Search

Abstract The potentials of biomass-based carbon quantum dot (CQD) as an adsorbent for batch adsorption of dyes and its photocatalytic degradation capacity for dyes which are congo red (CR) and methylene blue (MB) have been conducted in this study. The CQDs properties, performance, behaviour, and photoluminescence characteristics were assessed using batch adsorption experiments which were carried out under operating conditions including, temperature, pH and dosage. The morphological analysis revealed that CQDs are highly porous, uniform, closely aligned and multi-layered. The presence of hydroxyl, carboxyl and carbonyl functional groups indicated the significance of the oxygenated functional groups. Spectral analysis of photoluminescence for CQDs confirmed their photoluminescent quality by exhibiting high excitation intensity and possessing greenish-blue fluorescence under UV radiation. The removal percentage of the dyes adsorbed for both CR and MB dyes was 77% and 75%. Langmuir isotherm and pseudo-second-order models closely fitted the adsorption results. Thermodynamics analysis indicated that the adsorption process was exothermic and spontaneous, with excellent reusability and stability. The degradation efficiency of CQDs on both dyes was more than 90% under sunlight irradiation and obeyed the first-order kinetic model. These results demonstrated CQDs to be an excellent adsorbent and outstanding photocatalyst for organic dye degradation.

Despite of the emergence of revolutionary Forward Osmosis (FO) technology, the membrane is hindered by the severe effect of internal concentration polarization (ICP) which generated in membrane substrate layer. In current study, polyethersulfone (PES) membranes substrate layer were fabricated via phase inversion using three different polyvinylpyrrolidone (PVP; molecular weight of 10 kDa, 40 kDa and 360 kDa) which act as a pore former agent. Using 2 wt% of aqueous m-phenylenediamine (MPD) and 0.15 wt% of trimesoyl chloride (TMC) in hexane, the active polyamide layer was formed on the top surface of PES substrate via interfacial polymerization to produce thin film composite (TFC) FO membrane. The performance of TFC FO membranes were evaluated and three intrinsic parameters; A, B and S were determined by mathematical model. The results attained were compared to find the optimized PVP molecular weight for FO membranes with desired performance. It was observed that FO membrane prepared with molecular weight PVP of 40 kDa exhibited excellent performance with low ICP, thus reduce the replacement of draw solute in FO application.

Abstract Waste cooking oil (WCO) appears to be a potential carbonaceous source for synthesizing graphene sand composite (GSC) adsorbent in removing pollutants. This study presents a green synthesis method of GSC using WCO as a sustainable carbon source for the synthesis of GSC through the thermal graphitization method. Characterization analysis conducted on GSCWCO verified the successful coating of WCO onto the sand surface and conversion to graphene, which possessed distinct functional groups and features of graphene materials. GSCWCO adsorbent effectiveness in removing Congo Red dye through batch adsorption was studied under the influence of different initial concentrations (20 to 100 mg/L), and the optimum pH (pH 2 to 10), contact time (5 to 240 min), and temperature (25 to 45 °C) were investigated. The GSCWCO showed removal rates of 91.5% achieved at an initial dye concentration of 20 mg L−1, 1.0 g of adsorbent dosage, a temperature of 25 °C, and 150 min of contact time. The GSCWCO exhibited a maximum capacity of 5.52 mg g−1, was well-fitted to the Freundlich isotherm model with an R2 value of 0.989 and had an adsorption mechanism that followed the pseudo-second-order kinetic model. Negative values of enthalpy (ΔH) and Gibbs free energy (ΔG) revealed that CR adsorption onto GSCWCO was a spontaneous and exothermic process. The presence of functional groups on the surface of GSCWCO with such interactions (π–π attractive forces, hydrophobic forces, and hydrogen bonding) was responsible for the anionic dye removal. Regeneration of GSCWCO adsorbent declined after four cycles, possibly due to the chemisorption of dyes with GSC that resulted in inefficient adsorption. Being a waste-to-wealth product, GSCWCO possessed great potential to be used for water treatment and simultaneously benefited the environment through the effort to reduce the excessive discharge of WCO.

The black liquor generated from the alkaline pretreatment of lignocellulosic biomass is usually disposed of into wastewater, which could lead to environmental pollution. Alkaline black liquor (ALBL) contains a large amount of xylan with a small fraction of lignin, making it a promising raw material for the production of xylooligosaccharides (XOS). In this study, xylan was extracted from the ALBL generated upon treating the oil palm frond (OPF) with sodium hydroxide via two-stage precipitation for the separation of lignin and recovery of xylan. As a result, approximately 84.0% of xylan retrieved from the ALBL was recovered. Subsequently, enzymatic hydrolysis was optimized to recover the maximum amount of XOS from xylan. The results showed that enzymatic hydrolysis produced the highest XOS (62.5%) under optimal conditions of 50 °C, 4 U/mL xylanase, and 3% xylan loading for 48 h. The study provides insight for maximizing utilization of ALBL of OPF for future biorefinery economy.

The present study systematically investigated the influence of synthesis conditions (duration, reaction medium, and doping concentration) and formation mechanism of carbon dots (CDs) derived from low-cost and abundant biomass palm kernel shell (PKS). Surprisingly, the dopant (urea) did not enhance the photoluminescence of CDs as expected, which could be attributed to the low reactivity between the dopant and PKS macromolecules. Variation of synthesis duration from 30 to 120 s clearly indicated the formation mechanism of CDs, involving the stages of dehydration, carbonization, and nucleation. The CDs with the highest photoluminescent intensity and quantum yield was obtained at synthesis duration of 90 s, aligned well with the perfect spherical shape of CDs and the synergistic effects of both surface and carbogenic core conditions. Understanding the formation mechanism could be used to optimize the synthesis of CDs, and hence linked to quantum yield and fluorescent intensity. In terms of application potential, the CDs illuminated well as fluorescent ink and in bacteria cells imaging. The potential of CDs as sensing material has also been proven with the quenching of fluorescence in the presence of metal ions. The linear range for detection of Cu2+ ions was 0.1–0.5 mM with a detection limit as low as 0.05 mM. This signifies the potential of CDs fabricated from PKS as a low-cost and easily available material for Cu2+ ions detection in aqueous solution. The CDs possessed reasonable photo stability as indicated by its consistent fluorescence level even after exposure to UV radiation for a prolonged period of 180 minutes. Overall, a simple, straightforward, and fast method is developed to synthesis strong blue emissive CDs from green PKS that are potentially suitable for Cu2+ ions sensing in real application.

Abstract In this study, hematite graphene oxide (αFe2O3-GO) powder nanocomposites and thin-film hematite graphene oxide (αFe2O3-GO) were synthesized for application in the removal of Rhodamine B (RhB) from textile wastewater. αFe2O3-GO nanomaterials were placed onto the FTO substrate to form a thin layer of nanocomposites. Different analysis including XRD, FTIR, Raman spectra, XPS, and FESEM were done to analyze the morphology, structure, and properties of the synthesized composites as well as the chemical interactions of αFe2O3 with GO. The photocatalytic performance of two synthesized composites was compared with different concentrations of αFe2O3-GO. The results showed that powder nanocomposites are more effective than thin-film composites for the removal of RhB dye. αFe2O3-GO-5% powder nanocomposites removed over 64% of dye while thin-film nanocomposites had less removal efficiencies with just under 47% removal rate. The reusability test was done for both materials in which αFe2O3-GO-5% powder nanocomposites removed a higher rate of dye (up to 63%) in more cycles (6 cycles).

Abstract In this study, two biomass-based adsorbents were used as new precursors for optimizing synthesis conditions of a cost-effective powdered activated carbon (PAC). The PAC removed dyes from an aqueous solution using carbonization and activation by KOH, NaOH, and H2SO4. The optimum synthesis, activation temperature, time and impregnation ratio, removal rate, and uptake capacity were determined. The optimum PAC was analyzed and characterized using Fourier-transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), a field emission scanning electron microscope (FESEM), Zeta potential, and Raman spectroscopy. Morphological studies showed single-layered planes with highly porous surfaces, especially PAC activated by NaOH and H2SO4. The results showed that the experimental data were well-fitted with a pseudo-second-order model. Based on Langmuir isotherm, the maximum adsorption capacity for removing methylene blue (MB) was 769.23 mg g−1 and 458.43 mg g−1 for congo red (CR). Based on the isotherm models, more than one mechanism was involved in the adsorption process, monolayer for the anionic dye and multilayer for the cationic dye. Elovich and intraparticle diffusion kinetic models showed that rubber seed shells (RSS) has higher α values with a greater tendency to adsorb dyes compared to rubber seed (RS). A thermodynamic study showed that both dyes’ adsorption process was spontaneous and exothermic due to the negative values of the enthalpy (ΔH) and Gibbs free energy (ΔG). The change in removal efficiency of adsorbent for regeneration study was observed in the seventh cycles, with a 3% decline in the CR and 2% decline in MB removal performance. This study showed that the presence of functional groups and active sites on the produced adsorbent (hydroxyl, alkoxy, carboxyl, and π − π) contributed to its considerable affinity for adsorption in dye removal. Therefore, the optimum PAC can serve as efficient and cost-effective adsorbents to remove dyes from industrial wastewater.

Abstract Aiming to mitigate wastewater pollution arising from the palm oil industry, this university-industry research-and-development project focused on the integration of serial treatment processes, including the use of moving bed biofilm reactor (MBBR), pre-treatment with sand filters and activated carbon filters, and membrane technology for aerobically-digested palm oil mill effluent (POME) treatment. To assess the potential of this sustainable alternative practice in the industry, the developed technology was demonstrated in a pilot-scale facility: four combinations (Combinations I to IV) of unit operations were developed in an integrated membrane-filtration system. Combination I includes a MBBR, pre-treatment unit comprising sand filters and activated carbon filters, ultrafiltration (UF) membrane, and reverse osmosis (RO) membrane, while Combination II excludes MBBR, Combination III excludes UF membrane, and Combination IV excludes both MBBR and UF membrane. Life cycle assessment (LCA) was performed to evaluate potential environmental impacts arising from each combination while achieving the goal of obtaining recycled and reusable water from the aerobically-digested POME treatment. It is reported that electricity consumption is the predominant factor contributing to most of those categories (50–77%) as the emissions of carbon dioxide (CO2), sulfur dioxide (SO2), nitrogen oxides, and volatile mercury during the combustion of fossil fuels. Combination I in the integrated membrane-filtration system with all unit operations incurring high electricity consumption (52 MJ) contributed to the greatest environmental impact. Electricity consumption registers the highest impact towards all life cycle impact categories: 73% on climate change, 80% on terrestrial acidification, 51% on eutrophication, and 43% on human toxicity. Conversely, Combination IV is the most environmentally-friendly process, since it involves only two-unit operations – pre-treatment unit (comprising sand filters and activated carbon filters) and RO membrane unit – and thus incurs the least electricity consumption (41.6 MJ). The LCA offers insights into each combination of the operating process and facilitates both researchers and the industry towards sustainable production.

Selection of suitable disinfection technology is necessary with regards to wastewater reclamation goals. In this work, the performance of various disinfection technologies - single disinfection units and integrated disinfection systems - on local sewage was studied for non-potable reuse. Disinfection units used as stand-alone units include ultraviolet (UV) disinfection, chlorination, microfiltration (MF), and ultrafiltration (UF). The integrated disinfection system consists of UV or chlorination as the primary disinfection unit incorporated with either MF, UF, multi-media or granular activated carbon as pre-treatment. The performance of these disinfection units and integrated processes were evaluated based on the percentage of removal of biochemical oxygen demand, chemical oxygen demand, total suspended solids, ammonia nitrogen, nitrate nitrogen, phosphorus, Escherichia coli, and trihalomethane in bench-scale disinfection systems. The single unit of PES20kDa membrane and the integrated disinfection system of UF-Cl showed the most effective treatment among single disinfection units and integrated systems, respectively. The results showed that almost all disinfection units and integrated disinfection processes were useable for restricted and unrestricted area non-potable applications according to United State Environmental Protection Agency (US EPA) water reuse guidelines and managed to fulfil Singapore grey water quality for recycling. ABSTRAK: Pemilihan teknologi penyahjangkitan kuman yang sesuai adalah perlu selaras dengan matlamat pemulihgunaan air buangan. Kajian ini adalah tentang prestasi pelbagai teknologi penyahjangkitan kuman - unit tunggal penyahjangkitan kuman dan sistem penyahjangkitan kuman bersepadu pada air sisa kumbahan tempatan dikaji bagi penggunaan semula air minuman. Unit tunggal penyahjangkitan kuman yang digunakan mempunyai penyahjangkitan kuman ultraungu (UV), pengklorinan, mikro penurasan (MF), dan ultra penurasan (UF). Manakala, sistem penyahjangkitan kuman bersepadu terdiri daripada UV atau pengklorinan sebagai unit penyahjangkitan kuman utama yang digabungkan bersama samada dengan MF, UF, multi-media atau karbon teraktif berbutir sebagai proses pra-rawatan. Prestasi unit tunggal penyahjangkitan kuman dan proses-proses bersepadu dinilai berdasarkan pada peratus penyingkiran keperluan oksigen biokimia, permintaan oksigen kimia, jumlah pepejal terampai, nitrogen ammonia, nitrogen nitrat, fosforus, coli Escherichia, dan trihalometana dalam sistem penyahjangkitan kuman berskala-makmal. Unit tunggal penurasan ultra membran PES20kDa dan sistem penyahjangkitan kuman bersepadu UF-Cl menunjukkan masing-masing paling efektif dalam rawatan unit tunggal dan sistem penyahjangkitan kuman bersepadu. Keputusan menunjukkan bahawa hampir semua unit tunggal penyahjangkitan kuman dan proses penyahjangkitan kuman bersepadu boleh diguna pakai bagi aplikasi terhad dan tidak terhad mengikut garis panduan penggunaan semula air sisa rawatan yang ditetapkan oleh Agensi Pelindungan Alam Sekitar Amerika Syarikat (US EPA) dan kualiti kitar semula air sisa Singapura.

Freshwater deficiency has become a significant issue affecting many nations’ social and economic development because of the fast-growing demand for water resources. Nanofiltration (NF) is one of the promising technologies for water reclamation application, particularly in desalination, water, and wastewater treatment fields. Nevertheless, membrane fouling remains a significant concern since it can reduce the NF membrane performance and increase operating expenses. Consequently, numerous studies have focused on improving the NF membrane’s resistance to fouling. This review highlights the recent progress in NF modification strategies using three types of antifouling modifiers, i.e., nanoparticles, polymers, and composite polymer/nanoparticles. The correlation between antifouling performance and membrane properties such as hydrophilicity, surface chemistry, surface charge, and morphology are discussed. The challenges and perspectives regarding antifouling modifiers and modification strategies conclude this review.

Oily wastewater (OW) is detrimental towards the environment and human health. The complex composition of OW needs an advanced treatment, such as membrane technology. Membrane distillation (MD) gives the highest rejection percentage of pollutants in wastewater, as the membrane only allows the vapor to pass its microporous membrane. However, the commercial membranes on the market are less efficient in treating OW, as they are prone to fouling. Thus, the best membrane must be identified to treat OW effectively. This study tested and compared the separation performance of different membranes, comparing the pressure-driven performance between the membrane filtration and MD. In this study, several ultrafiltration (UF) and nanofiltration (NF) membranes (NFS, NFX, XT, MT, GC and FILMTEC) were tested for their performance in treating OW (100 ppm). The XT and MT membranes (UF membrane) with contact angles of 70.4 ± 0.2° and 69.6 ± 0.26°, respectively, showed the best performance with high flux and oil removal rate. The two membranes were then tested for long-term performance for two hours with 5000 ppm oil concentration using membrane pressure-filtration and MD. The XT membrane displayed a better oil removal percentage of >99%. MD demonstrated a better removal percentage; the flux reduction was high, with average flux reduction of 82% compared to the membrane pressure-filtration method, which experienced a lower flux reduction of 25%. The hydrophilic MT and XT membranes have the tendency to overcome fouling in both methods. However, for the MD method, wetting occurred due to the feed penetrating the membrane pores, causing flux reduction. Therefore, it is important to identify the performance and characteristics of the prepared membrane, including the best membrane treatment method. To ensure that the MD membrane has good anti-fouling and anti-wetting properties, a simple and reliable membrane surface modification technique is required to be explored. The modified dual layer membrane with hydrophobic/hydrophilic properties is expected to produce effective separation in MD for future study.

The ability of POME-based graphene shell composite (P-GSC), an adsorbent generated from oil palm wastes abundantly available in Malaysia such as POME and PKS, was examined in removing methylene blue (MB) dye by adsorption. Adsorption experiments, involving a batch column study and a batch equilibrium study, were conducted to investigate the efficiency of synthesized P-GSC from PKS as a base material in the removal of MB dye. The batch column study demonstrated that small-sized synthesized P-GSC from PKS as a base material could remove up to 98.5% for concentration. Therefore, the following batch equilibrium study was carried out on small-sized P-GSC only. Adsorption isotherms and kinetic isotherms were studied, from which the experimental data showed that the adsorption exhibited a good fit with the Freundlich model (R2=0.8923) and followed the pseudo-second order model (R2>0.98). FESEM, XPS, and XRD morphological and elemental analysis indicated the successful graphinization of POME on the P-GSC surface. The concept of deploying POME as the carbonaceous source to produce P-GSC, and then, deploying the resultant P-GSC as the adsorbent for MB dye removal has presented promising practical potential. Such cost-effective and environmentally friendly reuse of waste materials is envisioned to promote a ‘zero-waste industry.’

A life cycle assessment of anaerobic-treated palm oil mill effluent (POME) was conducted to assess the environmental performance on two integrated treatment processes: the typical hollow fiber membrane ultrafiltration module coupled with adsorption and electro-oxidation as pretreatment. The analysis was undertaken using the ReCiPe 2016 method and SimaPro v9 software was employed using a ‘cradle-to-gate’ approach. The results showed that hollow fiber membrane from the adsorption integrated membrane impacted significantly at 42% to 99% across all impact categories for both processes. Overall, the electro-oxidation integrated membrane was discovered to have a lesser environmental impact, particularly on the ozone formation (human health) (HOFP) at 0.38 kg NOx-eq in comparison to the adsorption integrated membrane at 0.66 kg NOx-eq. The total characterization factor of the endpoint category for human health is 8.61 × 10−4 DALY (adsorption integrated membrane) and 8.45 × 10−4 DALY (electro-oxidation integrated membrane). As membrane treatment is closely linked to energy consumption, the environmental impact with different sources of energy was evaluated for both processes with the impacts decreasing in the following order: Grid > Biogas > Grid/Solar. Future research should concentrate on determining the overall ‘cradle-to-grave’ environmental impact of treating POME, as well as other scenarios involving membrane treatment energy utilization using LCA. This study can help decision-makers in identifying an environmentally sustainable POME treatment and management, especially in Malaysia.

The toxicity of heavy metals can cause water pollution and has harmful effects on human health and the environment. Various methods are used to overcome this pressing issue and each method has its own advantages and disadvantages. Membrane filtration technology such as nanofiltration (NF) produces high quality water and has a very small footprint, which results in lower energy usage. Nanofiltration is a membrane-based separation technique based on the reverse osmosis separation process developed in the 1980s. NF membranes have a pore size of 1 nm and molecular weight cut off (MWCO) of 300 to 500 Da. The properties of NF membranes are unique since the surface charge of the membranes is dependent on the functional groups of the membrane. The rejection mechanism of NF membrane is unique as it is a combination of various rejection mechanisms such as steric hindrance, electric exclusion, dielectric effect, and hydration mechanism. However, these mechanisms have not been studied in-depth due to their complexity. There are also many factors contributing to the rejection of NF membrane. Many junior researchers would face difficulty in studying NF membrane. Therefore, this paper is designed for researchers new to the field, and will briefly review the rejection mechanisms of NF membrane by both sieving and non-sieving separation processes. This mini-review aims to provide new researchers with a general understanding of the concept of the separation process of charged membranes.

In order to minimize the adverse impacts of palm oil mill effluent (POME) towards the environment and to cope with the stress associated with water scarcity, membrane technology has been employed to reclaim water from POME. This study investigated the performance and fouling propensity of membranes in treating tertiary POME with the aim to recycle and reuse the reclaimed water as boiler feed water. Three types of membranes (NF270, BW30, and XLE) were used and their performances were evaluated based on the removal of chemical oxygen demand (COD), color, turbidity, total dissolved solids, phosphorus, and conductivity. All parameters were significantly reduced through XLE and BW30 membrane filtration processes in which the permeate was complied with the boiler feed water standard, except NF270 membrane where the COD value exceeded the allowable limit. High permeation drag of NF270 and rougher surface of XLE membranes resulted in the accumulation of foulant on the membrane surfaces which eventually reduced the permeate flux, whereas BW30 membrane was encountered for lower fouling propensity due to its low permeation rate. Hence, BW30 was deemed as the best candidate for water reclamation due to its low fouling propensity and because the production of permeate complied with boiler feed water standard.

Fertilizer-drawn forward osmosis (FDFO) is a potential alternative to recover and reuse water and nutrients from agricultural wastewater, such as palm oil mill effluent that consists of 95% water and is rich in nutrients. This study investigated the potential of commercial fertilizers as draw solution (DS) in FDFO to treat anaerobic palm oil mill effluent (An-POME). The process parameters affecting FO were studied and optimized, which were then applied to fertilizer selection based on FO performance and fouling propensity. Six commonly used fertilizers were screened and assessed in terms of pure water flux (Jw) and reverse salt flux (JS). Ammonium sulfate ((NH4)2SO4), mono-ammonium phosphate (MAP), and potassium chloride (KCl) were further evaluated with An-POME. MAP showed the best performance against An-POME, with a high average water flux, low flux decline, the highest performance ratio (PR), and highest water recovery of 5.9% for a 4-h operation. In a 24-h fouling run, the average flux decline and water recovered were 84% and 15%, respectively. Both hydraulic flushing and osmotic backwashing cleaning were able to effectively restore the water flux. The results demonstrated that FDFO using commercial fertilizers has the potential for the treatment of An-POME for water recovery. Nevertheless, further investigation is needed to address challenges such as JS and the dilution factor of DS for direct use of fertigation.

Membrane fouling is considered a serious obstacle for operation and cost efficiency in wastewater treatment using nanofiltration (NF). However, pretreatment is the most practical way to reduce this prior to NF. In this research, two types of wastewaters were pretreated with different methods prior to NF to examine the effect of pretreatment on membrane fouling in terms of turbidity, chemical oxygen demand (COD) and permeate flux. Turbidity and COD were measured to assess solid foulants and organic species in the wastewater, respectively. The first sample was secondary treated sewage, which was pretreated using coagulation-flocculation-sedimentation (CFS) only. Steady flux was increased from 24 L/m2h for wastewater without pretreatment to 32.1 L/m2h with pretreatment. COD was also eliminated after CFS/NF, and turbidity was reduced to 0.6 NTU. The second sample was diluted biodiesel wastewater, which was pretreated using a combination of powdered-activated carbon (PAC) adsorption and CFS (PAC/CFS). Steady flux was increased from 22.3 L/m2h for wastewater without pretreatment to 28.7 L/m2h with pretreatment; biodiesel wastewater quality also improved. Turbidity was reduced from 12 to 0.6 NTU, and COD was reduced from 526 to 4 mg/L after NF with PAC/CFS pretreatment, while COD was reduced from 526 to 95 mg/L using NF without pretreatment.

The growth in palm oil production also leads to an Increase in the production of palm oil mill effluent (POME). Nowadays, POME was treated using an open lagoon but this method is ineffectiveness in complying with the standards for water disposal. Therefore, efficient and cohesive treatment system is highly desired to ensure the final discharge of the treated water meets the effluent discharge standards. Initially, the POME was treated through adsorption, followed by UF membranes roomates were intended to reduce COD, TSS and turbidity up to 88%, 99%, and 98%, while the final treatment of RO membranes can reduce BOD, COD and color up to 92%, 98% and 99%. To determine the optimum condition of the RO membrane, response surface methodology (RSM) was used. The results showed there was correlation between all key variables. POME concentration, trans-membrane pressure, pH and time would give significant effects in reducing the parameters in POME treatment with the optimum condition of 15.77% for POME concentration, 3.73 for pH, 0.5 bar trans-membrane pressure and 5 hours for filtration time. To predict COD removal, the results were analyzed by applying the artificial neural network (ANN) to derive a mathematical model.

The layer-by-layer method is a technique used for the fabrication of ultra-thin defect free films which involves alternating sequential adsorption of polycations and polyanions, while conducting polymer is characterized by a conjugated structure of alternating single and double bonds. The use of layer-by-layer in producing a membrane for separation has received considerable interest due to its properties. However, the introduction of conducting polymer as a base membrane is relatively new. Therefore, in this review, we discuss in detail three types of LBL techniques (dip, spin and spray layer-by-layer) along with their parameters. We will also summarize current developments on the characterization of modified membrane prepared using the layer-by-layer techniques in terms of morphology, physical and chemical properties, and separation performances.

This study produced a novel polysulfone (PSF) membrane for dye removal using lemon-derived carbon quantum dots-grafted silver nanoparticles (Ag/CQDs) as membrane nanofiller. The preparation of CQDs was completed by undergoing hydrothermal treatment to carbonize the pulp-free lemon juice into CQD solution. The CQD solution was then coupled with Ag nanoparticles to form Ag/CQDs nanohybrid. The synthesized powders were characterized in terms of morphologies, functional groups and surface charges. A set of membranes was fabricated with different loadings of Ag/CQDs powder using the nonsolvent-induced phase separation (NIPS) method. The modified membranes were studied in terms of morphology, elemental composition, hydrophilicity and pore size. In addition, pure water flux, rejection test and fouling analysis of the membranes were evaluated using tartrazine dye. From the results, 0.5 wt % of Ag/CQD was identified as the optimum loading to be incorporated with the pristine PSF membrane. The modified membrane exhibited an excellent pure water permeability and dye rejection with improvements of 169% and 92%, respectively. In addition, the composite membrane also experienced lower flux decline, higher reversible fouling and lower irreversible fouling. This study has proven that the addition of CQD additives into membrane greatly improves the polymeric membrane’s properties and filtration performance.

Rapid development of nanotechnology has been in high demand, especially for silver nanoparticles (AgNPs) since they have been proven to be useful in various fields such as medicine, textiles, and household appliances. AgNPs are very important because of their unique physicochemical and antimicrobial properties, with a myriad of activities that are applicable in various fields, including wound care management. This review aimed to elucidate the underlying mechanisms of AgNPs that are responsible for their antiviral properties and their antibacterial activity towards the microorganisms. AgNPs can be synthesized through three different methods—physical, chemical, and biological synthesis—as indicated in this review. The applications and limitations of the AgNPs such as their cytotoxicity towards humans and the environment, will be discussed. Based on the literature search obtained, the properties of AgNPs scrutinizing the antibacterial or antiviral effect shown different interaction towards bacteria which dependent on the synthesis processes followed by the morphological structure of AgNPs.

Polyethersulphone (PES) membranes have been widely applied in various separation applications such as microfiltration, ultrafiltration and nanofiltration. This has occurred as these membranes are easy to form, have good mechanical strength and good chemical stability (resistant to acidic or alkaline conditions) due to the presence of aromatic hydrocarbon groups in the structure. PES membranes are commonly fabricated through the phase inversion method due to the simplicity of the process. However, PES membranes are generally hydrophobic, which usually requires them to be modified before application. In most cases, these methods can reduce the hydrophobicity of the membrane surface and thus reduce membrane fouling during application. This review will further discuss the recently developed UV-induced modifications of PES membranes. The UV-induced grafting method is easy to apply to existing PES membranes, with or without the need for a photo-initiator. Additionally, nanoparticles entrapped in PES membranes subsequently exposed to UV-irradiation have been reported to possess photo-catalytic activity. However, UV-irradiation methods still require special care in order to produce membranes with the best performance.

In this study, Ag2O was synthesized on polyethylene terephthalate fabrics by using an ultrasonic technique with Ag ion reduction in an aqueous solution. The effects of pH on the microstructure and antibacterial properties of the fabrics were evaluated. X-ray diffraction confirmed the presence of Ag2O on the fabrics. The fabrics were characterized by Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, and wettability testing. Field-emission scanning electron microscopy verified that the change of pH altered the microstructure of the materials. Moreover, the antibacterial activity of the fabrics against Escherichia coli was related to the morphology of Ag2O particles. Thus, the surface structure of Ag2O particles may be a key factor of the antibacterial activity.

Novel thin film composite (TFC) polyamide (PA) membranes blended with 0.01⁻0.2 wt.% of Acacia gum (AG) have been prepared using the interfacial polymerization technique. The properties of the prepared membranes were evaluated using contact angle, zeta potential measurements, Raman spectroscopy, scanning electron microscopy, and surface profilometer. It was found that the use of AG as an additive to TFC PA membranes increased the membrane’s hydrophilicity (by 45%), surface charge (by 16%) as well as water flux (by 1.2-fold) compared with plain PA membrane. In addition, the prepared PA/AG membranes possessed reduced surface roughness (by 63%) and improved antifouling behavior while maintaining NaCl rejection above 96%. The TFC PA/AG membranes were tested with seawater collected from the Arabian Gulf and showed higher salt rejection and lower flux decline during filtration when compared to commercial membranes (GE Osmonics and Dow SW30HR). These findings indicate that AG can be used as an efficient additive to enhance the properties of TFC PA membranes.

Kemampuan lempung alam Cengar untuk melepaskan kation Co(II) dari air limbah model telah diuji dengan proses adsorpsi. Lempung alam Cengar diimpregnasi dengan larutan garam ammonium 1 molar untuk meningkatkan kemampuan adsorpsinya. Kapasitas adsorpsi kation Co(II) oleh lempung Cengar yang diimpregnasi meningkat di bawah pengaruh waktu kontak dan menurun dengan temperatur. Beberapa model kinetika yaitu order-pertama pseudo, order-kedua pseudo, model Elovich dan difusi intra-partikel telah digunakan untuk mengevaluasi kinetika dan mekanisme interaksi Co(II) pada lempung Cengar. Mekanisme adsorpsi Co(II)-lempung Cengar mengikuti kinetika order-kedua pseudo pada waktu perolehan adsorbat maksimum 120 menit. Dengan model Elovich didapatkan adsorben lempung Cengar memiliki permukaan yang heterogen. Energi aktivasi proses adsorpsi juga dievaluasi di bawah pengaruh temperatur dan didapatkan energi aktivasi yang negatif.

This study was carried out to determine the potential use of nanofiltration (NF) membranes in treating the wastewater, generated from the fish and surimi industries. The possibility of recovering the protein from the wastewater was also investigated, since these effluents contain a large amount of protein,which could be concentrated by means of NF and recycled into the fishmeal process. The protein could also be traded as fertilizer or animal feed by-products. In this study, fish and surimi washing wastewater was generated in the laboratory. Then, the wastewater was subjected to pre-treatment by using a filter paper (due to the high concentration of suspended matter in these effluents) before it was treated/separated by using a polyamide NF membrane of 500 Da. Permeation experiments showed that NF was capable of reducing COD and TSS up to 93 % and 87 %, respectively. Study on long-term flux decline indicated that polyamide NF membrane fouled much more slowly.

The extracellular expression of monoclonal antibodies (mAbs) in mammalian cell culture provides both opportunities and restrictions for the design of robust harvest and clarification operations. With advances in cell culture media and cell lines, it is now possible to achieve high titers of over 5 g/l for mAbs. However, Mammalian cells are sensitive to breakage due to shear stress that can result in release of proteases and other host cell proteins (HCPs) which eventually affects product stability and purity. There is larger number of mAbs undergoing clinical development and it has placed significant importance on platform technologies of process development. Generally, Centrifugation and microfiltration are the primary harvest techniques used in the industry and depth filtration is also used as a step operation on clarification. This study compares the unit operations; centrifugation, microfiltration and depth filtration for maximum recovery of monoclonal antibodies. The results have shown that the depth filtration as more suitable operation for mammalian cell culture clarification since it gives 96% recovery of mAbs in comparison to centrifugation and microfiltration. ABSTRAK: Pengungkapan luar sel dari antibodi monoklon (monoclonal antibodies ((mAbs) dalam kultur sel mamalia memberi ruang dan batasan terhadap reka bentuk penuaian yang cekap dan penerangan operasi. Dengan kemajuan dalam media sel kultur dan cell lines (produk yang berupa sel kekal yang digunakan untuk tujuan kajian biologi), kini adalah berkemungkinan untuk memperolehi titer tinggi melebihi 5g/l untuk mAbs [2]. Walaupun begitu, sel mamalia sensitif terhadap retakan disebabkan tegasan ricih yang menyebabkan pengeluaran protease dan hos sel protein yang lain, (host cell proteins (HCPs)) akhirnya mempengaruhi kestabilan dan keaslian produk. Terdapat mAbs dalam jumlah besar yang masih menjalani pembangunan klinikal dan sesungguhnya ini penting sebagai satu landasan teknologi dalam proses pembangunan. Umumnya pengemparan dan mikropenurasan merupakan teknik asas tuaian dalam industri dan penurasan dalam juga digunakan sebagai satu pengendalian langkah dalam penjelasannya. Kajian ini membandingkan operasi unit: pengemparan, mikropenurasan dan penurasan dalam untuk perolehan antibodi monoklon yang maksima. Keputusan menunjukkan penurasan dalam adalah operasi yang lebih sesuai untuk penjelasan kultur sel mamalia kerana ia memberikan perolehan 96 % mAbs berbandingkan dengan cara pengemparan dan mikropenurasan.

This systematic review assessed the requirements and importance of intercultural communication competence (ICC) in human life in the 21st Century, focusing on its practical aspects and elements. The results reported in the current study are from a review of 45 papers published from 2000 to 2023 in 16 different Web of Science and SCOPUS-indexed journals. To record and select the related and required papers, an online search was done using two key terms, "intercultural competence" and "intercultural communication competence," and through the use of WoS and SCOPUS databases. A total of 87 items were recorded from the online search, and after a quick review of all records, 45 papers were selected and reviewed thoroughly. Based on the results from the reviewed papers, ICC is one of the main requirements of human life in today's globalized world, especially in modern education and international business. Findings indicate that the absence of ICC is a crucial reason for failure in many modern professionals. Based on the results, cultural awareness and intercultural sensitivity, language proficiency, empathy, flexibility, and some other traits and skills are among the main components of ICC. The results indicate that staying and studying in multicultural environments, participating in cultural programs, observing felling and emotions, flexibility, and other factors, discussed in the current work, help individuals improve their ICC. [ABSTRACT FROM AUTHOR]

‘Toba Tek Singh’ is an Urdu Short story written by Saadat Hassan Manto and ‘This Blinding Absence of Light’ is a French Novel Written by Taher Ben Jelloun. ‘Toba Tek Singh’ was perhaps written in 1954 and published in 1955 whereas ‘This Blinding Absence of Light’ was written in 2001. There is more than four decades span between both works of literature. ‘Toba Tek Singh’ is pure fiction but ‘This Blinding Absence of Light’ is although a novel but based on a true story or narration of a prisoner who spent eighteen years of his life in one of the worst prisons of the documented history. ‘Toba Tek Singh’ is written in the third person whereas ‘This Blinding Absence of Light’ is narrated in the first person. This research will be referring here to a 2002 translation of ‘This Blinding Absence of Light’ by Linda Coverdale in English. ‘Toba Tek Singh’ is a fictitious character who is a patient in a lunatic asylum. Before suffering from the mental illness ‘Toba Tek Singh’ was a landlord and during the partition of India, his village and his lands go to a Muslim majority country i.e., Pakistan. This research intends to study the effects of the pain, agony, and trauma on the psyche of the characters here. [ABSTRACT FROM AUTHOR]