Assessment of sludge management strategies in wastewater treatment systems using a plant-wide approach
| Autor: | Krist V. Gernaey, Damien J. Batstone, Theo Harding, Xavier Flores-Alsina, Sven Sotemann, Elham Ramin, D.S. Ikumi, Chris J. Brouckaert |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Environmental Engineering
Denitrification Nitrogen 0208 environmental biotechnology Population 02 engineering and technology 010501 environmental sciences Wastewater 01 natural sciences Waste Disposal Fluid Reject water treatment Water Purification South Africa Bioreactors Bio-solids beneficiation facility Nutrient removal education Waste Management and Disposal Effluent 0105 earth and related environmental sciences Water Science and Technology Civil and Structural Engineering Resource recovery education.field_of_study Sewage Ecological Modeling Thermal hydrolysis pretreatment modeling Environmental engineering Thermal hydrolysis Pollution BSM2 020801 environmental engineering Enhanced biological phosphorus removal Anammox Environmental science Sewage treatment |
| Zdroj: | Flores Alsina, X, Ramin, E, Ikumi, D, Harding, T, Batstone, D J, Brouckaert, C, Sotemann, S & Gernaey, K V 2021, ' Assessment of sludge management strategies in wastewater treatment systems using a plant-wide approach ', Water Research, vol. 190, 116714 . https://doi.org/10.1016/j.watres.2020.116714 |
| DOI: | 10.1016/j.watres.2020.116714 |
| Popis: | The objective of this paper is to use plant-wide modeling to assess the net impacts of varying sludge management strategies. Special emphasis is placed on effluent quality, operational cost and potential resource recovery (energy, nutrients). The study is particularly focused on a centralized bio-solids beneficiation facility (BBF), which enables larger, more capital intensive sludge management strategies. Potential barriers include the ability to process reject streams from multiple donor plants in the host plant. Cape Flats (CF) wastewater treatment works (WWTW) (Cape Town, South Africa) was used as a relevant test case since it is currently assessing to process sludge cake from three nearby facilities (Athlone, Mitchells Plain and Wildevoelvlei). A plant-wide model based on the Benchmark Simulation Model no 2 (BSM2) extended with phosphorus transformations was adapted to the CF design / operational conditions. Flow diagram and model parameters were adjusted to reproduce the influent, effluent and process characteristics. Historical data between January 2014 and December 2019 was used to compare full-scale measurements and predictions. Next, different process intensification / mitigation technologies were evaluated using multiple criteria. Simulation values for COD, TSS, VSS/TSS ratio, TN, TP, NH4+/NH3, HxPO43-x, NOx alkalinity and pH fall within the interquartile ranges of measured data. The effects of the 2017 severe drought on influent variations and biological phosphorus removal are successfully reproduced for the entire period with dynamic simulations. Indeed, 80% of all dynamically simulated values are included within the plant measurement uncertainty ranges. Sludge management analysis reveals that flow diagrams with thermal hydrolysis pre-treatment (THP) result in a better energy balance in spite of having higher heat demands. The flow diagram with THP is able to i) increase biodegradability/solubility, ii) handle higher sludge loads, iii) change methanogenic microbial population and iv) generate lower solids volumes to dispose by improving sludge dewaterability. The study also reveals the importance of including struvite precipitation and harvesting (SPH) technology, and the effect that pH in the AD and the use of chemicals (NaOH, MgO) may have on phosphorus recovery. Model-based results indicate that the current aerobic volume in the water line (if properly aerated) would be able to handle the returns from the sludge line and the contribution of a granular partial nitritation/Anammox (PN/ANX) reactor on the overall nitrogen removal would be marginal. However autotrophic N denitrification generates a much lower sludge production and therefore increases AD treatment capacity. The study shows for the very first time in Africa how the use of a (calibrated) plant-wide model could assist water utilities to decide between competing plant layouts when upgrading a WWTW |
| Databáze: | OpenAIRE |
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