Journal of Environmental Biology

Biological heat potential and temperature effect of an autothermal

thermophilic aerobic treatment (ATAT) system

 

Jui Min Hung¹, Chang Yu Chen², Fu Shih Huang¹ and Chih Jen Lu¹

Department of Environmental Engineering, National Chung Shing University, No. 250, Kuo-Kuang Road, 

Taichung City 402, Taiwan, Republic of China

²Department of Environmental Engineering, Hung Kuang University, No. 34, Chung-Chie Road, Sha-Lu Town,

Taichung County 433, Taiwan, Republic of China

(Received: August 13, 2007; Revised received: March 28, 2008; Accepted: April 10, 2008)

 

Abstract: This study focused on the evaluation of the specific biological heat potential (h_b) of a food-processing artificial wastewater in the autothermal thermophilic aerobic treatment (ATAT) system. A novel experimental method was developed to evaluate the h_b value by using the heat balance model under the steady state. This system was daily fed with oily and artificial wastewater at 21460 mg l^-1 COD. The sludge retention time (SRT) was controlled at 15 days.? The results showed that the average values of h_b were 3.25 to 3.63 kcal g^-1-COD-removed for the artificial wastewater. The values of true growth yield (Y₀) were 0.08 to 0.19 mg-MLSS mg^-1-COD for the food-processing wastewater at different temperatures. The COD removal efficiency was 77? to 91%, and it was decreased as temperature increased. But, the oil and grease (O and G) removal efficiency was 50? to 69%, and increased as temperature increased. These results might indicate that oil and grease become more soluble and accessible to microorganisms at high temperatures. The study indicated the temperature effect constant (?) of van?t Hoff-Arrhenius law was 0.958, which explained and showed typical characteristics in the low sludge yield of an ATAT process.

Key words: ATAT system; Temperature effect; Biological heat potential, Growth yield, Oily wastewater

 

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