DUYi-ming,LEIChun-yuan,HUANGTing-lin,et al.Reason for Performance Deterioration of Long-term Operating Homogeneous Filter Media and Recovery Measures[J].China Water & Wastewater,2024,40(19):45-51.
Reason for Performance Deterioration of Long-term Operating Homogeneous Filter Media and Recovery Measures
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第40卷
Number:
第19期
Page:
45-51
Column:
Date of publication:
2024-10-01
- Keywords:
- surface raw water; homogeneous filter media; deterioration of filtration performance; gradation of filter media
- Abstract:
- Aiming at the issues of high effluent turbidity and the reduced pollution interception capacity of homogeneous filter media in a water treatment plant located in Northwest China, the turbidity removal performance of old sand and new sand filter media were evaluated in a pilot filter system, focusing on the filter with obvious performance degradation. Under the identical operating conditions, the effluent turbidity of the old sand filter was approximately 0.2 NTU higher than that of the new one. The test results of the filter media characteristics demonstrated that the most significant disparity between the old sand and the new sand lay in the gradation of the filter media and the proportion of fine sand. The removal efficacies of four filter systems, packed with old sand, old sand supplemented with fine sand, and two new sands with distinct particle size gradations, were further compared. The filter media featuring the same gradation yet distinct surface properties exhibited the identical removal efficacy on turbidity and particulate matters, which implied that the principal cause for the degradation of the filtration performance of the old sand lay in the alteration of the filter media gradation, and the filtration performance of the media could be restored through sand filling in accordance with the loss of gradation.
Last Update:
2024-10-01