Co-pyrolysis and activation of microalgae and waste polypropylene in the synthesis of nitrogen doped and porous carbon for pollutant adsorption

Abstract

Algae and waste plastics are two promising raw materials for the preparation of carbon-based adsorbents, which are regarded as the promising adsorbent to remove pollutants in wastewater. To obtain an activated carbon with well-developed porous structure and abundant functional groups, the mixture of H-rich disposable waste polypropylene (WP) and N-rich Chlorella vulgaris (CV) were selected as precursors through co-pyrolysis and KOH activation. The optimum mass ratio of WP and CV for preparing co-pyrolysis carbon (CPC) was 1:3, while the optimum mass ratio of CPC and KOH for preparing co-pyrolysis activated carbon (CAC) was 1:5 at the activation temperature of 800 °C. The morphologies, mean pore diameter, material surface element and degree of graphitization of CAC were analyzed by SEM, BET, XRD, XPS and Raman spectroscopy, respectively. The adsorption kinetics and thermodynamics of tetracycline (TC) onto CPC were investigated. And the sustainability of algal-based activated carbon in adsorption of pollutants has been tested. This study provides a synthesis method of CAC by using algal-based biomass and waste plastics for the absorption of organic pollutants in wastewaters.