Seawater-based wastewater accelerates development of aerobic granular sludge: A laboratory proof-of-concept

Xiling Li, Jinghai Luo, Gang Guo, Hamish Mackey, Tianwei Hao, Guanghao Chen

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35 Citations (Scopus)

Abstract

This study aimed to develop an aerobic granular sludge process for the efficient treatment of highly saline wastewater and understand the granulation process in a seawater-based multi-ion matrix. Five identical sequencing batch airlift reactors (SBARs) are used to treat synthetic saline sewage with different proportions of real seawater (0%–100%). The results confirm that aerobic granular sludge can be successfully developed with various proportions of seawater up to 100% and show that seawater not only significantly accelerates granulation but also generates stronger granular structures than does freshwater. The increased presence of gel-forming alginate-like exopolysaccharides in the granules explains why a greater proportion of seawater leads to higher density and improves the cohesive strength of the granules. SEM-EDX analysis further revealed substantial presence of both Ca2+ and Mg2+ phosphate in the granule core as well as in the outer layers providing extra bridging forces in addition to alginate-like exopolysaccharides for accelerating the granule formation and maintaining the structure. It is hoped that this work could explore another approach for saline sewage treatment and bring some clues for the mystery of granulation mechanism.

Original languageEnglish
Pages (from-to)210-219
Number of pages10
JournalWater Research
Volume115
DOIs
Publication statusPublished - 2017

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Keywords

  • Aerobic granular sludge
  • Multi-ion impact
  • Rapid granulation
  • Seawater mixed sewage

ASJC Scopus subject areas

  • Ecological Modelling
  • Water Science and Technology
  • Waste Management and Disposal
  • Pollution

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