Mohd. Azraai Kassim

Novel polyethersulfone (PES)/hydrous manganese dioxide (HMO) mixed matrix membranes with improved anti-fouling properties for oily wastewater treatment process

In this work, hydrophilic hydrous manganese dioxide (HMO) nanoparticles were synthesized and used as the inorganic filler for the preparation of mixed matrix membranes (MMMs). The aim of adding HMO nanoparticles into the polyethersulfone (PES) membrane matrix is to improve membrane hydrophilicity and anti-fouling resistance against oil deposition and/or adsorption. The resulting membranes were characterized by SEM, AFM, FTIR, contact angle measurements and ultrafiltration (UF) of synthetic oily wastewater. Experimental results showed that the hydrophilicity of the PES/HMO membrane was significantly improved to a low value of contact angle (16.4°) by HMO loading, which as a consequence led to a promising pure water permeability (573.2 L m−2 h−1 bar−1). In comparison, the pristine PES membrane only demonstrated 69.5° and 39 L m−2 h−1 bar−1, respectively. Furthermore, the PES/HMO membrane exhibited an excellent oil rejection (almost 100%) and a promising water flux recovery (75.4%) when it was used to treat a synthetic oily solution containing 1000 ppm oil. The promising anti-fouling properties of the PES/HMO membrane could be attributed to the presence of hydrophilic –OH groups on the membrane surface resulting from HMO addition, making this membrane less susceptible to fouling when challenged with oil-in-water emulsions.

Conventional methods and emerging wastewater polishing technologies for palm oil mill effluent treatment: a review.

The Malaysian palm oil industry is a major revenue earner and the country is ranked as one of the largest producers in the world. However, growth of the industry is synonymous with a massive production of agro-industrial wastewater. As an environmental protection and public health concern, the highly polluting palm oil mill effluent (POME) has become a major attention-grabber. Hence, the industry is targeting for POME pollution abatement in order to promote a greener image of palm oil and to achieve sustainability. At present, most palm oil mills have adopted the ponding system for treatment. Due to the successful POME pollution abatement experiences, Malaysia is currently planning to revise the effluent quality standards towards a more stringent discharge limits. Hence, the current trend of POME research focuses on developing tertiary treatment or polishing systems for better effluent management. Biotechnologically-advanced POME tertiary (polishing) technologies as well as other physicochemical methods are gaining much attention as these processes are the key players to push the industry towards the goal of environmental sustainability. There are still ongoing treatment technologies being researched and the outcomes maybe available in a while. However, the research completed so far are compiled herein and reported for the first time to acquire a better perspective and insight on the subject with a view of meeting the new standards. To this end, the most feasible technology could be the combination of advanced biological processes (bioreactor systems) with extended aeration, followed by solids separation prior to discharge. Chemical dosing is favoured only if effluent of higher quality is anticipated.

Effect of Dispersed Multi-Walled Carbon Nanotubes on Mixed Matrix Membrane for O2/N2 Separation

Mixed matrix membranes (MMMs) consisting of multiwalled carbon nanotubes (MWCNTs) embedded within polyetherimide were prepared. Surfactants of different charges were utilized to disperse the nanotubes through a simple non-covalent approach. The characterization results suggest that proper selection of the dispersing agent contributed to better dispersion of nanotubes. The MMMs exhibited improved thermal stability and mechanical strength, which indicate the improvement of dispersion and compatibility within the polymer matrix. The resulting membrane exhibited permeance improvement of O2 and N2 as much as 87.7% and 120% respectively compared to that of neat polyetherimide. The results implied that Triton-X100 treated MWCNTs is a promising filler to enhance gas permeability.

POME Treatment Efficacy as Affected by Carrier Material Size in Micro-Bioreactor System

This paper presents the effect of different sizes of palm kernel shell (PKS) activated carbon as the carrier material in a micro-bioreactor system to treat the palm oil mill effluent (POME). Three different sizes of PKS activated carbon were used as the carrier material, i.e. 4.750 – 2.360 mm (large), 1.180 – 0.710 mm (average) and 0.425 – 0.300 mm (small). The systems were run for a total of 29 days under hydraulic retention time (HRT) of 24 hours. The performances of several effluent quality parameters of POME regarding the use of PKS activated carbon of different sizes were studied. PKS activated carbon with size 1.180 – 0.710 mm showed the highest removal performances for chemical oxygen demand (COD), ammoniacal-nitrogen (AN), and solids, with 41 %, 84.6 %, and 88 % of removal respectively. The system with PKS activated carbon of size 4.750 - 2.360 mm showed the highest performance in removing TP (45 %), while 1.180 – 0.710 mm size of PKS activated carbon showed the highest performance in removing TN (53 %). The system was also found to effectively reduce the effluent colour. In overall, the PKS activated carbon of size 1.180 – 0.710 mm showed the best results as a carrier material to be used in the micro-bioreactor system in treating POME compared to the other two sizes.

Copper in Water, Sediment and Strombus Canarium at South Western Coast of Peninsular Malaysia

Cu concentration was determined in water, sediment and soft tissue of deposit feeder Strombus canarium collected from two sites at western coast of Johor Straits, Malaysia. The sites are located at Tanjung Bin and the seagrass bed near Tanjung Kupang. The study found higher concentration in Strombus canarium from seagrass bed than those in Tanjung Bin which were 7.02 and 3.71 µg/g respectively. Smaller concentration in Strombus canarium from Tanjung Bin is due to less Cu accumulation from its surrounding. However, the concentrations were within the permissible limit of Malaysian Food Standard. The concentration of Cu in water at both sites exceeded the Malaysia Marine Water Quality Criteria and Standard for Class E, whereas sediment is classified as moderately polluted based on the proposed quality by Environmental Protection Agency.