Department of Agricultural and Biosystems Engineering, Kwame Nkrumah University of Science and Technology, Ghana.
Department of Civil, Environmental and Geomatics Engineering, School of Engineering, College of Science and Technology, University of Rwanda, Rwanda.
Waste Manag Res. 2021 Jun;39(6):871-878. doi: 10.1177/0734242X20957395. Epub 2020 Sep 29.
The study assessed the impact of volatile fatty acids (VFA) to total alkalinity (TA) ratio (VFA/TA), and percentage volatile solids (VS) reduction of batch and semi-continuous anaerobic co-digestion of palm nut paste waste (PNPW) and anaerobic-digested rumen waste (ADRW) on digester stability and biogas production under the environmental condition of 50 ± 1°C and hydraulic retention time of 21 days for the batch studies and 14 days for semi-continuous co-digestion. The co-digestion ratios were based on percentage digester volume corresponding to 90%:10%, 75%:25% and 50%:50%. During batch and semi-continuous anaerobic co-digestion, VFA/TA of 0.32-1.0 and VS reduction of 53-67% were observed as the stable range at which biogas production was maximum. In terms of semi-continuous anaerobic digestion (AD), except for the 50%:50% ratio where biogas production progressed steadily from the first to fourteenth days, biogas production initially dropped from 180.1 to 171.3 mL between the first and third days of the 90%:10% reaching a maximum of 184 mL on the fourteenth day. Biogas production declined from 198.8 to 187.5 mL on the second day and then increased to 198.8 ± 0.5 mL in the case of the 75%:25% with a significant difference between the treatment ratios at < 0.05. Therefore, the study can confirm that the 50%:50% ratio (PNPW:ADRW) is a suitable option for managing crude fat-based waste under thermophilic AD due to its potential for rapid start-up and complete biodegradation of active biomass within a 21-day period. This presupposes that residual methane as greenhouse gas will be void in the effluent if disposed of.
本研究评估了挥发性脂肪酸（VFA）与总碱度（TA）的比例（VFA/TA），以及分批和半连续厌氧共消化棕榈仁浆废物（PNPW）和厌氧消化瘤胃废物（ADRW）时挥发性固体（VS）的百分比减少率，对 50±1°C 的环境条件下消化器的稳定性和沼气产量的影响，批处理研究的水力停留时间为 21 天，半连续共消化的水力停留时间为 14 天。共消化比例基于对应于 90%:10%、75%:25%和 50%:50%消化器体积的百分比。在分批和半连续厌氧共消化过程中，观察到 VFA/TA 为 0.32-1.0 和 VS 减少 53-67%，这是沼气产量最大的稳定范围。就半连续厌氧消化（AD）而言，除了 50%:50%的比例从第一天到第十四天沼气产量稳定增加外，90%:10%的比例的沼气产量从第一天到第三天从 180.1 下降到 171.3mL，在第十四天达到 184mL 的最大值。第二天，沼气产量从 198.8 下降到 187.5mL，然后在 75%:25%的情况下增加到 198.8±0.5mL，处理比例之间存在显著差异（<0.05）。因此，该研究可以确认，50%:50%的比例（PNPW:ADRW）是管理基于粗脂肪的废物在嗜热 AD 中的一种合适选择，因为它具有在 21 天内快速启动和完全生物降解活性生物质的潜力。这假设如果处理，废水中将没有残留的甲烷作为温室气体。
