Mesophilic condition is more conducive to methane production yield and tylosin removal on tylosin fermentation dreg anaerobic digestion

Abstract

Anaerobic digestion (AD) of antibiotic fermentation dreg is effective because of its satisfactory methanogenic performance and antibiotic removal rate. Thermophilic AD, an important branch, has not been studied. This study explored the effects of mesophilic and thermophilic AD on tylosin fermentation dreg (TFD) alone-digestion and co-digestion with food waste. The methane production (245–420 mL/g-VS) of mesophilic AD was 20.7%–28.6% higher than thermophilic AD, but the maximum methane production rate (RM), lag period (λ), and hydrolysis rate constant (kh) of thermophilic AD were 1.81, 0.236 and 3.16 times higher than those of mesophilic AD, respectively. However, the residual tylosin in mesophilic AD was always higher than that in thermophilic AD. The addition of food waste increased the methane production rate and yield under both temperature conditions. Therefore, due to the higher rate and yield of methane production, mesophilic AD, especially co-digestion, is more suitable for the treatment of TFD.