With the development of industry and increasing water consumption, the amount of wastewater generated is also increasing. Every year, about 380 billion cubic metres of wastewater is produced worldwide as a result of human activity. About one third of this amount are industrial wastewaters polluted with various substances.

Due to its high sorption and ion-exchange properties, bentonite is widely used in wastewater treatment worldwide.

The use of bentonite-based sorbents provides:

  • effective sedimentation of suspended particles
  • reduction of organic compounds content (phenol, benzene, toluene, xylene, diesel fuel, etc.) as well as pesticides and herbicides
  • reduction of heavy metal cations and hardness salts (calcium, magnesium)
  • reduction of radionuclides
  • improve water colour.

It is important that bentonite is a natural mineral and its use has no negative impact on humans or the environment.

Fig. Scheme of bentonite use in wastewater treatment

The fine suspension of bentonite powder is fed into a tank with wastewater previously treated from coarse impurities.

To accelerate coagulation, micro additives of nutrient salts (aluminium or iron) are introduced into the water, after which the enlarged particles are flocculated and precipitated by adding a water-polymer solution.

The resulting precipitates are compacted and recycled into sand and gravel construction material.