Instructions for a Nalgene Settlometer

The Nalgene company is known for its high-grade plastic bottles used by outdoor enthusiasts. The Nalgene bottle actually originated from lab equipment. The Nalgene Settlometer is a container used specifically by wastewater management personnel. The device is used in a wastewater treatment facility to collect and test the quality of sludge via a settlometer and centrifuge test. A Nalgene Settlometer kit contains all needed materials to test wastewater from a wastewater facility aeration tank.

Things You'll Need

  • Nalgene Settlometer kit
  • Wide-mouth collection vessel
  • Small collection vessel (cup)
  • Timer
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Instructions

    • 1

      Using a wide-mouth collection vessel, collect a 2-liter sample of water from the wastewater facility aeration tank. Close the lid and agitate the container thoroughly.

    • 2

      Pour the liquid into the Settlometer container just past the "1000 cc" line. Agitate the liquid with the paddle included with the Settlometer kit.

    • 3

      Using a small vessel, remove enough liquid to bring the level to the "1000 cc" line exactly. Insert the paddle and rotate back and forth until the liquid is thoroughly mixed. Hold the paddle in the middle of the Settlometer for five to 10 seconds or until the turbulence in the water comes to a stop. Withdraw the paddle slowly from the Settlometer. Set a timer for five minutes.

    • 4

      Read the sludge blanket level located on the right scale of the container after five minutes has elapsed. The sludge blanket level is the interface between the solids present in the sludge and the clear liquids above the solids. Record the data on the data sheet included with the kit. Continue taking the readings every five minutes, recording data until you complete 15-, 20-, 25- and 30-minute readings.

    • 5

      Set the timer for 10 minutes. Take readings and record data every 10 minutes until you've completed 40-, 50- and 60-minute readings. These readings are known as the settled sludge volumes for five- and 10-minute intervals, or SSV-5 and SSV-10.

    • 6

      Plot the reading times and SSV numbers on Graph No. 1. Plot the SSV readings on the vertical axis. Plot the reading times on the horizontal axis. Connect the plotted points on the graph to get the settled sludge volume curve. At this time the sludge is settled. Leave the settled sludge in the Settlometer, undisturbed, for four hours.