Abstract
The focus of this study was to investigate the combined effects of hydrogen peroxide concentration and acid hydrolysis on ammonia and ortho-phosphate solubilization for subsequent struvite formation. A lower microwave temperature regime between 60 and 120 °C was of interest in this study because of the greater amount of polyphosphates found in the treated secondary sludge at these temperatures. At microwave-heating temperatures of 100 °C and 120 °C, it was found that increasing the hydrogen peroxide concentration resulted in an increased phosphorus and ammonia solubilization. At a reaction time of only 5 min, the combination of hydrogen peroxide and acid hydrolysis resulted in up to 61% of total phosphorus and 36% of TKN released into solution, as soluble ortho-phosphate and ammonia, respectively. The amount of soluble nitrogen in solution after microwave treatment was found to increase with the hydrogen peroxide concentration. Up to 39% of the total soluble nitrogen could be released into solution. Furthermore, the addition of hydrogen peroxide resulted in a dramatic decrease in the PO4:NH3 molar ratio, an important factor controlling struvite formation. In terms of facilitating poly-P breakdown into ortho-phosphate in the acid hydrolysis process, hydrogen peroxide was found to be the most effective at 80 °C and at a concentration of 1.5 wt% H2O2. At temperatures of 100 and 120 °C, the amount of soluble ortho-phosphate increased with the hydrogen peroxide concentration. Key words: advanced oxidation process, ammonia nitrogen, hydrogen peroxide, microwave, phosphorus release, sludge, struvite.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: 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.