removal of colour and cod in biologically pre-treated leachate using activated carbon from corn cobs

Activated carbon was prepared from corn cob agricultural waste with different impregnation ratios and pyrolysis times. the optimal adsorbent prepared using at 4:1 zncl2:corn cob char ratio at a temperature of 800 °c for 180 min provided the maximum brunauer-emmett-teller (bet) surface area, total pore volume and average pore width, with values of 912.47 m²/g, 0.52 cm³/g and 22.61 å, respectively. zncl2 was effective in creating well-developed pores on the surface of the activated carbon. the removal efficiency and adsorption capacity of the colour and the chemical oxygen demand (cod) of the biologically pre-treated leachate were examined utilizing the best corn cob activated carbon (ccac) with varying ccac dosages, contact times and initial ph values. the greatest colour and cod removal effectiveness were 88.6±0.2% and 83.7±0.4%, respectively, at the optimum ccac dosage of 12 g for 40 min with an initial ph value of 10. in addition, maximum adsorption capacities were achieved for colour and cod of 10.3±0.02 mg/g and 12.6±0.05 mg/g, respectively, under the same conditions. the kinetics of colour and cod adsorption fitted very well with pseudo-second-order kinetic model. the ccac performs well as an adsorbent for removing colour and cod in biologically pre-treated leachate.