As, Cd, Cr, Cu, Ni and Zn removal using granulated ferric hydroxide (GFH) in batch and column experiments
Sustainable process-product development & green chemistry
Sustainable & Clean Technologies-I: Extraction & Remediation (T1-4P)
Keywords: adsorption, GFH, heavy metal, humic acid, adsorption isotherm
Hülya Genç-Fuhrman, Peng Wu, Yushan Zhou, and Anna Ledin*
Institute of Environment & Resources, Technical University of Denmark, Building 115, DK-2800 Kgs. Lyngby, Denmark
* Corresponding author
As, Cd, Cr, Cu, Ni and Zn removal using granulated ferric hydroxide (GFH) in batch and column experiments
Hülya Genç-Fuhrman, Peng Wu, Yushan Zhou, and Anna Ledin*
Institute of Environment & Resources, Technical University of Denmark, Building 115, DK-2800 Kgs. Lyngby, Denmark
*Corresponding author
Abstract
Granulated ferric hydroxide (GFH) is widely used to remove As from aqueous solutions. In this study GFH is tested for its ability to remove a range of heavy metals (i.e. As, Cd, Cr, Cu, Ni, and Zn). Experimental results are further investigated using various modeling tools including Freundlich and Langmuir isotherms (for batch experiments), Thomas Model (for column experiments), surface complexation modeling (SCM), and PHREEQ-C geochemical modeling.
Batch experiments are used with various initial heavy metal concentrations (from 3 to 58,300 μg/L) to determine the adsorption capacities at the initial pH of 6.5. The isotherm parameters, such as and (for Langmuir isotherm) and K and (for Freundlich isotherm) are also calculated and presented in Table 1, where it can be seen that the Freundlich model fits the data better. Calculated adsorption capacities were 1.16, 2.19, 3.94, 1.17, 3.74, and 21.01 μmol/g for As, Cd, Cr, Cu, Ni and Zn, respectively.
Furthermore, the effect of humic acid and light on the heavy metal removal is also tested using up-flow column experiments. The total adsorbed capacities and total removal efficiencies related to the columns were determined by evaluating the breakthrough curves (BTCs) obtained at different conditions. Higher adsorption capacities were observed in column experiments compared to that of the batch. The data confirmed that the presence of 100 mg/L HA suppressed the heavy metal removal. On the other hand it is observed that light is a favourable condition for heavy metals adsorption using GFH at the absence of HA, while at the presence of HA, the light did not have any significant influence on the magnitude of heavy metal removal.
It is concluded that GFH has high affinity to heavy metals besides As, and it can be used (e.g. as a filter medium) to treat waters containing wide range of heavy metals (e.g. stormwater, industrial wastewater).
Presented Monday 17, 13:30 to 15:00, in session Sustainable & Clean technologies - I: Extraction-Remediation (T1-4P).
