Technology Proposals for Treatment Waste Sludge from Reverse Osmosis Leachate Treatment on the PWW Regional Sanitary Landfill in Jagodina

The main disadvantages of landfilling are: the need for a large space, due to the small reduction in the volume of waste, as well as the large negative impact of landfills on the environment. This negative impact is reflected in the creation of landfill gas consisting of greenhouse gases (carbon dioxide and methane) and leachate, which are formed by the passage of atmospheric precipitation through the body of the landfill and the leaching of various substances from waste, polluting them with various organic and inorganic materials. The quality of leachate is conditioned by physical, chemical and biological processes that take place in the body of the landfill. The composition of leachate depends on numerous factors: composition of waste, its pretreatment, process of stabilization and decomposition of waste at the landfill, height and age of disposed waste, filling technique and degree of waste compaction, weather and hydrological conditions at the site, etc., but regardless, leachate always contains extremely toxic and polluting substances. At sanitary landfills, leachate is collected by a leachate collection system and stored in a collection lagoon, where contaminants must be removed before leachate is discharged into the environment. Different methods are used for purification of leachate: use of aerated lagoons, evaporation, flocculation, reverse osmosis, adsorption, etc., but in order to reduce the concentration of pollutants to the permitted level, a combination of several methods is usually used. There is a regional sanitary landfill in the city of Jagodina, which was built and where waste is disposed of by the company PWW. Within the landfill there is also a collection lagoon for collecting leachate with a capacity of 4000 m3. Reverse osmosis is used as a method for purifying leachate. Waste sludge obtained as a by-product after leachate treatmentis a problem for the company PWW, because it contains pollutants that have an extremely negative impact on the environment, so additional treatment of this waste sludge is needed. On the other hand, waste sludge from water treatment plants is used worldwide in codigestion and co-incineration processes to obtain energy. The aim of this paper is to, based on available data on the quantities and composition of waste sludge generated by purification of leachate by reverse osmosis at the landfill in Jagodina, perform an analysis of proposed technologies for waste sludge treatment.