Phosphate removal from water using bottom ash: adsorption performance, coexisting anions and modelling studies
Khalid S Hashim1, Hind Mufeed Ewadh2, Adnan A Muhsin3
1Built Environment and Sustainable Technologies (BEST) Research Institute, Liverpool John Moores University, Liverpool L3 3AF, UK E-mail: k.s.hashim@ljmu.ac.uk; Faculty of Engineering, University of Babylon, Hilla, 5200, Iraq.
Summary
Industrial bottom ash effectively removes phosphate from freshwater, offering a sustainable solution for water remediation. This study optimized conditions for maximum phosphate removal using this cost-effective adsorbent.
Area of Science:
- Environmental Science
- Water Treatment Technologies
- Materials Science
Background:
- Phosphate contamination in freshwater impacts water quality and human health.
- Conventional phosphate removal methods include biological and electrochemical treatments.
- Adsorption presents a promising, convenient approach for water and wastewater remediation.
Purpose of the Study:
- To evaluate the efficacy of industrial bottom ash (BA) as a cost-effective adsorbent for phosphate removal from water.
- To investigate the influence of key parameters (solution temperature, humic acid concentration, pH, adsorbent dose) on phosphate adsorption by BA.
- To model and optimize the adsorption process using Central Composite Design (CCD) and assess adsorption using the Langmuir model.
Main Methods:
- Characterization of the physical and chemical properties of bottom ash.
- Batch experiments designed using Central Composite Design (CCD) to study adsorption parameters.
- Langmuir isotherm modeling to evaluate the adsorption mechanism and capacity.
- Development of a predictive model using CCD to simulate phosphate removal efficiency.
Main Results:
- Bottom ash (BA) achieved 83.8% removal of 5.0 mg/l phosphate under optimized conditions (35 °C, 20 mg/L humic acid, pH 5, 55 g/L adsorbent dose).
- The Langmuir isotherm indicated a favorable adsorption affinity between BA and phosphate.
- The CCD-developed model accurately predicted phosphate removal by BA, with a coefficient of determination (R²) of 0.99.
Conclusions:
- Industrial bottom ash is a viable, eco-friendly adsorbent for efficient phosphate removal from contaminated freshwater.
- Optimized conditions and a validated predictive model enhance the practical application of BA in water treatment.
- This study demonstrates a sustainable approach to managing phosphate pollution using industrial by-products.
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