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Hydroxyapatite nanoparticles: electrospinning and calcination of hydroxyapatite/polyvinyl butyral nanofibers and growth kinetics

Zakaria SM, Sharif Zein SH, Othman MR, Jansen JA

J Biomed Mater Res A, 2013 Jul;101(7):1977-85.
PMID: 23225849 DOI: 10.1002/jbm.a.34506

Electrospinning of hydroxyapatite (HA)/polyvinyl butyral solution resulted in the formation of fibers with average diameter of 937-1440 nm. These fibers were converted into HA nanoparticles with size <100 nm after undergoing calcination treatment at 600°C. The diameter of the fiber was found to be influenced by applied voltage and spinning distance. The injection flowrate did not affect the diameter significantly. The electrospinning method successfully reduced the commercial HA particle size in the range of 400-1100 nm into <100 nm. The dispersion of the finally calcined HA nanoparticles was improved significantly after anionic sodium dodecyl sulfate surfactant was introduced. The experimental data of HA growth kinetics were subjected to the integral method of analysis, and the rate law of the reaction was found to follow the first order reaction.
Nanophase hydroxyapatite as a biomaterial in advanced hard tissue engineering: a review

Zakaria SM, Sharif Zein SH, Othman MR, Yang F, Jansen JA

Tissue Eng Part B Rev, 2013 Oct;19(5):431-41.
PMID: 23557483 DOI: 10.1089/ten.TEB.2012.0624

Hydroxyapatite is a biocompatible material that is extensively used in the replacement and regeneration of bone material. In nature, nanostructured hydroxyapatite is the main component present in hard body tissues. Hence, the state of the art in nanotechnology can be exploited to synthesize nanophase hydroxyapatite that has similar properties with natural hydroxyapatite. Sustainable methods to mass-produce synthetic hydroxyapatite nanoparticles are being developed to meet the increasing demand for these materials and to further develop the progress made in hard tissue regeneration, especially for orthopedic and dental applications. This article reviews the current developments in nanophase hydroxyapatite through various manufacturing techniques and modifications.
Calcium phosphate-based composites as injectable bone substitute materials

Low KL, Tan SH, Zein SH, Roether JA, Mouriño V, Boccaccini AR

J Biomed Mater Res B Appl Biomater, 2010 Jul;94(1):273-86.
PMID: 20336722 DOI: 10.1002/jbm.b.31619

A major weakness of current orthopedic implant materials, for instance sintered hydroxyapatite (HA), is that they exist as a hardened form, requiring the surgeon to fit the surgical site around an implant to the desired shape. This can cause an increase in bone loss, trauma to the surrounding tissue, and longer surgical time. A convenient alternative to harden bone filling materials are injectable bone substitutes (IBS). In this article, recent progress in the development and application of calcium phosphate (CP)-based composites use as IBS is reviewed. CP materials have been used widely for bone replacement because of their similarity to the mineral component of bone. The main limitation of bulk CP materials is their brittle nature and poor mechanical properties. There is significant effort to reinforce or improve the mechanical properties and injectability of calcium phosphate cement (CPC) and this review resumes different alternatives presented in this specialized literature.
Comparison of activated carbon and low-cost adsorbents for removal of 2,4-dichlorophenol from wastewater using Aspen Adsorption and response surface methodology

Yasir HA, Zein SH, Holliday MC, Jabbar KJ, Ahmed U, Jalil AA

Environ Technol, 2023 Apr 14.
PMID: 37057364 DOI: 10.1080/09593330.2023.2202829

AbstractIn this paper, the adsorption of the chlorinated organic compound, 2,4-dichlorophenol, using activated carbon (AC), bagasse fly ash (BFA) and rice husk fly ash (RHFA) in a packed bed column was simulated using Aspen Adsorption software. The purpose of this study was to demonstrate the effectiveness of simulation software for identifying alternative low-cost adsorbents and optimising the adsorption process. The effect of process parameters such as initial concentration, bed height and inlet feed flow rate were evaluated using breakthrough curves. It was shown that the longest breakthrough times were at a higher bed height of 3 m and lower flow rate of 2 m3/hr and concentration had no effect on breakthrough time. After optimisation using response surface methodology, the AC, BFA and RHFA had a breakthrough time of 534 s, 426 s and 209 s, respectively. This shows the potential of BFA as a potential alternative for AC for the adsorption of 2,4-dichlorophenol and shows RHFA to be a relatively poor adsorbent in comparison. The economic evaluation illustrates that the overall cost of wastewater treatment with BFA and RHFA is lower than AC. The cost for the BFA and RHFA adsorbents is only a handling charge, but the cost for using AC adsorbent is £10,603/year. Therefore, the company can produce 17,520 m3/year of fresh water from the adsorbent and save £87,600/year. Therefore, it was concluded that BFA had a slightly weaker adsorption efficiency than AC but was more cost effective, allowing it to be more affordable and increasing its availability.
Fulltext Process design and life cycle assessment of furfural and glucose co-production derived from palm oil empty fruit bunches

Ng ZW, Gan HX, Putranto A, Akbar Rhamdhani M, Zein SH, George OA, et al.

Environ Dev Sustain, 2022 Oct 07.
PMID: 36246866 DOI: 10.1007/s10668-022-02633-8

In light of environmental issues, lignocellulosic empty fruit bunch (EFB) biomass is promoted as a carbon-neutral, environmentally friendly, and renewable alternative feedstock. A comprehensive environmental assessment of EFB biorefineries is critical for determining their sustainability in parallel with the bioeconomy policy. Nonetheless, no life cycle assessment (LCA) has been performed on co-producing food and biochemicals (furfural and glucose) derived from EFB biomass. This research is the first to evaluate the environmental performance of the furfural and glucose co-production processes from EFB biomass. Environmental analysis is conducted using a prospective gate-to-gate LCA for four impact categories, including global warming potential (GWP), acidification (ADP), eutrophication (EP), and human toxicity (HT). Aspen Plus is used to simulate the co-production process of furfural and glucose as well as generate mass and energy balances for LCA inventory data usage. The findings suggest that the environmental footprint in respect of GWP, ADP, EP, and HT is 4846.85 kg CO2 equivalent per ton EFB, 7.24 kg SO2 equivalent per ton EFB, 1.52 kg PO4 equivalent per ton EFB, and 2.62E-05 kg 1,4-DB equivalent per ton EFB, respectively. The normalized overall impact scores for GWP, ADP, EP, and HT are 1.16E-10, 2.28E-11, 6.12E-10, and 2.18E-17 years/ton of EFB, respectively. In summary, the proposed integrated plant is not only economically profitable but also environmentally sustainable. In the attempt to enhance the Malaysian economic sector based on the EFB, this study has the potential to serve as an indicator of the environmental sustainability of the palm oil industry.
SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10668-022-02633-8.
Reinforcement of calcium phosphate cement with multi-walled carbon nanotubes and bovine serum albumin for injectable bone substitute applications

Chew KK, Low KL, Sharif Zein SH, McPhail DS, Gerhardt LC, Roether JA, et al.

J Mech Behav Biomed Mater, 2011 Apr;4(3):331-9.
PMID: 21316621 DOI: 10.1016/j.jmbbm.2010.10.013

This paper presents the development of novel alternative injectable calcium phosphate cement (CPC) composites for orthopaedic applications. The new CPC composites comprise β-tri-calcium phosphate (β-TCP) and di-calcium phosphate anhydrous (DCPA) mixed with bovine serum albumin (BSA) and incorporated with multi-walled carbon nanotubes (MWCNTs) or functionalized MWCNTs (MWCNTs-OH and MWCNTs-COOH). Scanning electron microscopy (SEM), compressive strength tests, injectability tests, Fourier transform infrared spectroscopy and X-ray diffraction were used to evaluate the properties of the final products. Compressive strength tests and SEM observations demonstrated particularly that the concomitant admixture of BSA and MWCNT improved the mechanical properties, resulting in stronger CPC composites. The presence of MWCNTs and BSA influenced the morphology of the hydroxyapatite (HA) crystals in the CPC matrix. BSA was found to act as a promoter of HA growth when bounded to the surface of CPC grains. MWCNT-OH-containing composites exhibited the highest compressive strengths (16.3 MPa), being in the range of values for trabecular bone (2-12 MPa).
Recovery of oil from palm oil mill effluent using polypropylene micro/nanofiber

Semilin V, Janaun J, Chung CH, Touhami D, Haywood SK, Chong KP, et al.

J Hazard Mater, 2021 02 15;404(Pt B):124144.
PMID: 33212411 DOI: 10.1016/j.jhazmat.2020.124144

Residual palm oil that goes into the river untreated can become detrimental to the environment. Residual oil discharge during milling process into palm oil mill effluent (POME) is unavoidable. About 1 wt% of residual oil in POME causes major problems to the mills, in terms of environment, wastewater treatment and economy losses. This paper reports the recovery of residual oil from POME by adsorption on polypropylene micro/nanofiber (PP-MNF) and desorption of oil by hands pressing, and oil extraction from the PP-MNF using solvent and supercritical-CO2 extraction techniques. The characterization of the PP-MNF and the quality of oil extracted were analyzed using analytical instruments. The reusability of the PP-MNF was also investigated. The experimental results showed the adsorption capacity of the PP-MNF was 28.65 g of oil/g of PP-MNF on average using refined palm oil, whilst recovery of oil from POME was 10.93 g of oil/g of PP-MNF. The extraction yield of oil from PP-MNF using hand pressing was 89.62%. The extraction of residual oil from the pressed PP-MNF showed comparable yield between solvent and supercritical CO2 techniques. The quality of recovered oil was similar with the quality of the crude oil, and no trace of polypropylene contamination was detected in the oil recovered. The PP-MNF showed no significant physical change after the extraction process. In conclusion, the PP-MNF has great potential to be used commercially in residual oil recovery from POME.
Fulltext Process design, simulation, and techno-economic analysis of integrated production of furfural and glucose derived from palm oil empty fruit bunches

Mohammed MZR, Ng ZW, Putranto A, Kong ZY, Sunarso J, Aziz M, et al.

Clean Technol Environ Policy, 2023 Jan 07.
PMID: 36643617 DOI: 10.1007/s10098-022-02454-3

This study aims to propose a new process design, simulation, and techno-economic analysis of an integrated process plant that produces glucose and furfural from palm oil empty fruit bunches (EFB). In this work, an Aspen Plus-based simulation has been established to develop a process flow diagram of co-production of glucose and furfural along with the mass and energy balances. The plant's economics are analyzed by calculating the fixed capital income (FCI), operating costs, and working capital. In contrast, profitability is determined using cumulative cash flow (CCF), net present value (NPV), and internal rate of return (IRR). The findings show that the production capacity of 10 kilotons per year (ktpy) of glucose and 4.96 ktpy of furfural with a purity of 98.21 and 99.54%-weight, respectively, was achieved in this study. The FCI is calculated as United States Dollar (USD) 20.80 million, while the working and operating expenses are calculated as USD 3.74 million and USD 16.93 million, respectively. This project achieves USD 7.65 million NPV with a positive IRR of 14.25% and a return on investment (ROI) of 22.06%. The present work successfully develops a profitable integrated process plant that is established with future upscaling parameters and key cost drivers. The findings provided in this work offer a platform and motivation for future research on integrated plants in the food, environment, and energy nexus with the co-location principle.
Esterification of residual palm oil using solid acid catalyst derived from rice husk

Balan WS, Janaun J, Chung CH, Semilin V, Zhu Z, Haywood SK, et al.

J Hazard Mater, 2021 02 15;404(Pt B):124092.
PMID: 33091694 DOI: 10.1016/j.jhazmat.2020.124092

In this study, carbon-silica based acid catalysts derived from rice husks (RH) were successfully synthesised using microwave (MW) technology. The results showed that MW sulphonation produced Sulphur (S) content of 17.2-18.5 times higher than in raw RH. Fourier-transform Infrared Spectroscopy (FTIR) showed peak at 1035 cm-1 which corresponded to O˭S˭O stretching of sulphonic (-SO3H) group. XRD showed sulfonated RH catalysts (SRHCs) have amorphous structure, and through SEM, broadening of the RH voids and also formation of pores is observed. RH600 had the highest surface area of 14.52 m2/g. SRHCs showed high catalytic activity for esterification of oleic acid with methanol with RH600 had the highest initial formation rate (6.33 mmolL-1min-1) and yield (97%). The reusability of the catalyst showed gradually dropped yield of product for every recycle, which might be due to leaching of -SO3H. Finally, esterification of oil recovered from palm oil mill effluent (POME) with methanol achieved a conversion of 87.3% free fatty acids (FFA) into fatty acid methyl esters (FAME).