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Updated: Feb 5, 2026

Concentration of Virus Particles from Environmental Water and Wastewater Samples Using Skimmed Milk Flocculation and Ultrafiltration
Published on: March 17, 2023
[Effects of Different Substrates and Particle Sizes on Wastewater Purification]
Lin-Li Zhao1,2, Xue-Xin Shao1, Ming Wu1
1Wetland Ecosystem Research Station of Hangzhou Bay, Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China.
Abstract:
Choosing suitable substrate is key to improving the efficiency of wetland decontamination. However, little is known about the effect of particle size. In order to study the effect of substrate type and size on COD, TN, and TP removal from sewage, 1-2, 2-4, and 4-8 mm zeolite, 2-4, 4-8, and 8-16 mm gravel, and 2-4, 3-5, and 6-8 mm anthracite were selected for establishment of the constructed system of experimental media with three replications. Results showed that removal efficiency of COD, TN, and TP varied with different particle sizes of the same material. The greatest COD removal was achieved with 4-8 mm zeolite and gravel and 6-8 mm anthracite, with removal rates of 53.74%, 60.76%, and 62.93%, respectively. Denitrification is the main pattern of nitrogen removal in the artificial test column; results show that smaller particle size is more effective for removal of TN. The removal rate of TP is also higher with smaller sizes of gravel and anthracite, but the opposite pattern occurred with zeolite. The removal of COD, TP, and TN also varied by substrate type. Anthracite led to good removal of COD, TP, and TN. Zeolite was most effective for removal of TN but had lower removal of TP. Gravel has high removal rate for COD, and has a general removal effect on TP.
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