## 1 Introduction  
Asians of Chinese descent, including Thai-Chinese ethnicity, always use joss papers as one of various sacrificial offerings in order to worship their deities and primogenitors. The consumption rate of joss papers in Thailand alone is over 20 ton year\({}^{-1}\) and increasing continuously. During the production of joss papers, synthetic dyes are used to make them aesthetic, fashion, colors, and virtually modern designs. More than 20% of the dyes used in this industry are discharged to the environment, where they not only cause a deterioration in the aesthetic nature but are also an environmental problem, together with an inducement of some serious problems in the water ecosystem [1,2]. Then, light penetration is reduced due to the concealment of these dyes, causing tribulation in the photosynthetic of the aquatic plant. Most dyes are classified as a hazardous material to the health of the creatures [3]. Some of them such as azo metal complex, benzidine-based, and non azo textile dyes [3,4] are carcinogenic agents, and some are mutagenic. As known, a large volume of water is used to produce joss paper; consequently, a huge amount of wastewater with dye contamination is valid. Several technologies have been developed to remove the dyes from the wastewater, such as chemical coagulation [5, 6, 7], ozonation and advanced oxidations [5,8,9], photocatalytic degradation [10], membrane filtration [7], biological treatments [5,11,12], and adsorption [12, 13, 14, 15, 16]. Even though these techniques are effective, they each still have various economic, environmental, and logistic disadvantages. For example, chemical addition is required for coagulation, resulting in the production of precipitated sludge. Ozonation accompanied with oxidations and photocatalytic degradation may produce undesired complex toxic by-products. The cost of construction and operating of membrane filtration systems is quite high. A lower performance of microbes in biological treatments is obtained when less tendance is done. Among several methods, adsorption has become a promising potential method for dye removal due to its high performance, reasonable to good economics, wide adaptability, and easy operation. Nevertheless, in current practices, the removal of dye from the process water is manually overseen, potentially exposing the employees to direct contact with the harmful dyes. Moreover, it is better that making a longer life cycle of the process water free of threats and negative influence on the quality of the joss paper products, especially the color resolution, is required for the practical conservation of water usage. It is suggested to remove the dye before re-routing the water to the process. Most of the currently used dyes contain a hydrophobic aromatic part and a hydrophilic charged part, and so some sectors of the respective dye molecules contribute hydrophobic (e.g., van der Waals; vdW) interactions, while other sectors lean to hydrophilic (e.g., electrostatic) interactions, respectively. A novel adsorbent should take advantage of these interactions to achieve a high performance over a wide operating range of dyes and conditions. Moreover, the adsorbents should also be economical, environmentally friendly, easily accessible, and reusable. One interesting potential candidate is Mt-rich clay. The lamellar structure of clay is made up of an octahedral layer of alumina sandwiched between two tetrahedron layers of silicon dioxide. The gap between the lamellar is a gallery of some cations e.g., Na\({}^{+}\), K\({}^{+}\), Ca\({}^{2+}\), and Mg\({}^{2+}\). These cations are easily replaced by other ions and form strong active sites with an ion-exchange property. However, the clay is a good adsorbent for a charged adsorbate but not for the hydrocarbon adsorbates. Another disadvantage is that clogginess in the pipe-line system is found even though clay has a high specific surface area for adsorption.