Assessment the performance and morphological structures of asymmetric PES/surfactant membranes for nanofiltration of dyes wastewater

In this study, an asymmetric PES/surfactant based nanofiltration membrane was prepared via simple dry/wet phase inversion technique. A newly dope formulations consisting of different surfactants and polymer concentrations ranging from 17wt% to 21wt% were developed. The effect  of  these  parameters on  dyes  performance  in  terms  of  dyes  flux,  rejection  and morphological structure were examined. Experimental data showed that at different ranges of polymer concentration, NFS membranes results low permeation flux of dyes ranging from 9.256 L/m2h to 14.315 L/m2h at 4 bars of operating pressure. Significantly, the addition of surfactant as additives into the membranes was found to cause the increasing of dyes flux and rejection up to 79.698 L/m2h and 99.5% respectively. Moreover, morphological study shows that the fabricated membranes were having of fine morphological structures.Keywords: nanofiltration; surfactant; flux; rejection; morphological structur

Variation of Rare Earth Elements (REEs) in the Sulu and Celebes Seas of Malaysian waters during PMSE 09’ expedition using analytical and chemometric techniques

This study provides a dataset of rare earth elements (REEs) in the seawater of Sulu and Celebes Seas of Malaysian waters during the PMSE 09’ expedition, which was conducted to define the pattern of REEs in both seas. Samples were collected, filtered and pre-concentrated on-board ship then analyzed by using ICP-MS. Generally, the spatial distribution pointed out a high concentration of REEs in vicinities with high number of local settlements and Borneo Island riverine flush-outs. The chemometric analysis has showed the competition of binding sites between REEs and salt ions. The REEs normalized against NPDW evidence the influence of South China Sea waters lessen with the increase in water depth. Additionally, the studied area shows that both seas are affected by local river drainage from Borneo Island, Indonesia and Philippine archipelagos.Keywords: dissolved REEs; particulate REEs; Sulu Sea; Celebes Sea; environmetric analysi

Construction of cost effective homebuilt spin coater for coating amylose-amylopectin thin films

We report the construction of a cost effective and low power consumption spin coater from a direct current (DC) brushless motor. The DC mechanical component is widdely available in the central processing unit (CPU) cooler. This set up permits simple operation where the DC voltage can be controlled manually in order to adjust the spin speed ranging from 1500 to 4500 resolution per minute (rpm). The spin speed stability can be determined by a tachometer against the spinning time. In order to evaluate the performance of the spin coater, 25% Amylose-75% Amylopectin thin films were successfully deposited on SiO2 substrates. The thicknesses of the films were in the range of 96.1 nm to 225 nm.Keywords: spin coating; CPU cooler; thin film depositions; homebuilt spin coate

Influences of saccharides types and initial glucose concentration on microbial cellulose production by G. xylinus

Microbial cellulose (C6H10O5)n is a remarkable polysaccharide and has excellent characteristics as a highly potential biomaterial. To enhance microbial cellulose concentration in aerated and agitated cultivation, the influences of three different saccharides and initial glucose concentrations were investigated. Tests on agar slants and in agitated shake flasks using glucose, sucrose and lactose media exhibited that the cellulose producer, Gluconacetobacterxylinus DSM 46604 resembled good growth on glucose and produced cellulose. However, there was negligible growth on sucrose and lactose media.Further experiments with initial glucose concentrations between 40 and 100 g/L were carried out for five days. The maximum microbial cellulose concentration of 1.13 g/L was obtained from 50 g/L glucose media.Keywords: microbial cellulose; glucose concentrations; shake flasks; Gluconacetobacterxylinu