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This paper presents the isolation of kenaf bast fiber to produce cellulose nanofiber (CNF) using chemical-physical treatment (e.g. delignification, bleaching and ultrasonication). Raw bast fiber wa...

The immense demand of plastics worldwide has created a substantial pollution problem that appears not to have an end. New governmental policies and customers preferences towards environmental friendly materials require continued research on biodegradable materials derived from biological resource. In this work, residual palm oil (RPO) recovered from palm oil mill waste effluent was mixed with algae oil (AO) to produce rigid foam polyurethanes (bio-RFPU) at different ratios (AO/RPO) 10/90, 20/80, 30/70, 40/60 and 50/50 by one pot epoxidation and ring opening followed by polymerization with Methylene diphenyl diisocyanate (MDI). Prior to polymerization, significant improvement of 49% was found in the hydroxyl number of the RPO(AO) polyol when AO content was increased from 10 to 50%. Similarly, the homogeneous structure of the cell and the thermal stability of the final bio-RFPU was increased in the samples with 50% AO. Different characterization techniques such as scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA) and compression/flexural tests were conducted, and the results presented. The thermal degradation profile of the samples containing 40 and 50% of AO was found to be similar to RFPU with fire retardant and insulation properties. The compressive strength and the biodegradability of the bio-RFPU increased 60% when AO was increased between samples with 10 and 50% AO. Therefore, the developed bio-RFPUs is expected to have great potential as core materials in industrial applications such as sandwich panels as well as in other insulation material.

This paper demonstrates the potential use of toy-bricks as the building block of a mechanical tensile testing instrument for the mechanical characterisation of natural fibres. A table-top tensile testing instrument was developed using LEGO parts (Mindstorms EV3 and Technics) and a 2 kg capacity load cell, whereas deformation modes were programmed in an open source programming language. Experimental work was conducted on oil palm fibres under different tensile modes (i.e. constant deformation, triple-twisted-tension and deformation-relaxation modes), which showed anisotropic-viscoelastic behaviour, and microstructural damages due to deformation.

This research aimed to improve the stability of Chlorella-Alginate Beads (CABs) by zeolite molecular sieves 13X. Dissolution time of synthesized Zeolite-Algal-Alginate Beads (ZABs) in a chelating agent revealed a significant improvement on the beads stability (78.5 ± 0.5 min) compared to the control beads (51.5 ± 0.5 min) under the optimum conditions of zeolite/alginate (1.5:1), pH 5 and 2% of beads. Monitoring cell growth during 5 days of incubation showed good biocompatibility of zeolite 13X. Scanning electron microscopy (SEM) indicated rough surface and spherical shapes of ZABs. Energy dispersive X-ray spectroscopy (EDX) and Fourier transform infrared spectroscopy (FTIR) of ZABs confirmed the presence of zeolite 13X within the matrix. The zeta potential value of ZABs indicated that the beads were relatively stable. The findings of this research showed that zeolite molecular sieves 13X have the potential to improve the stability of algal-alginate beads compared to common beads.

The interest in utilizing algae for wastewater treatment has been increased due to many advantages. Algae-wastewater treatment system offers a cost-efficient and environmentally friendly alternative to conventional treatment processes such as electrocoagulation and flocculation. In this biosystem, algae can assimilate nutrients in the wastewater for their growth and simultaneously capture the carbon dioxide from the atmosphere during photosynthesis resulting in a decrease in the greenhouse gaseousness. Furthermore, the algal biomass obtained from the treatment process could be further converted to produce high value-added products. However, the recovery of free suspended algae from the treated effluent is one of the most important challenges during the treatment process as the current methods such as centrifugation and filtration are faced with the high cost. Immobilization of algae is a suitable approach to overcome the harvesting issue. However, there are some drawbacks with the common immobilization carriers such as alginate and polyacrylamide related to low stability and toxicity, respectively. Hence, it is necessary to apply a new carrier without the mentioned problems. One of the carriers that can be a suitable candidate for the immobilization is zeolite. To date, various types of zeolite have been used for the immobilization of cells of bacteria and yeast. If there is any possibility to apply them for the immobilization of algae, it needs to be considered in further studies. This article reviews cell immobilization technique, biomass immobilization onto zeolites, and algal immobilization with their applications. Furthermore, the potential application of zeolite as an ideal carrier for algal immobilization has been discussed.

The main objective of this work was to investigate the effects of the controlled periodic addition of anaerobic sludge during composting to increase amount of microbial DNA, which appears to be correlated to soluble sugar content which may relate to rate of lignocellulosic degradation. In this study, the composting of pressed-shredded oil palm empty fruit bunch with the periodic addition of palm oil mill effluent anaerobic sludge for moisture control in a newly designed in-vessel type composter was carried out. A control experiment was also conducted over the same period but with the periodic addition of water for moisture control instead of the anaerobic sludge. The lignocellulosic composition and the reducing sugar content were determined via fibre analysis and the spectrophotometric method respectively. The bacterial profile throughout the composting process was quantified by using qPCR. The growth of bacteria reached its peak at 48°C and the degradation of lignocellulose was highest during the thermophilic stage. The highest content of reducing sugar coincided with the highest degradation rate of lignocellulose and the highest DNA copy number during the thermophilic stage. Under the controlled experimental condition of increasing the microbial community, the composting was accelerated to 2.07% OM degradation per day compared to the water addition control at 0.60% OM per day.

Cellulose nanofiber (CNF) from kenaf bast fiber has potential to be used in enzyme immobilization. This study discloses the preparation of CNF, immobilization of cyclodextrin glucanotranferase (CGTase) on CNF via chemical coupling and its application using ultrafiltration membrane. Morphological analysis shows the diameter distribution of CNF in nano-order scale (

The use of plastics and composite materials as the base structure for a floating solar photovoltaic system commonly known as floatovoltaic system can cause negative impact to the environment especially the aquatic life and human. Additive materials are infused to form the plastics by which giving adverse effect to our metabolism. Despite the fact that the plastics are durable, to create and recycle it will produce toxic materials of many kinds in addition to the higher expenses for floatovoltaic installation. The unique approach of floatovoltaic is further discussed withstanding the continuous constraint of limited and suitable land for solar PV farms. This paper presents field analysis of the development of coconut-trunk as the base structure for a floatovoltaic system with regards to the environmental impact. A framework based on the density and buoyancy of the coconut trunk material is considered for the design

A large volume of oil palm empty fruit bunch (EFB) is generated as waste feedstock around the globe. This abundant waste containing 0.75% oil on average could be a promising feedstock for biodiesel production if oil recovery could be accomplished in an economically-viable and environmentally-friendly manner. To achieve that, a new method called High Pressure Water Spray (HPWS) system was introduced and performed by spraying pressurized water (500 psi) at 30 °C, 60 °C, and 90 °C and combination of water-steam at 120 °C and 150 °C onto the surface of the oil palm empty fruit bunches (EFB). The results obtained indicated that, the highest oil removal yield of 94.41 ± 0.02 wt% was obtained at 150 °C. Moreover, bioprospection of biodiesel properties based on fatty acid methyl ester (FAME) profile revealed that the biodiesels produced from the fresh crude palm oil and residual oil were comparable and were in accordance with international standards. In addition to that, the HPWS process led to an enhanced quality of the remaining lignocellulosic materials for conversion into other value added bio-products such as ligno-ethanol by decreasing lignin content and increasing cellulose content. In view of environmental impact assessment, the HPWS system showed favorable impacts on all the end-point damage categories especially in resources damage category. Moreover, economic assessment showed that the recovered CPO could be generated at a low price of USD 0.41 vs. USD 0.66 for CPO. Overall, this process could drastically increase the market value of an abundant type of waste in many parts of the world, i.e., EFB leading to the generation of additional wealth for the palm oil industry.

This research mainly focuses on developing a natural cellulose nanofibre (CNF) from kenaf bast fibre and its potential for enzyme immobilization support. CNF was isolated by using a combination between chemical and mechanical treatments such as alkaline process and high-intensity ultrasonication process to increase the efficiency of hemicellulose and lignin removal, and to reduce its size into nano-order. The morphological study was carried out by using scanning electron microscope (SEM), indicating most of CNF diameter in range of 50-90 nm was obtained. The result of chemical analysis shows that cellulose content of raw bast fibre, bleached pulp fibre and CNF are 66.4 %, 83.7 % and 90.0 %, respectively. By decreasing the size of cellulose fibre, it increases the number of (O–H) group on the surface that plays as important role in enzyme immobilization. Covalent immobilization of cyclodextrin glucanotransferase (CGTase) onto CNF support resulted in about 95.0 % of protein loading with 69.48 % of enzyme activity, indicating high immobilization yield of enzyme. The enzymatic reaction of immobilized CGTase was able to produce more than 40 % yield of α-CD. Reusability profile of immobilized CGTase resulted in more than 60 % of retained activity up to 7 cycles. Therefore, the CNF is highly potential to be applied as enzyme immobilization support.

The heterogeneous lignocellulosic contents of oil palm empty fruit bunch (OPEFB) fiber requires the use of chemical or biological pre-treatment for further value-added applications. An effective biological pre-treatment was preferred since it is mild, low energy, substrate specific and will not generate any inhibitory chemicals that interfere enzymatic activities and fermentation process. The biological pre-treatment of OPEFB fibers by local isolate Pycnoporus sanguineus was investigated in this work to improve its biodegradability through laccase production via solid-state fermentation approach. The effects of physical parameters (temperature, inducer concentrations, substrate loading) were explored to obtain maximum laccase production by P. sanguines. Results showed that the use of extractive-free OPEFB fiber at 30 °C supplemented with 4 mM of 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and 10 g of OPEFB loading yielded laccase production that was 2.1 fold higher compared to raw OPEFB. The changes of chemical and surface structures of raw, chemicals and laccase treated OPEFB were reported from Fourier-transform infrared spectroscopy (FTIR), thermogravimetric (TGA) and scanning electron microscopy (SEM) analyses. The simulated techno-economic analysis suggested economic feasibility of a batch bio-refinery for laccase production in an industrial scale feed at a maximum rate of 50 tons OPEFB/batch. From the simulated baseline study, the cost price forecast for laccase production was 14.26 US$/kg owing to the capital (65.87%) and raw materials costs (31.68%). This study reveals the potential of P. sanguineus to be used not only in biorefinery industry but also in biopulping, biobleaching (in textile and paper industries) and degrading phenolic waste (dye, colorant, pesticide waste).

Advances in biochar production and modification have extended the applications of biochar to wastewater treatment. However, not all feedstocks produced porous biochar at a moderate temperature suitable for wastewater treatment. In this study, biochar was produced from oil palm frond using steam pyrolysis at 500 °C and pulverized to granular and micro-fine particles. Both biochar particles were characterized and applied as adsorbents for treating final discharge of palm oil mill effluent. The effluent was also filtered and treated to examine the effect of suspended solids on adsorption capacity. The biochar had Brunauer-Emmett-Teller surface area of 406.6 m2 g−1. Pulverization eliminated the residual macropores in granular biochar, created new external surface area, and exposed constricted nanopores, which resulted in increasing the surface area to 457.7 m2 g−1. The adsorption capacity decreased from 24.6 to 6.1 mg g−1 for chemical oxygen demand and 49.0 to 10.9 Pt–Co g−1 for color by increasing the dosage of micro-fine biochar from 5 to 30 g L−1. The total suspended solids affected the adsorption capacity of granular biochar by blocking residual macropores that provide access to adsorption sites in micropores and mesopores. At 30 g L−1, the micro-fine biochar exhibited an effective reduction of chemical oxygen demand from 224 to 41.6 mg g−1 and color from 344 to 15 Pt–Co g−1 making the wastewater suitable for reuse in palm oil mills and safe for discharge into the aquatic environment.

Conventional aerobic treatment of facultatively treated palm oil mill effluent (POME) containing phenolic compounds such as phenol, encounters difficulty because of microbial inhibition. In this study, adsorption of phenol in facultatively treated POME was proposed as a solution for mitigating the inhibition. Low-cost biochars produced from oil palm frond using nitrogen or steam pyrolysis at 600 °C were characterized and investigated for efficient and effective removal of phenol. Nitrogen and steam pyrolysis yielded mesoporous biochars with Brunauer–Emmett–Teller surface area of 368.4 m2/g and 461.3 m2/g respectively. Within 8 h, steam-derived biochar attained equilibrium capacity of 59.6 mg/L in distilled water, which decreased to 18.5 mg/L in facultatively treated POME. Steam-derived biochar exhibited slightly higher adsorption capacity for phenol in facultatively treated POME due to higher surface area, wider nanopore size distribution, a larger volume of mesopores and a stronger affinity for phenol. More than 90% of phenol was removed using 16–20 g/L dosage, yielding a facultatively treated POME with 0% inhibition to aerobic microbial growth. Overall, low-cost biochar produced from oil palm frond can be used as an efficient and effective adsorbent for adsorbing phenol in facultatively treated POME to enhance the performance of aerobic treatment system.

The potential application of Zeolite 13X-Algal-Alginate Beads (ZABs) for copper biosorption was evaluated and compared with Blank-Alginate Beads (BABs) and Chlorella-Alginate Beads (CABs). Different process parameters were investigated including contact time, pH and initial metallic ion concentration. The findings indicated that the maximum biosorption capacity of ZABs was 85.88 mg/g biosorbent achieved at 180 min, pH 5 and initial metallic ion concentration of 150 mg/l whereas the maximum capacity of 70.02 and 77.32 mg/g biosorbent was obtained for BABs and CABs, respectively. ZABs showed higher stability than BABs and CABs in biosorption-desorption cycles. The kinetic and equilibrium data were analyzed via reaction/diffusion and Langmuir/Freundlich models, respectively. Scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX) and Fourier transform infrared spectroscopy (FTIR) indicated bonded metal ion to the ABs. Hence, this study confirmed an improvement in stability and biosorption capacity of microalgal-alginate beads.

The potential of Nelumbo nucifera in treating contaminated surface water was investigated in terms of biochemical oxygen demand (BOD), chemical oxygen demand (COD), turbidity, and nitrate reduction. Batch type lab-scale container cultivated with N. nucifera was exposed to the contaminated surface water for 30 days. Nitrate (NO3−) adsorption and pH level were monitored continuously to identify the plant survival and to avoid any additional contaminants into the samples such as plant decay. For comparison, water lily, Nymphaea, was prepared using the same experimental setup. After 30 days of phytoremediation, the BOD and COD values of the treated water using N. nucifera was significantly reduced to 97.1% and 55%, respectively, due to the unique gas transport mechanism that thermodynamically drive O2 gas from leaves at the water surface to the buried rhizomes located in the anoxic sediments. When treated with Nymphaea, the BOD value in water decreased by 64.5% and the COD value increased by 50.5%. The results indicate that N. nucifera was able to remove the organic contaminants from the surface water by supplying adequate amount of 0.2–2.1 mL/min O2 gas to increase the microbial activities from the control condition.

For decades agricultural waste materials have been a subject of study for the production of sustainable bioproducts such as biodegradable composite. In Malaysia millions of tonnes of palm oil biomass are produced annually including Oil Palm Decanter Cake (OPDC). In this study, the objective was to characterize the delignified OPDC for potential biodegradable composite development. Chemical delignification is a process of removing the lignin from the plant biomass by using chemicals. Delignification process was performed by treating the raw OPDC with 10% NaOH (alkaline treatment) followed by 25% H 2 SO 4 (acid treatment) and finally 10% H 2 O 2 (bleaching). The result of the treated OPDC showed that cellulose content had increased from 29.4 to 87.6%, while hemicellulose had decreased from 11.2 to 3.1% and finally lignin had decreased from 25.3 to 9.3%. TGA, FTIR and XRD analysis of the raw and treated OPDC samples supported the findings as well. Through morphological analysis of the treated OPDC using FESEM, it showed that the chemical treatment had caused the raw OPDC fibre surface to break-up and open its structure. At the end of this study, the treated OPDC was also exposed to lauric acid for hydrophilic properties study and the result showed that the hydrophobic properties had been developed in the treated OPDC and thus made it suitable for biodegradable composite development.

In Malaysia, the amount of food waste produced is estimated at approximately 70% of total municipal solid waste generated and characterised by high amount of carbohydrate polymers such as starch, cellulose, and sugars. Considering the beneficial organic fraction contained, its utilization as an alternative substrate specifically for bioethanol production has receiving more attention. However, the sustainable production of bioethanol from food waste is linked to the efficient pretreatment needed for higher production of fermentable sugar prior to fermentation. In this work, a modified sequential acid-enzymatic hydrolysis process has been developed to produce high concentration of fermentable sugars; glucose, sucrose, fructose and maltose. The process started with hydrothermal and dilute acid pretreatment by hydrochloric acid (HCl) and sulphuric acid (H2SO4) which aim to degrade larger molecules of polysaccharide before accessible for further steps of enzymatic hydrolysis by glucoamylase. A kinetic model is proposed to perform an optimal hydrolysis for obtaining high fermentable sugars. The results suggested that a significant increase in fermentable sugar production (2.04-folds) with conversion efficiency of 86.8% was observed via sequential acid-enzymatic pretreatment as compared to dilute acid pretreatment (∼42.4% conversion efficiency). The bioethanol production by Saccharomyces cerevisiae utilizing fermentable sugar obtained shows ethanol yield of 0.42g/g with conversion efficiency of 85.38% based on the theoretical yield was achieved. The finding indicates that food waste can be considered as a promising substrate for bioethanol production.

Highlights • Fabrication of enzyme-carrying polymeric nanofibers by electrospinning. • PVA nanofibers structure and size were not affected by the addition of enzyme. • The electrospun CGTase/PVA nanofibers show excellent immobilisation efficiency., Immobilisation of cyclodextrin glucanotransferase (CGTase) on nanofibres was demonstrated. CGTase solution (1% v/v) and PVA (8 wt%) solution were mixed followed by electrospinning (−9 kV, 3 h). CGTase/PVA nanofibres with an average diameter of 176 ± 46 nm were successfully produced. The nanofibres that consist of immobilised CGTase were crosslinked with glutaraldehyde vapour. A CGTase/PVA film made up from the same mixture and treated the same way was used as a control experiment. The immobilised CGTase on nanofibres showed superior performance with nearly a 2.5 fold higher enzyme loading and 31% higher enzyme activity in comparison with the film.

This paper investigates the membrane purification and fractionation of a mixture containing the homologous series of cyclodextrins CD6 to CD60 obtained by enzymatic conversion of starch. Three commercial polyamide thin film composite NF and UF membranes (HL, GH and GK from GE-Osmonics) were used for this purpose. In a first step, a binary mixture composed of glucose and heptacyclomaltose (β-cyclodextrin, CD7) was filtered to examine the separation performance of the studied membranes. A mathematical model based on mass balance was proposed for the simulation of the discontinuous diafiltration process assuming that the membrane separation performance is based on a sieving mechanism. A three stage diafiltration cascade (in retentate configuration) was then selected to fractionate the CD6–CD60 crude mixture. The experimental composition of the obtained permeate and retentate solutions in the targeted fractions (glucose, CD6–CD8, CD9–CD21, CD22–CD60) fit well with the predicted data indicating that membrane process enables purification and fractionation of the homologous series of large ring CDs. Some discrepancies were however observed implying that other mechanisms such as coupled transport also took place. The most striking effect was the presence of glucose in the GK retentate possibly as a result of the formation of inclusion complexes with the large ring CDs.