The effects of nutrients and folic acid on the biological treatment of petrochemical wastewater

Document Type: Original Article


1 Department of Environmental Sciences, Ardabil branch, Islamic Azad University, Ardabil, Iran

2 R&D unit, Tabriz petrochemical Company (TPC), Tabriz, Iran



Considering the advantages of biological systems for wastewater treatment in compatibility with the environment, the present study aimed to investigate the effects of different concentrations of folic acid, nitrogen, and phosphorus on the biological treatment of industrial wastewater at Tabriz Petrochemical Company (TPC) in Iran. The Taguchi method with the orthogonal array L9 was used to determine the optimal conditions of microorganism growth. Color, pH, nitrogen, phosphorous, sludge volume reduction, sludge volume index (SVI), and mixed liquor suspended solids (MLSS) were measured. According to the results, the three investigated factors could significantly reduce wastewater. After removing the folic acid color, modulating the pH, and reducing the SVI, the nitrogen factor was considered most effective. Nitrogen also had a significant effect on the removal of output wastewater (62.62%). In addition, the phosphorus factor had the most significant impact on wastewater reduction (65.25%). The optimal conditions were observed with 0.2 ppm of folic acid, 20 ppm of nitrogen, and 4 ppm of phosphorus in the three investigated parameters. Folic acid only significantly affected the increasing of MLSS (90.1%), and the optimal condition of this parameter was with 0.2 ppm of folic acid, 30 ppm of nitrogen, and 4 ppm of phosphorus. Sludge volume reduction was observed in all the reactors. The addition of folic acid, nitrogen, and phosphorous to the TPC wastewater lacking these materials could enhance the output parameters and reduce adverse environmental effects.


  1. Toth AJ, Haaz E, Szilagyi B, Nagy T, Janka Tarjani A, Fozer D, et al. COD reduction of process wastewater with vacuum evaporation. Waste Treatment and Recovery 2018; 3(1): 1-7.
  2. Bahmanpour H, Awhadi S, Enjili J, Hosseini SM, Raeisi Vanani H, Eslamian S, et al. Optimizing absorbent bentonite and evaluation of contaminants removal from petrochemical industries wastewater. Int J Civ Eng 2017; 3(2): 34-42.
  3. GrzesKowiak AZ, GrzesKowiak T, Zembrzuska J, Lukaszewski Z. Comparison of biodegradation of poly (ethylene glycol) s and poly (propylene glycol) s. Chemosphere 2006; 64(5): 803-9.
  4. Senorer E, Barlas H. Effects of folic acid on the efficiency of biological wastewater treatment. Fresenius Environ Bull 2004; 13(10): 1036-9.
  5. Strunkheide J. Stabilized folic acid vitamin for the reduction of excess sludge in sewage treatment plants., 2004.
  6. Nokandeh M, Khoshmaneshzadeh B. Removal of yellow acid-36 dye from textile industries waste water using photocatalytic process (UV/TiO2). Anthropogenic Pollution Journal 2019; 3(2): 10-17.
  7. Garfí M, Flores L, Ferrer I. Life cycle assessment of wastewater treatment systems for small communities: Activated sludge, constructed wetlands and high rate algal ponds. J Clean Prod 2017; 161: 211-9.
  8. Wang D, DuanY, YangQ, LiuY, NiB-J, Wang Q, et al. Free ammonia enhances dark fermentative hydrogen production from waste activated sludge. Water Res 2018; 133: 272-81.
  9. Haddad M, Abid S, Hamdi M, Bouallagui H. Reduction of adsorbed dyes content in the discharged sludge coming from an industrial textile wastewater treatment plant using aerobic activated sludge process. J Environ Manage 2018; 223: 936-46.
  10. Kube M, Jefferson B, Fan L, Roddick F. The impact of wastewater characteristics, algal species selection and immobilisation on simultaneous nitrogen and phosphorus removal. Algal Res 2018; 31: 478-88.
  11. Hantanirina JMO. Improving BOD removal at SNJ wastewater treatment plant by biological treatment. Master’s thesis of Environmental Engineering/Water Science and Technology, Faculty of Science and Technology, University of Stavanger, Norway; 2010.
  12. Takdastan A, Azimi AA, Jaafarzadeh N. Biological excess sludge reduction in municipal wastewater treatment by chlorine. Asian J Chem 2010; 22(3): 1665–74.
  13. Takdastan A, Eslami A. Application of energy spilling mechanism by para-nitrophenol in biological excess sludge reduction in batch-activated sludge reactor. Int J Energy Environ Eng 2013; 4(1): 26.
  14. Roy RK. A Primer on the Taguchi Method. 2nd ed., Society of Manufacturing Engineers, 2010.
  15. Ryckeboer J, Mergaert J, Vaes K, Klammer S, De Clercq D, Coosemans J, et al. A survey of bacteria and fungi occurring during composting and self-heating processes. Ann Microbiol 2010; 53(4): 349-410.
  16. Maier RM, Biochemical Cycling, Chapter 14. In: Maier, R.M., Pepper, I.L., Gerba, C.P. (eds). Environmental Microbiology, Academic Press, 1999, pp. 319-346.
  17. Akerboom RK, Lutz P, Berger HF. Folic acid reduces the use of secondary treatment additives in treating wastewater from paper recycling. International Environmental Conference and Exhibit, TAPPI Proceedings, Oregon, Portland; 1994.
  18. Dohme M. The effect of folic acid on the metabolism rate of activated sludge plants as shown by the example of the Uelzen and Suderburg sewage treatment works. Diploma Thesis, Fachhochschule Suderburg, Germany; 1998.
  19. Lanzrath M. Use of the auxiliary substance DOSFOLAT (folic acid) in wastewater treatment plants to increase performance and reduce costs using the example of the Bonn-Duisdorf clarification plant. Diploma thesis to obtain the degree of Diploma, Faculty of Koln, University of Applied Sciences, Koln, Germany; 2007.
  20. Ferrer-Polonio E, Fernandez-Navarro J, Alonso-Molina JL, Mendoza-Roca JA, Bes-Pia A, Amoros I. Towards a cleaner wastewater treatment: Influence of folic acid addition on sludge reduction and biomass characteristics. Journal of Cleaner Production 2019; 232: 858-66.