Industrial wastes treatment
1. Dehydration of industrial waste
Pumpable sludge is, without doubt, one of the most complex groundmasses to manage from a technical as well as cost point of view, as their treatment requires specialised equipment. Ecomed’s mechanical dehydration systems offer a flexible, modular solution designed for the volumetric reduction of sludge which substantially reduces the volume of waste to be disposed of.
At the same time, the removal or the chemical stabilisation of the main contaminants contained in the sludge can be carried out also facilitating disposal.
Ecomed owns numerous flexible, modular systems for the treatment of waste, all of which are quick to rig up in every situation; the technology used allows the treatment of a wide range of materials, guaranteeing:
- simplicity of operation, making the service offered trustworthy;
- flexibility and adaptability to different environmental situations, unparalleled by other similar systems;
- higher sludge dryness percentages than those achieved by other treatment systems (e.g. band presses or centrifuges), minimizing the disposal costs of the dehydrated panel.
The intrinsic flexibility of the systems allows them to be used alongside other types of available systems, if necessary integrating the treatment of pumpable sludge with the subsequent finishing of the refluent rather than with the solidification-stabilisation of the panel. In particular, the treatment process for refluents can be boosted to allow the re-use of water as processing fluid, rather than discharging it into sewers or a surface waterway. Ecomed systems can all be equipped with extractor units for gaseous emissions which allow the systems to be used in all environments also when dealing with treatments which can produce, if not managed correctly, environmentally damaging by-products in the treatment area. The captured vapour and gas are scrubbed before release into the air guaranteeing conformity with current relevant regulations.
The treatment process
The process applied is a chemical/physical treatment for the flocculation of the sludge in order to destabilise it and render it easy to dehydrate by filter press, and a mechanical dehydration treatment by filter press. Therefore, chemical additives are added carefully and correctly for the destabilisation of the suspensions, the precipitation of the micro-pollutants as insoluble salts and the flocculation of solids, to improve their separation from the aqueous phase.
The treatment phases are:
- Dosage of chemical reagents for the destabilisation of suspensions and the precipitation of pollutants in solution.
- Dosage of chemical reagents for flocculation of solids and subsequent separation from the aqueous phase.
- Mechanical dehydration by plate filter press.
Bearing in mind the extensive flexibility and modularity of the systems, a standard installation includes:
- Pumping and sludge screening station, composed of an extraction system from the storage tanks (single screw) and a system of preliminary screen cleaning;
- Sludge conditioning station, made up of an electric control panel, chemical storage tanks, dosage pumps, sludge conditioning tank with level measuring device and Ph sensor, slow-turning agitators, decanting pump (exit pump for conditioned sludge);
- System for the storage, preparation and dosage of lime milk from the hydrated lime storage silo, dosage spiral, metal frame tank for holding powders, lime milk release pump;
- Sludge dehydration station, composed of a supply tank for the filter press, supply pump, plate filter press, and extraction spiral for the filter pressed panel.
2. Inertisation of industrial waste
This systems can satisfy various requirements using the following equipment, which has:
- a variable treatment capacity from 15 to 100 ton/h;
- are designed for the treatment of pumpable sludge, shovelable sludge, soil and solid waste;
- allow the dosage of both powder reagents (either in sacks or loose) or liquid reagents, at the precise levels required by the process.
Ecomed’s plants are equipped with extractor units for gaseous emissions which allow the systems to be used in all environments, also when dealing with treatments which can produce, if not managed correctly, environmentally damaging by-products within the treatment area. The captured vapour gases are scrubbed before release into the air guaranteeing conformity with current relevant regulations.
The treatment process
The inertisation process allows waste which would otherwise be critical because of its consistency and/or its chemical/physical characteristics (solidification), to be moved and to inhibit the release of contaminants (stabilisation).
These two mechanisms together transform the waste into an easily moveable solid, with a limited surface area exposed to the surrounding environment and where the contaminants are sealed internally, blocked in insoluble compounds. This last phase allows a more cost-effective disposal of the lower categories of waste at disposal sites.
The two phases can be further developed, either together or individually, by the controlled addition of polymers, water binders and amendants.
The solidification process technology varies but the main differences relate to the type of additives used. These are based on concrete or lime (oxide or hydroxide), thermoplastic materials, organic polymers and amendants. The use of fixed additives triggers specific physical (encapsulation of contaminants) or chemical (polymerisation and adsorption/ disadsorption) mechanisms, or even a combination of the two.
