Adsorption of Cu(II) and Zn(II) Ions by Solidified Landfilled Sludge and its Pyrolyzed Produce

In this study, using solidified landfilled sludge (SLS) and its pyrolyzed produce (PSLS) as adsorbents, adsorption characteristics of Cu2+ and Zn2+ onto SLS and PSLS was investigated. These results revealed that PSLS had more irregular pores and its surface roughness increased, and the surface area of PSLS was twice than that of SLS. Adsorption studies showed that adsorption capacity of Cu2+ and Zn2+ increased with the increasing dosage of adsorbents, and the adsorption process of Cu2+ and Zn2+ onto SLS or PSLS could be divided into the first rapid step and the second slower step. Based on Langmuir equation, the maximum limiting adsorption capacities of Cu2+ and Zn2+ onto PSLS was much higher that onto SLS. Moreover, FTIR analysis showed that the adsorption of Cu2+ and Zn2+ on SLS depended on active functional group such as hydroxy aldehydes while that relied on the groups such as C=C bond of aromatic rings, Si-O-Si or Si-O-C structures for PSLS.