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

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 was...

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Bibliographic Details
Published in:Journal of environmental management 2023-10, Vol.344, p.118473-118473, Article 118473
Main Authors: Pan, Zhenxiang, Li, Zhongqiang, Zeng, Bizhen, Shen, Liguo, Lin, Hongjun
Format: Article
Language:English
Subjects:
Deep denitrification
Denitrification
Granular sludge
Ion exchange resin
Waste brine
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Summary: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. [Display omitted] •Innovative use of up-flow sludge blanket for high-salinity nitrate removal was proposed.•Optimal conditions for denitrification of resin regeneration wastewater were identified.•High denitrification efficiency (>95%) was achieved under optimal conditions.•Novel technology was developed for cost-effective treatment of resin regenerant wastewater.•Significant increase in filamentous bacteria and dominant species over time was found.
ISSN:0301-4797
1095-8630
DOI:10.1016/j.jenvman.2023.118473