How elevation dictates technology selection in biological wastewater treatment.

Most wastewater treatment facilities are built using procedures from previous designs which are predominantly from sites and regions not located at high elevation. Recognizing this limitation, we assessed the effects of elevation above sea level on the suitability of process configurations and technologies as well as their associated energy costs. Using the International Water Association (IWA) benchmark simulation model No.

A Critical Review of the Factors Affecting Modeling Oxygen Transfer by Fine-Pore Diffusers in Activated Sludge.

  In this review, the factors affecting the transfer of oxygen in activated sludge processes using fine-pore diffusers for water resource recovery are critically discussed. In water resource recovery facilities, the energy required for aeration constitutes 50% to 80% of the total energy consumed by the plant. This critical review highlights the use of fine-pore diffuser aeration and emphasizes the significance of accounting for the following factors: diffuser aging and fouling, diffuser layout, diffuser type, selector benefits, local environmental conditions (temperature and atmospheric pressure), influent wastewater variability, dissolved oxygen control systems, and airflow rates.