Polyethersulfone 3-Aminopropyltriethoxysilane-Silica Composite Hollow Fiber Membrane For Synthetic Oil-In-Water Emulsion Separation

Membrane fouling effect by oil is a critical issue in wastewater applications. Fouling can be mitigated by functionalizing the membrane with enhanced hydrophilic properties. Although, previous research have concluded that an increase in surface hydrophilicity is a feasible mechanism for fouling mitigation, other parameters such as membrane roughness and morphology may contribute as well. In this work, 3-aminopropyltriethoxysilane modified silica (APTES-SiO2) particle was synthesized via one pot reaction modification. Response surface methodology based on central composite design was used to prepare the PES composite HF membranes via dry-wet spinning process. The result shows that the ratio of polyethylene glycol to APTES-SiO2 particles must be equal to 1 or more than unity to ensure better dispersion of APTES-SiO2 in the PES matrix as well as improved performance. The optimum dope formulation obtained was subsequently used to develop PES/APTES-SiO2 composite membrane by varying ethanol fraction the bore fluid composition. In terms of bore fluid composition, HF membrane spun with 25/75 wt.% of ethanol shows a better surface morphology and improved permeation properties. Membrane properties were studied in terms of pore size, porosity, roughness, hydrophilicity, mechanical and thermal properties. The SEM images of the HF membranes shows that the particles have been successfully incorporated in the membrane matrix and well dispersed. The surface roughness of all composite membranes were lower as compared to the controlled membrane. The PES/APTES-SiO2 composite membrane show an improved hydrophilicity, permeability and anti-fouling effects when tested for wastewater applications. The rejection performance of PES/APTES-SiO2 composite membrane during filtration of synthetic oil in water shows that the incorporation of 2.5 wt.% of APTES-SiO2 was able to remove 99.87 of oil as compared to only 97.23 for pristine membrane. It was found that the composite membranes had low relative flux reduction, superior flux recovery ratio and fouling resistance as compared to the controlled which can be as a result of the decrease in surface roughness, pore structure and well dispersed APTES-SiO2 particles on the membrane surface. To get more details on the performance of the composite membrane, different operating conditions such as transmembrane pressure, feed concentration, and feed flow rates were also investigated. The intermediate block model was identified as the most critical factor that contributed to membrane fouling. This work demonstrated that by functionalizing SiO2 surface with APTES, HF membranes with low surface roughness and anti-fouling properties can be achieved for effective removal of oil from synthetic oil-in-water emulsion

Characterization and kinetic studies of poly(Vinylidene fluoride-co-hexafluoropropylene) polymer inclusion membrane for the malachite green extraction

Textile industry effluent contains a high amount of toxic colorants. These dyes are car-cinogenic and threats to the environment and living beings. In this study, poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-co-HFP) was used as the based polymer for PIMs with bis-(2-ethylhexyl) phosphate (B2EHP) and dioctyl phthalate (DOP) as the carrier and plasticizer. The fabricated PIMs were employed to extract the cation dye (Malachite Green; MG) from the feeding phase. PIMs were also characterized by scanning electron microscopy (SEM), atomic force micro-scope (AFM), contact angle, water uptake, Fourier-transform infrared spectroscopy (FTIR) and ions exchange capacity. The performance of the PIMs was investigated under various conditions such as percentage of carrier and initial dye concentration. With permeability and flux values of 0.1188 cm/min and 1.1913 mg cm/min, PIM produced with 18% w/w PVDF-co-HFP, 21% w/w B2EHP, 1% w/w DOP and 40% w/w THF and was able to achieve more than 97% of MG extraction. The experimental data were then fitted with a pseudo-second-order (PSO) model, and the calculated R2 value was ~0.99. This shows that the data has a good fit with the PSO model. PIM is a potential alternative technology in textile industry effluent treatment; however, the right formulation is crucial for developing a highly efficient membrane

Status of household waste segregation in municipal solid waste management for Kuching South City, Sarawak, Malaysia

Household attitudes in the community appear to be critical as their points of understanding in waste segregation eventually plays a significant role in providing answers to municipal solid waste management problems in Kuching South City. Despite the abundance of opportunities available for household waste segregation, its full potentials are yet to be exploited in Kuching South City. The objectives of this study were to determine the level of awareness and acceptance, constraints and household requirements for participation among residents of Kuching South City. It also aims to examine the existing practice in Kuching South City and hence make recommendations for effective waste segregation practice. This study gathered data from two main sources namely secondary and primary sources. The secondary data was sourced from various related and relevant articles, books and journals. The two main techniques employed in gathering primary data were household questionnaire sampled among 228 households and face to face interview conducted with delegates from Kuching South City Council and Natural Resource and Environmental Board, Sarawak. Descriptive statistics, correlation test, independent t-test and analysis of variance were used to answer the research questions and hypotheses

Removal of Humic Acid Using 3-Methacryloxypropyl Trimethoxysilane Functionalized MWCNT Loaded TiO2/PES Hybrid Membrane

In the present work, a highly efficient mixed matrix membrane (MMM) for humic acid (HA) removal was developed. Multiwalled carbon nanotubes (MWCNTs) were functionalized in the presence of 3-methacryloxypropyl trimethoxysilane using the co-condensation method and were subsequently loaded with TiO2 (prepared via the sol–gel route). The as-prepared material was then incorporated into a PES polymer solution to prepare a fMWCNT-TiO2/PES hybrid membrane via non-solvent induced phase inversion. The microstructure of the membrane was characterized using Fourier transform infrared spectroscopy, atomic force microscopy, scanning electron microscopy, water contact angle, thickness, porosity, and pore size. The fMWCNT-TiO2/PES hybrid membrane was tested for the removal of HA and antifouling performance. The results show that the surface hydrophilicity of the membranes was greatly improved upon the addition of the fMWCNT-TiO2 particles. The results show that 92% of HA was effectively removed after 1 h of filtration. In comparison with pristine membrane, the incorporation of fMWCNT-TiO2 nanoparticles led to enhanced pure water flux (99.05 L/m2 h), permeate flux (62.01 L/m2 h), higher HA rejection (92%), and antifouling improvement (RFR: 37.40%, FRR: 86.02%). Thus, the fMWCNT-TiO2/PES hybrid membrane is considered to be a great potential membrane for the improvement of ultrafiltration membranes

Characterization of polymer inclusion membranes (PIMs) containing Bis-(2-ethylhexyl) phosphate carrier for zinc (II) ions removal

Transportation using polymer inclusion membranes (PIMs) is one of the selective and effective methods that can be used for heavy metal ion removal. This study was performed to investigate the characteristics of fabricated PIMs by varying composition of liquid extracting agent, bis-(2-ethylhexyl) phosphate (B2EHP) carrier to amplify the zinc (II) ions removal from aqueous solution. The fabricated PIMs were characterized with respect to their surface morphology, surface chemistry, hydrophilicity and ion exchange capacity (IEC) using Scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FTIR) and goniometer, respectively. The performance of the fabricated PIMs was evaluated based on the Zn (II) ions removal efficiency at different composition of B2EHP carrier content. The experimental results show that the R5 membrane, which contains 30 percent carrier, had the highest IEC value of 0.746 mq/g with a contact angle of 50.4o, and thus had an outstanding removal efficiency of zinc (II) ion, which was greater than 99 percent. This study demonstrated that the B2EHP carrier improved the microstructure of the produced PIMs and served as an excellent ion carrier for the removal of Zn (II) ions

A Review on Metal Ions Modified TiO2 for Photocatalytic Degradation of Organic Pollutants

TiO2 is a semiconductor material with high chemical stability and low toxicity. It is widely used in the fields of catalysis, sensing, hydrogen production, optics and optoelectronics. However, TiO2 photocatalyst is sensitive to ultraviolet (UV) light; this is why its photocatalytic activity and quantum efficiency are reduced. To enhance the photocatalytic efficiency in the visible light range as well as to increase the number of the active sites on the crystal surface or inhibit the recombination rate of photogenerated electron–hole pairs electrons, various metal ions were used to modify TiO2. This review paper comprehensively summarizes the latest progress on the modification of TiO2 photocatalyst by a variety of metal ions. Lastly, the future prospects of the modification of TiO2 as a photocatalyst are proposed