Advancing Agro-Based Research

Taking the next sums up Universiti Putra Malaysia (UPM) approach to research. The university now aims to create an environment that inspires innovative research following its selection as a research university by the Higher Education Ministry in November 2006

Advanced Treatment of Pesticide-Containing Wastewater Using Fenton Reagent Enhanced by Microwave Electrodeless Ultraviolet

The photo-Fenton reaction is a promising method to treat organic contaminants in water. In this paper, a Fenton reagent enhanced by microwave electrodeless ultraviolet (MWEUV/Fenton) method was proposed for advanced treatment of nonbiodegradable organic substance in pesticide-containing biotreated wastewater. MWEUV lamp was found to be more effective for chemical oxygen demand (COD) removal than commercial mercury lamps in the Fenton process. The pseudo-first order kinetic model can well describe COD removal from pesticide-containing wastewater by MWEUV/Fenton, and the apparent rate constant (k) was 0.0125 min−1. The optimal conditions for MWEUV/Fenton process were determined as initial pH of 5, Fe2+ dosage of 0.8 mmol/L, and H2O2 dosage of 100 mmol/L. Under the optimal conditions, the reaction exhibited high mineralization degrees of organics, where COD and dissolved organic carbon (DOC) concentration decreased from 183.2 mg/L to 36.9 mg/L and 43.5 mg/L to 27.8 mg/L, respectively. Three main pesticides in the wastewater, as Dimethoate, Triazophos, and Malathion, were completely removed by the MWEUV/Fenton process within 120 min. The high degree of pesticides decomposition and mineralization was proved by the detected inorganic anions

Anti-Offset High-Voltage Wireless Power Transfer System Based on Many-to-One Topology

Aiming at the problems of limited semiconductor performance and positioning difficulties in the wireless power transfer (WPT) system of electric vehicles, the paper proposes a many-to-one high-voltage wireless charging anti-offset system. In order to be adapted to high-voltage applications, the system is designed with a series input inverter. At the same time, a multi-winding transformer is used to realize the equivalent parallel output of inverters and the function of transmitting power to primary loops. The many-to-one topology aims to expand the positioning range of electric vehicles to realize the anti-offset of wireless charging. In order to analyze the working mechanism of the multi-winding transformer and study the power transmission characteristics of the many-to-one topology, the equivalent circuit analysis and Matlab simulation are carried out, and a laboratory prototype for experimental verification is made. Based on the experimental and simulation results, the paper proposes a hybrid operating mode based on many-to-one WPT topology, which can effectively expand the positioning range of electric vehicles during wireless charging. Both the analytical and experimental results show that the topology proposed in the paper can effectively increase the input voltage of the system for high-voltage scenarios, and effectively expand the positioning range of the WPT system

Reusable Platinum-Deposited Anatase/Hexa-Titanate Nanotubes: Roles of Reduced and Oxidized Platinum on Enhanced Solar-Light-Driven Photocatalytic Activity

A new class of photocatalysts, referred to as Pt(0)- or Pt­(IV)-deposited anatase/hexa-titanate nanotubes (Pt(0)-TNTs-600 and Pt­(IV)-TNTs-600), were prepared through a three-step process: hydrothermal conversion of commercial TiO₂ to titanate nanotubes and subsequent deposition of Pt and calcination. At the optimal Pt dosage (0.1 wt %) and calcination temperature (600 °C), Pt(0)-TNTs-600 showed the highest photocatalytic activity for degrading phenanthrene. The apparent pseudo-first order rate constant (<i>k</i>₁) was determined to be 0.12 h^–1, which was ∼2 and 3 times of that for Pt­(IV)-TNTs-600 and P25. TEM, XRD, FTIR, and XPS analyses indicate that Pt(0)-TNTs-600 is a composite of anatase and hexa-titanate with metallic Pt deposited, where Pt facilitates transport of photogenerated electrons, thus inhibiting recombination of the electron–hole pairs. Moreover, DRS UV–vis analysis revealed a narrower optical energy gap of materials, resulting in enhanced absorbance in the visible region. The new photocatalyst could also produce more reactive oxygen species, i.e. ·OH, than the P25 and pristine TNTs. The material can be reused in multiple cycles of water treatment operations (with almost no activity loss after six consecutive cycles). The new photocatalyst appears promising for efficient photodegradation of a host of organic pollutants in water under solar light

Controlled synthesis of ultrathin lanthanide oxide nanosheets and their promising pH-controlled anticancer drug delivery

Various lanthanide oxides (Sm2O3 and Gd2O3) nanostructures were synthesized by a facile hydrothermal method. The loss of surfactants on the nanocrystals surface, followed by the resultant assembly is responsible for the formation of ultrathin nanosheets. Owing to strong surface effects, the different morphologies of the Sm2O3:5 % Eu and Gd2O3:5 % Eu nanocrystals present unique photoluminescence properties. As a proof-of-concept application, the as-obtained Sm2O3 and Gd2O3 ultrathin nanosheets exhibit promising pH-controlled anticancer drug-delivery behavior

High-Capacity and Photoregenerable Composite Material for Efficient Adsorption and Degradation of Phenanthrene in Water

We report a novel composite material, referred to as activated charcoal supported titanate nanotubes (TNTs@AC), for highly efficient adsorption and photodegradation of a representative polycyclic aromatic hydrocarbon (PAH), phenanthrene. TNTs@AC was prepared through a one-step hydrothermal method, and is composed of an activated charcoal core and a shell of carbon-coated titanate nanotubes. TNTs@AC offered a maximum Langmuir adsorption capacity of 12.1 mg/g for phenanthrene (a model PAH), which is ∼11 times higher than the parent activated charcoal. Phenanthrene was rapidly concentrated onto TNTs@AC, and subsequently completely photodegraded under UV light within 2 h. The photoregenerated TNTs@AC can then be reused for another adsorption–photodegradation cycle without significant capacity or activity loss. TNTs@AC performed well over a wide range of pH, ionic strength, and dissolved organic matter. Mechanistically, the enhanced adsorption capacity is attributed to the formation of carbon-coated ink-bottle pores of the titanate nanotubes, which are conducive to capillary condensation; in addition, the modified microcarbon facilitates transfer of excited electrons, thereby inhibiting recombination of the electron–hole pairs, resulting in high photocatalytic activity. The combined high adsorption capacity, photocatalytic activity, and regenerability/reusability merit TNTs@AC a very attractive material for concentrating and degrading a host of micropollutants in the environment

Recent technological developments and challenges for phosphorus removal and recovery toward a circular economy

This review aims to summarise the current state of the art technologies for phosphorus recovery from waste and wastewater. Information corroborated here shows a clear relationship between PO4-P content in the liquid phase and the cost of phosphorus recovery. In fact, all current commercial scale operations in this review involve a phosphorus-rich waste stream. In most cases, phosphorus recovery is achieved via two key steps: solubilising phosphorus into water and then phosphate recovery via chemical precipitation/crystallisation. Recent development has also included enrichment and pre-treatment of the phosphorus rich liquid stream. Phosphorus is also a contaminant in the aquatic environment. Thus, this work also reviews the post-treatment of the liquid stream after phosphorus recovery for environmental discharge or water reuse. This review places a spotlight on the requirement for further research work especially on phosphorus enrichment at pilot- and full-scale level. The review also demonstrates the need for further research on pre-treatment and post-treatment to complement the recovery process via chemical precipitation

Basic thermodynamic and dynamic characteristics of the glass forming intermetallics

Recent studies on intermetallic glasses challenged the conventional cognition that the glass formability would be deteriorated by the presence of intermetallics. To reveal the vitrification mechanism of intermetallics, three binary metallic alloys with multiple intermetallics and wide glass forming region are focused. The thermodynamics and dynamics of the intermetallics are studied by combining experiments and simulations, revealing that the glass forming systems can be featured by low melting entropy, low diffusion coefficient, and low formation enthalpy. Close inspection emphasizes the critical influence of the melting entropy in glass formation of intermetallics, and intermetallics with low melting entropy are of enhanced glass formability. In addition, for the glass forming intermetallics, the melting entropy shows close connection to the dynamics such as diffusion coefficients or viscosity of the liquids at melting temperature, with which a basic reference to design metallic glasses is substantiated

Efficient degradation of antibiotics in different water matrices through the photocatalysis of inverse opal K-g-C3N4: Insights into mechanism and assessment of antibacterial activity

The efficient degradation of fluoroquinolone antibiotics and the reduction of their antimicrobial activity were achieved in different water matrices through the photocatalysis of inverse opal potassium-doped carbon nitride (IO K-CN). The IO K-CN photocatalyst with optimum doping ratio of potassium performed much better than bulk carbon nitride and pure inverse opal carbon nitride for removing fluoroquinolone antibiotics, such as levofloxacin (LVX) and norfloxacin (NOR). The remarkably narrowed band gap resulting from potassium doping and the unique properties of the inverse opal construction jointly contributed to enhancing the activity of the photocatalyst. A possible mechanism and degradation pathway for LVX was proposed on the basis of a series of characterizations including electron spin resonance (ESR) experiments, and liquid chromatography-mass spectrometry (LC-MS) analysis. Meanwhile, the byproducts during the LVX photocatalytic degradation were shown to have much lower sterilization effect, implying that the toxicity and the potential risk of LVX were excellently reduced. The potential application for the treatment of antibiotic-containing wastewater was indicated by the excellent treatment efficiency and favorable durability of this photocatalyst. © 2020 Elsevier B.V.1