PHYSICOCHEMICAL CHARACTERIZATION AND EFFECTS OF FLY ASH GENERATED FROM BIOCHAR BRIQUETTES ON THE GROWTH OF CHINESE CELERY CABBAGE (BRASSICA RAPA SUBSP. PEKINENSIS)

Abstract

Agricultural waste biomass is considered a valuable source of eco-friendly renewable energy. Generally, biomass is processed through pyrolysis and is compressed to form biochar briquettes. After combustion, the remaining ash is the incombustible material that can be used in agriculture. The aim of this research is to investigate the physicochemical properties of fly ash derived from biochar briquettes and to evaluate its effect on the growth of Chinese celery cabbage (Brassica rapa subsp. pekinensis). Fly ash was analyzed using a scanning electron microscopy (SEM) equipped with an energy dispersive X-ray spectroscopy (EDS) and X-ray diffractometer (XRD). The results exhibited the major elements were carbon (C, 59.31%), oxygen (O, 24.48%) with additional elements including potassium (K), silicon (Si), aluminum (Al), and calcium (Ca). The XRD pattern confirmed the presence of silica (SiO2), calcite (CaCO3) and hydroxyapatite (Ca10(PO4)6(OH)2). Seedlings of the tested plants were grown in pots containing varying concentrations of local soil and biochar briquette ash (soil:ash, v/v), with treatments including 100% soil (control, T1), 80:20 (T2), 60:40 (T3), and 40:60 (T4). Growth parameters improved significantly with 40% ash (T3), while 60% ash (T4) had adverse effects. These results indicated that biochar briquette ash can be effectively used as an ash-based fertilizer.