Effect of temperature on the anaerobic thermophilic conversion of volatile fatty acids by dispersed and granular sludge.
Effect of temperature on the anaerobic thermophilic conversion of volatile fatty acids by dispersed and granular sludge.
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DOI：
10.1016/0043-1354(95)00107-v
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发表时间：
1996
期刊：
影响因子：
12.8
通讯作者：
J. B. Lier;Jose Luis Sanz Martin;G. Lettinga
中科院分区：
文献类型：
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作者：
J. B. Lier;Jose Luis Sanz Martin;G. Lettinga
采用间歇活性试验和连续流动试验研究了温度对55°C培养的嗜热产甲烷污泥转化挥发性脂肪酸（VFA）速率的影响。当使用低比活性的分散污泥时，37-70°C范围内醋酸盐转化率的温度依赖性可以通过阿伦尼乌斯推导的模型来描述。对于该污泥，发现最佳乙酸盐转化率在65°C下。然而，当使用具有高比产甲烷活性的颗粒污泥时，在50°C至65°C之间的温度范围内，最大乙酸盐利用率不受影响。压碎颗粒导致在60-65°C下最大活性增加2至3倍，表明转化率很可能受到乙酸盐扩散到颗粒中的速率的限制。以丁酸盐为底物得到了类似的结果。破碎颗粒的温度依赖性与活性较低的分散污泥的温度依赖性相似。与此相反，嗜热丙酸氧化速率最高的完整的颗粒污泥，而类似的温度依赖性被发现为颗粒和分散的污泥。对VFA的亲和力随着温度的降低而增加。这种现象在颗粒污泥中最为明显。在UASB反应器中，当采用中等低的负荷率（即20 kg COD·m−3·d−1）时，VFA混合物的高温处理似乎仅受温度的轻微影响。然而，温度有很强的影响，采用40-90 kg COD·m-3·d-1的负荷率伴随着高的出水VFA浓度。结果表明，如果使用具有颗粒污泥床的“高速”反应器，则嗜热废水处理工艺在45-60°C范围内具有高热稳定性。
The effect of temperature on the rate of volatile fatty acid (VFA) conversion by thermophilic methanogenic sludge, cultivated at 55°C, was studied using both batch activity tests and continuous flow experiments. The temperature dependence of acetate conversion in the range between 37–70°C could be described by an Arrhenius derived model when dispersed sludge with a low specific activity was used. For this sludge the optimum acetate conversion rate was found at 65°C. However, the maximum acetate utilization rate was not affected by temperature in the range between 50°C to 65°C when granular sludge with a high specific methanogenic activity was used. Crushing the granules led to a 2 to 3 fold increase in the maximum activity at 60–65°C, indicating that the conversion rate was very likely limited by the diffusion rate of acetate into the granules. Similar results were obtained with butyrate as the substrate. The temperature dependence of the crushed granules was similar to that of the less active dispersed sludge. In contrast, the thermophilic propionate oxidation rate was highest with the intact granular sludge while a similar temperature dependence was found for both the granular and dispersed sludges. The affinity for VFA increased with decreasing temperature. This phenomenon was most pronounced for the granular sludge. The thermophilic treatment of a VFA-mixture in a UASB reactor appeared to be only slightly affected by temperature when moderately low loading rates were applied, i.e. 20 kg COD·m−3·d−1. However, temperature had a strong effect applying loading rates of 40–90 kg COD·m−3·d−1accompanied with high effluent VFA concentrations. The results reveal a high thermostability of the thermophilic wastewater treatment process in the range 45–60°C if “high-rate” reactors with a granular sludge bed are used.