Modelling phosphorus sorption kinetics and the longevity of reactive filter materials used for on-sitewastewater treatment

• Published in: Water (Basel) Vol. 11; no. 4
• Main Authors: Hamisi, Rajabu, Renman, Gunno, Renman, Agnieszka, Wörman, Anders
• Format: Journal Article
• Language: English
• Published: 01.04.2019
• Subjects: Breakthrough; COMSOL modelling; Design and operations; Effluents; Emerging technologies; Filter bags; Filtration; P-filter bags; Passive filters; Phosphorus; Phosphorus saturation; Phosphorus sorption; Reactive materials; Small scale wastewater treatment; Solute transport; Wastewater treatment
• ISSN: 2073-4441; 2073-4441
• DOI: 10.3390/w11040811

Use of reactive filter media (RFM) is an emerging technology in small-scale wastewater treatment to improve phosphorus (P) removal and filter material longevity for making this technology sustainable. In this study, long-term sorption kinetics and the spatial dynamics of sorbed P distribution were simulated in replaceable P-filter bags filled with 700 L of reactive material and used in real on-site treatment systems. The input data for model calibration were obtained in laboratory trials with Filtralite P®, Polonite® and Top16. The P concentration breakthrough threshold value was set at an effluent/influent (C/C 0 ) ratio of 1 and simulations were performed with P concentrations varying from 1 to 25 mg L -1 . The simulation results showed that influent P concentration was important for the breakthrough and longevity, and that Polonite performed best, followed by Top16 and Filtralite P. A 100-day break in simulated intermittent flow allowed the materials to recover, which for Polonite involved slight retardation of P saturation. The simulated spatial distribution of P accumulated in the filter bags showed large differences between the filter materials. The modelling insights from this study can be applied in design and operation of on-site treatment systems using reactive filter materials.