03. Study on adsorption of ammonium ion from biogas effluent by bamboo biochar

Abstract

Biochar is the carbon-rich substance produced by the pyrolysis of biomass, which can be used in the treatment of nitrogen (N) pollution. The objective of this study is to evaluate the ammonium adsorption efficiency from biogas effluent by bamboo biochar pyrolysed at 700ºC. Several factors affecting ammonium adsorption capacity (i.e. solution pH, adsorbent dosage, contact time and initial ammonium concentration) were examined. The results showed that the experimental data was consistent with two isotherm adsorption models, Langmuir and Freundlich. In which, the Langmuir isotherm corresponded slightly better than the Freundlich isotherm. Optimal conditions for effective adsorption of ammonium were found at pH 8, 15 min contact time and adsorbent dose of 1 g L^-1. The maximum adsorption capacity of bamboo biochar for ammonium removal was 4.87 mg g⁻¹ based on the Langmuir isotherm.