Potential of direct granulation and organic loading rate tolerance of aerobic granular sludge in ultra-hypersaline environment

Jingxue Yue; Xushen Han; Yan Jin; Jianguo Yu

doi:10.1016/j.envres.2023.115831

Potential of direct granulation and organic loading rate tolerance of aerobic granular sludge in ultra-hypersaline environment

Environ Res. 2023 Jul 1:228:115831. doi: 10.1016/j.envres.2023.115831. Epub 2023 Apr 5.

Authors

Jingxue Yue¹, Xushen Han², Yan Jin³, Jianguo Yu⁴

Affiliations

¹ State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China; National Engineering Research Center for Integrated Utilization of Salt Lake Resources, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China.
² State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China; National Engineering Research Center for Integrated Utilization of Salt Lake Resources, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China. Electronic address: xushen.han@ecust.edu.cn.
³ National Engineering Research Center for Integrated Utilization of Salt Lake Resources, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China.
⁴ State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China; National Engineering Research Center for Integrated Utilization of Salt Lake Resources, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China. Electronic address: jgyu@ecust.edu.cn.

PMID: 37024036
DOI: 10.1016/j.envres.2023.115831

Abstract

Salt-tolerant aerobic granular sludge (SAGS) technology has shown potentials in the treatment of ultra-hypersaline high-strength organic wastewater. However, the long granulation period and salt-tolerance acclimation period are still bottlenecks that hinder SAGS applications. In this study, "one-step" development strategy was used to try to directly cultivate SAGS under 9% salinity, and the fastest cultivation process was obtained under such high salinity compared to the previous papers with the inoculum of municipal activated sludge without bioaugmentation. Briefly, the inoculated municipal activated sludge was almost discharged on Day 1-10, then fungal pellets appeared and it gradually transitioned to mature SAGS (particle size of ∼4156 μm and SVI₃₀ of 57.8 mL/g) from Day 11 to Day 47 without fragmentation. Metagenomic revealed that fungus Fusarium played key roles in the transition process probably because it functioned as structural backbone. RRNPP and AHL-mediated systems might be the main QS regulation systems of bacteria. TOC and NH₄⁺-N removal efficiencies maintained at ∼93.9% (after Day 11) and ∼68.5% (after Day 33), respectively. Subsequently, the influent organic loading rate (OLR) was stepwise increased from 1.8 to 11.7 kg COD/m³·d. It was found that SAGS could maintain intact structure and low SVI₃₀ (< 55 mL/g) under 9% salinity and the OLR of 1.8-9.9 kg COD/m³·d with adjustment of air velocity. TOC and NH₄⁺-N (TN) removal efficiencies could maintain at ∼95.4% (below OLR of 8.1 kg COD/m³·d) and ∼84.1% (below nitrogen loading rate of 0.40 kg N/m³·d) in ultra-hypersaline environment. Halomonas dominated the SAGS under 9% salinity and varied OLR. This study confirmed the feasibility of direct aerobic granulation in ultra-hypersaline environment and verified the upper OLR boundary of SAGS in ultra-hypersaline high-strength organic wastewater treatment.

Keywords: Fungal pellets; Metagenomic; Organic loading rate (OLR); Salt-tolerant aerobic granular sludge (SAGS); Ultra-hypersaline wastewater.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Aerobiosis
Bioreactors / microbiology
Nitrogen
Sewage* / microbiology
Waste Disposal, Fluid*
Wastewater

Substances

Sewage
Wastewater
Nitrogen