Coconut frond biochar as adsorbent in removal of methylene blue dye in aqueous solution

The biochar based on coconut fronds as adsorbent was successfully prepared for the removal of methylene blue dye. Several researchers proposed that low cost adsorbents from agriculture waste are effective and cheaper. Methylene blue dye will give some of harmful side-effects to environment and human health. Factors such as the effect of carbonization temperature of adsorbent (400 °c, 600 °c and 800 °c), adsorbent dosage (0.2 g, 0.5 g, 1 g, 2 g, 3 g and 4 g), initial dye concentration (50 mg/L, 100 mg/L 150 mg/L, 200 mg/L, 250 mg/L, 300 mg/L and 400 mg/L), contact time (5 min, 30 min, 60 min, 120 min and 240 min) and pH (2, 3, 4, 5, 6, 7, 8, 9, 10, 11) were studied. The calibration curve of methylene blue dye was plotted (R2 = 0.9961). Optimum values were obtained at 800 °C of carbonisation temperature, 1 g of adsorbent dosage, 100 mg/L of initial concentration, 60 min of contact time and pH 9. The experimental data was analysed with the Langmuir and Freundlich adsorption isotherm equations. The Langmuir isotherm model has given a best fitted line. Besides that, the adsorbent was characterized using Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Fluorescent (XRF) and Scanning Electron Microscope (SEM). Based on the research, results showed that the coconut frond have the highest percentage of methylene blue dye removal which reached up to 99% under optimum condition.