Hydrodynamic cultivation of aeration-free oxygenic photogranules is favored by sufficient amounts of organic carbon

Junrong Li; Liaofan Tang; Yuqing Zhang; Mingming Gao; Shuguang Wang; Xinhua Wang

doi:10.1016/j.biortech.2024.130736

Hydrodynamic cultivation of aeration-free oxygenic photogranules is favored by sufficient amounts of organic carbon

Bioresour Technol. 2024 Apr 24:401:130736. doi: 10.1016/j.biortech.2024.130736. Online ahead of print.

Authors

Junrong Li¹, Liaofan Tang¹, Yuqing Zhang¹, Mingming Gao¹, Shuguang Wang², Xinhua Wang³

Affiliations

¹ Shandong Key Laboratory of Water Pollution Control and Resource Reuse, Shandong Key Laboratory of Environmental Processes and Health, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China.
² Shandong Key Laboratory of Water Pollution Control and Resource Reuse, Shandong Key Laboratory of Environmental Processes and Health, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China; Weihai Research Institute of Industrial Technology of Shandong University, Weihai 264209, China.
³ Shandong Key Laboratory of Water Pollution Control and Resource Reuse, Shandong Key Laboratory of Environmental Processes and Health, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China. Electronic address: xinhuawang@sdu.edu.cn.

PMID: 38670289
DOI: 10.1016/j.biortech.2024.130736

Abstract

Oxygenic photogranules (OPGs) have great potential for the aeration-free treatment of various wastewater, however, the effects of wastewater carbon composition on OPGs remain unknown. This study investigated the hydrodynamic photogranulation in three types of wastewater with the same total carbon concentration but different inorganic/organic carbon compositions, each operated at two replicated reactors. Results showed that photogranulation failed in reactors fed with only inorganic carbon. In reactors with equal inorganic and organic carbon, loose-structured OPGs formed but then disintegrated. Comparatively, reactors treating organic carbon-based wastewater obtained regular and dense OPGs with better settleability, lower effluent turbidity, excellent structural stability, and higher carbon assimilation rate. Sufficient amounts of organic carbon were crucial for the formation and stability of OPGs as they promoted the secretion of extracellular polymeric substances (EPS) and the growth of filamentous cyanobacteria. This study provides a basis for the startup of OPGs process and facilitates its large-scale application.

Keywords: Carbon compositions; Extracellular polymeric substances; Filamentous cyanobacteria; Photogranulation; Sustainable wastewater treatment.