Coupling self-sustaining air flotation screening with conventional CSTR enhances anaerobic biodegradability of corn stover.

The anaerobic biodegradability of lignocellulosic crop waste could be improved by proper pretreatments, but little information is available on enhancing straw digestibility through the reactor configuration. In a lab-based batch experiment, a novel reactor was established to testify the possibility to enhance anaerobic biodegradability of corn stover (CS) by coupling a self-sustaining air flotation screening (SAFS) unit with conventional continuous stirred tank reactor (CSTR). The SAFS-CSTR improved the maximum methane production by 14.27% with the duration of 16 d compared with the conventional CSTR for 20 d. The temporal and spatial distribution of basic indexes significantly differed from conventional CSTR. Elevated bacterial diversity and marked shifts in bacterial community composition were observed in different locations of reactor, with Bacteroidetes and Proteobacteria being the dominant phyla. SAFS unit would serve to separate inhibitors effectively and meanwhile enhance the mass-transfer efficiency, thus providing reference to upgrade or retrofit the conventional CSTR.