Impacts of Surfactant on Bituminous Coal Biosolubilization by White-Rot Fungi Hypocrea lixii HN-1

Abstract

Biosolubilization of coal to produce non-fuel products (humic acid) has offered an alternative method for coal clean utilization. Previous studies have proved pretreating low-rank coal with surfactant can improve fugal biosolubilization. However, limited reports referred high-rank coal. In the present work, a fungus HN-1 isolated from Yanzhou coal mine soil in Shandong province, northeast China was used to biodegrade Shandong bituminous coal, and the possible degrading mechanism was analyzed. The results showed that the homology of HN-1 was 97% with the white-rot fungus Hypocrea lixii, so it was assigned as Hypocrea lixii HN-1. The fungal strain HN-1 had the ability to solubilize the bituminous coal to produce black droplets within 10 days. Furthermore, it appeared that pretreatment by the surfactant sodium dodecyl sulfate could promote coal biosolubilization. The weight losses after biosolubilization of raw coal (YM) and surfactant-treated coal (A coal) were 11.33% and 14.02%, while the humic acid of YM and A coal increased by 1.42% and 2.99%, respectively. The FT-IR showed that the raw coal almost remained unchanged after biosolubilization. However, some small molecule functional groups including disulfides, amino groups, hydroxyl groups and oxygen-containing were introduced into the coal after pretreatment with surfactant.