ABSTRACT

Anaerobic co-digestion of residual cabbage and cauliflower mixed at a ratio 1:1 (w/w) was investigated in two continuously stirred tank reactors under mesophilic conditions to ensure stability and enhanced methane generation. The experiments, including start-up, inoculum acclimatisation and treatment of the waste mixture, were carried out over a 65-day period. The characterisation results showed that the residual mixture contained a high proportion of total Kjeldahl nitrogen (around 37 g N/kg dry weight). The maximum value of methanogenic yield potential was found to be 250 L_STP/kg VS (volatile solid) added, at STP conditions (0°C, 1 atm), by loading organic substrate at a concentration of 1 g VS/L, while its biodegradability was 60%. However, instability of the biomethanisation process was observed after 17 days, which might be a consequence of the high concentration of nitrogen in the reactors. The evaluation of the kinetics of the valorisation process revealed that the waste mixture studied can easily be biodegraded through anaerobic co-digestion.

摘要

在两个连续搅拌的罐式反应器中，在中温条件下研究了以 1:1 (w/w) 的比例混合的残留卷心菜和花椰菜的厌氧共消化，以确保稳定性和增强的甲烷生成。实验，包括启动、接种物驯化和废物混合物的处理，进行了 65 天的时间。表征结果表明，残留混合物含有高比例的凯氏定氮氮（约 37 g N/kg 干重）。发现产甲烷产量潜力的最大值为 250 L _STP/kg VS（挥发性固体），在 STP 条件下（0°C，1 个大气压），通过以 1 g VS/L 的浓度加载有机底物，同时其生物降解性为 60%。然而，在 17 天后观察到生物甲烷化过程的不稳定性，这可能是反应器中氮浓度高的结果。对增值过程动力学的评估表明，所研究的废物混合物很容易通过厌氧共同消化进行生物降解。