Preservation of mesophilic mixed culture for anaerobic palm oil mill effluent treatment by convective drying methods

ABSTRACT

While anaerobic digestion is a reliable method that treats the waste and produces renewable biomethane fuel, the necessary sludge in liquid form is difficult to handle due to the constant biogas generation. Therefore, this study investigates the possibility of convective air drying, namely heat pump and hot air circulation oven as preservation methods for anaerobic microbial sludge. Drying was conducted at various temperatures, ranging from 22 to 70°C. The study found that heat pump drying at 22°C resulted in highest chemical oxygen demand removal of 55.3% as well as the least log reduction in methanogens and anaerobes at 1.4 and 2.4, respectively.

KEYWORDS:

• Chemical oxygen demand
• drying kinetic
• heat pump drying
• hot air circulation oven
• log reduction
• methane yield

Additional information

Funding

The authors would like to acknowledge Ministry of Science, Technology and Innovation (MOSTI) e-Science Fund (03-02-10-SF0122) for the financial support to this project.