Impact of cultivation conditions on olive mill wastewater pretreatment by means of Aspergillus niger van Tieghem

Abstract

An Aspergillus niger van Tieghem strain was used to treat olive mill wastewater (OMW) in an investigation aimed at exploring their dephenolization and discoloration ability and, consequently, the feasibility of using this strains in a pretreatment step in the processing of OMW. The results show that a peak COD reduction of 76% was reached at 28°C after 8 days with the following conditions: 4.57 initial pH, 0.5 g/l inoculums size, 3.4 g/l (NH₄)₂SO₄, 1.2 g/l KH₂PO_4, and 2.0 g/l NaCl. We conclude that A. niger could be effectively used in the pretreatment step of a combined aerobic/anaerobic process to solve the environmental problems caused by OMW in Mediterranean countries.

Keywords:

• Aspergillus niger van Tieghem
• OMW
• Phenolic compounds
• Pretreatment
• COD