Bilge water degradation and separation <italic>via</italic> a hybrid photocatalytic membrane reactor based on a polyvinylidene fluoride (PVDF)/halloysite nanotube clay (HNTs) nanocomposite membrane has been achieved by this study.
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Various Endocrine Disrupting Compounds (EDCs) either natural or synthetics have been identified including bisphenol A (BPA), dioxin, polychlorinated biphenyls, and dichlorodiphenyltrichloroethane (DDT). These compounds which present widely in the product of solvent industry, agricultural, pharmaceuticals and household convenience may directly or indirectly interrupt the normal function of endocrine system. Recently, the EDCs threats to human health have led to the increasing demand of clean water sources which excites a challenge for the contaminants removal processes. Conventional treatment methods may not completely remove the contaminants, meanwhile advanced oxidation process (AOPs) especially photocatalysis have been proven efficient in removing the contaminants. Even though photocatalysis is efficient in suspension of either nano-or microscale, the immobilizing TiO2 in the membrane matrix for catalyst separation purposes have decreased the adsorption of organic substances on the TiO2 surface with potential loss of TiO2 during long-time usage. This lead to the emerging in the exploration and fabrication of dual layer hollow fiber (DLHF) membrane for better performance of immobilized TiO2. Therefore, we exploit this fact to investigate the incorporation of photocatalysis into dual-layer hollow fiber membrane which are believed may improve the photocatalytic degradation and separation efficiency. The FESEM results showed that both layers are compatible with each other and there are no delamination found between layers. The presence of outer layer does not influence the surface roughness; however improve the hydrophilicity and membrane strength. Altogether, photocatalytic dual layer hollow fiber (DLHF) membrane was successfully fabricated using co-extrusion technique.
Over the past years, Malang (Indonesia) has encountered environmental problems due to municipal solid waste (MSW) overgeneration. Nevertheless, the increasing volume and complexity of MSW management in the city could be tackled using digital solutions. As a key location of ICT development, China is a key partner for Indonesia to improve its MSW management using digital technologies. As a miniature of China's sustainable waste management, Nanning represents a model of smart city that applies resource recovery paradigms using digitalization. Using a case-study approach, this work critically investigates how to strengthen waste recycling industry in Malang using digitalization-based circular economy (CE) according to Nanning's experiences in digitalizing waste recycling. It was found that lessons learnt from Nanning in MSW management were transferable and applicable for Malang to replicate its model, while paving the way forward for a transition towards a CE in waste sector. Traditionally, waste segregation at source was not properly conducted in Malang due to lack of environmental awareness and less public participation, while the waste management in Nanning is time-efficient and cost-effective. Nanning's experiences in digitalizing recyclable materials and/or recycled goods could facilitate Malang to shift towards a digitalization-based CE. Integrating automatic segregation and digitalization at waste banks is efficient in terms of time. With digitalization, over 90% of the solid waste in Malang is segregated properly, while diverting 60% of its non-biodegradable trash from landfills. Overall, the use of digital technologies has enabled waste banks to revolutionize waste industry, while promoting sustainable development at local level. To contribute their share to the UN SDGs, other cities in Indonesia are at their transition towards a digitalization-based CE. There is still a long way for them to attain full circularity and reap the benefits of digital transformation in the waste sector. Hence, it is necessary for stakeholders to promulgate effective policies and strengthen CE implementation on non-biodegradable waste through digital technologies.
Dual-layer hollow fiber (DLHF) micro-tubular solid oxide fuel cell (MT-SOFC) consisting of nickel oxide-yttria-stabilized zirconia (NiO-YSZ) anode/YSZ electrolyte was fabricated via a single-step phase inversion-based co-extrusion/co-sintering technique in order to investigate the effect of different electrolyte extrusion rates (1-5 mL min−1) at different sintering temperature (1350°C, 1400°C, and 1450°C) under methane (CH4) condition. The DLHF co-sintered at 1450°C was chosen as optimum temperature due to the good mechanical strength and gas-tight property. Meanwhile, 18 to 34 μm of electrolyte thickness was achieved when electrolyte extrusion rate increase from 1 to 5 mL min−1. Power density as high as 0.32 W cm−2 was obtained on the cell with the electrolyte layer of 18 μm in thickness (DLHF1) which is 20% higher than the cell with an electrolyte layer of 34 μm (DLHF5) which was only 0.12 W cm−2 when operated at 850°C. However, DLHF1 had suffered cracking formation that originated from anode site which shortened the stability test duration to only 8 hours of survival under 750°C. While DLHF5 can operate up to 15 hours but an increase in electrolyte thickness had resulted in higher ohmic area-specific resistance that lowering the power density. Fifty-seven percent reduction in cell performance was observed under methane condition when compared to the cell that performs using hydrogen gas due to the carbon deposition as proven by Raman spectroscopy and carbon, hydrogen, nitrogen, and sulfur analyzer.
Environmental pollution emanating from rapid industrialization has been considered a worldwide concern in recent years. Therefore, the scientific community is developing various kinds of new materials and techniques to minimize environmental problems. In this regard, aerogels have drawn much interest for the scientific community because of its extraordinary properties for various advanced applications, such as catalytic and energy storage devices. In this book chapter, fundamental synthesis method for preparing aerogel and its composites with metal and metal oxide has been reviewed. Moreover, properties of these aerogels can be further improved with graphene and its derivatives. Therefore, the composites of metal oxides and other inorganic materials with graphene, reduced graphene oxide, and graphene oxide have been reviewed. Water pollution is a major concern for the various countries. Different methods such as chemical oxidation process, distillation, membrane filtration, absorption, and photocatalytic are in practice to treat wastewater. However, the photocatalytic process is being considered an economical and efficient method to remove water pollutants. Therefore, the role of aerogels to cure the environmental issue by photocatalyst technique was also studied. In short, aerogels found attractive to degrade the various detrimental dyes such as methylene blue, rhodamine B, methyl orange, and congo red, etc.
Cerium-gadolinium oxide is a promising material for electrolytes of intermediate temperature solid oxide fuel cells (IT-SOFCs) due to its high electrical conductivity at relatively lower temperatures of 400–700 °C. However, a high sintering temperature of up to 1550 °C is typically required to produce dense CGO electrolyte, eventually leading to an interfacial interdiffusion between the electrolyte and electrode components as well as generate a highly resistive interface which reduces ionic conductivity. Lowering the sintering temperature of the electrolyte will greatly benefit the fabrication of SOFCs. This study examines the effectiveness of introducing nano size CGO particles as an approach to get dense CGO electrolyte at lower sintering temperature. A series of dope suspensions with 0–50% nano size loading were prepared to observe rheology and measure viscosity. Then, 30% loading was selected and casting into flat sheet via phase-inversion technique. The flat sheet was characterized by morphology, surface roughness and mechanical strength tests. The suspension was extruded into dual-layer hollow fiber (DLHF) as well. The electrolyte/anode dual-layer hollow fibers (DLHFs) half-cell of micro-tubular solid oxide fuel cells (MT-SOFCs) were prepared via phase inversion based co-extrusion/co-sintering technique. The developed half-cell was characterized by morphological and gas tightness tests which further compared them with fully micron ones. The results show that the incorporation of 30% nanoparticle yielded to dense and tight CGO layers sintered at temperature 1450 °C, which about 50 °C lower than those reported previously for 100% micron particles. The I–V measurements demonstrated the maximum power density of 0.66 Wcm−2 at temperatures 500 °C using 100% H2 as fuel. Therefore, this approach is able to reduce the energy cost for the microstructural control of the prepared fiber and thus is recommended for the fabrication of low-cost dual-layer hollow fiber micro tubular SOFCs.
The inability of most photocatalysts to continue the catalytic process after the removal of light irradiation is one of their major drawbacks. In this work, a ternary nanocomposite of titanium oxide (TiO2) supported with tungsten oxide (WO3) and hybridized with graphene oxide (GO) (TiO2-WO3@GO) photocatalyst with electron energy storage properties was synthesized for oilfield-produced water (OPW) treatment under visible light and in dark conditions. WO3 addition extended the light absorption range of TiO2 into the visible light while also serving as an electron storage material for dark catalysis (memory catalysis). The GO serves as an efficient electron acceptor and transporter to prevent charge carrier recombination, thereby enhancing interfacial electron transfer within the photocatalyst system. 2.5 wt%, 5 wt%, and 10 wt% of WO3 precursors were reacted with TiO2 precursor and GO was further added to synthesize the nanocomposites via a modified sol-gel and solution-based approach for the first time. The properties of the nanocomposite were assessed using a wide range of characterization. The nanocomposite containing 5 wt% WO3 showed the best photocatalytic activity with the total organic content (TOC) degradation of 27.7% within 4 h of photodegradation in visible light, which is better than 22 % in 5 h under UV light so far reported in the literature. The nanocomposite also exhibited electron energy storage properties for dark catalysis after pre-illumination, i.e., 16.6% TOC degradation in 3 h in dark conditions. This low % TOC degradation in the dark could be attributed to the complex nature of OPW. This work has further confirmed the possibility of the use of photocatalysts for dark catalysis.
Low-cost mullite-kaolinite material has recently received more attention as an alternative to conventional ceramic materials such as alumina and silica to prepare ceramic hollow fibre membranes (CHFMs) due to its high alumina contents and silica and thermal/chemical stability. However, weak bending strength is still one of the key bottlenecks that delay their commercial applications. In this work, we successfully fabricate a novel mullite-SS HFM with enhanced bending strength using mullite-kaolinite power with different stainless steel alloy (SS) 316 L contents of 0.0, 2.5, 5.0, 7.5, and 10% (w/w) as a reinforcement material by phase inversion/sintering techniques. The SS alloy was a potential material to enhance the mechanical strength of mullite HFMs due to its excellent mechanical properties. The effects of the major fabrication parameters of SS contents, mullite contents, fabrication parameters such as air gap distance, and bore fluid flow rates were well studied and evaluated through the fabrication process. Fabricated mullite-SS HFMs were characterised by morphology, porosity, pore size/pore size distribution, and bending strength. Afterwards, they were evaluated in an oil/water separation system regarding water flux and oil rejection rate. Based on the findings, an increment of the SS contents from 0 – 10% (w/w) improved the membrane morphology and crystallinity while reducing the porosity to 29 % (w/w). The satisfactory morphology with micro-void structure and higher crystallinity was obtained at 10 % (w/w) SS. The bending strength also improved to the highest value of 66.7 MPa at 10 % (w/w) SS due to additional bonding formation between SS and mullite particles at 1350 o C sintering temperature. This bending strength was significantly higher than that reported for mullite HFMs in previous works. Moreover, enhanced oil-water rejection performance was observed to attain about 96.9% by incrementing the SS contents from 0 – 10% (w/w), whereas water permeation was reduced to 290 L/m 2 . h due to pore size reduction by SS particles. These findings suggest the benefit of this membrane for various water treatment applications, such as oil/water separation, due to its outstanding physical properties.
This paper was written to give a clear picture about the importance of utilizing quality assurance tools to ensure high healthcare professionals' performance in one of the well-known public hospitals in Malaysia. Improving quality among healthcare professionals has become a unifying theme across any hospitals in Malaysia. The importance of improving performance was seen in growing attention to patient safety and reducing medical errors as well as seen as an attempt to reduce waste and inefficiency in the health sector. The rapid growth in healthcare industry in terms of number of competitors as in private medical centers and facilities has also led leaders to ensure their healthcare professionals have derived their performance to full limits. The objective of this paper was to identify the tools that gave the biggest impact towards healthcare professionals' performance and the outcome after complying with the whole quality assurance practice. Respondents selected were doctors and medical officers in Universiti Malaya Medical Centre (UMMC). The result of this paper showed that the three quality assurance tools identified were really critical to ensure the success of the healthcare professionals' performance. The organization and healthcare professionals must play their roles and support each other in enforcing the quality assurance practices to produce good result in meeting their standards and objectives. The application of quality assurance practices was really necessary for both organization and healthcare professionals in order create competitive advantage and to survive in the healthcare industry.
