ZHANGQiao-lin,WUGan-lin,LIAOSi-fan,et al.Application and Practical Implementation of iMLE Process for Enhancing Nitrogen Removal and Energy Saving and Consumption Reduction[J].China Water & Wastewater,2025,41(5):88-94.
Application and Practical Implementation of iMLE Process for Enhancing Nitrogen Removal and Energy Saving and Consumption Reduction
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第41卷
Number:
第5期
Page:
88-94
Column:
Date of publication:
2025-03-01
- Keywords:
- iMLE process; biological nitrogen removal; municipal sewage; production test; energy saving and consumption reduction
- Abstract:
- One of the biological treatment units at Shenshui Guangming Wastewater Treatment Plant were upgraded for enhancing nitrogen removal through the implementation of intermittent modified Ludzack-Ettinger (iMLE). In the production test, when the treatment capacity was 2.5×104 m3/d to 3.15×104 m3/d, the nitrogen removal efficiency, aeration air consumption, carbon source dosage, and sludge nitrification and denitrification activities of the iMLE process were analyzed under the conditions of rainy season, dry season, and dry season with high flow, respectively. During the rainy season (from August 1 to October 8), the dry season (from October 9 to December 2), and the dry season with high flow (from December 3 to December 31), the total nitrogen of the influent was 21.9 mg/L, 32.3 mg/L, and 42.2 mg/L, respectively. The corresponding BOD5/TN ratios were 2.9, 3.2, and 2.9. The total nitrogen volumetric load were 45.9 g/(m3·d), 61.8 g/(m3·d), and 92.3 g/(m3·d), respectively. These data indicated significant variations in the influent total nitrogen and volumetric load across the three periods, while the BOD5/TN ratios remained relatively consistent. The mean total nitrogen of the effluent in the three periods were 4.7 mg/L, 5.8 mg/L, and 8.5 mg/L, respectively, with corresponding average removal efficiencies of 78.2%, 81.7%, and 79.4%. During the field experiment, the iMLE process did not require the addition of any carbon source, thereby eliminating the associated cost of approximately 0.15 yuan/m3 compared to the parallel two-stage A/O process. During the dry season with high flow, the air consumption for removing unit COD using the iMLE process remained 41% lower compared to that of the two-stage A/O process. Under conditions of adequate carbon sources, the maximum specific denitrification rates for the iMLE process and the two-stage A/O process were 4.4 mg/(gVSS·h) and 3.6 mg/(gVSS·h), respectively. This indicated that the iMLE process exhibited superior denitrification activity compared to the two-stage A/O process. Therefore, the iMLE process enhances the efficiency of nitrogen removal, reduces the associated costs, and decreases carbon emissions, thereby offering a novel solution for wastewater treatment plant upgrading.
Last Update:
2025-03-01