Adsorption of Natural Organic Matter and Phosphorus from Surface Water Using Heated Aluminum Oxide (Predeposited) Dynamic Membrane Adsorber

Abstract

The paper reports the removal of phosphorus and natural organic matter (NOM) from surface water by dynamic membrane (DM) adsorber. DM filter builds up as a layer of particles deposited via permeation through the membrane’s surface. This study reports the application of Heated Aluminium Oxide Particles (HAOPs) as a dynamic membrane adsorber. Filtration experiments were conducted with surface water and batch tests were carried out with synthetic water. The efficiency of phosphorus removal along with the efficiency of organics (represented as UV-254) removal was evaluated. Additionally, the impact of HAOPs surface loading on the changes of transmembrane pressure (TMP), the kinetics, isotherm modeling of the adsorption and the effect of the pH, the effect of ionic strength, the effect of coexisting organic matter on phosphorus removal efficiency were studied. In the case of phosphorus removal in batch adsorption experiments, its sorption kinetic and isotherm data were analyzed using pseudo-first- and pseudo-second-order models and Langmuir and Freundlich models, respectively. The results indicated that Langmuir adsorption isotherm fits the experimental data best (0.9894). The kinetics of phosphorus adsorption on HAOPs was best described by the pseudo-second-order model and the best removal was achieved at the pH 6–7 (96.65% on average). An increase in ionic strength did not impact the efficiency of phosphorus removal significantly. The outcome of this study highlights HAOPs efficiency in NOM removal up to 92% in filtration experiments. In the case of phosphorous, removal efficiency varied. For the highest HAOPs dose, the degree of phosphorus removal ranged up to 93 ± 5%. The same removal efficiency was observed for the lowest dose while for 17 g/m2 of HAOPs the fluctuations were larger and varied from 64.7% to 92%. The results demonstrate that HAOPs could potentially be applied in the removal of phosphorus from surface water, especially when there is a high concentration of phosphorus in the water. However, this process requires further research and optimization of its parameters.