Effect of solids retention time on nitrogen and phosphorus removal from municipal wastewater in a sequencing batch membrane bioreactor

• Published in: Environmental technology 2017-04, Vol.38 (7), p.806-815
• Main Authors: Belli, Tiago José, Bernardelli, Jossy Karla Brasil, da Costa, Rayra Emanuelly, Bassin, João Paulo, Amaral, Miriam Cristina Santos, Lapolli, Flávio Rubens
• Format: Article
• Language: English
• Subjects: Bioreactors; Bioreactors - microbiology; Chemical oxygen demand; Efficiency; membrane bioreactor; Membranes; Nitrogen; Nitrogen - isolation & purification; Nutrient removal; Phosphates; Phosphorus - isolation & purification; Phosphorus removal; Reduction; Retention; sequencing batch reactor; solids retention time; Waste Disposal, Fluid - methods; Wastewater treatment; Water Purification - methods; Water treatment plants
• ISSN: 0959-3330; 1479-487X
• DOI: 10.1080/09593330.2016.1212934

This study evaluated the removal of organic matter, nitrogen and phosphate from a municipal wastewater in a sequencing batch membrane bioreactor (SBMBR) operated at different solids retention times (SRTs) and subjected to different aeration profiles. The results demonstrated that SRT reduction from 80 to 20 d had a negligible effect on chemical oxygen demand (COD) removal and only a slight negative effect on nitrification. COD removal efficiency remained stable at 97%, whereas ammonium removal decreased from 99% to 97%. The total nitrogen removal efficiency was improved by SRT reduction, increasing from 80% to 86%. Although the total phosphorus (TP) removal was not significantly affected by the SRT reduction, ranging from 40-49%, the P-release and P-uptake processes were observed to increase as the SRT was reduced. The implementation of a pre-aeration phase in the SBMBR operating cycle allowed a higher TP removal performance, which reached up to 76%. Batch tests suggested that the fraction of phosphate removed anoxically from the total (anoxic + aerobic) phosphate removal decreased with the SRT reduction.