Performance of dissolved organic matter removal from membrane bioreactor effluent by magnetic powdered activated carbon

• Published in: Journal of environmental management 2019-10, Vol.248, p.109314-109314, Article 109314
• Main Authors: Ittisupornrat, Suda, Phihusut, Doungkamon, Kitkaew, Duangta, Sangkarak, Sirirat, Phetrak, Athit
• Format: Article
• Language: English
• Subjects: Composite adsorbent; Dissolved organic matter; Humic acid; Iron impregnation; Molecular weight; Municipal solid waste leachate; Posttreatment
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2019.109314

Magnetic powdered activated carbon (Mag-PAC) was successfully developed and applied as an adsorbent for dissolved organic matter (DOM) removal from the effluent of a membrane bioreactor (MBR) using batch experiments. The results show that a coating of iron oxide particles is consistently distributed on the surface of powdered activated carbon (PAC), resulting in a decrease in the specific surface area and in the pH at the point of zero charge, even though the particle sizes of Mag-PAC and PAC were similar. A Mag-PAC dosage of 4 g/L exhibited efficient and fast DOM adsorption with a relatively short contact time of 5 min. The iron oxide coating on the surface of PAC may play an important role in the DOM removal efficiency. Temkin isotherm and pseudo-second order kinetic models well described the DOM adsorption, suggesting that the adsorption of DOM onto Mag-PAC could be mainly governed by a chemisorption mechanism. Humic acid- and fulvic acid-like compounds and aromatic DOM with molecular weights (MWs) between 2610 Da and 3030 Da were efficiently removed by Mag-PAC, whereas aromatic DOM with an MW of 1760 Da was poorly removed. Our results demonstrate that the application of Mag-PAC for DOM adsorption is attractive and yields benefits as a posttreatment system for MBR effluent due to its efficient and fast DOM adsorption. [Display omitted] •A novel composite adsorbent called Mag-PAC was successfully prepared.•Mag-PAC rapidly adsorbed DOM with a short contact time of 5 min.•DOM sorption onto Mag-PAC is mainly based on the principle of chemisorption.•Mag-PAC can be easily and rapidly separated using a magnet.