Author
Law Yong Ng
Other affiliations: National University of Malaysia
Bio: Law Yong Ng is an academic researcher from Universiti Tunku Abdul Rahman. The author has contributed to research in topics: Membrane & Nanofiltration. The author has an hindex of 17, co-authored 36 publications receiving 2329 citations. Previous affiliations of Law Yong Ng include National University of Malaysia.
Papers
More filters
••
TL;DR: In this paper, the photo-degradation mechanisms of persistent organic pollutants (POPs) and the recent progress in ZnO nanostructured fabrication methods including doping, heterojunction and modification techniques as well as improvements of ZnOs as a photocatalyst are reviewed.
Abstract: Persistent organic pollutants (POPs) are carbon-based chemical substances that are resistant to environmental degradation and may not be completely removed through treatment processes. Their persistence can contribute to adverse health impacts on wild-life and human beings. Thus, the solar photocatalysis process has received increasing attention due to its great potential as a green and eco-friendly process for the elimination of POPs to increase the security of clean water. In this context, ZnO nanostructures have been shown to be prominent photocatalyst candidates to be used in photodegradation owing to the facts that they are low-cost, non-toxic and more efficient in the absorption across a large fraction of the solar spectrum compared to TiO 2 . There are several aspects, however, need to be taken into consideration for further development. The purpose of this paper is to review the photo-degradation mechanisms of POPs and the recent progress in ZnO nanostructured fabrication methods including doping, heterojunction and modification techniques as well as improvements of ZnO as a photocatalyst. The second objective of this review is to evaluate the immobilization of photocatalyst and suspension systems while looking into their future challenges and prospects.
1,551 citations
••
TL;DR: The incorporation of nanoparticles into polymeric membranes has been the trend in the field of membrane research recently as discussed by the authors, and nanoparticles could produce synergistic effects when incorporated with different types of materials.
808 citations
••
TL;DR: The physical and chemical properties of C QDs, raw materials and methods used in the fabrication of CQDs, the stability of CZDs as well as their potential applications in wastewater treatment and biomedical field are discussed.
149 citations
••
TL;DR: Polyelectrolyte-modified membranes offer significant improvements, can be produced in a short period of time, require less energy during membrane modification or fabrication and incur lower production costs.
132 citations
••
TL;DR: The decoration of Ag on GO nanoplates could be a promising approach to resolve the agglomeration and leaching issues as well as reduce the amount of precious Ag in the synthesis of Ag-GO polyamide 6,6 membrane.
Abstract: Nanomaterials can be incorporated in the synthesis of membrane to obtain mixed-matrix membrane with marked improvement in properties and performance. However, stability and dispersion of the nanomaterials in the membrane matrix, as well as the need to use high ratio of nanomaterials for obvious improvement of membrane properties, remain a major hurdle for commercialization. Hence, this study aims to investigate the improvement of polyamide 6,6 membrane properties with the incorporation of silver nanoparticles decorated on graphene oxide (Ag-GO) nanoplates and at the same time focus is given to the issues above. Graphene oxide nanoplates were synthesized using the modified Hummers' method and decorated with silver before embedded into the polyamide 6,6 matrix. Physicochemical characterizations were conducted on both nanoplates and the mixed-matrix Ag-GO polyamide 6,6 membrane. The issues of Ag agglomeration and leaching were not observed, which could be attributed to the decoration of Ag on GO that helped to disperse the nanomaterials and provided a better anchor point for the attachment of Ag nanoparticles. The synthesized membrane showed marked improvement regarding flux (135% increment) and antifouling (40% lower irreversible fouling), which could be ascribed to the more negative charge of membrane surface (-14 ± 6 to -31 ± 3.8 mV) and hydrophilicity (46% enhancement) of the membranes. With minimal embedment of Ag nanoparticles, the membrane showed superior antibacterial property where the E. coli bacteria could not form a single colony on the membrane surface. Overall, the decoration of Ag on GO nanoplates could be a promising approach to resolve the agglomeration and leaching issues as well as reduce the amount of precious Ag in the synthesis of Ag-GO polyamide 6,6 membrane.
98 citations
Cited by
More filters
••
TL;DR: Nanofiltration (NF) membranes have come a long way since it was first introduced during the late 80's as mentioned in this paper, and significant development has taken place in terms of the fundamental understanding of the transport mechanism in NF membranes, which has been translated into predictive modeling based on the modified extended Nernst-Planck equation.
1,374 citations
••
TL;DR: In this article, a novel polyethersulfone (PES) mixed matrix nanofiltration membrane containing graphene oxide (GO) nanoplates was prepared via the phase inversion method.
826 citations
••
TL;DR: In this article, the authors summarized the recent scientific and technological advances in the development of nanocomposite membranes for water treatment and discussed challenges and future research directions in developing high performance nanocomposition membranes.
822 citations
••
TL;DR: In this paper, a review of polymeric membrane fabrication techniques for pressure driven membrane processes and membrane distillation is discussed, the fabrication technique, properties of the fabricated membranes and performance in water desalination are related.
790 citations
••
01 Feb 2017TL;DR: A review of membrane filtration, ion exchange, ion-exchange, adsorption, chemical precipitation, nanotechnology treatments, electrochemical and advanced oxidation processes are discussed in this article.
Abstract: Heavy metals like arsenic, copper, cadmium, chromium, nickel, zinc, lead, and mercury are major pollutants of fresh water reservoirs because of their toxic, non-biodegradable, and persistent nature. The industrial growth is the major source of heavy metals introducing such pollutants into different segments of the environment including air, water, soil, and biosphere. Heavy metals are easily absorbed by fishes and vegetables due to their high solubility in the aquatic environments. Hence, they may accumulate in the human body by means of the food chain. Various methods have been developed and used for water and wastewater treatment to decrease heavy metal concentrations. These technologies include membrane filtration, ion-exchange, adsorption, chemical precipitation, nanotechnology treatments, electrochemical and advanced oxidation processes. In this review, the methods as well as their mechanisms and efficiency are discussed.
724 citations