Utilization of sawdust as a pore-former in the fabrication of ceramic adsorbents for water purification

In this study, kaolin-based ceramic materials with sawdust addition (10 and 20 wt.%) were fabricated using a two-level full factorial design of experiments. Next, the effect of sintering temperature and compaction pressure on the physical, chemical, and mechanical properties of the ceramic materials was investigated. From these experiments, an optimum composition was selected and used to fabricate ceramic adsorbents. The filtration efficacy of the optimum adsorbent was tested by evaluating the filtration dynamics of water contaminated with heavy metals like zinc (Zn), copper (Cu), nickel (Ni), cadmium (Cd), and lead (Pb), and compared with an adsorbent fabricated without the inclusion of the pore former (sawdust). These experiments resulted in a higher heavy metal removal efficiency for the optimum adsorbent of approximately 3%, 61%, and 76% for Cu, Zn, and Ni, respectively, compared with 1%, 5.6%, and 6.4% as obtained for the adsorbent with no pore former. Nonetheless, the optimum ceramic adsorbent showed low efficiency towards the removal of Pb. Graphical abstract: [Figure not available: see fulltext.]