Electrochemical control and minimization of hydrogen sulfide formation in anaerobic systems
Hydrogen sulfide (H2S) is oxidized at the anode and removed from wastewater in the form of elemental sulfur and polysulfides.

Hydrogen sulfide (H2S) is formed by the biological reduction of sulfates and the decomposition of organic material. In spite of being present at relatively low concentrations in wastewater (i.e., 10-20 mg/L), sulfide represents a major problem for municipal wastewater systems as it is toxic, corrosive, and odorous. Sulfide is often formed in high concentrations during anaerobic digestion processes, where sulfate-reducing bacteria compete with methanogens and decrease the yield and quality of the produced biogas.

Currently applied methods for the control of sulfide production in sewers are based on the addition of large amounts of chemicals. Minimization of sulfide production in anaerobic digestion is also a challenge, as it is difficult to separate sulfide from wastewater without removing the organic matter, which is necessary for the growth of methanogens.

In the scope of JPI Water WATINTECH project, we are developing an electrochemical treatment unit based on flow-through anode materials, capable of efficiently oxidizing and removing sulfide from wastewater. We are adapting our system to streams containing low concentration of sulfide (e.g., municipal wastewater), as well as to highly concentrated, hydrogen sulfide - rich streams (e.g., digestate). The objective is to remove sulfide from wastewater/digestate without changing the wastewater composition or affecting the microbial community in anaerobic digestion.

People working on the project
Project information

Watintech project is a coordinated by Prof Ignasi Rodríguez-Roda, from the Technologies and Evaluation research area of ICRA. The project proposes the combination of different decentralised treatment approaches for sewage and urban run-off. The objective is to recover “on-demand” valuable products from these aqueous flows in a decentralized manner. The products to be recovered include water, energy (methane) and the generation of caustic and oxygen to avoid sewer corrosion and odours, all to be used locally.

  • irodriguezroda@icra.cat; info@electron4water.com
  • Tel (+34) 972 18 30 80