Chen Yun, Liu Siqi, Ren Zhiyin, Wang Qi, Zhang Ying, Zuo Yajie, Zhou Jian, Jia Hongtao, Wang Tiecheng
Ningxia Houde Environmental Protection Technology Co., Ltd Yinchuan 750000 China.
College of Natural Resources and Environment, Northwest A&F University Yangling Shaanxi Province 712100 PR China
RSC Adv. 2023 Jul 4;13(29):19869-19880. doi: 10.1039/d3ra02921b. eCollection 2023 Jun 29.
With increase in the construction of urban sewage treatment plants, the output of sludge also surges. Therefore, it is highly important to explore effective ways to reduce the production of sludge. In this study, non-thermal discharge plasmas were proposed to crack the excess sludge. High sludge settling performance was obtained, and the settling velocity (SV) dramatically decreased from the initial value of 96% to 36% after 60 min of treatment at 20 kV, accompanied by 28.6%, 47.5%, and 76.7% decreases in mixed liquor suspended solids (MLSS), sludge volume index (SVI), and sludge viscosity, respectively. Acidic conditions improved the sludge settling performance. The presence of Cl and NO slightly promoted the SV, but CO has adverse effects. ·OH and O˙ in the non-thermal discharge plasma system contributed to the sludge cracking, especially for ·OH. These reactive oxygen species destroyed the sludge floc structure; as a result, the total organic carbon and dissolved chemical oxygen demand obviously increased, the average particle size of the sludge decreased, and the number of coliform bacteria was also reduced. Furthermore, the microbial community abundance and diversity both decreased in the sludge after the plasma treatment.
随着城市污水处理厂建设的增加，污泥产量也激增。因此，探索有效减少污泥产生的方法非常重要。在本研究中，提出了利用非热放电等离子体破解剩余污泥。获得了较高的污泥沉降性能，在20 kV下处理60分钟后，沉降速度（SV）从初始值96%急剧降至36%，同时混合液悬浮固体（MLSS）、污泥体积指数（SVI）和污泥粘度分别下降了28.6%、47.5%和76.7%。酸性条件改善了污泥沉降性能。Cl和NO的存在略微促进了SV，但CO有不利影响。非热放电等离子体系统中的·OH和O˙有助于污泥破解，尤其是·OH。这些活性氧物种破坏了污泥絮体结构；结果，总有机碳和溶解性化学需氧量明显增加，污泥平均粒径减小，大肠菌群数量也减少。此外，等离子体处理后污泥中的微生物群落丰度和多样性均降低。
