• James Bellew

Wastewater Filter Presses – Why are they maligned!

Updated: May 4, 2021

How many times have you heard - or been told:

  • They don’t work!

  • The filters clog!

  • They are more trouble than they are worth!

  • I need an operator checking on it all the time!

Here are some points to think on when you are considering how best to treat and recycle your Batch Plant wastewater.

  1. A Filter Press is not designed to take the full brunt of cement and sand-ladened water.

  2. The filter membranes are designed to trap fine particles not coarse or small sized sand grains.

  3. You cannot and should not just pump the wastewater from whatever Reclaimer you are using directly to a Filter Press.

  4. As the aggregates and coarse grained sand is being separated in the wet concrete reclaimer, the contaminated wastewater should be drained into a sloping floor settling pit to allow the fine sand grains to settle out of suspension.

  5. The residual cement ladened slurry should then be directed into a “suspension” pit with an operating slurry stirrer. The stirrer is used to keep the cement micro-grains in suspension.

  6. From the suspension pit, the slurry should then be pumped to the Filter Press where it will be circulated through the filter membranes. The cement grains will be extracted and then compressed into a “Filter Cake” (which periodically drops to a collecting area below).

  7. Irrespective of the sales spin. no amount of artificial intelligence can supplant "eyes on the ground" when it comes to detecting an area or a corner of the filter cloth that the automatic cleaning system missed!

  8. The clarified water from the Filter Press, which in concrete plants is generally acidic, should be drained into a "Clarified Water" storage tank. At this point in the operation, the water can be automatically analysed and treated with appropriate dosing equipment to correct the pH level to allow it to be re-used in Plant cleaning and/or batching operations.

When used in conjunction with our Wet Concrete recycling Plant, the PLC controlled Filter Press can provide the correct solution to the ever increasing requirements of the EPA and local Councils, assist you to meet your environmental responsibilities and importantly, help reduce your water usage and costs.

Call us or chat on-line to obtain a typical recycle and treatment Plant layout and to discuss how we can assist you to become more profitable:

  1. Through retrieving raw materials by recycling your own waste wet concrete.

  2. By saving on water costs

  3. Be more environmentally conscious with your wastewater.

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