Biochar-ZnO Composites from Petung Bamboo Stems to Increase Adsorption and Photocatalytic Degradation of Methylene Blue in Wastewater

Abstract The rapid development of industrial sector worldwide has contributed greatly to environmental pollution. In many countries, surface and groundwater are polluted by industrial wastewater effluent, such as synthetic dyes. Dyes are difficult to decompose naturally and cause disruption to aquatic ecosystems. To eliminate risks associated with the presence of synthetic dyes, photocatalytic-adsorption is still considered the most environmentally friendly and effective for dye removal. In this work, a novel biochar-ZnO composite was synthesized from petung bamboo stems having a high cellulose content, and used to eliminate methylene blue dye in the water. Biochar-ZnO composite was prepared from bamboo stems via a two-step pyrolysis process in a furnace with nitrogen flow at 400°C and 700°C for one hour. The addition of ZnO into biochar enhanced methylene blue removal up to 94.6% at an initial concentration of 10 mg.dm -3 , pH 3, and contact time of 180 minutes, under UV light. It can be concluded that biochar-ZnO composite is highly feasible for dye removal from wastewater.