Shang Qingna, Li Lin, Zhang Yi, Shi Xueqing, Ratnaweera Harsha, Kim Dong-Hoon, Zhang Haifeng
National and Local & Joint Engineering Research Center for Urban Sewage Treatment and Resource Recycling, School of Environmental and Municipal Engineering, Qingdao University of Technology, 11 Fushun Road, Qingdao 266033, China.
Department of Smart City Engineering, Inha University, 100 Inharo, Michuhol-gu, Incheon 22212, Republic of Korea.
Toxics. 2025 Feb 28;13(3):183. doi: 10.3390/toxics13030183.
This study aimed to examine the impacts of hydraulic retention time (HRT) and organic loading rate (OLR) on the alginate-like exopolymers' (ALEs) recovery potential from a biofilm-based process. A lab-scale moving bed biofilm reactor (MBBR) was operated under different HRT (12.0, 6.0, and 2.0 h) and OLR (1.0, 2.0, and 6.0 kg COD/m/d) conditions. The results demonstrated that the reduction in HRT and increase in OLR had remarkable effects on enhancing ALE production and improving its properties, which resulted in the ALE yield increasing from 177.8 to 221.5 mg/g VSS, with the protein content rising from 399.3 to 494.3 mg/g ALE and the enhanced alginate purity by 39.8%, corresponding to the TOC concentration increasing from 108.3 to 157.0 mg/g ALE. Meanwhile, to illustrate different ALE recovery potentials, microbial community compositions of the MBBR at various operational conditions were also assessed. The results showed that a higher relative abundance of EPS producers (29.86%) was observed in the MBBR with an HRT of 2.0 h than that of 12.0 h and 6.0 h, revealing its higher ALE recovery potential. This study yields crucial results in terms of resource recovery for wastewater reclamation by providing an effective approach to directionally cultivating ALEs.
本研究旨在考察水力停留时间（HRT）和有机负荷率（OLR）对基于生物膜工艺的类藻酸盐胞外聚合物（ALE）回收潜力的影响。在不同的HRT（12.0、6.0和2.0小时）和OLR（1.0、2.0和6.0 kg COD/m/d）条件下运行一个实验室规模的移动床生物膜反应器（MBBR）。结果表明，HRT的缩短和OLR的增加对提高ALE产量和改善其性质具有显著影响，这导致ALE产率从177.8 mg/g VSS提高到221.5 mg/g VSS，蛋白质含量从399.3 mg/g ALE增加到494.3 mg/g ALE，藻酸盐纯度提高39.8%，对应于总有机碳（TOC）浓度从108.3 mg/g ALE增加到157.0 mg/g ALE。同时，为了说明不同的ALE回收潜力，还评估了MBBR在各种运行条件下的微生物群落组成。结果表明，HRT为2.0小时的MBBR中EPS生产者的相对丰度（29.86%）高于HRT为12.0小时和6.0小时的MBBR，表明其具有更高的ALE回收潜力。本研究通过提供一种定向培养ALE的有效方法，在废水回收利用的资源回收方面取得了关键成果。
