Document Type : Original Article
Department of Civil Engineering, University College of Omran-Toseeh, Hamedan, Iran
Department of Civil Engineering, Islamic Azad University, Hamedan Branch, Iran
Department of Environmental Science, Islamic Azad University, Hamedan Branch, Iran
The present study aimed to evaluate the treatment efficiency of the modified Ludzack-Ettinger (MLE) process using the conventional activated sludge (CAS) in Tafresh city, located in Iran during October-December 2016 (before upgrading) and October-December 2017 (after upgrading to the MLE process). The measured parameters in the study included chemical oxygen demand (COD), five-day biochemical oxygen demand (BOD5), nitrate-nitrogen, total suspended solids, phosphate, dissolved oxygen, ammonium-nitrogen, and pH. According to the obtained results, the treatment efficiency of the MLE process based on the BOD5 and COD was 92.11% and 91.20%, respectively. On the other hand, the treatment efficiency of the CAS process (before upgrading) based on the BOD5 and COD removal was 48.55% and 56.76%, respectively. Therefore, it could be concluded that the MLE process was able to successfully upgrade wastewater treatment services.