Krerkpong Charnpratheep creator Chongrak Polprasert Chairperson I, Fude Examination Committee Ahn, Kyu-Hong Examination Committee The Government of Australia Scholarship Donor text th Bangkok Asian Institute of Technology 1988 monographic eng 86 p. Waste stabilization ponds (WSP) installed with attached- growth media are called attached-growth waste stabilization ponds (AGWSP). Research was conducted to investigate chromium (Cr) removal efficiency in the laboratory-scale and the pilot-scale WSP and AGWSP units after subjected to one-day Cr shock loading. The laboratory-sea 1 e ponds, operated at the hydraulic retention times (0) of 5, 10 and 15 days, were fed with synthetic waste containing Cr concentrations of 5, 10, 20 and 30 mg/L while the Cr concentration of 20 mg/1 mixed with AIT sewage was introduced to the pilot-scale ponds operated at e = 10 days. Data from the laboratory-scale and pilot-scale AGWSP units showed a better Cr removal than that of the WSP units. The attached biomass in AGWSP were found to retain the applied Cr from 30 - 65 % while 10 - 91 % were overflowed in the effluents of the WSP units. Particulate Cr was a predominant fraction of total Cr concentration in the effluents. Physico-chemical mechanisms, particularly adsorption, was found to be a significant mechanism in removing soluble Cr from the pond water. An empirical model was developed to predict the total Cr removal ~h reas a mass transfer through the adsorbing-porous media model was applied to predict the soluble Cr removal. The significant effects of the Cr shock loadings on the pond performance in terms of total dissolved organic carbon (TDOC) removal and ammonia nitrogen (NH3-N) removal were not obvious. However, most of the AGWSP units showed a better performances than the WSP units after the Cr shock loadings. Decreasing of chlorophyll ~ and suspended solid concentrations in the effluents of all units were generally observed. A thesis submitted in partial fulfilment of the requirements for the degree of Master of Science, School of Environment, Resources and Development Thesis (M.Sc.) - Asian Institute of Technology, 1988 Sewage lagoons Sewage Purification Chromium removal Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B18882 http://203.159.5.9/ait-thesis/detail.php?q=B18882 120399 20260817172714.0