Properties and Filtration Performance of Porous Clay Membrane Produced Using Sawdust as Pore Forming Agent

This study investigated the effect of sawdust at 0, 10, 20, 30 and 40 wt% towards physical properties and filtration efficiency of porous clay membrane. Sawdust in various quantities was added into water containing clay, polyethylene glycol and sodium silicate and then stirred to form homogenized slurry. The slurry then was casted into Plaster of Paris (PoP) mould. The green body was cut into required sizes, dried and sintered in furnace at 1000 °C. The porosity and density of porous clay was determined by Archimedes principle, while morphology was observed by Hitachi Tabletop Scanning Electron Microscope (TTSEM). The filtration test was examined on a dead-end filtration setup in batch mode operation using nitrogen as carrier gas. Distilled water was filtered and used to determine membrane permeability, while aquaculture wastewater filtration was used to determine the turbidity removal. Turbidity of aquaculture wastewater and effluent (after filtration) were measured using turbidity meter. The results indicated that porosity increased from 38 % to 64 %, while density decreased from 1.5 g/cm3 to 0.8 g/cm3 with increasing amount of sawdust from 0 to 40 wt%. This data was supported by TTSEM which is indicate that the amount of pores increased with increasing amount of sawdust. Permeation of membrane increased from 45289 to 143999 L.h-1.m-2.bar-1 and efficiency of turbidity removal increased from 87 % to 89 % with increasing amount of sawdust from 0 to 40 wt%. As conclusion, 30 wt% was an optimum amount of sawdust which is produced ceramic membrane with good structure integrity, porosity, high permeability and high turbidity removal.

Effect of Starch Addition on Microstructure and Strength of Ball Clay Membrane

The use of starch as pore-forming agent is one of the frequently used methods to produce porous ceramics membrane with controlled microstructure (porosity and pore size) because corn starch are cheap, non- toxic and environmental friendly. A membrane with the mixture 0–35 wt% of corn starch and ball clay were prepared by compaction process and sintered at 1200°C. Thermal analysis has been done to identify the minimum sintering temperature for ball clay. The sintered membranes show the range value of shrinkage is 4.5–22.76 % and apparent porosity of 9.14–31.83 % depending on the starch content. The pore structures were analyzed by FESEM. The strength of sintered samples was tested by 3-point bending test. The flexural strength reduced from 21–7 MPa. These clay membrane are promising porous ceramic structure for water filtration applications due to their excellent combination physical and mechanical properties.

Effect of Sintering Temperature on Membrane Properties of Sayong Ball Clay

Sayong ball clay membrane can be fabricated as a cheap membrane material and available commonly at Malaysia. This work was concerned with the study of Sayong ball clay membrane as a water filtration by gel casting technique. Gel casting involves mixing process of Sayong ball clay with the solvent, monomer, dispersant, initiator and catalyst in a certain composition. Tubular membrane was fabricated by controlling the sintering temperature (1000, 1100, 1200, 1300°C). The physical measurements (shrinkage, apparent porosity, and bulk density), microstructure analysis, filtration process (flow rate) and water quality assessments (pH, color, Chemical Oxygen Demand (COD), solid suspended (SS)) were carried out at different sintering temperature. Apparent porosity and bulk density of the samples were measured by using Archimedes method. The effect of sintering temperature on microstructure of the membranes has been investigated using SEM. The experimental results showed that the shrinkage and bulk density increase with increasing sintering temperature. It gives the improvement in water quality with the lowest SS (192 mg/L), lowest COD (4 mg/L) and most colorless (1.1 Gardner units) filtered wastewater as compared to others.