Study on the co-pyrolysis behavior of copper slag and biomass and the adsorption of Cr (VI)

Abstract

Abstract The co-pyrolysis behavior of PS(pine sawdust) biochar doped with CS(copper slag) and the adsorption performance of the prepared CS catalyzed composite adsorbent is studied.Thermogravimetric,SEM and BET is used to analyze the co-pyrolysis characteristics and the adsorption performance of PS and its mixed samples with different ratios of PS and CS. When the mixing ratio PS: CS = 3:1, the pyrolysis release characteristics were the highest, The most favorable for the pyrolysis reaction. The co-pyrolysis of CS and PS effectively improves the activation energy of the reaction process. The activation energy increased by co-pyrolysis shows a trend of first increasing and then decreasing with the increase of reaction order. When the reaction order n = 1, the activation energy increased by co-pyrolysis of PS and CS is the highest, at 13.311 kJ/mol. The H3PO4, KOH, and ZnCl2 was used to modify PS carbon improved its adsorption capacity. The results showes that the modified PS carbon has a larger specific surface area and providing more adsorption sites, effectively improving the adsorption effect. The adsorption capacity of PS carbon is inversely proportional to the concentration of Cr (VI) solution.Under the conditions of catalyzing PS at 1:1 based on CS, the concentration of Cr (VI) solution is 20mg, and the adsorption effect is best in an acidic environment with pH = 1. Realized the high value-added utilization of metallurgical solid waste and agricultural waste, namely the governance concept of "treating danger with waste".