Air Purification Capability of Charcoal and Its Evaluation

摘要

Charcoal has gotten a lot of attention recently according to the various kinds of functions to humans. Especially, it has been set in an indoor space and the deodorizing capability has been applied. However, the evaluation method is not established. It is necessary to construct the method and introduce the capability to general public using an index value. General public can understand the capability easily due to the value and use it positively. In this study, an evaluation method was proposed, namely the capability was evaluated in an experimental chamber using a tin oxide gas sensor, which could output the signal according to the concentration of air polluting chemical. The sensor output increases as the chemical concentration increases. The index value (Pa) indicating the capability can be represent using the sensor output characteristic to the chemical, namely peak value (h) and half-value width (tw). Pa = h / tw. The peak value means the voltage from base level to the peak value of the sensor. Four kinds of charcoals were examined. Especially the ones for Japanese cedar and Japanese oak were investigated. As the results, the both ones indicated almost same value (about Pa = 10). The cedar charcoal is cheaper and the heat is lower than the one for the oak. It is good factor for the cedar charcoal. It is considered that the installing charcoal in indoor environment to purify air quality will penetrate masses and humans can have a safe and comfortable life. Charcoal has the function to remediate the indoor environment.