Industrial oil wastewater treatment by free and immobilized Aspergillus niger KX759617 and the possibility of using it in crop irrigation Eman H. F. Abd El-Zaher 1 • Alaa M. Abou-Zeid 1 • Azza A. Mostafa 2 • Doaa M. Arif 1 Received: 16 January 2016 / Accepted: 24 October 2016 Ó Accademia Nazionale dei Lincei 2016 Abstract The current study indicated the ability of Aspergillus niger KX759617 in its free and immobilized form in chitosan and sodium alginate (calcium alginate) matrices to treat industrial oil wastewater. A. niger KX759617 possesses the ability to decrease oil and greases (O&G), chemical oxygen demand (COD), total dissolved solid (TDS) and electric conductivity (EC). The results showed that immobilized A. niger KX759617 on chitosan gave the highest removal rate of O&G and COD reaching 83 and 81%, respectively. Different factors affecting oil wastewater treatment by free and immobilized A. niger KX759617 were investigated. The immobilized A. niger KX759617 on Ca-alginate and chitosan had better ther- mostability compared to free A. niger KX759617. The optimum temperature for treatment of industrial oil wastewater was 32 °C. Also, it was found that different pH values had a pronounced effect on decrease of (O&G), (COD), (TDS) and (EC) at pH 6. These results suggested that immobilized A. niger KX759617 might be applicable to the oil wastewater treatment system. It was found that using chitosan with immobilized A. niger KX759617 for treatment oil and soap wastewater gave positive results on the irrigation of the Vicia faba plant, and the results were good and nearly similar to those from tap water. Keywords Aspergillus niger Á Oil wastewater Á Immobilization Á Chemical oxygen demand Á Oil and greases 1 Introduction After industrial development, it was found an increase in the amount of oil used and due to various technical and man- agement development that are not perfect and this make a lot of oil into the water, forming environmental pollution. Oily wastewater is generated in the oil industry: oil refining, oil storage, transportation and petrochemical industries in the production process. Oily soap wastewater pollution had a bad effect on drinking water and ground water resources, human health, make atmospheric pollution, affecting crop production and destructing the natural landscape because of coalescence of the oil burner safety issues that arise (Li et al. 2013). Oil and its derivative from oil manufacturing plants have received much attention because of their widespread use. Disposal of this wastewater into the environment causes serious problems due to its high oil content, chemical oxygen demand (COD) and color. Microbial degradation of oil wastewater is of concern in recent years. A variety of microorganisms, such as bacteria, molds and yeasts, have been shown to be capable of completely degrading oil wastewater (Dhouib et al. 2006; Ammar et al. 2005; Ettayebi et al. 2003; Kissi et al. 2001; Erguder et al. 2000). The use of native biomass (such as bacteria, yeast, fungi and algae) for degradation of toxic compounds in the freely suspended state is of limited effectiveness owing to the inherent disadvantages, such as small particle size, possible clogging and low mechanical strength of the biomass (Godjevargova et al. 2004). & Eman H. F. Abd El-Zaher eimanabdelzaher@science.tanta.edu.eg; eimanabdelzaher@yahoo.com 1 Botany Department, Faculty of Science, Tanta University, Tanta, Egypt 2 Biological and Environmental Department, Faculty of Home Economics, Al-Azhar University, Tanta, Egypt 123 Rend. Fis. Acc. Lincei DOI 10.1007/s12210-016-0578-7