Iron and manganese removal: Recent advances in modelling treatment efficiency by rapid sand filtration

• Published in: Water research (Oxford) 2017-02, Vol.109, p.35-45
• Main Authors: Vries, D., Bertelkamp, C., Schoonenberg Kegel, F., Hofs, B., Dusseldorp, J., Bruins, J.H., de Vet, W., van den Akker, B.
• Format: Article
• Language: English
• Subjects: Adsorption; Filtration; Iron; Manganese; Oxidation; Rapid sand filter; Silicon Dioxide; Water Pollutants, Chemical; Water Purification
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2016.11.032

A model has been developed that takes into account the main characteristics of (submerged) rapid filtration: the water quality parameters of the influent water, notably pH, iron(II) and manganese(II) concentrations, homogeneous oxidation in the supernatant layer, surface sorption and heterogeneous oxidation kinetics in the filter, and filter media adsorption characteristics. Simplifying assumptions are made to enable validation in practice, while maintaining the main mechanisms involved in iron(II) and manganese(II) removal. Adsorption isotherm data collected from different Dutch treatment sites show that Fe(II)/Mn(II) adsorption may vary substantially between them, but generally increases with higher pH. The model is sensitive to (experimentally) determined adsorption parameters and the heterogeneous oxidation rate. Model results coincide with experimental values when the heterogeneous rate constants are calibrated. [Display omitted] •Iron and manganese sorption capacity varies along filter depth and between sites (83 characters).•Sorption capacity generally increases with increasing pH of influent water (71 characters).•Adsorption isotherm values are critical for modelling iron and manganese removal (82 characters).•Heterogeneous oxidation rate constant critically defines the modelled removal (81 characters).