Figure 1

Scanning electron micrographs of biochar samples at magnifications of 450× (CR, CS), 170× (OP), 330× (PO), 1000× (SB), and 200× (WH). (CR = charcoal fines; CS = coconut shell; OP = orange peel; PO = palm oil bunch; SB = sugarcane bagasse; WH = water hyacinth).