Decentralised Composting Units
Decentralized composting facilities
The Decentralized Processing Unit will process pre-selected organic waste and prunings and will be of closed type technology (closed system) and will consist of the following individual processing units / departments:
- Entry Gate with truck scale for the registration and control of all incoming transport vehicles / garbage trucks as well as all vehicles in general.
- Administration Building: will be constructed to meet the needs of the project staff. It will include at least the following areas:
- Composter control room
- Staff room
- Sanitary facilities (WC)
- Warehouse
- Reception and pre-treatment area: This area will be the reception and pre-treatment area for incoming waste. The reception area will have a waterproof and impervious concrete floor with slopes to prevent drains from being channeled into the rest of the facility. Shredded green waste will also be deposited in this area and will be mixed on site with pre-selected organic matter. Next to the site, bins will be installed for depositing visible impurities. This waste will be removed manually, as soon as it is detected. Pre-selected organic and green waste will be mixed on site with the help of a loader and fed to the bioreactor.
- Biological treatment area: The biological processes will take place inside the bioreactor. The biological process takes place in aerobic cells (closed system), where the material remains for at least 12-16 weeks.
- Maturing Shelter: The shelter of the maturing square has an indicative area of 15-20m2 and a clear height of 6 m. The roof of the maturing square will be metallic. The maturing area will be compartmentalized in order to separate the maturing material. Also, it will be formed around the perimeter with “Π” shaped walls made of concrete and the floor will be made of concrete as well. The material will be left to mature for a minimum of 42 days (6 weeks) and will be stirred periodically with a loader to better stabilize the material.
- Refinery area: in this area there will be the required equipment (sieves) for refining the material to remove unwanted impurities. The rotary screen will have 20mm holes and the vibrating screen 10mm holes (hole openings and equipment arrangement are indicative).
- Finished product storage shed: The refined product will be stored in a covered area and there will be the possibility of storing compost in bulk for a short period of time.
- Fencing – entrance gate: Fencing will be necessary to demarcate the area of the composting unit as well as to prevent the entry of any unauthorized person. Indicatively, it is proposed to construct a fence made of iron stakes 2.50m high from the ground. A gate will be built at the entrance. This gate is proposed to be electrically controlled. The height of the gate will be 2m. The entrance will be illuminated at night, with lights hanging on the pillars.
- Truck scale: It is necessary to carry out continuous monitoring of the quantities of incoming bio-waste, both for statistical reasons, but also for essential reasons, which have to do with the orderly operation of the project. For the weighing of those entering the unit, but also for the weighing of the outgoing products, two weighbridges will be constructed at the entrance of the facilities, one in the entry stream and one in the exit stream of the vehicles.
- Car Parking Areas: For the proper operation of the facility, car parking areas will be constructed in various parts of the facility.
- Green Spaces: For the ultimate visual concealment of the space, perimeter tree planting will be developed alongside the fencing.
- Fire protection: All necessary measures are taken to minimize the effects of a fire.
- All the required networks will be built. Water supply, irrigation, firefighting, drainage, electricity networks.
- Internal road construction: The internal road construction is intended to serve the movement of garbage trucks and other operating and service vehicles of the unit. Both horizontal and vertical signage will be installed throughout the internal road network, since it is considered necessary to guide and inform employees and visitors.
Benefits of Decentralized composting facilities
- Transportation costs are lower
- Comparatively less maintenance costs
- Low level skills required
- Smaller facilities compared to Integrated Waste Management Facilities
- Higher quality compost since waste is efficiently separated and risks for contamination are minimized
- Final product ends in fields or parks as soil improver