Harnessing conductive materials to reshape sewer microbiomes and mitigate corrosion from sulfide and hydrogen sulfide...

Sewer corrosion, primarily driven by sulfate, sulfide, and hydrogen sulfide metabolism, accelerates pipeline deterioration and has been linked to sinkhole formation and road collapses. This study explores the use of nickel (Ni) and iron-based magnetite black (MTB) as conductive lining materials to enhance sulfide, sulfate, and hydrogen sulfide degradation. Lab-scale concrete reactors (CCRs) were constructed with three configurations: 5% Ni-lined, MTB-lined, and 100% Portland cement. The experiment was conducted in 12 cycles. Results showed that both Ni- and MTB-lined CCRs significantly improved sulfate removal efficiency, achieving complete sulfate depletion by the 10th and 11th experimental cycles, respectively. The MTB-lined CCR exhibited the highest sulfide and hydrogen sulfide removal capacity, reducing sulfide concentrations by 99% while also suppressing sulfide emission to a maximum of 100 mg/L, compared to the Ni-lined CCR (134 mg/L) and Portland (155 mg/L). This substantial performance is attributed to the synergistic activity of sulfate-oxidizing and sulfate-reducing bacteria, along with contributions from non-sulfur-metabolizing bacteria. Furthermore, methanogens actively consumed sulfide, supported by enhanced electron transfer through Ni and MTB conductive materials. These findings highlight the potential of conductive material linings to mitigate sulfide-induced sewer corrosion, offering a sustainable approach for improving sewer infrastructure durability.