Key Laboratory of Recycling and Eco-treatment of Waste Biomass of Zhejiang Province, School of Environmental and Natural Resources, Zhejiang University of Science and Technology, Hangzhou, 310023, China.
Environ Sci Pollut Res Int. 2022 Aug;29(40):60933-60944. doi: 10.1007/s11356-022-20177-2. Epub 2022 Apr 18.
Carbonized products of waste agricultural straws used for soil remediation can reduce impact of heavy metals on soil ecology and crop growth. Here, we demonstrated straw fermentation residues to be suitable for preparation of soil remediation agents by pyrolysis. Lignocellulose degradability of filamentous fungi during fermentation was found to significantly enhance properties of biochar for cadmium (Cd (II))-contaminated paddy soil remediation. Obtained biochars were indicated to have rich oxygen-containing groups, thus showing enhanced removal ability of Cd (II). Adsorption capacity of biochar (BaWS) prepared from wheat straw, which has been fermented by Trichoderma asperellum T-1, reached 105.9 mg g, 372.8% higher than that from natural wheat straw (BWS). Fermentation of straws by Trichoderma reesei QM6a can also improve the adsorption performance of biochar, but the effect is much weaker. The content of bioavailable Cd (II) in paddy soil reduced 83.7% within 15 days after addition of 1% BaWS. Significantly, adding 1% BaWS had better effect on increasing soil pH and removing available Cd (II) , than adding 3% BWS. These results suggest that the used dosage of microbial pretreated straw biochar for the remediation of Cd (II)-contaminated paddy soil was only 1/3 of that of conventional biochar. The enhanced property of biochar was attributed to deconstruction of straws by filamentous fungi before being pyrolyzed. Thus, fermented straws were indicated more suitable for the preparation of biochar used as effective soil remediation agents.
废弃农业秸秆碳化产物可降低重金属对土壤生态和作物生长的影响。在这里，我们证明了秸秆发酵残渣通过热解适合制备土壤修复剂。发现丝状真菌在发酵过程中对木质纤维素的降解能力显著提高了生物炭对镉（Cd（II））污染稻田土壤修复的性能。得到的生物炭表明含有丰富的含氧基团，因此表现出增强的 Cd（II）去除能力。由 Aspergillus niger T-1发酵的小麦秸秆制备的生物炭（BaWS）的吸附容量达到 105.9 mg g，比天然小麦秸秆（BWS）高 372.8%。里氏木霉 QM6a 发酵秸秆也可以提高生物炭的吸附性能，但效果要弱得多。添加 1% BaWS 可在 15 天内将稻田土壤中有效态 Cd（II）的含量降低 83.7%。显著的是，添加 1% BaWS 比添加 3% BWS 更有利于提高土壤 pH 值和去除有效态 Cd（II）。这些结果表明，用于修复 Cd（II）污染稻田土壤的微生物预处理秸秆生物炭的用量仅为常规生物炭的 1/3。生物炭性能的增强归因于丝状真菌在热解前对秸秆的解构。因此，发酵秸秆更适合制备用作有效土壤修复剂的生物炭。
