Ai Fuke, Zhang Yang, Fan Xiaoni, Li Yameng, Zhang Haorui, Jiao Yinggang, Zhang Quanguo, Yong Cheng, Zhao Jinfei, Petracchini Francesco, Paolini Valerio, Zhang Zhiping
Key Laboratory of New Materials and Facilities for Rural Renewable Energy, MOA of China, Henan Agricultural University, Zhengzhou, China.
Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing, China.
Front Bioeng Biotechnol. 2022 May 16;10:906968. doi: 10.3389/fbioe.2022.906968. eCollection 2022.
Clean- and high-value recovery and reuse of the residue of biohydrogen production (biohydrogen slurry) is an urgent problem to be solved. In this study, sodium alginate (SA) gel was used to concentrate nutrients quickly from biohydrogen slurry, which was prepared into gel microspheres (GMs), just like "capsule." The immobilization and release efficiency of conventional and reverse spherification were investigated. Better immobilization and release efficiency were detected under the conventional spherification method. The effect of GM sizes and concentrations of SA and calcium chloride (CaCl) was further studied in terms of sphericity factor, nutrient release, yield, encapsulation efficiency, and loading capacity. The best immobilization effect was obtained with a 1.6-mm syringe needle, 3.0 wt% SA, and 6 wt% CaCl, in which the sphericity factor, nitrogen release, yield, nitrogen encapsulation efficiency, and nitrogen loading capacity reached to 0.047, 96.20, 77.68, 38.37, and 0.0476%, respectively. This process not only avoids environmental pollution from biohydrogen slurry but also uses them at a high value as a fertilizer to nourish the soil. The feasibility of "slurry capsule" preparation will realize the clean recovery and reuse of biohydrogen slurry, which provides a new idea for ecological protection and carbon neutral goals and has important significance for sustainable development.
生物制氢残渣（生物制氢淤浆）的清洁与高值回收利用是亟待解决的问题。本研究采用海藻酸钠（SA）凝胶快速从生物制氢淤浆中浓缩养分，将其制备成凝胶微球（GMs），宛如“胶囊”。考察了常规法和反相法制备凝胶微球的固定化及释放效率。结果表明，常规法具有更好的固定化及释放效率。进一步研究了凝胶微球尺寸、海藻酸钠和氯化钙（CaCl）浓度对球形因子、养分释放、产率、包封率和载药量的影响。采用1.6 mm注射器针头、3.0 wt%海藻酸钠和6 wt%氯化钙时固定化效果最佳，此时球形因子、氮素释放率、产率、氮素包封率和氮素载药量分别达到0.047、96.20、77.68、38.37和0.0476%。该工艺不仅避免了生物制氢淤浆对环境的污染，还将其作为肥料高值利用滋养土壤。“淤浆胶囊”制备的可行性将实现生物制氢淤浆的清洁回收与再利用，为生态保护和碳中和目标提供新思路，对可持续发展具有重要意义。
