Abstract
From an experimental and theoretical investigation of the continuity of influent inorganic suspended solids (ISS) along the links connecting the primary settling tank, fully aerobic or N removal activated sludge and anaerobic and aerobic digestion unit operations, it was found that the influent wastewater (fixed) ISS concentration is conserved through activated sludge and aerobic digestion unit operations. However, the measured ISS flux at different stages through a series of wastewater treatment plant unit operations is not equal to the influent ISS flux, because the ordinary heterotrophic organism (OHO) biomass contributes to the ISS flux by differing amounts depending on the active (OHO) fraction of the Volatile Suspended Solids (VSS) at that stage. Literature data indicated that conservation of influent ISS through primary sludge anaerobic digestion was within 10%, which is too wide to be conclusive. Water SA Vol.32 (3) 2006: pp.277-285
Highlights
The inorganic suspended solids (ISS) needs to be included in plant-wide wastewater treatment plant (WWTP) models because this parameter is commonly used for design and operation of WWTPs
From the experimental data of Van Haandel et al (1998a), the influent wastewater ISS concentration is conserved through AS and waste activated sludge (WAS) aerobic digestion (AerD) systems
From the experimental data of Izzett et al (1992) and Moen et al (2001), the evidence is inconclusive whether the influent wastewater settleable ISS concentration is conserved through primary sludge (PS) anaerobic digester (AD)
Summary
The inorganic suspended solids (ISS) needs to be included in plant-wide wastewater treatment plant (WWTP) models because this parameter is commonly used for design and operation of WWTPs. The steady state models (e.g. WRC, 1984) and ASM1 (Henze et al, 1987), of which aerobic digestion is a subset, do not include the reactor ISS concentration directly – this is calculated from an estimated VSS/TSS ratio for the AS (Ekama and Wentzel, 2004).
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call