Abstract
A simple technology for phosphate (Pi) recovery has been developed using a bifunctional adsorption–aggregation agent. The bifunctional agent was prepared by soaking calcium silicates in hydrochloric acid solution. Importantly, recyclable calcium silicates were available almost free of charge from the cement industry and also from the steel industry. The acid treatment was essential not only for enhancing the ability of calcium silicates to remove Pi from aqueous solution but also for enabling the high settleability of removed Pi. On-site experiments using a mobile plant showed that approximately 80% Pi could be recovered from anaerobic sludge digestion liquor at a wastewater treatment plant. This technology has the potential to offer a simple, compact service for recycling Pi from wastewater to farmland in rural areas.
Highlights
Various technologies are potentially applicable to phosphate (Pi) recovery from secondary phosphorus (P) resources such as sewage sludge, incinerated sludge ash, animal manure, and steelmaking slag (Ohtake and Okano 2015)
XRD analysis showed that Autoclaved lightweight concrete (ALC) particles exhibited several peaks corresponding to tobermorite and quartz, while dried A-calcium silicate hydrates (CSHs) exhibited several peaks characteristic of Ca(OH)2 (Fig. 2a)
Amorphous calcium silicate hydrates (A-CSHs) showed no peaks corresponding to tobermorite, regardless of whether they were washed with distilled water
Summary
Various technologies are potentially applicable to phosphate (Pi) recovery from secondary phosphorus (P) resources such as sewage sludge, incinerated sludge ash, animal manure, and steelmaking slag (Ohtake and Okano 2015). Their implementation has often been economically infeasible because of the high cost of plant development, construction, and operation. Approximately 1000 small plants are operating to treat blackwater and septic tank sludge in rural areas where no sewage service is available. Pi recovery in small WWTPs is likely a common challenge for recycling nutrients from wastewater to farmland in rural areas
Sign-in/Register to view highlights & summary 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 callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
