Pumice Water Filtration & Desalination

Striving for further excellence in the supply of materials to the water and wastewater treatment industry, RBH have conducted recent trials on pumice filtration grains.

Using a state-of-the-art testing rig we can provide accurate data on back-washing rates vs bed expansion, and head loss vs forward flow water rates, at various temperatures and salinity levels. We also offer detailed results on particle size, porosity, hardness, density, and chemical composition.

Our product portfolio includes

  • Filtration Grains and Bio Filtration Media
  • Flocculation Aids/Ballasting Agents
  • pH adjusters

Filtration Media – Pumice

Pumice grains are used within dual and multimedia filters in waste water, potable water and seawater reverse osmosis (SWRO) treatment plants.   Most recently, a major application of pumice grains can be found in the pre-treatment processes of reverse osmosis (RO) desalination systems.  The pumice ensures the removal of particulates in gravity and pressure filtration systems thus preventing the fouling of membranes.

Recommended grades include the pumice NMP4 and NMP4N grains.  In multi-media filters, we are also able to supply supplementary filtration grains including sand and anthracite.

Testing: Further to our detailed specifications, our pumice grades have been tested in action, using a state-of-the-art testing rig.  Results include accurate data on back-washing rates vs bed expansion, head loss vs water rate, against variations in temperature and salinity.  We also offer comprehensive results on the particle size, porosity, hardness, attrition, density and chemical composition.

For further information and results please contact us – an example can be found below.

backwashing graph

Odour Control – Pumice

Pumice lumps are also used in bioscrubbers and biofilters, acting as a support medium for bacteria.  Polluted air passes through the pumice biofilm, where microbes enable the transfer of contaminants into the liquid medium through oxidation. Such units are installed throughout waste water, sewage and industrial effluent systems enabling the treatment of hydrogen sulphide and other volatile organic compounds.  Its low density, high surface area, neutral pH and high strength make pumice an ideal material within these systems. Pumice can also act as a longer term solution to fast degrading organic alternatives such as peat, heather and wood chippings.

Flocculation Aids (Ballasting Agents) – Talc

Within activated sludge systems talc can be used as a flocculent aid to improve floc formation and sedimentation rates, during times of high organic load.  The fact that talc is a natural, environmentally friendly mineral additive, that can be added manually, has meant it has been preferable to other chemical alternatives.  Using talc is a quick solution to settleabillity problems, especially where other conventional methods have failed.

Recommended grades include Magsil Sapphire 350 and Magsil Star 350

pH Adjusters – Calcined Magnesite

Calcined Magnesite is a cost effective source of chemical grade magnesium oxide used as an alkali for acid neutralisation, both in process and in subsequent effluent treatment.  Our calcined magnesite has been used as a means of securing optimal pH for subsequent coagulation and clarification steps.

Magnesium Hydroxide can also be used as an alternative to caustic soda in wastewater treatment as a means of increasing the pH.  Optimal pH is a necessity for ensuring the effective performance of microbial and coagulation steps in the treatment of industrial wastewater.

As a key supplier to the water and wastewater treatment industry we would welcome any opportunities to work with you on your requirements.