Carranza Muñoz Andrea, Malovanyy Andriy, Singh Abhijeet, Baresel Christian, Karlsson Jesper, Stark-Fujii Kristina, Schnürer Anna
Department of Environmental Technology, IVL Swedish Environmental Research Institute, Valhallavägen 81, 114 28 Stockholm, Sweden.
Department of Molecular Sciences, SLU Swedish University of Agricultural Sciences, Almas Allé 8, 750 07 Uppsala, Sweden E-mail:
Water Sci Technol. 2025 Jul;92(1):139-152. doi: 10.2166/wst.2025.086. Epub 2025 Jun 25.
To meet future nitrogen removal targets, Henriksdal wastewater treatment plant (WWTP) will require external carbon addition, estimated at 8 tons COD/day by 2040, due to low influent BOD/TN ratios, precipitation chemical use, and low temperatures. Methanol, the projected option, is fossil-based and contributes to indirect greenhouse gas emissions. This study evaluated a volatile fatty acid (VFA)-based fermentate produced from primary sludge and food waste in a 2 m mesophilic fermenter as a carbon source for denitrification. The filtrated fermentate was tested as carbon source in both batch denitrification tests and pilot-scale MBR (4.5 m/h), where it was dosed for 70 days, replacing glycerol currently used at Henriksdal and Henriksdals WWTP. In batch tests, the fermentate achieved a 40% higher denitrification rate than glycerol. Pilot trials showed a 30% higher denitrification rate and 50% lower carbon consumption while maintaining effluent concentration below 3 mg NO -N/L. Microbial analysis revealed no significant community changes with the carbon source transition, indicating effective VFA uptake by existing microorganisms. Full-scale projections suggested that replacing methanol would require 10% of the plant's primary sludge plus food waste. Although this sludge use would reduce biogas production, methane potential tests showed that recycling of the fermentate solid fraction would result in only 2% lower biogas production, representing a minor trade-off.
为实现未来的氮去除目标，由于进水的生化需氧量/总氮（BOD/TN）比值低、使用沉淀化学品以及温度低，亨里克达尔污水处理厂（WWTP）将需要添加外部碳源，预计到2040年为8吨化学需氧量/天。预计选用的甲醇是以化石为基础的，会导致间接温室气体排放。本研究评估了在一个2米的中温发酵罐中由初沉污泥和食物垃圾产生的基于挥发性脂肪酸（VFA）的发酵产物作为反硝化碳源的情况。过滤后的发酵产物在间歇反硝化试验和中试规模的膜生物反应器（4.5米/小时）中作为碳源进行了测试，在中试规模的膜生物反应器中添加了70天，取代了目前在亨里克达尔和亨里克达尔污水处理厂使用的甘油。在间歇试验中，发酵产物的反硝化速率比甘油高40%。中试试验表明，反硝化速率提高了30%，碳消耗量降低了50%，同时出水浓度保持在3毫克NO₃-N/L以下。微生物分析表明，随着碳源的转变，群落没有显著变化，这表明现有微生物能够有效吸收VFA。全面预测表明，替代甲醇将需要该厂10%的初沉污泥加食物垃圾。虽然这种污泥的使用会减少沼气产量，但甲烷潜力测试表明，发酵产物固体部分的再循环只会使沼气产量降低2%，这是一个较小的权衡。
