Enhancement of anaerobic digestion effluent treatment by microalgae immobilization: Characterized by fluorescence excitation-emission matrix coupled with parallel factor analysis in the photobioreactor

Weijia Gong; Binghan Xie; Shihai Deng; Yuhui Fan; Xiaobin Tang; Heng Liang

doi:10.1016/j.scitotenv.2019.04.440

Enhancement of anaerobic digestion effluent treatment by microalgae immobilization: Characterized by fluorescence excitation-emission matrix coupled with parallel factor analysis in the photobioreactor

Sci Total Environ. 2019 Aug 15:678:105-113. doi: 10.1016/j.scitotenv.2019.04.440. Epub 2019 Apr 30.

Authors

Weijia Gong¹, Binghan Xie², Shihai Deng³, Yuhui Fan⁴, Xiaobin Tang⁵, Heng Liang⁵

Affiliations

¹ School of Engineering, Northeast Agricultural University, 600 Changjiang Street, Xiangfang District, Harbin 150030, PR China. Electronic address: gongweijia@126.com.
² State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin 150090, PR China; National University of Singapore Environmental Research Institute, National University of Singapore, 5A Engineering Dr. 1, Singapore 117411, Singapore.
³ National University of Singapore Environmental Research Institute, National University of Singapore, 5A Engineering Dr. 1, Singapore 117411, Singapore; School of Civil Engineering, Beijing Jiaotong University, Beijing 100044, PR China.
⁴ School of Engineering, Northeast Agricultural University, 600 Changjiang Street, Xiangfang District, Harbin 150030, PR China.
⁵ State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin 150090, PR China.

PMID: 31075577
DOI: 10.1016/j.scitotenv.2019.04.440

Abstract

The bacterial-microalgal consortium has been investigated to anaerobic digestion effluent (ADE) treatment in the photobioreactor (PBR). However, the high concentrations of nutrients reduced the ADE treatment efficiency and the transformation of organic pollutants in PBR was still unclear. In this study, two-sequencing batch PBRs were operated with suspended Microcystis aeruginosa (M. aeruginosa, SMA) and immobilized M. aeruginosa (IMA) to compare the ADE treatment performance. Fluorescence excitation-emission matrix coupled with parallel factor analysis (EEM-PARAFAC) was conducted to identify organics degradations. The results showed that the proportion of living M. aeruginosa cell (86.4%) in PBR (IMA) was highly significant (p < 0.05) higher than that in PBR (SMA) (75.2%). This indicated immobilized microalgae beads enhanced the resistance to the high concentration of nutrients in PBR (IMA). EEM-PARAFAC analysis displayed the biodegradation order in the bacterial-microalgal consortium system was humic-like substances > tyrosine-like substances > tryptophan-like substances. The removals of humic-like matters (94.05 ± 0.92%) and tyrosine-like matters (91.13 ± 2.49%) in PBR (IMA) were significantly (p < 0.01) higher than those in PBR (SMA). Notably, the average removals of nutrients in PBR (IMA) were significantly (p < 0.05) higher than those in PBR (SMA). This result verified that microalgae immobilization benefitted nutrients removals with 93.05 ± 1.45% of NH₄⁺-N and complete PO₄^3--P removal in PBR (IMA). Moreover, the enrichment of functional genera Flavobacterium and Opitutus contributed to decreasing the organics loadings and strengthening the ADE treatment performance. Therefore, this study verified microalgae immobilization enhanced the actual ADE treatment. Additionally, fluorescent organic pollutants degradations were further evaluated by EEM-PARAFAC analysis in the bacterial-microalgal consortium.

Keywords: Anaerobic digestion effluent (ADE); Bacterial-microalgal consortium; EEM-PARAFAC analysis; M. aeruginosa immobilization; Photobioreactor (PBR).

MeSH terms

Anaerobiosis
Biodegradation, Environmental
Microalgae
Microcystis
Photobioreactors
Waste Disposal, Fluid / methods*