当前位置: X-MOL 学术Water Res. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Nitrogen removal as nitrous oxide for energy recovery: Increased process stability and high nitrous yields at short hydraulic residence times.
Water Research ( IF 12.8 ) Pub Date : 2020-02-04 , DOI: 10.1016/j.watres.2020.115575
Zhiyue Wang,Sung-Geun Woo,Yinuo Yao,Hai-Hsuan Cheng,Yi-Ju Wu,Craig S Criddle

The Coupled Aerobic-anoxic Nitrous Decomposition Operation (CANDO) is a two-stage process for nitrogen removal and resource recovery: in the first, ammonia is oxidized to nitrite in an aerobic bioreactor; in the second, oxidation of polyhydroxyalkanoate (PHA) drives reduction of nitrite to nitrous oxide (N2O) which is stripped for use as a biogas oxidant. Because ammonia oxidation is well-studied, tests of CANDO to date have focused on N2O production in anaerobic/anoxic sequencing batch reactors. In these reactors, nitrogen is provided as nitrite; PHA is produced from acetate or other dissolved COD, and PHA oxidation is coupled to N2O production from nitrite. In a pilot-scale study, N2O recovery was affected by COD/N ratio, total cycle time, and relative time periods for PHA synthesis and N2O production. In follow-up bench-scale studies, different reactor cycle times were used to investigate these operational parameters. Increasing COD/N ratio improved nitrite removal and increased biosolids concentration. Shortening the anaerobic phase prevented fermentation of PHA and improved its utilization. Efficient PHA synthesis and utilization in the anaerobic phase correlated with high N2O production in the anoxic phase. Shortening the anoxic phase prevented reduction of N2O to N2. By shortening both phases, total cycle time was reduced from 24 to 12 h. This optimized operation enabled increased biomass concentrations, increased N2O yields (from 71 to 87%), increased N loading rates (from 0.1 to 0.25 kg N/m3-d), and shorter hydraulic residence times (from 10 to 2 days). Long-term changes in operational performance for the different bioreactor systems tested were generally similar despite significant differences in microbial community structure. Long-term operation at short anaerobic phases selected for a glycogen-accumulating community dominated by a Defluviicoccus-related strain.

中文翻译:

脱氮作为一氧化二氮用于能量回收:在较短的水力停留时间下,提高了工艺稳定性,并提高了亚硝酸盐收率。

耦合好氧-缺氧的氮气分解操作(CANDO)是分两步进行脱氮和资源回收的过程:首先,氨在好氧生物反应器中被氧化为亚硝酸盐;在第二种方法中,聚羟基链烷酸酯(PHA)的氧化将亚硝酸盐还原为一氧化二氮(N2O),将其汽提用作沼气氧化剂。由于对氨氧化的研究已经深入研究,所以迄今为止,CANDO的测试都集中在厌氧/缺氧顺序批处理反应器中的N2O生产中。在这些反应器中,氮气以亚硝酸盐形式提供;PHA由乙酸盐或其他溶解的COD产生,PHA氧化与亚硝酸盐产生的N2O耦合。在一项中试规模的研究中,N2O的回收率受COD / N比,总循环时间以及PHA合成和N2O产生的相对时间段的影响。在后续的基准规模研究中,使用不同的反应器循环时间来研究这些操作参数。增加COD / N比可改善亚硝酸盐的去除并增加生物固体的浓度。缩短厌氧阶段可防止PHA发酵并提高其利用率。厌氧相中有效的PHA合成和利用与缺氧相中N2O的高产生有关。缩短缺氧相阻止了N2O还原为N2。通过缩短两个阶段,总循环时间从24小时减少到12小时。这种优化的操作可以提高生物质浓度,增加N2O产量(从71%到87%),增加氮的装载速率(从0.1到0.25 kg N / m3-d​​)和缩短水力停留时间(从10到2天)。尽管微生物群落结构存在显着差异,但测试的不同生物反应器系统的运行性能的长期变化通常相似。为与Defluviicoccus相关的菌株为主的糖原积累社区选择了在短厌氧期进行的长期操作。
更新日期:2020-02-04
down
wechat
bug