Effect of pretreatment on water quality before entering reverse osmosis desalination system

This study focused on evaluating the effectiveness of different filter media including activated carbon, Pyrolox and Greensand in improving water quality based on key parameters such as color, turbidity, dissolved oxygen, total dissolved solids, pH, hardness, and sludge density index. Preliminary results showed that each filter material had its own advantages. Specifically, activated carbon showed superior performance in removing color (8.3 TCU–9.233 TCU) and turbidity (0.5 NTU–0.767 NTU), while Pyrolox showed the highest efficiency in reducing dissolved oxygen in the range of 4.657–6.85 mg/L. Notably, Greensand was recorded as the best filter material in reducing sludge density index (3.52 ± 0.252), an extremely important factor for membrane filtration systems. The study also found that these filter media had no significant impact on pH, total dissolved solids and hardness of water. In addition, another important finding is that the use of filters with smaller pore sizes significantly improves color removal efficiency. These findings provide valuable data for the selection and optimization of water treatment systems to meet diverse water quality requirements in preparation for reverse osmosis desalination.