Beyond The Energy Bill: Direct Emissions, Sludge and The Climate Footprint of Wastewater Reuse Trains in Lebanon

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@article{1724365,
      author = {Rayan El Hage Moussa, Mohammed Abdalghafoor},
      title = {Beyond The Energy Bill: Direct Emissions, Sludge and The Climate Footprint of Wastewater Reuse Trains in Lebanon},
      journal = {Iconic Research And Engineering Journals},
      year = {2026},
      volume = {10},
      number = {4},
      pages = {4982-4994},
      issn = {2456-8880},
      url = {https://www.irejournals.com/formatedpaper/1724365.pdf},
      abstract = {Water reuse is central to water security in Lebanon, but the climate burden of producing reclaimed water is rarely assessed under the country's conditions of diesel-dependent electricity and uncontrolled sludge disposal. This study compares seven complete treatment trains, from conventional activated sludge (CAS) with UV disinfection to reverse osmosis, each matched to a Lebanese reuse category. The functional unit is 1 m³ of reclaimed water. A streamlined LCA combines a technology inventory with IPCC 2019 methods for direct N₂O and CH₄, dissolved methane and sludge disposal, five improvement scenarios and a 10,000-run Monte Carlo analysis.

Gross climate impacts range from 1.24 kg CO₂ eq/m³ for an anaerobic membrane bioreactor (AnMBR) to 2.34 for a train with reverse osmosis. Direct emissions and sludge disposal account for 50–91% of the impact of every train except reverse osmosis. AnMBR, CAS + UV and a constructed wetland overlap within uncertainty, while reverse osmosis is the highest in 94% of runs. Upgrading from restricted to unrestricted irrigation quality adds only 0.15–0.20 kg CO₂ eq/m³ without reverse osmosis. Recovering 70% of dissolved methane lowers AnMBR to 0.68, a vertical-flow wetland reaches 0.98, and solar power cuts the MBR and reverse osmosis trains by 40–46%. Displacing groundwater pumping roughly halves every train's net footprint.

The results indicate that methane and N₂O control, controlled sludge management and renewable electricity should be core design criteria for wastewater reuse in Lebanon.},
      keywords = {life cycle assessment; water reuse; wastewater treatment; nitrous oxide; dissolved methane; anaerobic membrane bioreactor; constructed wetland; sludge; Lebanon},
      month = {October},
      doi = {https://doi.org/10.64388/ire1724365}
  }