Title |
Ammonium removal and recovery from effluent of AnMBR treating real domestic wastewater using polymeric hydrogel |
ID_Doc |
15265 |
Authors |
He, MB; Ng, TCA; Huang, SJ; Xu, BY; Ng, HY |
Title |
Ammonium removal and recovery from effluent of AnMBR treating real domestic wastewater using polymeric hydrogel |
Year |
2022 |
Published |
|
DOI |
10.1016/j.seppur.2022.121376 |
Abstract |
Anaerobic membrane bioreactor (AnMBR) technology has been considered promising to transform domestic wastewater (DWW) treatment as a net energy producer via bioenergy recovery. However, ammonium-nitrogen (NH4+-N) in DWW cannot be removed by anaerobic process, which raises the risk of eutrophication and prevents the wide-scale adoption of AnMBRs. This study proposed adsorption/desorption by poly (acrylic acid) (PAA) hydrogel as the post-treatment of AnMBRs to remove and recover NH4+-N, thus simultaneously promoting AnMBR technology and the circular economy. Batch experiment results showed that NH4+-N could be rapidly adsorbed by PAA hydrogels within 30 min with excellent maximum adsorption capacities of 110.6-120.8 mg N/L (10-50 degrees C). Furthermore, PAA hydrogels retained 81.1 % of NH4+-N adsorption capacity when treating AnMBR effluent, preliminarily suggesting their practical feasibility in complex water matrix. Thereafter, PAA hydrogels were packed into a bench-scale fixed-bed column. Up to 98.5% of NH4+-N in AnMBR effluent could be captured in the hydrogel column at the breakthrough point at flow rate of 0.5 mL/min, achieving a polished effluent concentration of <1.5 mg N/L and thus meeting the strictest discharge regulations. The hydrogel column could be regenerated for 10 adsorption/desorption cycles with an insignificant decline in adsorption capacity of -4.7%, highlighting its excellent reusability. More importantly, we for the first time proposed the strategic recirculation of 1 mol/l HCl solution as eluent and obtained an NH4+-N enrichment factor of -10 over four rounds of adsorption/desorption, demonstrating the promise of this strategy to concentrate NH4+-N as resources. The economic analysis based on our experimental results showed that PAA hydrogel-based adsorption/desorption process coupled with eluent recirculation has the potential to remove and recover NH4+-N from AnMBR effluent cost-effectively. Overall, this study could potentially expand the application of AnMBRs and foster innovations in sustainable wastewater treatment. |
Author Keywords |
Anaerobic membrane bioreactor; Adsorption; Ammonium-nitrogen; Desorption; Poly (acrylic acid) hydrogel; Resource recovery |
Index Keywords |
Index Keywords |
Document Type |
Other |
Open Access |
Open Access |
Source |
Science Citation Index Expanded (SCI-EXPANDED) |
EID |
WOS:000808473200006 |
WoS Category |
Engineering, Chemical |
Research Area |
Engineering |
PDF |
|