Phycoremediation of secondary treated synthetic refinery wastewater using Scenedesmus valocatus sp. NITD 23: Experiment and analysis

• Published in: Journal of water process engineering 2024-02, Vol.58, p.104910, Article 104910
• Main Authors: Kandar, Bulti, Rai, Abhilasha, Sau, Arnab, Ghanta, Kartik Chandra, Dutta, Susmita
• Format: Article
• Language: English
• Subjects: Biomolecules; Oil & Grease; Phenol; Phycoremediation; Refinery wastewater
• ISSN: 2214-7144; 2214-7144
• DOI: 10.1016/j.jwpe.2024.104910

The present study aims at phycoremediation of pollutants from secondary treated refinery wastewater. The algal strain Scenedesmus valocatus sp. NITD 23 was found to be the most susceptible to the maximum concentrations of all pollutants during the screening study and hence, was used for treatment of refinery wastewater containing ammoniacal-N (300 mg/L), phenol (14 mg/L), Oil & Grease (5600 mg/L) and TDS (6200 mg/L). The susceptibility of the selected strain was tested in the synthetic solutions of ammoniacal-N:75–300 mg/L, phenol:11–14 mg/L, Oil & Grease:800–5600 mg/L, and TDS (Total Dissolved Solids):1500–6200 mg/L for 16 days. The optimum concentrations were found as ammoniacal-N: 75 mg/L, phenol:11 mg/L, TDS: 1500 mg/L, Oil & Grease: 800 mg/L. Inoculum size and initial pH of solutions were maintained at 15 % and 9, respectively. The maximum removal of pollutants was found as phenol: 80.83 ± 0.07 %, ammoniacal-N: 78.33 ± 1.25 %, TDS: 65.87 ± 8.08 %, Oil & Grease: 85.5 ± 0.005 %, BOD (Biochemical Oxygen Demand): 63.7 ± 4.15 %, and COD (Chemical Oxygen Demand): 65.5 ± 7.67 %. The biomass generated was analyzed in terms of carbohydrate, protein and chlorophyll contents. The increased concentration of chloride as shown by Energy Dispersive X-Ray Spectroscopy study of treated biomass proves the biosorption of salt vis-à-vis TDS by the algal cells. Real industrial wastewater was treated with the selected microalgal strain and the concentrations of all parameters were found to be below permissible limit after 14 days of incubation period. Finally, it can be stated that the present strain Scenedesmus valocatus sp. NITD 23 can efficiently be applied for treatment of refinery wastewater. [Display omitted] •Phycoremediation of pollutants from secondary treated refinery wastewater.•Application of Scenedesmus valocatus sp. NITD 23 for such purpose.•Consideration of ammoniacal-N, phenol, TDS, Oil & Grease as model pollutants.•Assessment of biomass for biomolecule production.•Characterization of biomass using FTIR, FESEM, EDX, and TGA.