Maximization of organic acids production by Aspergillus niger in a bubble column bioreactor for V and Ni recovery enhancement from power plant residual ash in spent-medium bioleaching experiments.

摘要: Spent-medium bioleaching of V and Ni from a power plant residual ash (PPR ash) was conducted using organic acids produced by Aspergillus niger. The production in bubble column bioreactor optimized through selecting three most influencing factors. Under optimum condition aeration rate 762.5(ml/min), sucrose concentration 101.9(g/l) inoculum size 40(ml/l), respectively 17,185, 4539, 1042 502(ppm) oxalic, gluconic, citric malic were produced. Leaching experiments carried out biogenic under leaching environment temperature 60°C rotary shaking speed 135rpm, with various pulp densities 1, 2, 3, 5, 7 9(%w/v). results showed that leached much more efficiently than so even at high density 9(%w/v), 83% recovered while recovery yield 30%.