Vol.:(0123456789) 1 3 International Journal of Environmental Science and Technology https://doi.org/10.1007/s13762-018-1780-1 ORIGINAL PAPER Pollution potential of the wastes of used oil treatment plants and their possible remediation techniques M. T. Jebeli 1  · N. Heidarzadeh 1  · S. Gitipour 2 Received: 19 May 2017 / Revised: 13 October 2017 / Accepted: 11 May 2018 © Islamic Azad University (IAU) 2018 Abstract In this research, wastes of used oil treatment plants have been studied for their pollution potential and geotechnical charac- teristics. A random sampling plan was used to collect 11 samples from the dump site. Moreover, statistical analysis indicated that six samples were required to prepare a representative sample for the wastes. Thus, a mixed sample was prepared to determine moisture content, pH, Atterberg limits and density of the waste. The analysis of organic compounds and heavy metals showed the presence of total petroleum hydrocarbons (TPH) and Barium as the main pollutants. The results also showed waste as a fne-grained soil heavily contaminated by petroleum hydrocarbons. The mean concentration of TPH was more than 216 g/kg, which is 832, 108 and 433 times greater than the acceptable cleanup levels for diesel range organics, oil range organics and TPH, respectively. Nevertheless, heavy metals concentrations are lower than proposed cleanup levels for industrial area. The moisture content, pH, liquid limit, plastic limit, plastic index and density of the mixed sample were 12.26%, 9.6, 25.91, 15.83, 10.08 and 1.22 g/cm 3 , respectively. After that, several remediation techniques were evaluated to propose the best one based on the physical and chemical properties of the waste, the applicability of the method and implementation costs. Finally, solidifcation/stabilization technique using organophilic clay as the stabilizer, incineration and bioremediation techniques was recommended for cleanup of the site. Keywords Total petroleum hydrocarbons · Heavy metals · Cleanup levels · Hydrocarbon-contaminated soil remediation Introduction Many amounts of used oils are annually produced in several activities such as internal combustion engines, automotive maintenance facilities, manufacturing companies, hydraulic plants and metal fnishing plants. The volume of the gener- ated used oils is about 1.3 billion gallons per year (Pich- tel 2005) and 300,000–350,000 t/y (Amiri et al. 2011) in the USA and Iran, respectively. Improper disposal of the used oils in the environment can contaminate soil, air, water resources, hence destroying plants and animals. Each gal- lon of used oil, the amount of oil used in each period of oil changing for a car, can contaminate one million gallons of clean water (Kajdas 2000). This amount of water is equal to 50 persons’ annual water need, 100-year period irrigation for a plant, or irrigation of a feld with an area of four hectares (Mohammadi and Ghorbani 2011). Six hundred tons of base oils can be reproduced from 1000 tons of used lubricant oils, while this amount has been produced from 6000 tons of crude oil. Oil production from base oil will reduce petro- leum consumption and environmental pollution, in addition to having economical advantages and forming the oil refn- ing industry in the world (Karimi and Soroush 2008). There are several methods of used oil recycling such as solvent extraction method (Mortier and Orszulik 2010) and Acid/Fuller’s earth method (UNEP 2002; Hamawand et al. 2013; Shri Kannan et al. 2014). The Acid/Fuller’s earth method is the oldest method of used oil recycling. This method is also the most widely used one in the world, especially in developing countries such as Iran. The main reasons of the attraction of the method are supporting a variety of conditions, simplicity of process and low investment (UNEP 2002). Due to large amount of acid sludge produced in the method and also its environmental Editorial responsibility: M. Abbaspour. * N. Heidarzadeh n.heidarzadeh@khu.ac.ir 1 Department of Civil Engineering, Technical and Engineering Faculty, Kharazmi University, Tehran, Iran 2 Faculty of Environment, University of Tehran, Tehran, Iran