ABSTRACT
Batch biosorption experiments were carried out for the removal of four dyes; Drimarene yellow CL4R (Y), Drimarene blue K2RL (B), Congo Red (CR) and Malachite Green (MG) from their aqueous solutions using two raw algal biomasses namely Gelidium latifolium (Grev.) Bornet et Thuret (a red alga) and Ulva lactuca Linnaeus (a green alga). Additionally, the studied algal biomasses were applied under the optimum concluded conditions to treat real polluted industrial effluents from Borg El-Arab region, Egypt. Meanwhile these algal biomasses before and after the biosorption process were characterized using SEM and FTIR spectroscopy. Ulva lactuca has shown much better dyes biosorption efficiency particularly with solid/liquid ratio: 1/1000 g/mL, initial dye concentration: 400 mg/L, temperature: 40° C, contact time: 1 hour, pH: 1, 2, 8 and 7 for Y, B, CR and MG, respectively. This biosorption was nonspontaneous, endothermic and chemical in nature. Freundlich isotherm model fitted slightly better than the Langmuir model indicating multilayer coverage (heterogeneous sorption). The applied decolourization of coloured samples reached 97.46 %.
We concluded that, algal biomasses of Ulva lactuca followed by Gelidium latifolium showed promising results in the field of water treatment and removal of water coloring. Beside that, the studied algal biomasses are considered as natural, low-cost and eco-friendly tool, so that they can help to a great extent in improving quality of water resources and to keep a clean environment via elimination of industrial pollution and its subsequent hazards on all biota especially human being.