Palm oil industry is among thelargest industry in Malaysia. According to statistical report by Malaysian PalmOil Board (MPOB), as of the year 2016, there are 5,737,985 hectares of oil palmplanted in Malaysia and yields 15.91 tonnes of fresh fruit bunch of palm oilper hectares.
Generally, fresh fruit bunch contains about 21% palm oil, 6–7%palm kernel, 14–15% mesocarp fibre, 6–7% palm kernel shell and 23% empty fruitbunch where mesocarp fruit fibre, palm kernel shell and empty fruit bunch arethe waste material (Husain et al., 2002). Preparing activated carbon frompalm kernel shell (PKS) by physical and chemical activation have beenextensively studied. Sulaiman et al.
,prepared PKS activated carbon by using carbon dioxide (CO2) emissionfrom calcium carbonate (CaCO3) as an activating agent and found anincrement in diameter of the pores and development of micropore and mesoporeson the surface as the activation time increases. The adsorption of CO2 capabilityalso was higher (31.38 mg/g) compared to the commercial PKS activated carbon(18 mg/g) when using 45g CaCO3 as an activating agent and atactivation temperature of 950 ?C(Sulaiman et al., 2013). In otherwork, Rugayah et al.
, described a preparation of activated carbon fromPKS by physical activation with steam and produced PKS based activated carbonwith Brunauer-Emmett-Teller (BET) surface area of 607.76 m2/g with541.76 m2/g micropore area and can removed 80.7% of chemical oxygendemanded from palm oil mill effluent with 8.83 mg/g adsorption capacity(Rugayah et al., 2014).
Preparation of PKS activated carbonby chemical activation using potassium hydroxide (KOH), zinc chloride (ZnCl2)and phosphoric acid (H3PO4) also have been studied (Andaset al., 2017, Afdhol et al., 2017 and Nik et al., 2006). Andas et al., suggest an optimalcondition of impregnation ratio (1:1.
5 raw PKS/KOH) and activation temperatureof 800 °C to produce highly porous PKS activated carbon (Andas et al.,2017). Afdhol et al.
in theirwork suggest the use of KOH as an activating agent is better than using ZnCl2as it will produce higher iodine number and lager surface area of PKSactivated carbon (Afdhol et al., 2017). Nik et al., propose an optimum concentration of H3PO4(30%) with activation temperature of 500 ?C and holding time of 2 hours to produce PKS activated carbon with BETsurface area of 1058 m2/g and average pore diameter of 20.
64 nm andalso capability to adsorb 100 % chromium, 99.8 % lead, 99.5 % cadmium and 25 %copper in artificial waste water (Nik et al., 2006).
A study suggests that PKS activatedcarbon from chemical activation using ZnCl2 as an activating agentproduced larger BET surface area compared to PKS activated carbon produced byphysical activation with steam (Hidayu & Muda, 2016). Some researchers suggest that PKS activatedcarbon is better than coconut shell activated carbon in terms of micropore andmesopore development, surface area and carbon dioxide adsorption capacity (Daudet al., 2014 and Hidayu & Muda, 2016).