Decolourization of anaerobically digested and polyaluminium chloride treated distillery spentwash in a fungal stirred tank aerobic reactor

Abstract

Decolourization of anaerobically digested and polyaluminium chloride treated distillery spentwash was studied in a fungal stirred tank aerobic reactor without dilution of wastewater. Aspergillus niger isolate IITB-V8 was used as the fungal inoculum. The main objectives of the study were to optimize the stirrer speed for achieving maximum decolourization and to determine the kinetic parameters. A mathematical model was developed to describe the batch culture kinetics. Volumetric oxygen transfer coefficient (k (L) a) was obtained using dynamic method. The maximum specific growth rate and growth yield of fungus were determined using Logistic equation and using Luedeking-Piret equation. 150 rpm was found to be optimum stirrer speed for overall decolourization of 87%. At the optimum stirrer speed, volumetric oxygen transfer coefficient (k (L) a) was 0.4957 min(-1) and the maximum specific growth rate of fungus was 0.224 h(-1). The values of yield coefficient (Y ( x/s)) and maintenance coefficient (m (s)) were found to be 0.48 g cells (g substrate)(-1) and 0.015 g substrate (g cells)(-1) h(-1).

Decolourization of Polyaluminium Chloride and Fungal Sequencing Batch Aerobic Reactor Treated Molasses Spentwash by Ozone

“…Physical treatment like coagulation with Polyaluminium chloride(PAC) is also very effective in decolourization of DSW [5]. In the earlier studies by the authors, digested spentwash(DSW) was pretreated with polyaluminium chloride and fungal decolourization in a fungal sequencing batch aerobic reactor(FSBAR) was performed [6,7]. The total decolourization obtained after fungal treatment of PAC treated DSW was 87%.…”