Biomass fermentation provides a potential route toward the ecological disposal for the bauxite residue(BR)with high alkalinity issues.However,how to accelerate the remediation of the alkaline problem with a long-term ...Biomass fermentation provides a potential route toward the ecological disposal for the bauxite residue(BR)with high alkalinity issues.However,how to accelerate the remediation of the alkaline problem with a long-term durability is still a big challenge.Herein,we investigated the acceleration of the decomposition of straw toward organic acid species via a pyrolysis strategy as well as the pH stability during long-term dry-wet aging for the treated BR.The pH of pyrolytic BR at 300℃ is stabilized at around 8.90 after 70 days’dry-wet aging.During the aging,the main Ca-contained alkaline minerals of calcite and cancrinite are dissolved and the content of exchangeable Na+is reduced.This pyrolysis process can decompose straw quickly and produce more organic matters that are easily degraded to fulvic and humic acid as evidenced by 3D fluorescence spectrum analysis.Compared to the fermentation with straw under natural conditions,the alkalinity regulation of BR after pyrolysis is featured with shorter period and lower pH as well as long-term pH stability.Therefore,the synergistic pyrolysis of BR with straw provides an alternative method to address the alkaline issues,which is conducive to promoting the soil formation of BR.展开更多
基金supported by the National Natural Science Foundation of China(Nos.42030711,41877511)the Fundamental Research Funds for the Central Universities of Central South University。
文摘Biomass fermentation provides a potential route toward the ecological disposal for the bauxite residue(BR)with high alkalinity issues.However,how to accelerate the remediation of the alkaline problem with a long-term durability is still a big challenge.Herein,we investigated the acceleration of the decomposition of straw toward organic acid species via a pyrolysis strategy as well as the pH stability during long-term dry-wet aging for the treated BR.The pH of pyrolytic BR at 300℃ is stabilized at around 8.90 after 70 days’dry-wet aging.During the aging,the main Ca-contained alkaline minerals of calcite and cancrinite are dissolved and the content of exchangeable Na+is reduced.This pyrolysis process can decompose straw quickly and produce more organic matters that are easily degraded to fulvic and humic acid as evidenced by 3D fluorescence spectrum analysis.Compared to the fermentation with straw under natural conditions,the alkalinity regulation of BR after pyrolysis is featured with shorter period and lower pH as well as long-term pH stability.Therefore,the synergistic pyrolysis of BR with straw provides an alternative method to address the alkaline issues,which is conducive to promoting the soil formation of BR.
