Beverage, Petrochemical, Refining, Wastewater, Water treatment