The adsorption indicated that the GSA adsorbent possessed an excellent chemical oxygen demand (COD) and American Dye Manufacturers Institute (ADMI) colour degree removal efficiency which fulfilled the Seventh Schedule (Regulation 12) of Environmental Quality (Industrial Effluents) Regulation 2009. In the adsorption process, actual batik wastewater from a batik factory in Terengganu was sequentially pre-treated prior to treatment by the GSA adsorbent. The detail characterization of GSA strongly confirmed that the developed material was hybrid geopolymer/alginate bead with extremely porous microstructure which porosity was 87.64%, and surface area, average pore diameter and pore volume was 80.60 m 2 /g, 3.3110 nm and 0.0466 cm 3 /g, respectively. The GSA beads with the diameter 2-4 mm were drained, washed and cured at 60☌ for 24 h. Finally, the slurry was added dropwise in calcium chloride (CaCl 2 ) solution (2.0 wt%) and the formed beads were kept in the solution for 24 h at room temperature.
Then, SA solution (2.0 wt%) was mixed with the geopolymer slurry prior to the addition of egg white.
The geopolymer slurry was firstly prepared by using sodium hydroxide (NaOH) as the alkaline activator with mass ratio of FA to NaOH was 3:1. Additional to that, natural egg white was utilized as the foaming agent. The GSA adsorbent preparation involved a simple method where the FA based geopolymer entrapped into sodium alginate followed by cross-linking of Ca 2+ ion and sodium alginate (SA). In this work, high-porosity hybrid fly ash (FA) geopolymer/sodium alginate (GSA) adsorbent was produced and used as an effective and economical adsorbent in the treatment of batik wastewater.