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How to Treat Chelated Metals in Wastewater

Not every water treatment plant is meant to tackle sewer water. Some of them are part of metal-producing factories that produce wastewater considered dangerous to the environment as-is. One step in the treatment of wastewater full of metals is stabilizing them by chelation. Afterward, these new chemical structures need to be removed -- which can produce further treatment needs.

Things You'll Need

Chelated wastewater in tank
Treatment chemical of choice (DTC, ferrous sulfate, sodium sulfide, polyelectrolyte, sodium borohydride, or ferrous dithionite)

Instructions

- 1
  Collect the pH-leveled wastewater into its tank during the treatment process. Once full, shut off the drainage system to prevent backflow.
- 2
  Choose the treatment chemical to use according to your specific budget and needs. Add the treatment chemical to the wastewater, for example: polyelectrolytes. Though very expensive, the polymers will remove the chelated metals without producing an overabundance of sludge to process. DTC is commonly used, but has its own drawbacks.
- 3
  Begin occasionally stirring the treated wastewater according to the chemical treatment maker's instructions. Though the metals will settle into sludge at the bottom, occasionally stirring the water will aid in the chemical processes involved in removing the metals as much as possible. Continue this action for at least 24 hours.
- 4
  Separate the water from the sludge. Drain the water to its next stage in the water treatment process. Drain the sludge to its separate treatment process (such as dewatering).

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