Response surface methodology (RSM) analysis of organic acid production for Kaolin beneficiation by Aspergillus niger

摘要: Abstract In the present investigation, Aspergillus niger isolated from pistachio shell was applied to remove iron impurities an Iranian kaolin sample. order study effects of initial pH, sucrose and spore concentration on oxalic citric acid production, consequently dissolution, response surface methodology based a five-level, three-variable central composite design experiments employed. Three models were suggested predict values mentioned variables. The most important variables dissolution concentration, respectively. Also, highest 311.30 mg/l, obtained when pH 2, 70 g/l, 35 × 107 spore/l, represented removal 67.4% total contents clay.