Characterization of adsorbent from pine strobilus active charcoal (Pinus merkusii) and its performance in adsorption of methylene blue

Indonesia is a tropical country that has forest areas around 162 million hectares. One of the forestry results is a pine tree. The pine trees have male and female reproductive organs called strobilus. Strobilus pine has a high potential for charcoal fiber. However, the use of pine strobilus is still limited. Strobilus can be converted into activated charcoal as an adsorbent. This study aimed to analyze the characteristics of activated charcoal from pine strobilus using ZnCl2 and Na2CO3 as the activators and to determine the ability of its adsorption to methylene blue. The research steps begin with making pine strobilus activated charcoal using ZnCl2 and Na2CO3 as the activators. Then, the active charcoal characteristics test was carried out in the form of water content, ash content, and activated charcoal adsorption ability of methylene blue was analyzed by UV-Vis spectrophotometer at a wavelength of 665 nm. The selection of activators in the form of ZnCl2 and Na2CO3 was based on previous research, which stated that activated charcoal with activator ZnCl2 had greater adsorption energy than other activators. The result of the study showed differences in the characteristics of activated charcoal with ZnCl2 and Na2CO3 as the activators. The characteristic of activated charcoal strobilus pine with the ZnCl2 activator was 22.37% water content, and the Na2CO3 activator was 45.99%. The ash content test result with ZnCl2 activator was 15.76% and with activator Na2CO3 was 14.06%. Pine strobilus activated charcoal with Na2CO3 activator has a higher adsorption capacity of methylene blue, which is 2.4131 mg/g sample, compared with the ZnCl2 activator which only 2.3508 mg/g sample.