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15:19
Development of Sulfidogenic Sludge from Marine Sediments and Trichloroethylene Reduction in an Upflow Anaerobic Sludge Blanket Reactor
Published on: October 15, 2015
Evaluation of substrate removal kinetics for UASB reactors treating chlorinated ethanes
Debolina Basu1, Shyam R Asolekar
1Centre for Environmental Science and Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India. debolina.basu@gmail.com
Environmental Science and Pollution Research International
|January 31, 2012
Summary
This study investigated upflow anaerobic sludge blanket reactors for treating chlorinated ethanes. The Grau second-order model accurately predicted reactor performance, showing optimal removal at hydraulic retention times above 24 hours.
Area of Science:
- Environmental Engineering
- Biotechnology
- Wastewater Treatment
Background:
- Hazardous chlorinated ethanes like 1,1,2-trichloroethane (TCA) and 1,1,2,2-tetrachloroethane (TeCA) pose environmental risks.
- Anaerobic treatment of such pollutants in upflow anaerobic sludge blanket (UASB) reactors requires further investigation.
- Understanding substrate removal kinetics is crucial for optimizing UASB reactor performance.
Purpose of the Study:
- To quantify the behavior of UASB reactors treating wastewaters contaminated with TCA and TeCA.
- To predict the performance of these reactors based on overall organic substrate removal.
- To evaluate the suitability of different kinetic models for describing the treatment process.
Main Methods:
- UASB reactors (R2 for TCA, R3 for TeCA) were operated at varying hydraulic retention times (HRTs) from 12 to 36 hours.
- Food-to-mass ratios ranged from 0.2 to 0.7 mg COD/mg VSS/day.
- Substrate utilization kinetics were modeled using first-order, Grau second-order, and Michaelis-Menten models.
Main Results:
- Reduced COD removal efficiencies and increased effluent pollutant concentrations were observed when HRT was lowered below 24 hours.
- The Grau second-order model demonstrated a strong fit (R² > 0.95) for substrate utilization kinetics.
- Grau second-order substrate removal constants (K₂) were determined as 1.12 day⁻¹ for R2 and 7.53 day⁻¹ for R3.
Conclusions:
- The Grau second-order kinetic model is suitable for predicting UASB reactor performance in treating chlorinated ethanes.
- Optimal reactor performance for TCA and TeCA removal is achieved at HRTs above 24 hours.
- This kinetic model aids in understanding and managing anaerobic treatment of hazardous chlorinated ethanes.
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