Journal of Environmental Biology

Evaluation of specific biological heat potential of oily wastewater in an autothermal thermophilic aerobic treatment system

 

Jui Min Hung¹, Chang Yu Chen², Yeong Shing Wu³ and Chih Jen Lu*¹

 

¹Department of Environmental Engineering, National Chung Shing University - 402, Taiwan

²Department of Environmental Engineering, Hung Kuang University - 433, Taiwan

³Sinotech Engineering Consultants, Inc. Environmental Engineering Research Center - 105, Taiwan

 

(Received: October 17, 2006; Revised received: May 26, 2007; Accepted: June 10, 2007)

 

Abstract: This study focuses on the specific biological heat potential (h_b) of oil and grease wastewater in an autothermal thermophilic aerobic treatment (ATAT) system. A novel experimental device was applied to evaluate h_b by using heat balance model under steady state. In the study, the treatment system was daily fed with realistic and artificial wastewater at 11250 and 17420 mg COD l^-1, respectively. The wastewater was rich in oil and grease at 1220 and 600 mg l^-1, respectively.? The sludge retention time (SRT) was controlled at 5 days. The results showed that the average values of h_b were 3.7 and 3.1 kcal g^-1 COD removed and the true growth yield (Y₀) were 0.10 and 0.13 mg MLSS mg^-1 COD for realistic and artificial wastewater, respectively. These two systems could maintain reactor operating temperatures at 43 ^oC and 48^oC, respectively. The COD removal efficiency was as high as 90 to 97%. The oil and grease reduction was 68 to 72%. The high organic matter removal capacity and low sludge yield of ATAT process have been demonstrated.

 

Key words:??? Autothermal thermophilic aerobic treatment (ATAT), Specific biological heat potential, Oil and grease wastewater

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