Investigating the Efficiency of Lightweight Expanded Clay Aggregate (LECA) in Wastewater Treatment of Dairy Industry


1 1Department of Environment, Faculty of Engineering, Islamic Azad University, Shahrood Branch, Shahroud, Iran

2 Department of Chemical Engineering, Faculty of Engineering, Islamic Azad University, Shahrood Branch, Shahroud, Iran


Lightweight expanded clay aggregate due to its physical and chemical properties; it can increase the process of adsorption and ion exchange. In this study, the efficiency 2 types of Lightweight Expanded Clay Aggregate in reducing the amount of COD, BOD, TSS, nitrate and phosphate in dairy industry wastewater were investigated and the impact of different factors such as adsorbent dosage, mixing speed and mixing time were studied. The results showed that the efficiency of COD reduction of wastewater after touch with the granular type after 20 h is 65.9%. TSS and BOD have also been greatly reduced. Also the use of powder type, the highest removal efficiency was 31.81%, mixing speed 100 rpm, mixing time 20h, and adsorbent dosage 10 gr/l in addition; increasing the rate of mixing speed increases the amount of nitrate absorption. The most effective nitrate removal is 63.87% which was at mixed speed 200 rpm and absorbent dose 4 g/l. Results show that, the mixing speed has little effect on the absorption of phosphate. So, after 30 minutes, even with increasing mixing speed for doses 2 & 4 g/l, the reduction efficiency also decreases the change in absorbent dose from 1 g/l to 4 g/l was virtually unaffected. Increased mixing speed is due to better distribution of nitrate and phosphate molecules in the solution and their contact with adsorbent increased the absorption rate. According to the results, the LECA granular has more ability to remove the COD.


  1. Asantewah, , Christy, A., William Francis, G., (2012), the use of lightweight expanded clay aggregate (LECA) as sorbent for PAHs removal from water, Hazardous Materials, 217-218:360-365.
  2. A., Mahvib. A. H., Naseri. S., Rezaei Kalantaryc. R., Saberid. M, (2014), nitrate removal from aqueous solution by using modified Clinoptilolite zeolite, Arch Hyg Sci 2014; 3(1):184-92.
  3. Cusido, J. A., Cecilia SorianoJoan A. Cusido, Cecilia Soriano, (2011), Valorization of pellets from municipal WWTP sludge in lightweight clay ceramics, Waste Management 31.
  4. DOE, (2006), Department Of Environment, Drinking water and wastewater standards, IRAN, http//
  5. Dordio, A. J., Carvalho. P, (2013). Constructed wetlands with light expanded clay aggregates for agricultural wastewater treatment, Science of the Total Environment 463–464.
  6. Ehlers, E. G., (1958), the mechanism of lightweight aggregate formation, Am. Ceram. Soc. Bul., 2, 95–99.
  7. Eikebrokk Björnar., Torgeir Saltnes, (2002), NOM removal from drinking water by chitosan coagulation and filtration through lightweight expanded clay aggregate filters,aqua.
  8. EPA, (2015), Process design manual for land treatment of municipal wastewater. Report 625/1-77-008 version 2015,. Us Environment Protection Agency, Cincinnati, Ohio.
  9. Esmaili, A. S., Nasseri, S. A., Mahvi. A., 2004, the absorption of copper and nickel from aqueous solutions by a type of mineral lightweight expanded clay aggregate (LECA), Hormozgan Medical Journal, Issue I, pages 39-33.
  10. Hamidian, A. M., (2000), reviews sewage plants Industrial Town Semnan and provide the best treatment method, Master thesis Environment, Natural Resources Faculty of Tehran.
  11. Haque Nazmul., Gregory. Morrison, Irene Cano-Aguilera, Jorge L. Gardea-Torresdey, (2008), Iron-modified light expanded clay aggregates for the removal of arsenic (V) from groundwater, Microchemical Journal 88.
  12. Imran A., Mohd A., Tabrez A., (2012), Low cost adsorbents for the removal of organic pollutants from wastewater, Environmental Management, 113:170-183.
  13. Kargi, F., Uygur, A., (2003), Effect of carbon source on biological nutrient removal in a sequencing batch reactor.Bioresour. Techno, 89; 89-93.
  14. Kavoosi, A., Barqaee, M., (2005), using Lightweight expanded clay aggregate (LECA) as a biofilm support in the treatment of wastewater, water and sewage Journal, No. 53.0.
  15. J., Zygadlo. M., (2009). Effect of Sewage Sludge Addition on Porosity of Lightweight Expannded Clay Aggregate (LECA) and Level of Heavy Metals Leaching From Ceramic Matrix, Environment Protection Engineering, Vol 35, No 2.
  16. Malakootian. M., Nouri. J., Hossaini. H., (2009), Removal of heavy metals from paint industry’s wastewater using Leca as an available adsorbent, International Journal of Environment. Sci. Tech., 6, 2 - 183-190.
  17. Mary Selecky, J. A., (2005), Denise Clifford. Guidance Document Nitrate Treatment Alternatives for Small Water Systems, Washington State Department of Health.
  18. Mc Graw – Hill, (2000), Land Treatment system for Municipal and Industrial wastes/Ronald W.Crites etal.
  19. Mohammadi Kalhori, E., Yetilmezsoy, K., Uygur, N., Zarrabi, M., Abu Shmeis, R. M., (2013). Modeling of adsorption of toxic chromium on natural and surface modified expanded clay aggregate (LECA), Applied Surface Science 287.
  20. Naddafi, K., Saeedi, Mohebbi M. R., (2005), Bio-sorption and Removal of Heavy Metals from Water and Wastewater, Water and Environment Journal, 63: 33-39.
  21. Sharifnia, S. H., Khadivi, M., Shojaemehr, T., (2012), Characterization, isotherm and kinetic studies for ammonium ion adsorption by light expanded clay aggregate (LECA), Chemical Society, xxx.
  22. Tor Arne, Hammer., Klaas van Breugel., Steinar Helland., Ivar Holand., Magne Maage., Jan P. G. Mijnsbergen., Edda Lilja Sveinsdóttir, (2000), "Materials for Buildings and Structures". Euromat 99, 6: 18.
  23. Zarabi, M., Samarghandi, M. R., Norisepehr, M., Mohammad Kalhor, Nowruzi, M., Jafari, S. J., Fazllzadeh, M., (2011), modified the performances Lightweight expanded clay aggregate (LECA) wastewater treatment, health and of health magazine, Volume II, Issue I, pages 30-19.
Volume 1, Issue 1 - Serial Number 1
September 2017
Pages 9-17
  • Receive Date: 08 August 2017
  • Revise Date: 04 September 2017
  • Accept Date: 14 September 2017
  • First Publish Date: 14 September 2017