Evaluation of Characteristics of Activated Carbon from Rice Husk Impregnated with Zinc Chloride and Phosphoric Acid

Abstract

Activated carbon is essential in adsorption process of different dye and metals from waste streams. The molecular size of different species is different. So they could have some restriction to move into the pore in activated carbons smaller than their molecule size. In this regards a study is conducted to evaluate the adsorption characteristics of zinc chloride and phosphoric acid impregnated activated carbon. Methylene blue (MB) and nitrogen having two distinct molecular sizes are adsorbed to evaluate the adsorption characteristics of the activated carbons. Nitrogen molecules have access into smaller pores compared to MB molecules. Nitrogen adsorption test shows higher specific surface area compared to MB adsorption test. In methylene adsorption test, phosphoric acid impregnated activated carbon shows higher specific surface area (646 m 2 g -1 ) compared to that of zinc chloride impregnated activated carbon (599 m 2 g -1 ). In contrast zinc chloride shows higher specific surface area (927 m 2 g -1 ) compared to that of phosphoric acid impregnated activated carbon (718 m 2 g -1 ) in liquid nitrogen adsorption test. This happened because zinc chloride could develop smaller size pore in higher degree compared phosphoric acid during activation process. Results show that development of pore size is affected by two different agents. MB and nitrogen adsorption test reveals that zinc chloride activated material produced more number of small pores compared to phosphoric acid activated material. From this study it is concluded that the desired size of pores in activated carbon could be achieved for adsorption of species with specific molecular diameter by varying the type of activation agents.

Effect of Activation Agents on COD Reduction Using Activated Carbon from Agricultural Residue

“…For both materials, the degree of porous structure was highest with KOH activation followed by ZnCl2 and H3PO4. Ahiduzzaman [3] found rice husk treated with ZnCl2 showed well developed micro pore structures compared to rice husk treated with H3PO4 which displayed larger pores. Another study by Xia [4] claimed that KOH activation carbon has abundant circular pores, thus supported the result in this study for KOH activation.…”

Removal of Methyl Red using Chemical Impregnated Activated Carbon Prepared from Parkia speciosa Pod (Petai) as a Potential Adsorbent

“…It proclaims that activated carbon treated with zinc chloride is significantly microporous and suitable for activated carbon production. Ahiduzzaman and Abul, (2016) also report that zinc chloride has higher surface area with higher micro and nano pores developed. This evidence supports activated carbon D for its highest dye removal percentage properties.…”

Single and Ternary Removal of Heavy Metals from Aqueous Solution Using Fe3O4 Magnetic Nano-particles

“…The areas of FeN and FeN-S were determined by using methylene blue as an adsorbate as described by Ahiduzzaman and Islam (2016). Methylene blue concentrations of 50, 100, 200 and 300 ppm were put in the test batch jars and 0.02 g of FeN was added to each batch and mixed for 2 hours at room temperature.…”