Aspergillus niger culture supernatant is used for bioleaching process. Before starting bioleaching process, fly ash was washed with distilled water. This removed 100 % sodium, 47 % (+/- 0.45) boron, 38.07 % (+/- 0.12) calcium, 29.89 % (+/- 0.78) magnesium, and 11.8 % (+/- 0.05) potassium. The pH was reduced from 10.5 to 8.5 after water washing. During bioleaching process, around 100 % metal removal was achieved in 4 h for all metals except chromium 93 % (+/- 1.18), nickel 83 % (+/- 0.32), arsenic 78 % (+/- 0.52), and lead 70 % (+/- 0.20). The process parameters including temperature, shaking speed, and solid/liquid ratio were optimized for bioleaching process. Experiments were conducted to evaluate effect of fly ash on growth of mung bean (Vigna radiata). At 20 g/100 ml fly ash concentration no germination of V. radiata seeds was observed. With an increasing concentration of untreated fly ash, a gradual decrease in root/shoot length was observed. After bioleaching process 78 % (+/- 0.19) germination of V. radiata was observed with 20 g/100 ml fly ash. This study will help to develop an efficient process to remove the toxic metals from fly ash.