Bimodal Porous Ceramic Membrane Via Nanosized Polystryene Templating : Synthesis, Characterization And Performance Evaluation [TA455.C43 L576 2008 f rb].

Membran seramik mempunyai rintangan yang tinggi terhadap haba dan bahan kimia, tetapi kebolehtelapannya adalah lebih rendah secara relatif berbanding dengan membran organik. Ceramic membranes possess great resistance toward heat and chemicals, but the permeability of ceramic membranes is relatively low compared to polymeric membranes

Microwave-assisted conversion of palm kernel shell biomass waste to photoluminescent carbon dots

In the present work, palm kernel shell (PKS) biomass waste has been used as a low-cost and easily available precursor to prepare carbon dots (CDs) via microwave irradiation method. The impacts of the reacting medium: water and diethylene glycol (DEG), and irradiation period, as well as the presence of chitosan on the CDs properties, have been investigated. The synthesized CDs were characterized by several physical and optical analyses. The performance of the CDs in terms of bacteria cell imaging and copper (II) ions sensing and removal were also explored. All the CDs possessed a size of 6–7 nm in diameter and the presence of hydroxyl and alkene functional groups indicated the successful transformation of PKS into CDs with carbon core consisting of C = C elementary unit. The highest quantum yield (44.0%) obtained was from the CDs synthesised with DEG as the reacting medium at irradiation period of 1 min. It was postulated that the high boiling point of DEG resulted in a complete carbonisation of PKS into CDs. Subsequently, the absorbance intensity and photoluminescence intensity were also much higher compared to other precursor formulation. All the CDs fluoresced in the bacteria culture, and fluorescence quenching occurred in the presence of heavy metal ions. These showed the potential of CDs synthesised from PKS could be used for cellular imaging and detection as well as removal of heavy metal ions

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

Non-Solvent Influence of Hydrophobic Polymeric Layer Deposition on PVDF Hollow Fiber Membrane for CO2 Gas Absorption

The implementation of hydrophobicity on membranes is becoming crucial in current membrane technological development, especially in membrane gas absorption (MGA). In order to prevent membrane wetting, a polypropylene (PP) dense layer coating was deposited on a commercial poly(vinylidene fluoride) (PVDF) hollow fiber membrane as a method of enhancing surface hydrophobicity. The weight concentration of PP pellets was varied from 10 mg mL−1 to 40 mg mL−1 and dissolved in xylene. A two-step dip coating was implemented where the PVDF membrane was immersed in a non-solvent followed by a polymer coating solution. The effects of the modified membrane with the non-solvent methyl ethyl ketone (MEK) and without the non–solvent was investigated over all weight concentrations of the coating solution. The SEM investigation found that the modified membrane surface transfiguration formed microspherulites that intensified as PP concentration increased with and without MEK. To understand the coating formation further, the solvent–non-solvent compatibility with the polymer was also discussed in this study. The membrane characterizations on the porosity, the contact angle, and the FTIR spectra were also conducted in determining the polymer coating properties. Hydrophobic membrane was achieved up to 119.85° contact angle and peak porosity of 87.62% using MEK as the non-solvent 40 mg mL−1 PP concentration. The objective of the current manuscript was to test the hydrophobicity and wetting degree of the coating layer. Hence, physical absorption via the membrane contactor using CO2 as the feed gas was carried out. The maximum CO2 flux of 3.33 × 10−4 mol m−2 s−1 was achieved by 25 mg modified membrane at a fixed absorbent flow rate of 100 mL min−1 while 40 mg modified membrane showed better overall flux stability

From drainage to resource: a practice approach to reuse greywater for household irrigation purposes

The United Nations indicates that available freshwater resources will decrease significantly due to pollution growth and urbanization; two-thirds of the world's population may face water shortages by 2030. Extended use of greywater is an alternative option for reducing potable water consumption in urban areas. Recently, the reuse of treated greywater for home gardens, peri-urban agriculture, and landscaping has become a widespread concern in many developing countries. This paper presents a study on a low-cost system that can perform greywater treatment for household use. This treatment system employed physical filtration by ceramic filters, quartz gravel, hollow fiber membrane, and UV disinfection. Three greywater samples collected from the kitchen, washing basins, and bathroom were investigated. The operation process determines the system's effectiveness by considering turbidity, coliform, Biochemical Oxygen Demand (BOD5), and Chemical Oxygen Demand (COD) concentration of the inlet and outlet water. As a result, high removal efficiency (i.e., >60%) could be obtained for each investigated parameter. Results also showed that grey water generated from washing basins has the highest potential for reuse since the water quality after treatment satisfies the water reuse standards for household irrigation. The findings encourage further exploration and implementation of greywater reuse practices. HIGHLIGHTS A greywater treatment system with six filter layers and a PVDF hollow fiber membrane was investigated.; The system's performance was assessed by measuring the pH, turbidity, BOD5, COD, and coliform concentration.; UV disinfection made washing basin greywater suitable for garden irrigation, meeting international standards.; An efficient and cost-effective system for greywater reuse in Southeast Asian households.

A short review of CO2 responsive polymeric adsorbents and membranes for water quality control

Separation processes using adsorbents and membranes can be regulated by incorporating stimuli-responsive materials. A wide range of polymers demonstrates changes in characteristics and performance reacted to an external stimulus including pH, temperature, gases, or pressure. Among the stimuli, CO2 is a nontoxic and abundant stimulus that can also be easily added or removed from the separation processes. In this paper, the progress of CO2 responsive adsorbents and membranes was studied. The tertiary amine or amidine groups of the CO2-responsive polymers could be easily protonated by CO2 bubbling, causing characteristic changes to regulate the separation. The synthesis, characteristics, and separation performance were examined. Poly(diethyl-amino-ethyl methacrylate) (PDEAEMA) modified microparticles were used to adsorb protein, but protein recovery remained unclear. The grafting of PDEAAMA and poly(2-(di-methylamino)ethyl methacrylate) (PDMAEMA) on microparticles allowed the adsorption of heavy metals, but higher recovery was attained by PDMAEMA modified microparticles under CO2 bubbling. The CO2- responsive polymeric microparticles were successfully applied in forward osmosis, producing water from salt solution without high temperature or pressure. PDEAEMA modified membranes were extensively studied in the separation of oil and water mixture due to their switchable surface hydrophilicity. PDEAEMA and PDMAEMA modified membranes were also tested in nanofiltration since they exhibited changes in pore size and zeta potential to control pollutant rejection. Nevertheless, CO2-responsive membranes could be cleaned under CO2/N2 bubbling

Characterization of hydrophobic-treated recycled paper mill sludge in bituminous materials

The experimental investigation of the performance of hydrophobic-treated recycled paper mill sludge (RPMS) incorporated into asphalt mixtures is presented in this paper. This research implements RPMS as a solid waste additive to partially replace the mineral filler in the asphalt mixture while practicing green asphalt technology. The raw RPMS required mechanical pre-treatments and its hydrophilic property was modified chemically. The hydrophobicity was assessed by Hydrophilic Coefficient, Water Contact Angle (WCA) and Scanning Electron Microscopy (SEM). The ethanol method, which involved the esterification of ethyl esters that utilized 7ml of waste cooking oil (WCO) and 50ml of ethanol, was adopted. In the Marshall mix design, RPMS was incorporated at 0.5% and 1.0% of the weight of aggregates. Conventional 60/70 PEN bitumen and granite aggregates were used. The optimum binder content (OBC) was evaluated and justified by its adsorption strength. The mechanical properties of asphalt mixtures were determined and compared with the Public Work Department (PWD) specifications. All the volumetric properties satisfied the standard specification by PWD for 0.5% modified RPMS asphalt mixture, and thus it is preferable as it also involved lower binder cost due to the lower OBC achieved