Soil contamination by waste transformer oil: A review

Soil pollution is the environmental problem globally as it affects the growth of plants and genetic variation. Waste transformer oil (WTO) belongs to the class of waste oils when the properties of transformer oil degraded during operation due to mechanical and electrical stresses occur in the transformer. When WTO is disposed of in landfills, the toxic substances such as PAHs, PCBs, heavy metals present in WTO get mixed with soil and increase the hydrocarbons and CO2 in the soil which results in degradation of soil quality. Heavy metals present in WTO change the activity and composition of soil microbial communities. These pollutants from soil then go into the plants and causes adverse effect on human and other living beings. Recycling and reuse of WTO can reduce the harmful effects on soil. Waste transformer oil can be used as an alternative fuel since fossil fuel reserves decreasing day by day and WTO has some properties which are similar to diesel fuel. It can also be used to produce grease and also as a base for lubricant composition for drilling muds.