An experimental study was carried out on the treatment of domestic sewage by macrohydrophyte ponds, including water hyacinth and water peanut (AlterantheraPheloxiroides) ponds. The study indicated that both the water hyacinth and water peanut ponds were more effective and efficient in removing BODs (90-98%), TP (75-85%), PO4(90-99%), SS (90-95%), total bacteria (99.9-99.99%), and E. Coli (99-99.9%) in their growth seasons compared with the algae/bacterial symbiotic ponds with the pollutant removal rate constant ratio (k value in WHP or WPP/k value in ABP ponds) being: COD, 4.0-5.0, BOD5, 1.5-2.0, TN, 1.5-2.0, NH4+−N,2.0-3. 01 TP, 3.5-4.0; and PO43−2.8-5.7. The study found that the intensification effect was mainly ascribed to the microbial community in the root system, which was found to consist of Bacillus, Pseudomonas, Alcaligens, Brevibacterium, Ammonia fier, Nitrosonionas, Nitrobacter, and Denitrifier.
A mathematical model to describe the water flow pattern and BOD5 removal rule across the WPP pond based on the diffusion flow pattern model was developed with very low D values, which means that the water flow in the WHP and WPP ponds is near plug flow pattern.