Struvite Precipitation from Centrate—Identifying the Best Balance Between Effectiveness and Resource Efficiency
Year: 2025
Type: article
Abstract: In the context of struvite precipitation, the most significant gap pertains to the transfer of knowledge from scientific research to practical applications. The primary objective of this study is twofold: firstly, to identify the most critical process parameters influencing struvite precipitation and, secondly, to translate these parameters into a pragmatic tool for real-world applications. This study investigates the precipitation of struvite from digestion centrate to obtain information on the appropriate precipitation conditions for different initial chemical compositions. We carried out 24 lab-scale experiments to investigate the effect of varying pH value (7.0–8.5), temperature (5 °C and 33 °C) and initial phosphate concentrations (353; 165; 68 mg/L) on struvite precipitation. Varying the pH had the strongest influence on precipitation efficiencies. Adjusting pH from 7 to 8.5 increased PO4-P removal from 1.4% to 98.8%, whereas temperature had little impact on PO4-P removal. Furthermore, we found that a saturation index of at least 1.7 is imperative to precipitate at least 90% of the available PO4-P. Based on the results, we developed a nomogram showing the resulting saturation index and the associated PO4-P removal efficiency for variable initial PO4-P and pH levels. The tool developed in this study enables users to directly identify the so-called ‘sweet spot’, which is the optimal balance between process effectiveness and resource efficiency, for each centrate.
Source: Resources
Authors: Andreas Kolb, Tim Gebhardt, Thomas Dockhorn
Institution: Technische Universität Braunschweig
Language: English
Subfield: Waste Management and Disposal
Field: Environmental Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,930
OpenAlex ID: W4408937784