Enhanced denitrification performance of granular sludge for the treatment of waste brine from ion exchange resin process

Zhenxiang Pan; Zhongqiang Li; Bizhen Zeng; Liguo Shen; Hongjun Lin

doi:10.1016/j.jenvman.2023.118473

Enhanced denitrification performance of granular sludge for the treatment of waste brine from ion exchange resin process

J Environ Manage. 2023 Oct 15:344:118473. doi: 10.1016/j.jenvman.2023.118473. Epub 2023 Jul 4.

Authors

Zhenxiang Pan¹, Zhongqiang Li², Bizhen Zeng³, Liguo Shen⁴, Hongjun Lin⁵

Affiliations

¹ College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, 321004, China; Key Laboratory of Watershed Earth Surface Processes and Ecological Security, Zhejiang Normal University, Jinhua, 321004, China. Electronic address: 838265202@zjnu.edu.cn.
² College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, 321004, China. Electronic address: 173659243@qq.com.
³ College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, 321004, China; Key Laboratory of Watershed Earth Surface Processes and Ecological Security, Zhejiang Normal University, Jinhua, 321004, China. Electronic address: 1900045193@qq.com.
⁴ College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, 321004, China; Key Laboratory of Watershed Earth Surface Processes and Ecological Security, Zhejiang Normal University, Jinhua, 321004, China. Electronic address: lgshen@zjnu.cn.
⁵ College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, 321004, China; Key Laboratory of Watershed Earth Surface Processes and Ecological Security, Zhejiang Normal University, Jinhua, 321004, China. Electronic address: hjlin@zjnu.cn.

PMID: 37413732
DOI: 10.1016/j.jenvman.2023.118473

Abstract

Ion exchange resin process is a widely used process in wastewater treatment plants, but its waste brine is characterized by high salinity and nitrate concentration, leading to costly treatment. This study innovatively explored the use of an up-flow anaerobic sludge bed (USB) for the treatment of waste brine from ion exchange resin process, following a pilot-scale ion exchange resin process. Specifically, the D890 ion exchange resin was employed for nitrate removal from secondary effluent, with resin regeneration using 4% NaCl solution. The USB was inoculated with anaerobic granular sludge and acclimated under various single-factor conditions, which revealed the optimal pH range of 6.5-9, salt concentration of 2%, hydraulic retention time of 12 h, C/N ratio of 3.3, and up-flow velocity of 1.5 m/h for reactor operation. This study provides a novel approach for the cost-effective treatment of waste brine from ion exchange resin process. The study found that the denitrification efficiency was highest when the NO₃^--N concentration was around 200 mg/L, with NO₃^--N and TN removal rates exceeding 95% and 90%, respectively, under optimal operating conditions. Characterization of the granular sludge during different phases of the operation revealed a significant increase in proteobacteria and gradually became the dominant species over time. This study presents a novel, cost-effective approach to treat waste brine from ion exchange resin process, and the long-term stable operation of the reactor offers a reliable option for resin regeneration wastewater treatment.

Keywords: Deep denitrification; Denitrification; Granular sludge; Ion exchange resin; Waste brine.

MeSH terms

Bioreactors / microbiology
Denitrification
Ion Exchange Resins
Nitrates* / chemistry
Nitrogen
Sewage* / chemistry
Sodium Chloride
Waste Disposal, Fluid

Substances

Sewage
Nitrates
Ion Exchange Resins
brine
Sodium Chloride
Nitrogen