Biomass-derived activated carbon for removal of 222Rn from air

Radon (222Rn) and its decay products are considered harmful to humans because of their toxicity and is regard as a prior cause of lung cancer in non-smokers. This research thus focuses on the application of activated carbon synthesised from pinecone for mitigating the risk of radon in indoor environments. Characterization of the prepared carbon was evaluated using FESEM, TGA, and BET surface area and total pore volume analyzer. BET surface area of the prepared carbon was found to be 839 m2 g-1 and a total pore volume of 0.476 cm3 g-1. Fixed-bed adsorption method was used to estimate the adsorbent efficiency by varying process parameters such as bed length, bed diameter and flow rate. On the basis of these parameters, breakthrough curves were generated to calculate the breakthrough time for obtaining the adsorption coefficient(K) of the prepared carbon which was found to be in the range of 3.05–4.90 m3 kg-1. Regeneration studies were done at different temperatures for 50 min which showed that heating at 70–90 °C resulted in complete degassing of the adsorbed 222Rn, with K equivalent to that of the pristine carbon.