## 1 Introduction  
Industrial effluents frequently contain dyes that are poisonous, carcinogenic, mutagenic, allergic, and/or resistant to biological degradation [1, 2]. Furthermore, the color they give to effluents makes it difficult to disperse sunlight, which also interferes with photosynthesis and limits the ability of aquatic biota to develop and function. Moreover, due to the complexity of the dye's structure molecules, their removal becomes difficult, and dye-laden effluents from industries continue to be the most complicated to treat [1, 3]. Hence, conventional treatment methods have been applied, such as physical, chemical, and biological methods, but they are not effective and cannot, therefore, be used to control the enormous amount of organic contaminants that are discharged in the effluents. The adsorption technique is preferable for industrial processes because it has a straightforward design, and it is simple to use, inexpensive, and feasible at extremely low concentrations; therefore, it is an effective method for wastewater treatment [3, 4, 5]. Activated carbons are well-known adsorbents used for their outstanding adsorption capacity. However, the cost of production and the difficulty of regeneration make them expensive [5, 6]. Therefore, there is a growing interest in finding readily accessible and affordable options to substitute commercial activated carbons with other materials derived from wastes, such as sawdust, orange peel, or corn cobs. Particularly, activated carbons derived from biomass wastes usually have several advantages, such as being simple to prepare, affordable, versatile, and renewable [7; 8]. Woody materials are considered a good alternative in the manufacture of activated carbon since they have the proper carbon content and a low level of ash. Typically, the lumber industry produces enormous amounts of wood waste in the form of sawdust, which is periodically burned for energy or dumped at disposal sites nearby since they are not fully utilized [9]. Several studies have reported the use of sawdust as a precursor of activated carbons. Thus, [PERSON] et al. [3] used sawdust from _Acacia nilotica_ to produce activated carbon for the removal of Indigo Carmine dye. [PERSON] et al. [10] investigated the removal of Bismark Brown dye onto activated carbons from rubberwood sawdust, and [PERSON] et al. [9] used _Intsia bijuga_ sawdust to remove basic and reactive dyes. As an established method for comparing adsorbents, batch experiments were commonly chosen to assess their capacity for removing different adsorbates. Although these studies are relevant, the continuous fixed-bed column is the most commonly used for wastewater treatment in industries since it presents numerous advantageous, such as easy operation, high yield, and simplicity of scaling up [2; 11; 12]. Then, to optimize the column process, it is very important to perform the modeling of the dynamic behavior, since the concentration in the liquid and solid phases changes with time and space, through the prediction of the breakthrough-curve's shape based on various models like Thomas, Yoon-Nelson, and Bohart-Adams. In addition, due to the flexibility of the column to distinct processes and easy handling, it is the preferred option for industries [2; 8]. Previous studies [13] in batch mode were performed with several activated carbons from pine sawdust to remove blue, red, and black wood dyes from aqueous solutions, demonstrating that those carbons are capable adsorbents for dye removal since some presented high adsorption capacities at high initial dye concentrations in a short time. Nevertheless, for the shift to practical and large-scale applications, design and optimization of the fixed-bed column process are needed. Thus, a suitable quantitative model can be used to analyze, predict, and optimize the adsorption process under changing conditions [14]. As far as the authors know, there are no studies on the use of activated carbon produced from pine sawdust in continuous mode.