Light triggers green recovery: Boosted biomethane production from ammonia-stressed anaerobic digestion through optimized illuminated bioreactor
Light triggers green recovery: Boosted biomethane production from ammonia-stressed anaerobic digestion through optimized illuminated bioreactor
复制标题
DOI：
10.1016/j.cej.2022.138173
复制
发表时间：
2022-07
影响因子：
15.1
通讯作者：
Yunxin Zhu;Zhiyuan Liu;Cheng Zhang;J. Ming;Guoping Chen;Yingnan Yang
中科院分区：
文献类型：
--
作者：
Yunxin Zhu;Zhiyuan Liu;Cheng Zhang;J. Ming;Guoping Chen;Yingnan Yang
厌氧消化(AD)过程中产生的过量氨氮经常对垃圾生物转化为能源提出了巨大的挑战，这就需要可行的策略来提高其性能。因此，利用响应面方法(RSM)，设计了一种新型的光辅助生物反应器，用于增强氨应激的AD。提出的最佳光照条件(225W/m2,630min/d)与白炽灯照明相比，CH4产率(198±115mLCH4/g-DOC去除)是氨胁迫下暗反应器的两倍。这种光诱导增强在不同氨水平(2500-8000 mg/L)下都是可靠和适应的，表明它对各种富氨废物的处理是有效的。此外，在模拟太阳光照射(紫外线照射)下获得的相似性能也证实了太阳光利用的实际可行性。此外，所开发的生物反应器在2个多月的时间内表现出稳定和优越的转化效率，表明其长期运行的可持续性。其机理揭示了光照对氨胁迫厌氧菌的刺激作用，有效地调控了酶活性、功能微生物群和污泥性质，缓解了氨氮的抑制作用。产甲烷途径中的关键辅酶(遗传营养和乙酰营养)在光照下表达上调。同时，适当的光刺激使耐氨发酵类群(水解菌和产乙酸菌)多样化，它们与富含甲烷八叠球菌共同协作。在氨气压力下，富集型厌氧菌聚集成紧密的菌团，热力学上有利于污泥的电活性和疏水性，有利于合养生物转化。因此，提出的生物反应器将是一种很有前途的技术，可以解决氨抑制问题，实现太阳能集成的可持续垃圾生物转化。
Excess ammonia generated during anaerobic digestion (AD) often poses a great challenge on efficient waste-to-energy bioconversion, which requires feasible strategies to improve the performance. Herein, by response surface methodology (RSM), an innovative light-assisted bioreactor was designed for boosting ammonia-stressed AD. The proposed optimal light condition (225 W/m2with 63 min/day) with incandescent lighting boosted CH4yield (198 ± 15 mL CH4/g-DOCremoval), which was twofold of the dark reactor under ammonia stress. This light-induced enhancement was further found to be reliable and adaptive at different ammonia levels (2500–8000 mg/L), revealing its effectiveness for treating various ammonia-rich wastes. Additionally, the practical feasibility of sunlight utilization was confirmed by the similar performance obtained under simulated solar lighting (ultraviolet cut). Furthermore, the developed bioreactor exhibited a stable and superior conversion efficiency for 2 months, suggesting its sustainability for long-term operation. The mechanism insights revealed that light acted as stimulus on ammonia-stressed anaerobes, effectively regulated the enzyme activities, the functional microbiome, and the sludge properties to alleviate the ammonia inhibition. The critical coenzymes involved in methanogenic pathways (hydrogenotrophic and acetotrophic) were upregulated by light. Meanwhile, proper light stimulation diversified the ammonia-tolerant fermentative taxa (hydrolytic and acetogenic genera), which jointly collaborated with the enrichedMethanosarcina. Under ammonia pressure, those enriched anaerobes aggregated in compact clusters which thermodynamically favored the sludge electroactivity and hydrophobicity, and assisted the syntrophic bioconversion. Therefore, the proposed bioreactor would be a promising technique to solve ammonia inhibition and achieve the sustainable waste-to-energy bioconversion with solar integration.