Comparison between traditional and low cost materials to remove residues of Methylene Blue dye from aqueous solutions Mounes, H. A. M and Reham, A. A. Department of Limnology, Central laboratory for Aquaculture Research, Abbassa, Agricultural Research Center, Egypt. Correspondence: E-mail: HMOANS80@hotmail.com Received: March. 16, 2020; Accepted: May.20, 2020 published: 2020 Vol.10 (4):39-56 ABSTRACT Dyes considered harmful pollutants that represent a serious threat to the aquatic environment, which require expensive materials to get rid of. It is consequently producing a critical situation that requires the availability of all efforts to solve, especially in conditions of water scarcity expected in the near future. Hence, the urgent need, to use cheap and eco-friendly adsorbents instead of traditional materials to purify and reuse water several times. It becomes one of the most important motives for conducting this research. This experiment was conducted, to compare the effect of using low cost adsorbent material against a traditional one with various dosages and various contacting periods at an ambient conditions of pH and temperature that are suitable for aquatic animals to remove Methylene Blue (MB) dye residues from water. The highest removal efficiency percentages of 0.1 g chitosan and silica gel toward 100 mg/l of MB dye were 93.1 % and 86.9 % respectively, after 60 minutes of contacting period. The equilibrium adsorption behavior data were fitted well to Langmuir and Freundlich adsorption isotherm models. Based on the achieved results, we recommend that the use of chitosan in purifying the aquatic environment from some organic pollutants such as dyes, which are widely used in many industries, because of the advantages of chitosan, which are low cost, wide availability and completely safe for the environment. Key words: Methylene Blue, Dye, Chitosan and Silica gel Introduction Synthetic dyes are extensively used by many industries including dye houses, pulp and paper printers, textile dyers, color photography, chemicals, metallurgy, leather, paint, and coatings industry, food, packaging, pharmacy, plastics and as additives in petroleum products consume considerable amounts of water, and chemical reagents during processing, dyeing and finishing operations (Zollinger, 1991; Selvam et al., 2003). The textile industry (54 %) discharges the largest amount of dye wastewater, contributing to more than half of the existing dye effluents observed in the environment worldwide (Katheresan et al. 2018). The effluents of these industries are composed of non-biologically oxidisable organic components because of the molecular size and Egyptian Journal for Aquaculture P-ISSN: 2090-7877 E-ISSN: 2636-3984 www.eja.journals.ekb.eg Soha Ahmed, 2020; 10 (4):39-56 DOI: 10.21608/eja.2021.48543.1040