Biochar Derived from Water Hyacinth Biomass Chemically Activated for Dye Removal in Aqueous Solution

Rapid industrial development has led to the use of numerous dyes responsible for significant water pollution worldwide. Adsorbents have been developed to treat these waters, mainly in the form of activated biochar, which has several advantages, one of which is its good surface characteristics, such as high surface area and pore volume. The objective of the investigation was to analyze the efficiency of removing the methylene blue model dye in aqueous solutions through the adsorption process using biochar chemically activated from the leaf and stem of water hyacinth (Eichhornio crassipes) as a bioadsorbent. This study carbonized the stem and leaf containing zinc chloride at 600 °C. The materials were characterized by different techniques and were tested for their ability to adsorb methylene blue. The activated stem and leaf biochars removed approximately 285.71 and 322.58 mg g−1 of the dye, respectively, indicating that the adsorption is more significant in the leaf. Pseudo-second-order kinetics was the most suitable model to describe dye adsorption on biochars, and the experimental isotherm data fit the Langmuir model. It is concluded that the application of activated water hyacinth biochar is a renewable resource with the potential for effluent treatment.