Phosphorus removal from wastewater using Ca-modified attapulgite: Fixed-bed column performance and breakthrough
1Laboratory of Environmental Biotechnology, School of Environmental and Civil Engineering, Jiangnan University, Wuxi, 214122, PR China; Jiangsu Key Laboratory of Anaerobic Biotechnology, Wuxi, 214122, PR China; Jiangsu Cooperative Innovation Center of Technology and Material of Water Treatment, Suzhou, 215009, PR China.
Journal of Environmental Management
|December 15, 2022
Summary
Calcium-modified attapulgite (Ca-GAT) effectively removes phosphorus from wastewater. This study details its dynamic adsorption, regeneration, and application potential in fixed-bed systems for low-concentration phosphorus removal.
Area of Science:
- Environmental Science
- Water Treatment Technology
- Materials Science
Background:
- Low-concentration phosphorus wastewater poses environmental challenges.
- Calcium-modified attapulgite (Ca-GAT) shows promise for phosphorus removal.
- Dynamic adsorption and industrial applicability require further investigation.
Purpose of the Study:
- To evaluate the dynamic phosphorus adsorption performance of Ca-GAT.
- To determine optimal parameters for phosphorus removal in fixed-bed columns.
- To assess the regeneration efficiency and real-world application potential of Ca-GAT.
Main Methods:
- Dynamic adsorption experiments were conducted varying initial phosphate concentration, flow rate, and bed height.
- Breakthrough curves were analyzed using Adams-Bohart, Thomas, Yoon-Nelson, and BDST models.
- Column regeneration was tested using NaOH, NaOH + NaCl, and HCl solutions.
- Ca-GAT was applied to treat actual membrane bioreactor (MBR) effluent.
Main Results:
- Adsorption capacity and breakthrough time increased with bed height and flow rate, and decreased with higher initial phosphorus concentrations.
- The Thomas model predicted a maximum adsorption capacity of 13.477 mg/g.
- 0.5 mol/L NaOH demonstrated the most effective regeneration.
- A fixed-bed column treated MBR effluent for 177 hours before reaching a breakthrough point of 0.5 mg/L.
Conclusions:
- Ca-GAT exhibits significant potential for the dynamic removal of phosphorus from low-concentration wastewater.
- Optimized parameters enhance adsorption efficiency and column longevity.
- Effective regeneration and successful application in treating MBR effluent support its industrial viability.
