Int. J. Environment and Waste Management, Vol. 21, No. 1, 2018 37 Copyright © 2018 Inderscience Enterprises Ltd. Biodegradation of petroleum industry oily sludge and its application in land farming: a review Zahida Nasreen* and Sehrish Kalsoom Department of Biological Sciences, Sub Campus Mianwali, University of Sargodha, Pakistan Email: qureshi_1477@hotmail.com Email: sehrish.kalsoom1820@gmail.com *Corresponding author Abstract: One of the foremost solid wastes produced by petrochemical industries is oily sludge. Oily sludge being a mixture of various kinds of hydrocarbons has been characterised as a hazardous waste by Environment Protection Act and Hazardous Wastes Handling Rules which contributes a lot in environmental pollution. Polycyclic aromatic hydrocarbons (PAHs), which are components of crude oily sludge, represent serious environmental concerns, as most of them are mutagenic, cytotoxic and carcinogenic. Several methods for degradation of oily sludge and other petroleum related contaminants have been discussed in literature. This review paper presents the most efficient process of remediating these contaminants from environment, i.e., biodegradation by microorganisms. It is attaining significance as an increasingly efficient and potentially inexpensive cleanup strategy. Its potential contribution as a countermeasure biotechnology for decontamination of oil polluted systems could be vast, as it also leads towards mineralisation of complex organic compounds to simple compounds enhancing soil organic contents. So it can be concluded that biodegradation strategy of petroleum oily sludge, even with some limitations, have proved to be one of the most cost effective and promising technology with potential application in land farming. Keywords: oily sludge composition; toxicity; alkanes; poly aromatic hydrocarbons; PAHs biodegradation; microorganisms; biosurfactants and land farming. Reference to this paper should be made as follows: Nasreen, Z. and Kalsoom, S. (2018) ‘Biodegradation of petroleum industry oily sludge and its application in land farming: a review’, Int. J. Environment and Waste Management, Vol. 21, No. 1, pp.37–57. Biographical notes: Zahida Nasreen is a faculty in the area of biological sciences at the Sargodha University Sub Campus Mianwali. She obtained her PhD in Zoology from the Punjab University Lahore in 2013.Her research areas include various aspects of solid waste management such as composting and biofuel production. Sehrish Kalsoom is a student of BS Zoology at the Department of Biological Sciences, University of Sargodha, Sub campus Mianwali. Her research interests include waste management and environmental awareness/education.