Hybrid Cornstalk Biochar-TiO₂ for Enhanced Color Degradation in Wastewater Treatment

Dye-contaminated wastewater poses a significant threat to ecosystems and human health. Many synthetic dyes are highly toxic, non-biodegradable, and resistant to conventional treatments. These dyes can block sunlight penetration in water bodies, disrupting aquatic life by hindering photosynthesis and reducing oxygen levels. Moreover, some dyes, particularly azo dyes, degrade into carcinogenic compounds, increasing the risk of cancer and genetic mutations in exposed populations [1]. Conventional wastewater treatments, such as filtration, coagulation, and chemical oxidation, often fail to degrade complex dye molecules to comply with the stringent regulations. Therefore, advanced treatments that are capable of addressing both dye adsorption and degradation are urgently needed. Photocatalysis is an effective process to remove organic contaminants in the environment. The most typical photocatalyst is nanoparticle titanium dioxide (TiO2) which is available commercially. Biochar is a carbon-rich material characterized by a large surface area and beneficial surface functional groups. Biochar could be produced from natural carbon-based materials, such as coconut shells, wood, and agricultural waste [3]. Producing biochar from agricultural waste such as cornstalk is a way to utilize the material and reduce amounts of waste that is highly possible burnt and create air pollution [3]. It is also highly effective for pollutant removal. Many studies fabricated biocharsupported photocatalyst such as TiO2 [3], ZnO [4,5], and tested for their efficiency to remove methylene blue and methyl orange in water. The results indicated that biochar-supported catalyst showed better pollutant removal than pure photocatalyst [4]. In this study, cornstalk biochar was incorporated with TiO2 to form a hybrid photocatalyst for the removal of dye from pulp industrial wastewater.