© by PSP Volume 25 – No. 6/2016, pages 1877-1882 Fresenius Environmental Bulletin 1877 THE TECHNOLOGICAL PROCESS OF SOLIDIFICATION FOR THE TREATMENT OF HAZARDOUS WASTE Sonja Ketin 1 , Predrag Dasic 2,4 , Slobodan Neskovic 3 , Boban Kostic 3 , Rade Biocanin 5 1 University of Novi Sad, Faculty of Technical Science, Environmental Engineering, Trg Dositeja Obradovica 6, Novi Sad, Serbia 2 High Technical Mechanical School for Professional Studies, Radoja Krstića Street No. 19, 37240 Trstenik, Serbia 3 University of Novi Sad, University of Business Academy, Cvecarska 2, Novi Sad, Serbia 4 SaTCIP Publisher Ltd., Trzni Centar Pijaca 101, 36210 Vrnjacka Banja, Serbia 5 State University of Novi Pazar, Vuka Karadzica bb, Novi Pazar, Serbia ABSTRACT This paper presents the technological process of solidification for the treatment of hazardous waste in Petrochemical plant. The treatment is based on the technological process of physical and chemical reactions of waste mixtures with additives on the basis of calcium and obtaining a reaction product as a solid inert powder (solidificate). The technological process is carried out in terms of exothermic molecular encapsulation. KEY WORD: solidification, hazardous waste, sludge, treatment INTRODUCTION Several methods of biological sludge processing are in application (inorganic and flotation sludge according to their characteristics can be treated only by dehydration):  conventional aerobic sludge stabilization and dehydration  exothermic aerobic sludge stabilization and dehydration  anaerobic sludge treatment in two-stage digesters with a mesophilic enzymatic reaction in the primary digester and sludge dehydration  anaerobic sludge treatment in two-stage digesters and dehydration  anaerobic treatment of sludge in the contactor digester with the mesophilic enzymatic reaction of sludge and then dehydration of the sludge  dehydration of unprocessed - raw sludge and stabilization, solidification or incineration. Conventional aerobic sludge stabilization and dehydration. This procedure requires large investments (large pool for sludge), and the power consumption is very high. Exothermic aerobic sludge stabilization and dehydration. This procedure is often used. As the operating temperatures of the stabilization process are higher (auto ignition of the sludge), retention time is less and relatively small pools for sludge are needed, and the power consumption is a significantly lower. Until now, this procedure was used for municipal sludge. Anaerobic sludge treatment. The Anaerobic method is good and acceptable, but is not applicable in Petrochemicals due to the presence of heavy metals in biological sludge that can act as inhibitors. Dehydration of unprocessed - raw biological sludge, stabilization, solidification or incineration. Sludge dehydration is theoretically possible in the following ways:  with belt filter presses  with chamber filter presses  with vacuum filters  with centrifuges of the decanter [1-3]. MATERIALS AND METHODS DESCRIPTION OF TECHNOLOGICAL PROCESS OF WATER TREATMENT PLANTS IN PETROCHEMICALS Factory for water treatment in HIP- Petrochemicals is designed to accept and process wastewater from manufacturing plants of petrochemical complex and Oil Refinery. The wastewater passes through pretreatment processes contained within manufacturing plants that have the role of removing the dominant characteristic pollutants. The role of pretreatment at each facility consists in the fact that specific pollution is removed entirely or to a degree that allows adequate quality treatment in the primary and secondary phase in the plant for water treatment. Pretreatment is of great importance because certain flows are toxic, others contain high mineral oil or additives of inorganic substances whose presence