Article

Aerobic digestion of starch wastewater in a fluidized bed bioreactor with low density biomass support.

Department of Chemical Engineering, Annamalai University, Annamalai Nagar, 608002 Tamil Nadu, India.
Journal of Hazardous Materials (Impact Factor: 3.93). 06/2007; 143(1-2):82-6. DOI: 10.1016/j.jhazmat.2006.08.071
Source: PubMed

ABSTRACT A solid-liquid-gas, multiphase, fluidized bed bioreactor with low density particles was used in this study to treat the high organic content starch industry wastewater. The characteristics of starch wastewater were studied. It shows high organic content and acidic nature. The performance of a three phase fluidized bed bioreactor with low density biomass support was studied under various average initial substrate concentrations, by varying COD values (2250, 4475, 6730 and 8910 mg/L) and for various hydraulic retention times (8, 16, 24, 32 and 40 h) based on COD removal efficiency. The optimum bed height for the maximum COD reduction was found to be 80 cm. Experiments were carried out in the bioreactor at an optimized bed height, after the formation of biofilm on the surface of low-density particles (density=870 kg/m(3)). Mixed culture obtained from the sludge, taken from starch industry effluent treatment plant, was used as the source for microorganisms. From the results it was observed that increase in initial substrate concentration leads to decrease in COD reduction and COD reduction increases with increase in hydraulic retention time. The optimum COD removal of 93.8% occurs at an initial substrate concentration of 2250 mg/L and for the hydraulic retention time of 24h.

1 Bookmark
 · 
517 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In this study, a biocarrier made up of low density polypropylene of surface area 524 mm2 per particle and of density 870 kg/m3 was used in the treatment of wastewater using fluidized bed reactor. Holdup studies are performed for bed heights (0.2 m to 0.8 m) to predict the operating conditions. The effect of Bed height (0.6 m to 1 m), Hydraulic retention time (6 hr to 40 hr), and superficial gas velocity (0.00106 m/s, 0.00159 m/s, 0.00212 m/s), Concentration (2 g/l – 7.5 g/l) on the percentage of COD reduction were studied. For bed height of 0.8m, optimum holdup and maximum COD reduction was obtained. From the results, it was observed that percentage of COD reduction increases as the superficial gas velocity increases and decreases as the initial concentration decreases. A COD reduction of 97.5% was achieved at an initial concentration of 2 g/l and for a superficial gas velocity of 0.00212 m/s at hydraulic retention time of 40 hr.
    Energy Procedia 07/2014; 50:214-221.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Hydrogen production from starch wastewater industry via up-flow anaerobic staged reactor was investigated. The reactor was operated at an average organic loading rate of 13.17 ± 8.35 g COD/L d and hydraulic retention time of 8 h. The reactor achieved chemical oxygen demand (COD) and carbohydrate removal efficiencies of 84 and 92%, respectively. The total volatile fatty acids increased from 58.5 ± 30.0 (influent) to 235.6 ± 190.8 mg/L in the treated effluent, indicating that acidogenesis bacteria were dominant in the reactor. The system achieved maximum hydrogen production rate (HPR) and hydrogen yield of 2.48 L H2/d and 8.8 mL H2/g CODremoved, respectively. Simulated model tracks the experimental data with a correlation coefficient (R2 = 0.893). Maximum substrate utilization rate (μmax,s) and maximum volumetric HPR (μmax,h) were calculated at different food to micro-organisms (F/M) ratios of 0.15, 0.31, 0.46, 0.62, and 0.93 g COD/g VSS. Results showed that μmax,s increased to −0.76 g COD/L h at F/M ratio of 0.46, and then remained relatively constant at a value of −0.68 g COD/L h. Similar trends were observed for HPR, where it peaked (μmax,h of 93.89 mL H2/h) at F/M ratio of 0.46.
    Desalination and water treatment 01/2014; 52(1-3):1-9. · 0.85 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In this study, a biocarrier made up of low density polypropylene of surface area 524 mm2 per particle and of density 870 kg/m3 was used in the treatment of wastewater using fluidized bed reactor. Holdup studies are performed for bed heights (0.2 m to 0.8 m) to predict the operating conditions. The effect of Bed height (0.6 m to 1 m), Hydraulic retention time (6 hr to 40 hr), and superficial gas velocity (0.00106 m/s, 0.00159 m/s, 0.00212 m/s), Concentration (2 g/l – 7.5 g/l) on the percentage of COD reduction were studied. For bed height of 0.8m, optimum holdup and maximum COD reduction was obtained. From the results, it was observed that percentage of COD reduction increases as the superficial gas velocity increases and decreases as the initial concentration decreases. A COD reduction of 97.5% was achieved at an initial concentration of 2 g/l and for a superficial gas velocity of 0.00212 m/s at hydraulic retention time of 40 hr.
    Energy Procedia 01/2014; 50:214–221.

Full-text (2 Sources)

View
56 Downloads
Available from
Jun 2, 2014