To develop managing guidance of occupational noise exposure for metal working facility, we have studied about drafting contour map of noise exposure, methods of noise assessment and actual calculation method of time weighted noise exposure. Therefore we have suggested that contour maps of noisy workplace are very important for controlling metal working fluid facility and two kinds of noise assessment method, so called, personal and static exposure are necessary to avoid argument between workers and managing group. Finally we would like recommend that the Korean specfication of noise exposure should be modified to protect ONIHL(occupational noise induced hearing loss).

To improve coagulation characteristics and to reduce dossage of chemicals in watertreatment, polyaluminium sulfate was manufactured by reaction of polymerization between aluminium sulfate and sodium aluminate. As the results of affirmation and performance test, the yield of product was about 24% from molecular cut off levels by ultrafilteration method. The type of molecular is nearly affirmated as a kind of complex like Alm. (OH)n^(3m-n)+ from Scanning Electr Electron Mipy(S.E.M.) and X-ray diffraction test. Since the synthesized polymer was supposed to be quasi, further study for stabilization was required.