Switching to Mercury free Float Switches

Mercury pollution by source
Mercury pollution by source

Apptech, like many in the wastewater industry, has been using mercury float switches for years; they are simple, reliable, and safe when in regular use. However, mercury switches are one of the primary products contributing to environmental mercury pollution; through manufacturing emissions and improper disposal  In order to ensure that Apptech products are not a source of any hazardous waste and to join the growing effort to phase out the manufacture of mercury switches, Apptech Solutions will no longer be using mercury float switches in future projects. Mercury float switches currently in use pose no threat, so if you are currently operating a plant with mercury switches installed there is no need to worry. However, it is critical that when such switches are replaced, they are disposed of in a responsible manner. Apptech urges all other water and wastewater equipment and infrastructure manufacturers to join our pledge to go mercury free. To help accelerate that process, Apptech engineers have reviewed some of the common alternatives to mercury floats:

  • Mechanical float switches: These economical float switches are commonly used in wastewater and water applications, though they are less reliable than mercury float switches due to jamming and mechanical wear.
  • Tilt float switches: Working by the same principal as mercury tilt switches, these level switches are fairly reliable and inexpensive.
  • Optical liquid sensor switches: These are a good option for relatively clean water such as that found in the secondary clarifier or post aeration basin. With no moving parts, these switches last longer than tilt switches and and are more somewhat more costly.
  • Ultrasonic level sensors: These level sensors are costly, but have the advantage of not being in contact with the liquid, meaning that they remain clean and uncorroded.
  • Pressure transducers: A more cost effective option than ultrasonic level sensors, these level sensors are effective for water and wastewater and provide more information that simple level switches.

Apptech will use primarily tilt float switches in combination with pressure transducers to provide the most cost effective and low-maintenance level sensing capabilities in its water and wastewater products.

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