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Updated: Jul 21, 2026

Electrochemically and Bioelectrochemically Induced Ammonium Recovery
Published on: January 22, 2015
Recovery mechanism of heterotrophic ammonia assimilation system under chromium hexavalent stress
Tong Jiao1, Chuanfu Zhao1, Mengru Zhang1
1School of Civil Engineering, Shandong University, Jinan, Shandong, PR China; Laboratory of Water-sediment Regulation and Eco-decontamination, Jinan, Shandong, PR China.
Abstract:
Heterotrophic ammonia assimilation (HAA), an innovative technology for high-salinity wastewater treatment, demonstrates self-recovery capability following Cr (VI) stress. This study investigated the inhibitory effects and self-restoration mechanisms of Cr (VI) at various stress levels. The removal efficiencies of NH4+-N and Cr (VI) in the HAA gradually decreased with increasing influent Cr (VI) concentration. Exposure to Cr (VI) increased the amounts of high-molecular-weight proteins in soluble microbial products and stimulated the generation of extracellular polymeric substances. Heterotrophic functional microorganisms with Cr (VI) tolerance, such as Marinobacter and Planktosalinus, were enriched. An assimilation pathway gene (glnA) and a Cr (VI)-related gene (atoB) were also upregulated. After ceasing Cr (VI) addition, the HAA system demonstrated a 17.1 % increase in the removal efficiency of NH4+-N, which was attributable to its self-recovery ability. This study provides a scientific and theoretical foundation for the HAA process in resisting the impact of heavy-metal-containing wastewater and self-recovery.
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