Shock loads change the resistance, resiliency, and productivity of anaerobic Co-digestion of municipal sludge and fats, oils, and greases
Shock loads change the resistance, resiliency, and productivity of anaerobic Co-digestion of municipal sludge and fats, oils, and greases
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DOI：
10.1016/j.jclepro.2022.132447
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发表时间：
2022-05
影响因子：
11.1
通讯作者：
A. Berninghaus;T. Radniecki
中科院分区：
文献类型：
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作者：
A. Berninghaus;T. Radniecki
意外的有机过载(冲击负荷)是脂肪、油和油脂厌氧共消化(雾)失败的常见原因。尽管如此，关于冲击负荷如何改变厌氧消化器的沼气生产率和对未来有机负荷的反应的问题仍然存在。为了解决这一知识差距，这项研究利用OLR或冲击负荷的短暂增加，使一个反应器适应雾化共消化，并将其反应与在类似有机负荷下测试的非适应消化器的反应进行比较。还进行了一项长期研究，其中采用了顺序冲击事件和干扰到故障事件(有机负荷率从2.5到9.0微克vs/L/d)来研究它们对反应堆稳定性和性能的影响。当暴露在中等和较大冲击负荷(分别为3.0和9.0微克vs/L/d)时，先前暴露在雾冲击负荷下的厌氧消化池具有更高的阻力和弹性。对于中度冲击，非适应性反应器分别比适应性反应器多花29.8天、43天、44天和19天才能恢复到基线水平的甲烷含量、有机酸(OA)、pH和mcrA浓度。对于较大的激波，改进型和非改进型反应堆的恢复时间更接近，非改进型反应堆需要比改进型反应堆多11天、18天、19天和0天才能分别恢复到甲烷含量、OA、pH和mcrA浓度的基线水平。然而，暴露在连续的大冲击负荷下会降低厌氧消化器的抵抗力和弹性。有机酸积累值和甲烷含量值恢复到冲击前的时间长度一般随着每次连续的大冲击载荷而增加。对于OA，反应器从第一次、第二次和第三次大冲击恢复分别需要35、39和43天，而相同冲击时间的甲烷含量恢复时间分别为27.5、26.5和34.5天。因此，这项工作表明，无论是有意的还是意外的，雾冲击负荷都存在一个转折点，从提高厌氧消化器的整体稳定性到显著恶化其整体性能。
Accidental organic overloading (shock loading) is a common cause of failure in the anaerobic co-digestion of fats, oils, and greases (FOG). Nonetheless, questions still remain about how shock loads alter an anaerobic digester's biogas productivity and response to future organic overloads. To address this knowledge gap, this study utilized short increases in OLR, or shock loads, to adapt one reactor to FOG co-digestion and compare its response to that of a non-adapted digester tested at similar organic loads. A long-term study was also conducted where sequential shock events and disturbance-to-failure events (with organic loading rates ranging from 2.5 to 9.0 g VS/L/d) were employed to study their effects on reactor stability and performance. When exposed to moderate and large shock loads (3.0 and 9.0 g VS/L/d, respectively), the anaerobic digester previously exposed to FOG shock loads had greater levels of resistance and resiliency. For a moderate shock, it took the non-adapted reactor 29.8, 43, 44, and 19 days longer than the adapted reactor to recover to the baseline levels for methane content, organic acids (OA), pH, andmcrAconcentrations, respectively. For a large shock, the adapted and non-adapted reactors saw more similar recovery times with the non-adapted reactor requiring an additional 11, 18, 19, and 0 days longer than the adapted reactor to recover to baseline levels for methane content, OA, pH, andmcrAconcentrations, respectively. However, exposure to successive large shock loads decreased the anaerobic digester's resistance and resilience. The length of time it took for the organic acid accumulation and methane content values to return to their pre-shock values generally increased with each successive large shock load. For OA, the reactor required 35, 39, and 43 days to recover from the first, second, and third large shocks, respectively, while the methane content recovery times were 27.5, 26.5, and 34.5 days for the same shock periods. Thus, this work demonstrates that there is a tipping point in which FOG shock loads, whether intentional or accidental, go from improving the overall robustness of an anaerobic digester to significantly deteriorating its overall performance.