Application of a 2-step process for the biological treatment of sulfidic spent caustics

作者：de Graaff Marco^*; Klok Johannes B M; Bijmans Martijn F M; Muyzer Gerard; Janssen Albert J H

来源：Water Research, 2012, 46(3): 723-730.

DOI：10.1016/j.watres.2011.11.044

• Spent caustics
• Haloalkaliphilic
• Sulfide oxidation
• Bioreactor modeling
• Thioalkalivibrio

This research demonstrates the feasibility and advantages of a 2-step process for the biological treatment of sulfidic spent caustics under halo-alkaline conditions (i.e. pH 9.5; Na+ = 0.8 M). Experiments with synthetically prepared solutions were performed in a continuously fed system consisting of two gas-lift reactors in series operated at aerobic conditions at 35 degrees C. The detoxification of sulfide to thiosulfate in the first step allowed the successful biological treatment of total-S loading rates up to 33 mmol L-1 day(-1). In the second, biological step, the remaining sulfide and thiosulfate was completely converted to sulfate by haloalkaliphilic sulfide oxidizing bacteria. Mathematical modeling of the 2-step process shows that under the prevailing conditions an optimal reactor configuration consists of 40% %26apos;abiotic%26apos; and 60% %26apos;biological%26apos; volume, whilst the total reactor volume is 22% smaller than for the 1-step process.

• 出版日期2012-3-1