Effect of Biochars Made From Different Materials On Wastewater N and P Adsorption.

Biochar was reported to have effects of adsorption on heavy metals and harmful organic material, which was produced from slow pyrolysis progress during the production of bio-fuel. The adsorption characteristics were significantly influenced by the material and producing condition. This study compared the adsorption of N and P in municipal wastewater by 4 different biochars produced from different materials, a commercial biochar (Dynamotive Canada), ABE (peanut Hull), Bagasse (sugar beet tailing) and hardwood, compared to commercially activated carbon as a control. The rates of 0, 0.1, 0.2, 0.4, 1, 2, and 4 g of biochar were selected to treat 40 ml of wastewater in 50 ml polymeric tubes. NH₄-N adsorption by Dynamotive and ABE increased significantly with the biochar rate, while that of activated carbon did not show any increase until the rate of 1:100. The adsorption of Bagasse and hardwood increased from the rate of 1:400 and decreased from the rates of 1:40 to 1:10 significantly. The ortho-P adsorption by biochars from Dynamotive, hardwood, bagasse and activated carbon increased with application rates and materials in the order of bagasse > hardwood > Dynamotive > activated carbon. The ABE was found releasing P significantly to the water. The highest NH₄-N and ortho-P decreased in the water by biochars reached up to 80.4% and 98.1%, which showed good potential of being used as wastewater treatment materials.

Key word: biochar, wastewater, NH4-N, Ortho-P, adsorption