Biosorptive Treatment of Dye-Containing Effluents with Freshwater Green Algal Waste Biomass. (I) Biosorbent Characteristics and Its Preliminary Efficiency

A feasible alternative to the use of conventional adsorbents for separation of polluting dyes from different industrial effluents before discharging its into the environment is considered freshwater algal waste biomass because is abundant, easy to prepare and process, cost-effective, has high biosorption capacity due to numerous functional groups on their surface, and can be reused or additionally valorized. This study presents the experimental data performed onto Spirogyra, a filamentous charophyte green algae (of different ages) waste biomass, which was collected and processed by drying and shredding, sieved at different sizes (< 2 mm), subjected to preliminary advanced analysis (TG, DTG, FTIR), heat treated in oven (100 ℃) or subjected to pyrolysis (6 h) at 300 ℃. All types of prepared algal biomass waste were used as biosorbents for retaining the Remazol Rosso RB azo dye from simulated aqueous effluents, and the adequate operating conditions (pH, dosage, operating regime, temperature, influence of different loads in aqueous effluent as dissolved salts) were proposed for highest biosorption efficiency in dye and color removal (40–60%) in association with some information on biosorption mechanism and further selection of variation fields for all important process variables. The results indicate that this terrestrial green algal biomass waste can be efficiently used in the biosorption process, even in condition of large and frequent fluctuation in flowrate, dye content, or pH of treated dye-containing effluent, and can be also applied for other polluting species present in aqueous effluent with high retention efficiency.