Optimization of phthalic acid batch biodegradation and the use of modified Richards model for modelling degradation

TY - JOUR

T1 - Optimization of phthalic acid batch biodegradation and the use of modified Richards model for modelling degradation

AU - Fan, Yanzhen

AU - Wang, Yingying

AU - Qian, Pei Yuan

AU - Gu, Ji Dong

N1 - Funding Information: Research was supported by Hong Kong Innovative Technology Fund (ITS/276/00) and RGC Central Allocation grant (CA00/01.Sco1). Additional financial support was from industrial partnership with Peako Engineering Co. and Kou Hing Hong Scientific Supplies. We thank the technical support of Jessie Lai.

PY - 2004

Y1 - 2004

N2 - Microbial degradation of phthalic acid was investigated using cultures of aerobic bacteria enriched from a sewage sludge. The Gompertz function and the Richards function were modified and compared to describe the phthalic acid (PA) degradation process, and both models successfully fitted the biomass growth curve when PA was used as the sole source of growth controlling substrate. However, the modified Richards model was superior in describing the depletion curve of PA. The additional parameter, m, in the modified Richards model may be corresponding to the relative importance of the substrate consumption for maintenance. Based on the maximum degradation rates calculated using the modified Richards model, the optimal degradation conditions were determined by an orthogonal test for environmental factors including initial pH, C:N:P ratio and salt concentrations of the culture medium. More than 99% of PA at an initial concentration of 4000 mg 1-1 was degraded within 5 days under the optimized condition: namely initial pH 6.0, C:N:P=100:5:1, and NaCl concentration 10 g l-1. Our results suggest that both substrate depletion and microbial biomass formation can be modelled and predicted using the modified Richards model and the limitation factor of phthalic acid degradation is the initial pH of the culture.

AB - Microbial degradation of phthalic acid was investigated using cultures of aerobic bacteria enriched from a sewage sludge. The Gompertz function and the Richards function were modified and compared to describe the phthalic acid (PA) degradation process, and both models successfully fitted the biomass growth curve when PA was used as the sole source of growth controlling substrate. However, the modified Richards model was superior in describing the depletion curve of PA. The additional parameter, m, in the modified Richards model may be corresponding to the relative importance of the substrate consumption for maintenance. Based on the maximum degradation rates calculated using the modified Richards model, the optimal degradation conditions were determined by an orthogonal test for environmental factors including initial pH, C:N:P ratio and salt concentrations of the culture medium. More than 99% of PA at an initial concentration of 4000 mg 1-1 was degraded within 5 days under the optimized condition: namely initial pH 6.0, C:N:P=100:5:1, and NaCl concentration 10 g l-1. Our results suggest that both substrate depletion and microbial biomass formation can be modelled and predicted using the modified Richards model and the limitation factor of phthalic acid degradation is the initial pH of the culture.

KW - Aerobic

KW - Degradation

KW - Gompertz model

KW - Phthalic acid

KW - Richards model

UR - http://www.scopus.com/inward/record.url?scp=0347627878&partnerID=8YFLogxK

U2 - 10.1016/j.ibiod.2003.10.001

DO - 10.1016/j.ibiod.2003.10.001

M3 - 文章

AN - SCOPUS:0347627878

SN - 0964-8305

VL - 53

SP - 57

EP - 63

JO - International Biodeterioration and Biodegradation

JF - International Biodeterioration and Biodegradation

IS - 1

ER -