Adsorption of Anionic Dye Onto ZSM-5 Zeolite-based Bio Membrane: Characterizations, Kinetics and Adsorption Isotherm

In this study, we report polyvinyl alcohol/carboxymethyl cellulose/gelatin/ZSM-5 zeolite (PVA/CMC/GEL/ZSM-5) membrane for anionic dye (rhodamine B, Rh B) removal from aqueous solution. The prepared membrane was characterized using different techniques such as Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), optical microscopy (OM), universal testing machine (UTM) and water contact angle respectively. XRD, FT-IR and SEM analysis indicates successful incorporation of zeolite into PVA/CMC/GEL membrane. The improved hydrophobicity of the zeolite loaded membrane was confirmed by contact angle analysis. The Rh B removal efficiency of zeolite loaded PVA/CMC/GEL membrane was investigated through batch adsorption technique. The effect of different parameters such as initial dye concentration, zeolite dosage, contact time, temperature and pH on the adsorption was examined. Rh B dye adsorption onto the membrane followed Freundlich isotherm model. The kinetic studies revealed that Rh B dye adsorption on the membrane could be explained using pseudo-second-order model. Finally, the recyclability test revealed that the membrane exhibits good recycle efficiency and is stable after 6 recycle.

Application of Cationic Surfactant Modified Mengkuang Leaves (Pandanus atrocapus) for the Removal of Reactive Orange 16 from Batik Wastewater: A Column Study

The feasibility of Mengkuang leaves (Pandanus atrocarpus) as a non-conventional low-cost adsorbent for the removal of an anionic dye, Reactive Orange 16 (RO16), was investigated. Among the dyes that have been commonly used in the Batik industry was reactive dye. In this study, Mengkuang leaves were chemically modified with cetyltrimethylammonium bromide (CTAB), a cationic surfactant, to improve their adsorption performance toward anionic dyes. The adsorbent’s morphological characteristics were analyzed using a scanning electron microscope (SEM). The surface of modified Mengkuang leaves seems to be irregular and uneven, with more porous structures than raw Mengkuang leaves. Adsorption of RO16 dye in fixed bed column using modified Mengkuang leaves adsorbent indicated the breakthrough time increased at higher bed height and lower flow rate. The breakthrough times for bed height of 0.5, 2, and 4 cm were at 16, 68, and 165 min, respectively. Meanwhile, breakthrough time for the flow rate of 2,5 and 7 mL.min-1 were at 327, 104, and 43 min, respectively. However, the study utilizing raw Mengkuang leaves showed no significant removal of RO16. Thus, it can be concluded that the cationic surfactant modification of Mengkuang leaves is advantageous for anionic dye removal. This anionic dye removal is significantly influenced by column parameters such as bed height and flow rate as the plotted breakthrough curves obtained from experimental data were similar to the typical breakthrough curve. When applied to the Yoon-Nelson model, the adsorption data provided the best fit with the R2 value above 0.95. The time taken for the breakthrough is very similar to model prediction values. Experiments with real batik dye wastewater showed the immense potential of modified Mengkuang leaves where total removal of real Batik wastewater was instantaneous.