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Published on: October 15, 2015
Temporal sulfur redox reprogramming enables control-oriented intensification of sulfur-based autotrophic
Kun Zheng1, Han-Bing Xiao1, Yi-Lu Sun1
1Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
Water Research
|June 28, 2026
Summary
Sulfur disproportionation can be used to enhance sulfur-based autotrophic denitrification, creating an internal electron donor buffer. This method intensifies nitrate removal in wastewater treatment without reactor changes.
Area of Science:
- Environmental Microbiology
- Environmental Chemistry
- Biogeochemical Cycles
Background:
- Sulfur-based autotrophic denitrification (SAD) is crucial for nitrate removal from low-carbon wastewater.
- Tuning SAD capacity is challenging due to the slow supply of solid-phase electron donors.
- Sulfur disproportionation (SDP) typically occurs under nitrate-depleted conditions and is considered a failure mode due to sulfide production.
Purpose of the Study:
- To investigate the potential of converting sulfur disproportionation (SDP) into a controllable process.
- To couple SDP with sulfur-based autotrophic denitrification (SAD) to create an endogenous electron donor buffer.
- To enhance denitrification rates and resilience in wastewater treatment systems.
Main Methods:
- Laboratory-scale packed bed reactors operated for 70 days with controlled SDP inductions.
- Pilot-scale validation in a 40 m³ system.
- Analysis of denitrification rates, sulfide and sulfate concentrations, and interfacial chemical changes (XPS, Mössbauer spectroscopy).
- Microbial community structure analysis.
Main Results:
- Temporal coupling of SDP and SAD increased denitrification rates by 1.45-2.61-fold in lab studies and up to 3.9-fold in pilot studies.
- Enhancement persistence varied from 1 to 12 days, correlating with SDP intensity and sulfide levels.
- Interfacial analysis revealed reversible sulfur and iron reduction during SDP.
- Microbial communities adapted without significant enrichment of obligate sulfur disproportionators.
- Pilot-scale operation achieved higher loading rates and reduced effluent sulfide under increasing nitrate loads.
Conclusions:
- Temporal coupling of SDP and SAD effectively creates an internal sulfur buffer, intensifying denitrification.
- This approach enhances the resilience of denitrification processes under fluctuating nitrate conditions.
- The findings offer a novel strategy for optimizing wastewater treatment efficiency and stability.
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