MODEL FOR MIXING PROCESS IMPROVEMENT AT WATER TREATMENT PLANT BY INTEGRATING LEAN MANUFACTURING AND PARAMETER DESIGN

Abstract

The aim of integrating lean manufacturing and parameter design is to minimize seven non-value wastes in addition to the traditional waste in clean water production. These additional wastes to be considered are overproduction, waiting, motion, transportation, inventory, overprocessing, and defects. Information obtained from each waste is the input for the parameter design of the mixing process. The result of interaction between these seven types of waste in the lean production of clean water reveals that overprocessing waste is the most influential input in the parameter design of the Taguchi method. In the process of adding the level of concentration of poly aluminium chloride coagulant in the mixing process, a turbidity level below 5 nephelometric turbidity units is obtained, which in fact is in accordance with the health standard for clean water. An observation was also made on the behavior of flocs as the effect of Brownian motion due to the attractive force of poly aluminium chloride coagulant and colloid particle. The particle was then examined using a scanning electron microscope to find out the dimension of grain-sized flocs as the result of sedimentation in the mixing process. By properly integrating lean manufacturing and parameter design to minimize waste, a quality water meeting the set standard would be produced.