Assessment of sludge management strategies in wastewater treatment systems using a plant-wide approach

• Model library for sludge management strategies compatible with plant-wide context is developed. Both plant wide models and can be simulated simultaneously. A mass balance method quantifies fate of COD, N & P through multiple units/models. Set criteria effluent quality, cost potential N, recovery. Scenario analysis shows the effect operational settings. The objective this paper to use modeling assess net impacts varying strategies. Special emphasis placed on resource recovery (energy, nutrients). study particularly focused a centralized bio-solids beneficiation facility (BBF), which enables larger, more capital intensive Potential barriers include ability process reject streams from donor plants in host plant. Cape Flats (CF) wastewater treatment works (WWTW) (Cape Town, South Africa) was used as relevant test case since it currently assessing cake three nearby facilities (Athlone, Mitchells Plain Wildevoelvlei). model based Benchmark Simulation no 2 (BSM2) extended phosphorus transformations adapted CF design / conditions. Flow diagram parameters were adjusted reproduce influent, characteristics. Historical data between January 2014 December 2019 compare full-scale measurements predictions. Next, different intensification mitigation technologies evaluated using criteria. values TSS, VSS/TSS ratio, TN, TP, NH 4 + /NH 3 , H x PO4 3-x NO alkalinity pH fall within interquartile ranges measured data. effects 2017 severe drought influent variations biological removal are successfully reproduced entire period dynamic simulations. Indeed, 80% all dynamically included measurement uncertainty ranges. Sludge reveals that flow diagrams thermal hydrolysis pre-treatment (THP) result better energy spite having higher heat demands. THP able i) increase biodegradability/solubility, ii) handle loads, iii) change methanogenic microbial population iv) generate lower solids volumes dispose by improving dewaterability. also importance including struvite precipitation harvesting (SPH) technology, AD chemicals (NaOH, MgO) may have Model-based results indicate current aerobic volume water line (if properly aerated) would returns contribution granular partial nitritation/Anammox (PN/ANX) reactor overall nitrogen marginal. However autotrophic denitrification generates much production therefore increases capacity. very first time Africa how (calibrated) could assist utilities decide competing layouts when upgrading WWTW.