Preliminary Studies of Methylene Blue Remotion from Aqueous Solutions by Ocimum basilicum

The continuous expansion in the textile industry results in high loads of coloured wastewa-ters that heavily pollute the limited freshwater sources. Therefore, a wide array of treatment methods has been used to remediate water/wastewater from dyes. One common practice is the use of plants to degrade, absorb, metabolise, and detoxify different types of pollutants, including dyes. This study employs sweet basil (Ocimum basilicum) as a phytoremediation model herb to remove different concentrations (5–25 mg/L) of methylene blue (MB) dye from synthetic water, taking into account the effects of the MB dye concentration (5–25 mg/L) and contact time (up to 10 days). The results showed that the ability of Ocimum basilicum to absorb MB dye decreased with the increase of the MB dye concentration and increased with the increase of the contact time. The best removal of the MB dye was 93% when the concentration of the MB dye was 25 mg/L and the contact time was 10 days. Additionally, it was noticed that the relative growth rate (RGR) of the herbs was adversely influenced by increasing MB dye concentrations and that the best RGR value was 2.2 g/day when the MB dye concentration was 5 mg/L.