Sapkota, Danda Prasad creator Orth, Hermann M. Chairperson Chongrak Polprasert Examination Committee I, Fude Examination Committee The Royal Norwegian Government Scholarship Donor text th Bangkok Asian Institute of Technology 1987 monographic eng 47 p. One set of parallel oxidation ponds was used for comparing ·the treatment efficiency of pond system with and without water hyacinth in full-scale study under similar conditions. Experiments were performed from t he last week of October till the last week of January , 1987. Mean COD loadings to t he systems were 106 kg/(ha .d) and 98 kg/(ha.d) for the hyacinth pond and the free pond respectively. During the period of observation effluent concentrations in the hyacinth pond for hundred percent hyacinth coverage were 9 , 20 , 2 and 0 . 36 mg/L for SS, COD, TKN and TP respectively. The corresponding effluent concentrations in the free pond were 45, 94, 5.6 and 1.2 mg/L for SS, COD, TKN and TP respectively. Mean mass of COD, TKN and TP were removed at 78, 76 and 74. 8% respectively in the hyacinth pond system, whereas in the free pond system, mass COD, TKN and TP were removed at 20, 44.4 and 18.30% respectively . At 100 % hyacinth coverage, mass COD, TKN and TP removed, in the hyacinth pond were, at 84, 79.6 and 79.4% respectively. In the free pond system mass COD, TKN and TP were removed at 24, 44. 8 and 22% respectively . Hyacinth pond showed better performance than the free pond in removing SS, COD, TKN and TP from the wastewater . Laboratory experiments were conducted for comparing the efficiency of aquatic plants namely water hyacinth, water lily and salvinia. The influent loading used were 41 and 86 kg COD/ (ha. d) . Results indicated that hyacinth pond system showed the best performance in removing pollutants followed by salvinia and water lil y for t he applied loadings. A thesis submitted in partial fulfilment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development Thesis (M.Eng.) - Asian Institute of Technology, 1987 Sewage Purification Aquatic plants Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B19247 http://203.159.5.9/ait-thesis/detail.php?q=B19247 011298 20260817173344.0