ABSTRACT

This experiment is carried out to study on four types of membranes supplied by model TR-14 which include (1) AFC90 (polyamide film), (2) AFC40 (polyamide film), (3) CA202 (cellulose acetate) and (4) FP100 (PVDF). These four membranes have different pore sizes which will separate water from sodium chloride solution at different purity. The purity of water is based on the presence of permeates weight after membrane separation process. Pore size will classifies membrane whether it is used for microfiltration, ultrafiltration, Nano filtration or reverse osmosis. This experiment is started by opening the correct valves mentioned in the lab manual. Membrane maximum inlet pressure is adjusted and the equipment is allowed to run about 5 minutes. Samples are collected for every 1 minute until up to 10 minutes. The samples are collected and weighed directly by using digital weight balance. The same procedure is repeated for membrane (2), (3) and (4). After collecting all data, a graph weight of permeates versus time is plotted. From the graph plotted, membrane 4 has the sharpest line compared to membrane 1, 2 and 3. It means that membrane 4 has the highest permeates weight followed by membrane 2, 1 and 3 after undergoes membrane separation process. As a result, membrane 4 is used for microfiltration, membrane 2 is used for ultrafiltration, membrane 1 for nanofiltration and membrane 3 for reverse osmosis.

INTRODUCTION

Membrane process utilizes semipermeable or perm selective membrane to achieve separation of various chemical substances whether in a solid, liquid or in gas form. Membrane is a thin layer of material which contains pore size capable of separating substances from microscopic to molecular level by applying driving force across the membrane.

The membrane separations are different from many the other separation processes like solvent extraction, chromatographic methods involving partition, adsorption and ion exchange which involve equilibrium between the substances getting separated and the separating phases. Membrane is widely used in industry for removal of bacteria and other microorganism, particulate material and natural organic material, which can impart color, tastes, and odors to the water and causes infection by-products.

In membrane separation process, two bulk phases are separated by a barrier called as a membrane. The pore size of membrane controls the chemical substances that can passes through it. Some of the chemical substances that can pass through and contaminating other bulk phase will call as permeates. Figure 1 below shows a membrane separate bacteria from pass through with water in a filtration process.

Figure 1: Filtration using membrane separation

Permeation also known as the contaminant can pass through membrane by applying driving force. This can be in the form of hydrostatic pressure difference, temperature difference, concentration difference, partial pressure difference or electrical potential gradient.There are few types of pressure-driven membrane processes include microfiltration (MF), ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO).

Microfiltration (MF) is a process mainly used for the separation of submicron size (