Wilasinee Saktaywin creator Ozaki, H. Chairperson Visvanathan, C. Examination Committee Preeda Pakpian Examination Committee The Royal Netherlands Government Scholarship donor text series technical report th Bangkok Asian Institute of Technology 1999 continuing eng 100 leaves : ill. In an effort to determine the potential application of ultra low pressure reverse osmosis (ULPRO) membrane in electroplating processes, experimental investigations were conducted to evaluate the performance of ULPRO membrane for the removal of nickel, copper and chromium. The influences of pressure, initial feed concentration, pH, competing compounds and operation period on ULPRO membrane performance were also determined. In this study, the experiment had been divided into two parts. The first part consisted of the uses of synthetic wastewater containing heavy metal (Ni, Cu or Cr). The ULPRO membrane model ES20 was used in the experiments. The experimental study ranges of pressure, concentration, pH, competing compounds (Ca2 + and Mg2 +) were 0.1-0.5 MPa, 50 mg/L Ni, Cu and Cr and 5, 50 and 500 mg/L NaCl, pH 3-9, 5-30 mg/L Ca2 +, 3-15 mg/L Mg2 + according! y. Results showed that the removal efficiency for ULPRO membrane could be obtained 97 to 99.4% for Ni, 97.3 to 99.4% for Cu and 98 to 99.9% for Cr. Higher pressure, higher feed concentration and higher pH showed positive response, while presence of competing compounds showed negative response on Ni, Cu and Cr rejection. In the second part of this study using real wastewater from the small electroplating shop. The experimental study used ultra low pressure type composite reverse osmosis membrane (ES20), RO membrane (NTR-759HR) and NF membrane (LFlO and NTR-729HF). The study used of pressure and pH were 0.45 and 0.9 MPa, pH 3 and 7 for combined wastewater and Cr rinse water. Results showed that ES20 membrane gave the highest flux and rejection. All results shown that the ES20 membrane requires about half of the operating pressure of NTR-759HR, LFlO and NTR-729HF membrane to achieve the same level of metal ions removal. Transmission electron micrographs of the membrane surface demonstrate that the structure of the membrane skin layer is the reason for improved performance. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science, School of Environment, Resources and Development Thesis (M.Sc.) - Asian Institute of Technology, 1999 Sewage Purification Reverse osmosis process Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B12091 http://203.159.5.9/ait-thesis/detail.php?q=B12091 041199 20260817163003.0