Success story: ZLD for leachate treatment

Wastewater from the treatment of municipal waste is very difficult to treat. Only less than a handful of companies worldwide know the recipe. In arid countries or where regulations demand it, the quality of the treated water must fulfil certain criteria for irrigation or re-use.
After 18 years of operation, the MBR BIOMEMBRAT® leachate treatment plant of the Lloret de Mar Landfill has been extended and upgraded to Zero Liquid Discharge (ZLD).

WEHRLE - Success story: ZLD for leachate treatment

WEHRLE mainly carried out the following works:

  • Extension of the biological volume of the MBR by installing a new pressure tank
  • Expansion of the capacity of the ultrafiltration for sludge separation by using additional membrane modules
  • Capacity expansion and integration of a second treatment step in the reverse osmosis post-treatment
  • Supply of a treatment system for the concentrates produced in the reverse osmosis stage, using evaporation via heat compression
  • Supply of a lime and cement stabilization system for the superconcentrates produced in the heat compression evaporator
  • Integration of new units in the existing PLC/SCADA control system

Results achieved:

  • 95 % of the leachate is purified to reach the necessary quality for re-use
  • 3.5 % of the excess sludge produced in the MBR is used for composting
  • All non-biodegradable contaminants are concentrated and reduced to a minimal percentage of 1.5 % and will be led back to the landfill once they are stabilized and immobilized

Goal achieved: Re-use and Zero Liquid Discharge for the treatment of leachate at sustainable costs


Picture: ZLD process scheme for the treatment of leachate in Lloret de Mar (Spain)Picture: ZLD process scheme for the treatment of leachate in Lloret de Mar (Spain)