Techniques

Envisan has the know-how and technology that is required to offer tailor-made solutions for the treatment, processing and storage of all kinds of industrial waste. 

Depending on the project and the waste flow to be treated, the following techniques are applied:

Techniques for the treatment of waste from the oil and petrochemical industry

Pre-treatment

A correct pre-treatment is essential for the effective processing of oil sludge and tar. The treatment method is established after a thorough prior study by the R&D department. For the treatment itself, Envisan has disposal of sieving plants, mixing plants, centrifuges and filter chamber presses to make sure this can be done safely and efficiently.

These plants can also be used for dewatering and pre-treating industrial waste flows.

Incineration
Often, waste from remediation projects must be incinerated. For this, Envisan can use its own plants or work together with local incineration plants. 

Envisan itself also designed and built a modern fluidized bed incinerator in Pitesti, Rumania, in which oil sludge and (acid) tar can be treated. In this process, the generated heat is recovered for the production of electricity. This treatment centre for polluted soil, sludge and water in lagoons consists of 4 parts: storage area, pre-treatment, thermal treatment and waste water treatment plant.

The state-of-the-art centre was originally developed as part of a contract with Petrom, a Rumanian oil refinery for which Envisan remediated three large oil sludge lagoons.

 
Romania - Arpechim

Thermal desorption

Soil and materials polluted with oil residues and volatile compounds can be treated by applying thermal desorption. In this process, the pollution is evaporated and converted into gas. The use of a full-fledged flue gas treatment unit ensures that the emission standards are always observed. For specific projects, the oil fraction can be recovered and re-used. Envisan already applied this technique several times, both on project sites and in its soil treatment centre in Ghent.


Borealis

Techniques for the separation and treatment of waste and material flows

Separation techniques

Envisan offers a wide range of separation techniques for the treatment and valorisation of waste and material flows. The installation that is available for specific projects or on a permanent basis includes, among others, (hydro)cyclones, sieves, spirals, centrifuges and decanters.   

Immobilisation techniques

Envisan has disposal of a set of injection and line mixers with which many different additives can be added to waste flows in an efficient manner.

Techniques for the rehabilitation of old dumpsites

Dumpsite redevelopment
Certain waste substances cannot be treated or processed. Therefore, Envisan also specialised itself in the design, construction and redevelopment of specific dumpsites. For remodelling and redeveloping old dumpsites Envisan can use the comprehensive range of machines of is mother company, Jan De Nul Group.


IMOG - Moen

Covering
Using several techniques, dumpsites of household and industrial waste can be safely developed and covered. Envisan has to this end an experienced team of foil welders among its staff who can work with all types of foil and clay liners. The new cover can be equipped with landfill gas recovery and valorisation systems. 

Enhanced Landfill Mining
With this technique, stored materials and energy from a landfill are recovered in as sustainable a way as possible, maximizing both the recycling of material and the production of energy.