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A versatile synthetic approach for development of highly fluorescent nitrogen-doped carbon dots (N-CDs) from carboxymethylcellulose in the presence of linear polyethyleneimine (LPEI) has been developed. According to single factor method, central composite design incorporated with response surface methodology matrix was applied to find and model optimal conditions for the temperature (220–260 °C), duration (1–3 h) and LPEI weight (0.5–1.5%). The statistical results show that duration was the most significant parameter for efficient carbonization conversion rate in comparison with temperature and LPEI weight. The reduced cubic model (R2 = 0.9993) shows a good correlation between the experimental data and predicted values. The optimal variables were temperature of 260 °C, duration of 2 h and LPEI weight of 1%. Under these conditions, quantum yield of up to 44% was obtained. The numerically optimized N-CDs have an average size of 3.4 nm with graphitic nature owing to the abundant amino species incorporated into the carbon core framework. The blue-green N-CDs possess emission dependent upon the solvent polarity, wide pH stability with enhanced emission in an acidic environment. Impressively, the N-CDs show long-shelf-life for up to 1 year with no noticeable precipitation. The N-CDs were able to recognize a high concentration of Fe3+ ions with a detection limit of 0.14 μM in acidic solution owing to the special coordination for Fe3+ to be captured by electron-donating oxygen/ amino groups around N-CDs. Moreover, the N-CDs can also be used as a new kind of fluorescent ink for imaging applications.

The aim of this study is to assess the curing behaviour and thermal properties of phenol–formaldehyde (PF) adhesives with different degree of tannin substitution using several thermal analysis techniques. Tannin from Acacia mearnsii bark was copolymerized with PF to form a bonding agent for plywood. The resin mixture was heated at 50 °C prior to adding 40% w/w tannin solution, followed by a continuous stirring for 2 h. The amounts of tannin substitution were 20%, 30% and 40% (w/w of PF solids) and 100% PF were used as control. The study shows that the addition of tannin quickened the gel time of the resin notably, parallel with the increase in viscosity of the resin. The dry shear bond strength of the tannin phenol–formaldehyde (TPF) co-polymer ranged between 1.71 and 2.58 MPa as compared to 3.41 MPa for PF. At higher addition of tannin, the shear bond strength reduced significantly predominantly the 40% tannin substitution. Formulation containing 20% tannin was found comparable to that of neat PF. Thermal test revealed that TPF starts to degrade at a lower temperature than PF resin. All TPF resins started to cure at about 125 °C and peaked at 160 °C compared to PF that began to cure at 145 °. The DMA of the resin showed an increase in the resin stiffness with an addition of tannin. These results imply that even though TPF starts to degrade at lower temperature, the cured TPF is relatively stronger than pure PF.

New ways of synthesizing organic-based fluorescent carbon dots (CDs) are required in environmental application. This is crucial for mitigation and control of pollutants without increasing the risk of releasing byproduct pollutants as the case with non-organic (metallic) quantum based substrate. Notably, this study provides current research on sustainable synthesis of CDs and their applications through analytical concept of recent and advance techniques for efficient and optimized processes. New scrutinized methods of synthesis and applications of CDs are beneficial and essential to optimize the state-of-art practices. The value distilled in this study adds to the field of sustainable production and application of CDs.

Hydro-distillation (HD) has been widely used in the extraction of essential oil, yet it is a low efficient method that consumes time and energy. In this work, A. malaccensis’ oils have been extract...

In this study, a techno-economic assessment of an on-farm biogas system using an anaerobic biofilm reactor utilizing cow manure as a fermentation substrate was evaluated. A projection model was developed using Microsoft Excel software with three outputs, the size and dimension of a bioreactor, experimental microbial kinetic studies, and the economic studies based on the experimental results. Characterization analysis of cow manure wastewater showed the total solid (TS), total volatile solid (TVS), total carbohydrate (TC), chemical oxygen demand (COD), and pH values which were 10.95 g/L, 8.65 g/L, 6.65 g/L, 57.80 g/L, and 7, respectively. Using the modified Gompertz equation for the microbial studies, it was found that, at 37 °C and 20 days hydraulic retention time (HRT), the biogas yield was 934.54 mL/gVS, the volume of biogas produced was 11.28 m3/d, and 22.56 kWh of electricity was generated. The Gompertz prediction helps to determine the optimal HRT for the system so that the microorganisms are at their optimum stage to produce biogas. The economic analysis was done, and the results illustrated that, when the rate of cow manure produced was at 55 L/day.cow, the net present value (NPV) was RM 611,936.09, with a 13% internal rate of return (IRR), 0.14 return on investment (ROI), and 7.02 years of payback period (PP). By developing a techno-economic assessment that included all the necessary parameters such as sizing of the bioreactor, microbial kinetic studies, and economics of the plant, farmers could easily implement the system into their farms. This model showed that the anaerobic digestion system utilizing an attached biofilm with cow manure as a fermentation inoculum and substrate was applicable on an industrial scale to generate electricity and reutilize to the farm, at the same time generating additional income from the production of fertilizer.

As a remedy for environmental pollution, a versatile synthetic approach has been developed to prepare polyvinyl alcohol (PVA)/nitrogen-doped carbon dots (CDs) composite film (PVA-CDs) for removal of toxic cadmium ions. The CDs were first synthesized using carboxymethylcellulose (CMC) of oil palms empty fruit bunch wastes with the addition of polyethyleneimine (PEI) and then the CDs were embedded with PVA. The PVA-CDs film possess synergistic functionalities through increasing the content of hydrogen bonds for chemisorption compared to the pure CDs. Optical analysis of PVA-CDs film was performed by ultraviolet-visible and fluorescence spectroscopy. Compared to the pure CDs, the solid-state PVA-CDs displayed a bright blue color with a quantum yield (QY) of 47%, they possess excitation-independent emission and a higher Cd2+ removal efficiency of 91.1%. The equilibrium state was achieved within 10 min. It was found that adsorption data fit well with the pseudo-second-order kinetic and Langmuir isotherm models. The maximum adsorption uptake was 113.6 mg g&minus, 1 at an optimal pH of 7. Desorption experiments showhe that adsorbent can be reused fruitfully for five adsorption-desorption cycles using 0.1 HCl elution. The film was successfully applied to real water samples with a removal efficiency of 95.34% and 90.9% for tap and drinking water, respectively. The fabricated membrane is biodegradable and its preparation follows an ecofriendly green route.

A method that delivers a high yield and excellent quality of essential oil, which retains most of its value-added compounds, and undergoes least change after the extraction process, is greatly sought after. Although chemical free methods are acceptable, they call for an extensive processing time, while the yield and quality from these methods are often disappointing. This work utilizes subcritical water technology to address these issues. In this undertaking, essential oil was extracted from Aquilaria malaccensis wood by way of subcritical conditions, and characterized through gas chromatography/mass spectroscopy (GC/MS). Optimization through response surface methodology revealed temperature to be the most critical factor for the extraction process, while the optimum conditions for temperature, sample-to-solvent ratio, and time for subcritical water extraction was revealed as 225 &deg, C, 0.2 gr/mL, and 17 min, respectively. The subcritical water extraction technique involves two simultaneous processes, which are based on good fitting to the two-site kinetic and second order model. In comparison to the hydrodistillation method, GC/MS results indicated that the quality of A. malaccensis&rsquo, wood oils, derived through the subcritical water technique, are of significantly better quality, while containing many constructive value-added compounds, such as furfural and guaiacol, which are useful for the production of pesticides and medicines. Pore size, functional groups, and morphology analysis revealed the occurrence of substantial damage to the samples, which facilitated an improved extraction of bio-products. In comparison to conventional methods, the use of the subcritical method not only involves a shorter processing time, but also delivers a higher oil yield and quality.

Heat explosions are sometimes observed during the synthesis of phenol formaldehyde (PF) resin. This scenario can be attributed to the high latent heat that was released and not dissipated leading to the occurrence of a runaway reaction. The synthesis temperature and time played important roles in controlling the heat release, hence preventing the resin from hardening during the synthesis process. This study aims to assess the rheological and viscoelasticity behaviors of the PF resin prepared using paraformaldehyde. The prepared PF resin was designed for laminate applications. The rheological behavior of the PF resin was assessed based on the different molar ratios of phenol to paraformaldehyde (P:F) mixed in the formulation. The molar ratios were set at 1.00:1.25, 1.00:1.50 and 1.00:1.75 of P to F, respectively. The rheological study was focused at specific synthesis temperatures, namely 40, 60, 80 and 100 &deg, C. The synthesis time was observed for 240 min, changes in physical structure and viscosity of the PF resins were noted. It was observed that the viscosity values of the PF resins prepared were directly proportional to the synthesis temperature and the formaldehyde content. The PF resin also exhibited shear thickening behavior for all samples synthesized at 60 &deg, C and above. For all PF resin samples synthesized at 60 &deg, C and above, their viscoelasticity results indicated that the storage modulus (G&prime, ), loss modulus(G&Prime, ) and tan &delta, are proportionally dependent on both the synthesis temperature and the formaldehyde content. Heat explosions were observed during the synthesis of PF resin at the synthesis temperature of 100 &deg, C. This scenario can lead to possible runaway reaction which can also compromise the safety of the operators.

This study focused on developing a hydrophilic hybrid polyvinylidene fluoride (PVDF)-polyethylene glycol (PEG) hollow membrane by incorporating Nano-magnesium oxide (NMO) as a potent antifouling mediator. The Nano-hybrid hollow fibers with varied loading of NMO (0 g, 0.25 g, 0.50 g, 0.75 g and 1.25 g) were spun through phase inversion technique. The resultants Nano-hybrid fibers were characterized and compared based on SEM, EDX, contact angle, surface zeta-potential, permeability flux, fouling resistance and color rejection from palm oil mill effluent (POME). Noticeably, the permeability flux, fouling resistance and color rejection improved with the increase in NMO loading. PVDF-PEG with 0.50 g-NMO loading displayed an outstanding performance with 198.35 L/m2&middot, h, 61.33 L/m2&middot, h and 74.65% of water flux, POME flux and color rejection from POME, respectively. More so, a remarkable fouling resistance were obtained such that the flux recovery, reversible fouling percentage and irreversible fouling percentage remains relatively steady at 90.98%, 61.39% and 7.68%, respectively, even after 3 cycles of continuous filtrations for a total period of 9 h. However, at excess loading of 0.75 and 1.25 g-NMO, deterioration in the flux and fouling resistance was observed. This was due to the agglomeration of nanoparticles within the matrix structure at the excessive loading.

Bio-resins are bio-based materials derived from vegetable resources, especially from vegetable seed oils. It is widely known that bio-resources are renewable, highly available, and sustainable. Resins and most polymers are largely derived from petroleum-based sources that are known to pose chemical risks. Resins have practical applications in printing inks, plasticisers and diluents, as well as in coating materials. Vegetable oils possess a large number of oxirane groups, which are essential for epoxidation to occur, resulting in the production of bio-resins. This undeniably serves as a promising candidate for competing with fossil-fuel-derived petroleum-based products. Thus, the aim of this review paper is to highlight aspects related to the production of bio-resins, including the chemical route of vegetable oil epoxidation process and its influencing factors, the reaction kinetics, bio-resins and the physico-chemical and mechanical properties of bio-resins, along with their applications. The resins industry has seen some remarkable progress towards the commercialisation of several bio-resins originating from vegetable oils, such as soybean oil, castor oil, and linseed oil. This success has undoubtedly intensified further efforts in fields related to bio-resin applications. Research and development is ongoing with the aim of customising a feasible formulation for the synthesis of bio-resins with the desired properties for catering to various applications

The performance of plastic optical fiber sensors in detecting nitro aromatic explosives 1,4-dinitrobenzene (DNB) have been investigated by fluorescence spectroscopy and analyzed by using fluorescence quenching technique. The plastic optical fiber utilized is 90 degrees cut tip and dip-coated with conjugated polymer MEH-PPV poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] thin films for detection conjugants. The thicknesses of the MEH-PPV coating were varied to improvise the sensitivity whilst slowly reducing the fluorescence intensity. It was shown that fluorescence intensity from thinner film decreased by (82% in 40 s) in the presence of DNB signifying an improvement of 28% reduction with time 13 s less than that of the thicker film.

A new commercial cationic polyelectrolyte chitosan (CM), obtained from the waste of mushroom production, was examined using models of water and wastewater namely kaolin and palm oil mill effluent (pome). As it is biocompatible, widely available, and economically feasible, chitosan mushroom has high potential to be a suitable replacement for alum. Also, it can be a promising alternative to chitosan obtained traditionally from Crustaceans due to its higher zeta potential and homogeneity based on the raw material required for its production. A wide range of coagulant dose (5-60 mg l-1) and wastewater pH (2-12) were taken into account to find the optimal conditions of coagulation. The optimal doses are 10 and 20 mg l-1 at best pH (11 and 3) when treated with kaolin and palm oil mill effluent, respectively, while 1200 mg l-1 of alum was not enough to reach the efficiency of chitosan mushroom. On the other hand, the optimum dose of chitosan mushroom (20 mg l-1) at pH 3 of pome produced (75, 73, and 98%) removal of chemical oxygen demand (COD), biological oxygen demand (BOD), and total suspended solids (TSS), respectively. The significant potential of chitosan mushroom was proved by zeta potential measurement. Indeed, it possesses the highest zeta potential (+70 mV) as compared to the traditional chitosan produced from crustaceans. In short, chitosan mushroom as a biocoagulant is eco-friendly and it enhances water quality that meets the requirements of environmental conservatives.

Alternative natural coagulants from Jatropha curcas seed and press cake were investigated for coagulative behaviors and abilities to treat real wastewater. The characterization of the seed and press cake was done by proximate analysis while characterization on extracts which contain the active coagulant agent was conducted using FTIR, amino acid analysis, and zeta potential. The coagulation performance was evaluated using Jar Floc test on palm oil mill effluent. Proximate analysis indicated that Jatropha seed contained more protein (54%) than press cake (28%). Through HPLC analysis, 18 types of amino acid were detected in Jatropha curcas (JC) seed and press cake extracts. FTIR results confirmed the functional groups that existed in all the amino acids. The zeta potential of the extracts was positive at pH 4, respectively. Hence, the mechanism of coagulation at pH 4, adsorption and interparticle bridging dominates. Dosages of 140 mg L−1 of Jatropha seed and 120 mg L−1 of press cake were required to treat 3500 NTU of POME to give 99 and 93% turbidity removal, respectively. Jatropha seed gave maximum turbidity removal at pH 3, while press cake at pH 2. The final pH of the treated POME was not altered greatly and the sludge produced was lesser in comparison to alum. In conclusion, the protein was the compound responsible for Jatropha coagulating behavior and its ability to treat real wastewater is promising. © 2017 American Institute of Chemical Engineers Environ Prog, 2017

Nowadays, to ensure sustainability of smart materials, it is imperative to eliminate or reduce carbon footprint related to nano material production. The concept of design of experiment to provide an optimal synthesis process, with a desired yield, is indispensable. It is the researcher&rsquo, s goal to get optimum value for experiments that requires multiple runs and multiple inputs. Herein, is a reliable approach of utilizing design of experiment (DOE) for response surface methodology (RSM). Thus, to optimize a facile and effective synthesis process for fluorescent carbon dots (CDs) derived from tapioca that is in line with green chemistry principles for sustainable synthesis. The predictions for fluorescent CDs synthesis from RSM were in excellent agreement with the artificial neural network (ANN) model prediction by the Levenberg&ndash, Marquardt back propagation (LMBP) algorithm. Considering R2, root mean square error (RMSE) and mean absolute error (MAE) have all revealed a positive hidden layer size. The best hidden layer of neurons were discovered at point 4-8, to confirm the validity of carbon dots, characterization of surface morphology and particles sizes of CDs were conducted with favorable confirmations of the unique characteristics and attributes of synthesized CDs by hydrothermal route.

Plant oils and their derivatives have been vigorously exploited as alternatives for synthesis of epoxides due to depletion of petroleum resources. In this study, crude jatropha oil (CJO) was subjected to a transesterification process to form jatropha methyl esters (JME) using peroxyacetic acid generated in situ from hydrogen peroxide and acetic acid via an acidic ion exchange resin (AIER). The effect of temperature, molar ratio of hydrogen peroxide to unsaturation, molar ratio of acetic acid to unsaturation, and catalyst loading were investigated. This study revealed that the maximum 89.9% relative conversion to oxirane rings was achieved after 6 h with the optimal reaction conditions of temperature at 70 ˚C, the molar ratio of hydrogen peroxide to unsaturation of 1.5 mol, the molar ratio of acetic acid to unsaturation of 0.5 mol, and catalyst loading of 16%. Fourier Transform Infrared (FTIR) spectra of the epoxidized jatropha methyl esters (EJME) showed oxirane peaks (doublet) at 825 and 843 cm-1.1H NMR confirmed the diepoxide group at 2.85 ppm and 2.98 ppm, while the diepoxide signals of 1C NMR were present at 56.88-57.06 ppm. Production of bio-epoxides from Jatropha methyl esters hence looks promising with favorable physicochemical properties, availability, and versatility.

This study aims at reviewing the alternative techniques for bioethanol recovery, highlighting its advantages and disadvantages, and to investigate the technical challenges facing these alternatives to be widely used. The findings showed that the integration of these techniques with the fermentation process did not meet a large acceptance in the industrial sector. The majority of conducted studies were mainly focusing on ethanol recovery from aqueous standard solution rather than the investigation of these techniques performance in fermentation-separation coupled system. In this context, pervaporation has received more attention as a promising alternative to distillation. However, some challenges are facing the integration of these techniques in the industrial scale as the fouling problem in pervaporation, the toxicity of solvent in liquid extraction, energy consumption in vacuum fermentation. It was also found that there is a lack of the technical economic analysis for these techniques which may limit the spread of its application in the large scale. Currently, hybrid systems integrating distillation with other alternative techniques are considered as an innovative solution to reduce the high cost of the distillation process and the low separation efficiency of the alternatives techniques.

This paper describes the development of a lab-on-chip (LOC) device that can perform reliable online detection in continuous-flow systems for microorganisms. The objective of this work was to examine the performance of a fibre optic detection system integrated into a LOC device. The microfluidic system was fabricated using dry film resist (DFR), integrated with multimode fibre pigtails in the LOC. Subsequently, the performance of the fibre optic detection was evaluated by its absorbance spectra, detection limit, repeatability and reproducibility, and response time. The analysis was carried out using a constant flow rate for three different types of microorganisms which are Escherichia coli, Saccharomyces cerevisiae, and Aeromonas hydrophila. Under the experimental conditions used in this study, the detection limit of 1.0×105 cells/mL for both A. hydrophila and E. coli, while a detection limit of 1.0×106 cells/mL for S. cerevisiae cells were measured. The results also revealed that the device showed good repeatability with standard deviations less than 0.2 for A. hydrophila and E. coli, while standard deviations for S. cerevisiae were larger than 1.0. The response times for A. hydrophila, E. coli, and S. cerevisiae were 104 s, 122 s, and 78 s, respectively, although significant errors were recorded for all three species for reproducibility experiment. It was found that the device showed generally good sensitivity, with the highest sensitivity towards S. cerevisiae. These findings suggest that an integrated LOC device, with embedded multimode fibre pigtails, can be a reliable instrument for microorganism detection.

colourants substances in palm oil mill effluent (POME) are carcinogenic, unfortunately, the commonly applied conventional activated sludge system has been unable to remediate these contaminants. The need for more efficient treatment approach is fundamental in order to sanctuary the environment. A novel start-up approach, which involves augmentation of yeast-extract and diary-waste as recipes added into activated sludge to remediate colourants concentration in POME was employed in this study. The decolourization performance obtained was compared with that of the conventional activated sludge operated under the same conditions. The augmented recipes that best sustained the active biomass was identified and then applied in the subsequent studies. Because of this, the acclimation duration drastically shortens to 31 days, as against 87 days of that of the conventional method. The swift acclimation was due to the adequacy and stability of the sludge active sites, which was successfully increased by 35.31% using the augmented recipe. The decolourization efficiency at steady aeration of 5 L/min and OLR of 0.895gCOD L−1d−1 using augmented sludge was 63.45%, which was far greater than 37% obtained by the conventional sludge. Monod Kinetic model excellently described the degradation process of both augmented and conventional sludge based on COD depletion with a respective R2 value of 0.9923 and 0.9839. The calculated kinetic coefficients proved that microbial growth-substrate utilization rate of the augmented sludge was superior with biomass yield of 2.1142 mg MLVSS/mg COD. The significant improvement in the decolourization was attributed to the augmented recipes, which successfully enhanced the metabolic and xenobiotic activities of the active biomass.

More recent attention has been focused on the utilization of Jatropha curcas in the field of water treatment. The potential of Jatropha oil in the synthesis of membrane for water filtration had been explored, its performance compared to the addition of graphene oxide (GO) in the polymer matrix. Jatropha oil was modified in a two-step method to produce Jatropha oil-based polyol (JOL) and was blended with hexamethylene diisocyanate (HDI) to produce Jatropha polyurethane membrane (JPU). JPU was synthesized in different conditions to obtain the optimized membrane and was blended with different GO loading to form Jatropha/graphene oxide composite membrane (JPU/GO) for performance improvement. The synthesized pristine JPU and JPU/GO were evaluated and the materials were analyzed using fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), contact angle, water flux, and field emission scanning electron microscopy (FESEM). Results showed that the ratio of HDI to JOL for optimized JPU was obtained at 5:5 (v/v) with the cross-linking temperature at 90&deg, C and curing temperature at 150&deg, C. As GO was added into JPU, several changes were observed. The glass transition temperature (Tg) and onset temperature (To) increased from 58&deg, C to 69&deg, C and from 170&deg, C to 202&deg, C, respectively. The contact angle, however, decreased from 88.8&deg, to 52.1&deg, while the water flux improved from 223.33 L/m2.h to 523.33 L/m2.h, and the pore distribution in JPU/GO became more orderly. Filtration of copper ions using the synthesized membrane was performed to give rejection percentages between 33.51% and 71.60%. The results indicated that GO had a significant impact on JPU. Taken together, these results have suggested that JPU/GO has the potential for use in water filtration.

A gamma-ray irradiation technique was used to functionalize graphene oxide (GO) with alkylamines of various alkyl chain lengths. Functionalization of the alkyl chains onto the GO was confirmed by nuclear magnetic resonance (1H NMR), Fourier transform infrared (FTIR), and X-ray diffraction (XRD). FTIR of the functionalized GO showed the appearance of significant peaks around 2960–2850 cm−1 (–CH2) which came from long alkyl chains, together with a peak around 1560–1450 cm−1, indicating the formation of C–NH–C. XRD showed an additional diffraction peak at a lower 2θ angle, indicating that the intercalation of the alkylamine was successful. The effects on the morphological and thermal properties of GO functionalized with alkyl chains of various lengths were investigated. Scanning electron microscopy (SEM) analysis showed an increase in surface roughness when the alkyl chain length was increased. The addition of alkyl chains on GO surfaces significantly improved the thermal stability of the GO, suggesting that these surfaces have great potential for use as a hydrophobic material in industry.

This research focuses on the detection ofAeromonas hydrophilausing fiber optic microchannel biosensor. Microchannel was fabricated by photolithography method. The fiber optic was chosen as signal transmitting medium and light absorption characteristic of different microorganisms was investigated for possible detection. Experimental results showed thatAeromonas hydrophilacan be detected at the region of UV-Vis spectra between 352 nm and 354 nm which was comparable to measurement provided by UV spectrophotometer and also theoretical calculation by Beer-Lambert Absorption Law. The entire detection can be done in less than 10 minutes using a total volume of 3 μL only.This result promises good potential of this fiber optic microchannel sensor as a reliable, portable, and disposable sensor.

Malaria is a leading parasitic disease endangering the lives of half of the world's population. Microfluidics paves way to indispensable portable sensors to enable early sensing hence defend lives. In this paper, we demonstrate a portable sensor based on dielectric spectroscopy capable of pre-diagnostic and malaria parasite detection. The complete sensor system consists of the separation zone to separate the white blood cells and the detection zone, which is connected to portable impedance circuit board to measure the dielectric value of red blood cells to detect the infection. The current work highly emphasize on the separation part only while a little light is shed on detection zone.

This paper presents the characterization of angled microelectrode array as dielectrophoretic microfluidic device for the continuous flow-through separation of particles. The operation of the device is demonstrated using samples of colloidal latex beads of 1 μm and 2 μm in diameter sizes, achieving 100% particle deflection with operating voltage as low as 10V and frequency as minimum as 1 MHz. This characterization is essential for dielectrophoretic separation to get the specific suggestion for each type of particle behavior via its own deflection throughout the arrays of the angled microelectrode. The paper also exhibits and discusses the detail of the theoretical background of the separation method; the structure of the device and also the result obtained that is achievable by choice of voltage and frequency.

Palm oil mill effluent contains carcinogenic coloured compounds that are difficult to separate due to their aromatic structure. Though colour treatment using adsorption processes at lower pH (&lt, 4) have been reported effectual, due to its acidity the remediated effluent poses an environmental hazard as a result. Thus, the current study focused on achieving decolourization at neutral pH by enhancing the morphology of the coconut shell activated carbon (CSAC) using N2 as activating-agent with microwave irradiation heating. The microwave pretreated and non-pretreated CSAC were characterized using scanned electron microscopy (SEM), energy dispersive X-ray (EDX) and Brunauer-Emmett-Teller (BET) analysis. A significant modification in the porous structure with a 66.62% increase in the specific surface area was achieved after the pretreatment. The adsorption experimental matrix was developed using the central composite design to investigate the colour adsorption performance under varied pH (6&ndash, 7), dosage (2&ndash, 6 g) and contact time (10&ndash, 100 min). At optimum conditions of neutral pH (7), 3.208 g dosage and contact time of 35 min, the percentage of colour removal was 96.29% with negligible differences compared with the predicted value, 95.855%. The adsorption equilibrium capacity of 1430.1 ADMI &times, mL/g was attained at the initial colour concentration of 2025 ADMI at 27 &deg, C. The experimental data fitted better with the Freundlich isotherm model with R2 0.9851.

Over the years, different types of alternative technologies have been developed and used for palm oil mill effluent (POME) treatment. Specifically, membrane bioreactor (MBR) has been employed to relegate pollutants contained in POME under different operating conditions, and the technology was found to be promising. The major challenge impeding the wider application of this technology is membrane fouling, which usually attracts high operating energy and running cost. In this regard, novel methods of mitigating membrane fouling through the treatment processes have been developed. Therefore, this review article specifically focuses on the recent treatment processes of POME using MBR, with particular emphasis on innovative processes conditions such as aerobic, anaerobic, and hybrid processing as well as their performance in relation to fouling minimization. Furthermore, the effects of sonication and thermophilic and mesophilic conditions on membrane blockage were critically reviewed. The types of foulants and fouling mechanism as influenced by different operating conditions were also analyzed censoriously.