The choice of method for dealing with sediment depends on their properties. The proceedings leading to the natural use is possible only if the sediment is suitable bacteriological and parasitological characteristics and does not contain excessive amounts of heavy metals.
Raw divisional organic sediments in wastewater treatment plants (sludge and sludge after preliminary biological treatment) are dangerous sanitary, because they contain pathogenic bacteria, viruses, and parasites. These deposits have the ability to zagniwania, ie anaerobic decomposition of organic compounds, which is always associated with the secretion of very unpleasant and annoying odors. Sediments are an important raw threat to the environment and their stabilization is needed.
Stabilization of the chemical composition of sludge can be carried out in the processes of biological, chemical or thermal.
During the stabilization of sediments are changes in the content of the liquid occurs because hydrolysis and decomposition of solids, changes in content and properties of solids (sludge particles) and changes in the amount of dissolved gases.
Stabilized sludges are subjected to dewatering to reduce their volume.
Finally, sludge management depends on the bacteriological and parasitological characteristics and heavy metal content. If they comply with the requirements, the sludge can be applied to natural or agricultural purposes. If the reason for the difficulty of fitting natural or agricultural sediment characteristics are its bacteriological or parasitological, it is possible to apply sludge hygienization quicklime, which is essentially a chemical stabilization process. If the concentration of heavy metals in the sediment exceed acceptable standards, it is the only treatment of its exports to the landfill area. It is recommended that removal of sludge after dewatering to reduce export costs.
