Abstract:

Activated carbon is an excellent adsorbent, which has been used extensively for the removal of various pollutants from drinking water and wastewater. In the present study production, characterization and application of activated carbon from indigenous waste materials such as Shisham Wood and Coconut Shell was studied. In order to achieve this objective first of all a detailed literature review is carried out. Different raw materials for the production of activated carbon and their impact on final product are also studied. Detail study on two major activated carbon production techniques (physical and chemical activation) was carried out. Finally chemical activation selected to apply on coconut shell and shisham wood based on studies elsewhere using phosphoric acid as an activating agent. The experimental work consists of cleaning, crushing and sizing of these raw materials followed by impregnation with phosphoric acid. Obtained activated carbon was then shifted into furnace at a temperature of 600°C for 45 minutes in order to achieve maximum available surface area of activated carbon. The final product was washed to neutralize the sample and then it was dried and stored. For characterization, surface area is determined by using BET technique through surface area analyzer and iodine number using titration, whereas moisture content, ash content and volatile matter content is determined using gravimetric technique and pH value is measured by using pH meter. Adsorption capacity for both types of activated carbons is determined using a dye methylene blue as an adsorbent. Adsorption isotherm data for both activated carbons at different adsorbent concentrations were obtained using spectrophotometer and two adsorption models (Langmuir and Freundlich) are studied for this data and also a best-fit model is suggested on the basis of this study. It was found that produced activated carbon has adsorptive capacity (50.6 gm of MB per gm of Coconut shell AC and 73 .11 gm of MB per gm of Shisham wood AC) and adsorption isotherm follows the Freundlich isotherm model, moreover the surface area of shisham wood AC and coconut shell AC was found to be 812 m²/g and 735 m²/g respectively. The use of AC as electrode material couldn't be possible, as available technologies demand larger surface area of activated carbon (i.e. > 1000 m²/g). Literature review revealed that the high surface area can be prepared by simultaneous physical and chemical activation techniques that employ carbon dioxide and zinc chloride as physical and chemical activating agents respectively. The main aim of further research may be upon increasing the surface area of activated carbon to produce electrode materials for treating the raw water at NED University.