Mixed (organic and inorganic) contaminants removal ability of water fern biomass-based biochar on starch industry wastewater

Starch represents one of the primary dietary ingredients and acts as raw substances for a variety of dietary supplements that benefit human health, but during the manufacturing process, massive amounts of wastewater are released into the surroundings. This investigation was conducted to assess the physicochemical properties of Tapioca processing wastewater and to propose an ecologically sound method for treating this problem using water fern biomass-based biochar. The typical physicochemical attributes investigation demonstrated that the majority of the parameters exceeded the acceptable limits, potentially facilitating eutrophication. Particularly, the concentration of dissolved oxygen was significantly low, which may encourage eutrophication. The problematic water fern weed biomass was used as a feedstock for biochar production through pyrolysis. Temperatures that ranged from 200 °C to 400 °C and a residence time of 20–60 min have been demonstrated to be suitable for significant yields (55–32%). Moreover, 20 g L⁻¹ of water fern biochar demonstrated the highest pollutant adsorption compared to other dosages in 1 L of wastewater. At a dosage of 20 g L⁻¹, biochar can effectively remove contaminants from wastewater at 40 °C and 30 °C, respectively. The toxicity of treated water analysis on Vigna radiata germination was determined using different sample ratios, and water fern biochar application significantly reduced pollutants/toxicity in starch industry wastewater. These findings indicate that the majority of contaminants in starch industry wastewater were efficiently adsorbed under such optimal conditions.