CSDU Granges, France case study

Design & Build of a Landfill Leachate Treatment Plant

The Client
The landfill, opened in 1980 and managed by Veolia Propreté, receives about 110,000 tons/year of waste, producing 38 m3/day of leachate.

The Challenge
The client's main needs, which are typical of all companies operating in this sector, were the reduction in volume of the leachate to be disposed of, ensuring that any streams produced can be discharged from site in accordance with environmental obligation, and recovering the waste heat coming from the biogas plant engine to supply the evaporators

Our Solution
Thanks to its considerable experience and vast knowledge in this particular sector, VWS Italia was able to provide the client with a landfill leachate treatment plant with a maximum capacity of 75,000 l/day, allowing a reduction of 98% of the total volume to be disposed of, with the consequent dramatic reduction of the relevant costs, at the same time fully complaying with environmental legislation.

Solutions & Technologies
Pre-treatment:

• pH adjustment with hydrochloric acid: in this phase, the ammonium becomes salt for a consequent reduction of its concentration in the distillate.
• Degassing: degassing of leachate to reduce formation of foam within the evaporator.

Pre-concentration & Post-treatment

• Osmoper 75: Reverse osmosis - the leachate and the distillate coming from the first evaporation phase and the second evaporation phase go through the membranes, followed by treatment through an ion exchange unit and activated carbon to ensure that the discharge standards are met.

Evaporation/Concentration:

• Evaled AC EW 40000: First Phase Concentration - the RO concentrate flows into the vacuum hot/cold water evaporator, with forced circulation, producing a concentrate and a distillate.
• Evaled AC RW 3000: Second Phase Concentration - the concentrate from the first phase is further concentrated via a hot/cold water evaporator with natural circulation and heat exchanger with scraped heating surfaces. This second phase of concentration further reduces disposal costs.The obtained substance is a semi-solid residue disposable within the same landfill, fully complying with the current local environmental regulations.

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