Preparation and sorption properties of porous materials from refuse paper and plastic fuel (RPF)

Porous materials consisting of activated carbon and amorphous CaO-Al2O3-SiO2 (CAS) compound were prepared from refuse paper and plastic fuel (RPF), (a mixture of old paper and plastic) by carbonizing and/or activating treatments. Samples formed by chemical activation using K2CO3 showed a high specific surface area (SBET) of 1330 m2/g but a lower ash content due to being washed after activation. By contrast, samples prepared by physical activation using steam showed rather lower SBET (510 m2/g) due to higher ash contents. The physically activated samples showed much higher uptake properties for Ni2+ (a representative heavy metal) and phosphate ions (a representative of a harmful oxyanion) than the chemically activated samples because of the higher content of amorphous CAS in the former samples. By contrast, the chemically activated samples showed higher uptake for methylene blue (MB, a representative organic material) than the physically activated samples because of the higher activated carbon content of higher surface area. Although differences in the sorption properties for Ni2+, phosphate ion and MB were found between the physically and chemically activated samples, both samples show excellent multiple sorption properties for cation-anion combinations and inorganic-organic sorbents.