Utilization of green waste arising in Soroksár public area and SZIE Experimental farm
– Case study, Hungary –
Waste management tasks
n the Budapest region waste management tasks (eg. hazardous, non-hazardous solid and liquid waste treatment, disposal) are provided by the public service, FKF Zrt. Thus two fields remain in the responsibility of municipalities, illegal dumping prevention and the management of green waste generated at public places.
In addition to the national waste management concept, Budapest has its own waste management concept, however it is not broken down by district level. Thus it is centralized, it cannot fully serve the local features.
Problem definition
Legislation – the actual knowledge and technology are not in harmony with the legal opportunities and market potentials (there is sufficient knowledge background, but green waste management is not adequately supported by the legal background, it is not sufficiently concerned as useful material, too much restrictions, the widely spread fertilizers pull back the agricultural utilization of the compost products.
Goals
Assessment of the district
Illegal dumping is a problem in all the districts. However, Soroksár has a special characteristic, it has one of the largest green area in the capital. Consisting of 95% garden area of the district’s territory, maintaining public parks, streets and the riverside of the Danube, the Municipality of Soroksár has to manage significant green-waste. Ongoing agricultural activites are also carried out in the district. A Research and Experimental Farm of Szent István University is located in Soroskár, which has a long-term professional experience of horticulture and carries on horticultural activities.
Therefore, our field of interest is green waste management. Currently, this activity is carried out by an external company (disposal, landfill – we have no information about the further recovery or reuse). As a matter of fact, today this valuable resource is lost for the Municipality.
Project plan of Soroksár
Today in Soroksár 900 tons of green waste is generated at public places a year, which is not sufficient for self-composting, in addition the moisture and organic matter content of the green waste varies with the seasons. So we contacted the local authorities of the neighboring districts, who are struggling with similar problems. Together with the 4 neighboring districts the annual amount of green waste generated at public places is approximately 9 000 tons, which can be a good basis for creating a subregional composting plant.
Nyíregyháza, meeting with experts
Since our field of interest is green waste management, we were looking forward to seeing similar project ideas and management technologies of our partners in the Wastecosmart project. We also had to look at our own conditions, regarding the amount of available green waste and other additives, transporting possibilities, thereby rationalizing the costs of waste management.
Another unresolved issue is the appropriate disposal of sewage sludge generated by the treatment of liquid waste. There are difficulties with the placement of the remaining waste still containing significant organic material after the biogas recovery. Nevertheless this material is perfect for green waste management; it is used as composting additive.
We visited similar projects and technologies in Hungary as well. In these locations composting methods are used based on the local conditions and technological options.
Nyíregyháza site visit May, 2015
Two composting process take place at Nyíregyháza. One of them proceeds with a closed composting system technology treating sewage sludge mixed with straw. The other one treats green household waste by open air composting where the compost maturation process takes much longer.
Gödöllő composting site
On Gödöllő site, the management of green waste and organic household waste is carried out by a semi-permeable cover (GORE Cover technology) thus reducing the odor impact as well.
Sewage sludge disposal site in Csomád
The area used to be a sewage sludge disposal site, the basic infrastructure was available, such as leachate drainage and collection, pretreatment and special machines. Thus, under the right conditions, they could develop a composting process of sewage sludge. The site could accommodate 70 000 m³ of sewage sludge from the waste water treatment plant of northern Budapest. Today, the compost product is only used for energy purposes from this year, power plants located nearby are taking over virtually unlimited quantities. Production of compost for agricultural purposes is not happening at the moment. (70% dry matter content should be the power plant, 40% is needed for the agriculture)
Wastewater treatment plant of southern Budapest
The central wastewater treatment plant of the southern part of Budapest is connected to our district’s area. We contacted the operator of the plant, who could not only guarantee the necessary sewage sludge for our composting project, but also offered the required space for our project activity within the area of the treatment plant. This way transporting costs can be significantly reduced, which improves selling opportunities of the compost product.
Project plan of Soroksár II.
ccordingly, we had to determine what technology is to be chosen, and for what purpose the obtained product can be utilized for.
The proposed technology is based on a continuous active composting in the 12 months of the year, in which conditionalities providing the highest composting qualities are continuously controlled and directed (oxygen, temperature, nutrients, moisture content).
Together with external experts we conducted preliminary calculations on what other costs have to be taken into account in case of managing the green waste collected from the public places of the 5 districts, on the assets and human resources required and found a possible investment cost based on them.
25 000 tons of compost product can be produced mixed with other substances (manure, sewage sludge).
Return of investment 3-5 years
Needed space: approx. 5000 m2 (production hall, road for dumping, social room…etc)
Employment: 12-15 persons (12 months a year)
Estimated investment (without machines, assets): 470 million HUF
Machines, assets: 570 million HUF
Collection and transportation can be switched to the technology, as part of the waste stream process, as well as to promote awareness-raising.