An Estimate of Energy Available via Microbial Sulfate Reduction at a Quaternary Aquifer in Northern Japan considered for Low Temperature Thermal Energy Storage

Water

Seiichiro Ioka¹ 

关键词: energy availability;    microbial sulfate reduction;    low temperature thermal storage;    Quaternary aquifer;    northern Japan;   

DOI  :  10.3390/w6040858

来源: mdpi

【 摘 要 】

The energy available via microbial sulfate reduction was estimated for a Quaternary aquifer in northern Japan that is a candidate site for low temperature aquifer thermal energy storage. In evaluating whether microbial sulfate reduction proceeded or ceased, it was assumed that electron donor/acceptor concentrations were unchanged by temperature increase. The estimated energy availability via microbial sulfate reduction at 9 °C with no thermal disturbance was 37, 51, and 53 kJ·(mol SO₄²⁻)⁻¹. The low estimate of 37 kJ·(mol SO₄²⁻)⁻¹ was attributed to low concentration of SO₄²⁻. Excluding the sampling site with low concentration of electron acceptors, energy availability was estimated 52 and 54 kJ·(mol SO₄²⁻)⁻¹ at 20 °C; 54 and 57 kJ·(mol SO₄²⁻)⁻¹ at 40 °C; and 57 and 59 kJ·(mol SO₄²⁻)⁻¹ at 60 °C. These results indicate that possible energy availability via microbial sulfate reduction at approximately 40–60 °C exceeded the range of available energy (compiled from previous studies) at which sulfate reduction would cease. Thus, microbial sulfate reduction at this site may proceed at approximately 40–60 °C.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.