Industrial oil wastewater treatment by free and immobilized Aspergillus niger KX759617 and the possibility of using it in crop irrigation

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 thermostability 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.