Untreated Coconut Research Articles

Methylene blue dye removal by adsorption with coconut coir and acid-treated forms: adsorption-desorption study, MPR and modeling using artificial intelligence

A batch study is conducted to remove methylene blue (MB) dye from an aqueous solution using coconut coir and its acid-treated forms. The sulfuric acid-treated coconut coir (SCC), phosphoric acid-treated coconut coir (PCC) and untreated coconut coir (UCC) were prepared. Adsorbents were characterized via BET, SEM, pHPZC, FTIR, and FT-Raman analysis. Adsorbent’s total organic carbon (TOC) and the number of oxygen-containing functional groups like carboxylic, lactonic and phenolic, total acidic, and basic groups were also estimated. FTIR and FT-Raman studies establish functional groups responsible for dye removal. The operating parameters were optimized through experiments. Dye was removed maximally at the lowest temperature, 303K. Langmuir and Temkin isotherm models use linear equations, and the Pseudo-second-order kinetic model uses a nonlinear equation, which fits well. The adsorption capacity of SCC, PCC and UCC adsorbents was 88.18 ± 0.63 mg/g, 92.68 ± 2.74 mg/g and 76.39 ± 0.36 mg/g, respectively, for 303K. Intraparticle diffusion dominated more than film diffusion. Physisorption was estimated by applying the Dubinin-Radushkevich (D-R) isotherm model. Thermodynamic study indicates a spontaneous, favorable, exothermic process. 75% glacial acetic acid and 100% methanol are the best solvents for desorbing dye-loaded adsorbents. Porous coir and non-covalent interactions like hydrogen bonding, van der Waals force and π-π interaction between dye and coir are vital in the dye removal process. The regression equation has been successfully formulated, and the application of a genetic algorithm has predicted the percentage removal of methylene blue dye.

Nutrient Removal Efficiencies in a Bioretention Cell Using Pre-Treated Coconut By-Product as Carbon Source

Abstract In this research, the appropriateness of alkali pre-treatment on coconut by-products was managed by exposing coconut husk and shell to 2M NaOH. The powdered samples were analysed for morphology observation, Fourier Transform Infrared (FTIR), Particle Size Analyzer (PSA), and water quality tests. Weakening the hemicellulose structure resulted from subjecting the coconut shell to alkali pre-treatment shown in the morphology observation. Furthermore, the FTIR analysis exhibited the presence of O-H stretch in all pre-treated samples representing an indication for occurring the lignin breakdown, while an absence of the C=O functional group was shown in both additive samples after their subjection to alkali pre-treatment. In PSA analysis, the particles of all samples were found finer than the particle size distribution standards, in which the smallest D50 was obtained for the treated coconut shell (TCS), followed by untreated coconut shell (UCS), untreated coconut husk (UCH), and treated coconut husk (TCH). Among all the powdered samples (TCS, UCS, UCH, and TCH) analysed in this study, only TCH values met the ranges provided and recommended by the Urban Stormwater Management Manual for Malaysia (MSMA) and the Australian Department of Sustainability, Environment, Water, Population, and Communities (DSEWPC). Meanwhile, a poor removal rate for total suspended solids (TSS) was attained due to the contribution of TSS by the filter media which caused the TSS rates to surpass the inlet values. Additionally, the presence of a high concentration of total phosphorous (TP) in all the tested samples indicated their capabilities to provide PO43 in the bioretention cell, which is a vital nutrient for the plant’s growth. In contrast, Ammoniacal Nitrogen (AN) with a concentration rate as low as 4 mg/L was observed throughout the test periods which showed a significant reduction compared to the rate of AN at the inlet samples ranged between 5.2 and 11.4 mg/L. The findings indicated that coconut by-products, when subjected to an alkali pre-treatment process, are appropriate for incorporation as additives in bioretention filter media.

KEMULURAN DAN KEKUATAN PUTUS TALI SABUT KELAPA BERLAPIS KITOSAN

Coating of coconut coir rope as a material for fishing gear is carried out to inhibit the decomposition process and increase the breaking strength and elongation of the rope. In this study,the coating of coconut coir rope using chitosan as an antimicrobial is expected to inhibit the growth of micro-organisms. This study aims to determine the elongation and breaking strength of chitosancoated coconut coir ropes. The research method used is experimental. Data analysis used the Kolmogorov–Smirnov normality test and RAL (Completely Randomized Design)- to determine the effect of chitosan coating on the elongation and breaking strength of coconut fiber ropes. The results showed that the chitosan coir rope had a dark brown color, while the control coir rope had a light brown color. The direction of the twist is "S", with a "hard" type of twist so that the rope tends to be stiff. The fiber type is staple fiber (short fiber). The elongation of the chitosan coir rope was 10.21 cm, 17.55% higher than the untreated coconut coir rope, which was 8.68 cm. The average breaking strength of chitosan coir rope was 37.41 kgf or 11.87% higher than untreated coconut coir rope, which was 33.44 kgf.
 Keywords: elongation, breaking strength, chitosan, chitosan coconut fiber rope.

Adsorptive removal of crystal violet dye from aqueous solution onto coconut coir

The untreated and sodium chlorite-treated coconut coir was implemented to remove crystal violet (CV) dye from an aqueous solution by batch adsorption experiments. The adsorption capacity, equilibrium time, and adsorption kinetics of CV on both adsorbents were regulated by the pH of the dye solution. High pH favors the comparative adsorption capacity for both adsorbents. In contrast, the untreated coconut coir (UT-CC) shows higher adsorption efficiency (9.61 mg g-1) than sodium chlorite-treated coconut coir (SCT-CC) at low pH. At lower pH (2.00), the equilibrium was established within 60 min by both adsorbents. However, the quick attainment of the equilibrium (30 min) was observed using both the adsorbents at higher pH (8.00). The isotherm data for both the adsorbents was found to have better agreement with the Freundlich than the Langmuir model at pH 8.00. The kinetic data was well-fitted with Ho?s pseudo-second-order model. Both adsorbents were characterized by FTIR and SEM to get evidence for the proposed adsorption mechanism. Density functional theory (DFT) also supports this result which illustrates the adsorption of CV on lignin of CC with the adsorption energy -51.16 kJ/mol at the B3LYP/6-31(d,p) level of theory.

Tribology analysis of MMT nanoclay alkali-treated coconut sheath reinforced hybrid composite

This research paper focuses on the tribology analysis of MMT - Montmorillonite nanoclay alkali-treated coconut sheath reinforced hybrid composite. The study aims to analyze the mechanical properties of coconut sheath reinforced polymer composites as compared to traditional synthetic fibers. The specific impact of MMT clay on the material’s mechanical properties is also considered. The experimental method involves the use of compression molding for fabrication, and various treatments are applied to the coconut sheath to improve its mechanical properties. The microstructure, tensile, flexural, and impact characterization of the specimens are analyzed. The results indicate that alkali-treated coconut sheath outperforms untreated coconut sheath in terms of surface quality. Additionally, the addition of MMT clay improves the bonding and surface area coverage, resulting in better mechanical properties. However, the brittleness of the treated coconut sheath specimen increased, reducing its energy absorption in impact tests. Overall, the study highlights the potential of coconut sheath as a natural fiber reinforcement for polymer composites and the impact of MMT clay on its mechanical properties.

Study of Treatment Effect on the Cocos Nucifera Lignocellulosic Fibers as Alternative for Polymer Composites

ABSTRACT The usage of new cellulosic fibers in industrial applications is massive because of its excellent performances. These fibers are utilized especially for manufacture of high-performance composites. Coconut leaf sheath (CLS) fibers are extracted for leaf sheath of coconut tree. The aim of this paper is to study the possibility of using a natural fiber CLS as an alternative for polymer composites. In the current study, the consequence of NaOH treatment on structural, thermal and morphological behavior of treated and untreated coconut leaf sheath (CLS) fiber in terms of single fiber tensile strength, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (×RD), thermogravimetric analysis (TGA) and differential scanning calorimeter (DSC) has been explored. From SEM analysis, it was identified globular lumps spread consistently over the fiber which could help the mechanical interlock with the resin. The outcomes from the experimentation exposed that the NaOH treatment has impacted in the eradication of amorphous hemicellulose and lignin contents from the CLS fiber surface and in turn resulted in excellent structural and thermal stability behaviour of fiber. The present work endorses the great potential of CLS fibers to be utilized for bio-reinforcement in order to fabricate lightweight composite structures, employed in automobile and structural applications.

Ductility and cracking behavior of reinforced coconut shell concrete beams incorporated with coconut shell ash

Coconut shell concrete beams containing coconut shell ash are a feasible alternative to traditional reinforced concrete beams in structural applications. Coconut shells in reinforced concrete beams are essential in earthquake-prone areas because of their ductility properties, which contribute to enhancing earthquake resistance. This research investigates the flexure, ductility, shear, and cracking behavior of reinforced concrete beams made from the incorporation of a minimum quantity of untreated coconut shell particles (CSP) at 5% substitution of coarse aggregate (CA) modified with coconut shell ash (CSA) at 10% substitution of Ordinary Portland cement (OPC). Two beams were evaluated for flexural, strain, ductility, and cracking behavior. In contrast, the other two were evaluated for flexural, shear, strain, ductility, and cracking behavior by repositioning the loading point to the distance of 200 mm close to the support. In comparison to control beams evaluated for flexural, shear, strain, ductility, and cracking behavior, the ductility ratio of concrete beams with 10% CSA and 5% CSP improved by 8.8%. The ductile improvement was observed with a 17.3% decrease in flexural load. The shear capacity of reinforced concrete beams with 10% CSA and 5% CSP improved compared to the reference literature in the study. Finally, it was discovered that combining 10% CSA and 5% CSP in reinforced concrete beams can improve ductility without significantly reducing ultimate failure load.

Engineering and Durability Properties of Modified Coconut Shell Concrete

Making low-cost concrete from coconut shell ash and coconut shell aggregate increases sustainability and reduces pollution. This research investigates untreated Coconut Shell Particles (CSP) incorporated with coconut shell ash (CSA) to improve the durability properties at elevated temperatures and in sulphuric acid. Initially, the physical and mechanical properties of cube and cylinder specimens after 7, 28, 56, and 90 days of moist curing were studied. The durability properties were then carried out after the pozzolanic component of CSA in modified concrete was activated. CSA and CSP were used as partial substitutes for ordinary Portland cement and coarse aggregate in class 30 concrete with a constant water to cement ratio of 0.55. Concrete mixes included control, 5% CSP, 10% CSA, and a mixture of 5% CSP incorporated with 10% CSA. According to test results, adding 10% of CSA to CSP concrete decreased the workability, density, and water absorption properties compared to the rest of the concrete mixes. However, these results were within acceptable limits. The compressive strength of 10% CSA concrete at 90 days of moist curing was reduced by 3.23% when 5% CSP was added compared to control. The addition of 10% of CSA to 5% CSP concrete improved the split tensile strength by 2.76% higher than concrete with only 5% CSP. Concrete containing the combination of 10% CSA and 5% CSP showed a 9.37% increment in the split tensile strength compared to concrete having only 5% CSP after sulphuric acid exposure. Also, the compressive strength of 10% CSA and 5% CSP concrete improved by 30.7% when the temperature was elevated to 500 °C for 1 hour compared to the control concrete. Moreover, the reduction in the compressive strength after exposure to the elevated temperature of 500 °C for 1 hr. was still much less by an average of 75.38% compared to other waste materials blended into the concrete by previous works. Doi: 10.28991/CEJ-2022-08-02-013 Full Text: PDF

Investigation of moisture absorption rate and diffusivity of plant fibre-reinforced composites

This research investigated the moisture absorption rate and diffusivity of plant Fibers-reinforced-composites; using bamboo fiber, raffia and coconut fibers through laboratory experimental investigations. The major limitation of using natural fibers in durable composite applications are their high moisture absorption and poor dimensional stability (swelling); and this swelling of fibers causes micro-cracking and degradation of the composites. In this investigation, the fibers were treated with sodium hydroxide (NaOH) chemical and acetylation to decrease the hydroxyl group in the fibers. Experimental results reveal that the moisture absorption and degree of swelling of the treated bamboo raffia and coconut fiber composites are 25 - 35% lower than those of composites produced with untreated bamboo, raffia and coconut fibers. Experimental results also show that strong intermolecular fiber-matrix bonding decreases the rate of moisture absorption in bio-composites. The diffusivity of the bamboo, raffia and coconut fibers-reinforced-composites for 24hrs at 1000C were experimentally measured to be 4.91, 3.33, and 3.94 mm2/sec respectively. The results showed that when these fiber plant materials are treated with sodium hydroxide (NaON) the diffusivity rate of the fiber reinforced composite material is brought under considerable control and its dimensional stability immensely enhanced though improved strong intermolecular fiber-matrix bonding and the reduction of swelling.

Assessment of Thermophysical and Mechanical Properties of Composite Panels Fabricated from Untreated and Treated Coconut Husk Particles for Structural Application

Large quantities of coconut husks generated are under-utilized. In developing countries, this situation warrants their disposal by open burning or indiscriminate dumping. Either practice adversely affects the environment and public health. In this study, test samples were fabricated from untreated coconut husk particles (UCP) at 0%, 25%, 50%, 75%, and 100% weight proportions with treated coconut husk particles (TCP) using epoxy resin as binder. Five representative samples were prepared per formulation and then subjected to various intended tests. The test results revealed water absorption, bulk density, thermal conductivity, specific heat capacity, thermal diffusivity, nailability, flexural strength, and compressive strength to be (24.88 ± 0.04) %, (459.78 ± 0.05) kgm-3, (0.0867 ± 0.0001) Wm-1K-1, (1573.76 ± 1.14) Jkg-1K-1, (1.198 ± 0.002) x 10-7 m2s-1, (100.0 ± 0.0) %, (11.94 ± 0.03) N/mm2, and (22.86 ± 0.04) N/mm2 respectively for the control sample with UCP content. Also, the respective values of the properties were (29.05 ± 0.06) %, (583.87 ± 0.05) kgm-3, (0.1009 ± 0.0002) Wm-1K-1, (1402.66 ± 1.45) Jkg-1K-1, (1.232 ± 0.004) x 10-7 m2s-1, (100.0 ± 0.0) %, (14.58 ± 0.03) N/mm2, and (33.27 ± 0.02) N/mm2 for the counterpart sample containing the TCP. All the samples showed better tendencies for thermal insulation performance compared to conventional ceilings like plywood, PVC, and asbestos. Thus, utilization of coconut husks as described in this study could alternatively help to solve the disposal problems of such wastes while availing building industries with suitable raw materials to manufacture cost-effective heat-insulating ceilings.

Biodegradable nano composite reinforced with cellulose nano fiber from coconut industry waste for replacing synthetic plastic food packaging

Environmental pollution due to the usage of non-biodegradable synthetic plastic and agro-waste disposal/burning are major issues nowadays. Hence, in the present study, agro-waste (coconut shells) was selected as raw material to synthesize cellulose nanofibers, and it was incorporated into a biodegradable packaging film to enhance its properties. Coconut shell cellulose nanofibers (CNF) were synthesized by a combination of mechanical (ball milling), chemical (acid hydrolysis), and physical (ultra-sonication) methods with an excellent yield of 41.67 ± 1.07%. After each treatment, the crystallinity index was improved, it was 74.38% for the untreated coconut shell powder, and 98.62% for the CNF obtained after ultra-sonication. After chemical treatments, FTIR analysis was done to confirm the removal of non-cellulosic material. The structure and morphology of the nanofiber were concluded from SEM, AFM, TEM, and the size obtained was up to 29 nm. The cellulose nanofibers were then incorporated into polyvinyl alcohol (PVA) polymer matrix with the linseed oil and lemon oil. The essential oil improved the antioxidant properties of PVA-CNF film, and free radicle scavenging activity was 31.52 ± 0.08% upon the addition of oils. Moreover, PVA–CNF–oil-based composite film showed good antimicrobial activity against food-borne pathogens. Hence, it can be used in the preparation of active packaging in the food industry. Similarly, the mechanical and thermal properties of bio nanocomposite film inferred superior quality than neat PVA film. The optical properties of the developed film were on par with polyethylene film. The film also exhibited excellent biodegradability; 87.34 ± 0.91% degradation was obtained on the 45th day. Another major objective of the study was to provide a hydrophobic nature to PVA-based film. It was improved by incorporating essential oil and coconut shell nanofibers; the contact angle measured was 91.3° ± 0.79°. Hence, the prepared bio nanocomposite film is suggested as an alternative material for non-biodegradable food packaging, thereby reducing plastic pollution.

Preparation and ultrasonic characterization of modified epoxy resin/coconut shell powder biocomposites

AbstractA new bio‐based epoxy resin (BER) is produced by the esterification reaction between sebacic acid (SAc) as bio‐based acid and epichlorohydrin (ECH). The epoxy resin (ER) is modified with the BER. The biocomposites are prepared using untreated coconut shell powder (CSP), modified coconut shell powder (MCSP), and MER. The CSP and MCSP particles are mixed with MER in varied compositions (10–50 wt%) for preparation of the MER/CSP and MER/MCSP biocomposites. The influences of CSP and MCSP bio‐fillers amounts on the physical properties (density, elastic constants, acoustic impedance, ultrasonic micro‐hardness, and attenuation coefficient) of biocomposites are investigated using the ultrasonic pulse‐echo overlap method (PEOM). It was seen that the densities, both ultrasonic longitudinal and shear waves' velocity values of obtained biocomposites were higher than those of the MER. All elastic moduli of the MER/MCSP biocomposites have higher values than of the neat MER and MER/CSP biocomposites.

Batoko plum (Flacourtia inermis) peel extract attenuates deteriorative oxidation of selected edible oils

The oxidation of oils has an adverse effect on the organoleptic properties and shelf-life of stored oils. Flacourtia inermis is one of the underutilized fruits grown in Sri Lanka with promising antioxidant properties. F. inermis peel extract (FIPE) was used to retard rancidity in edible oils. The efficacy of added FIPE (500, 1000, 2000 ppm) on sunflower oil (SO) and virgin coconut oil (VCO) was monitored at 3-day intervals at 65 ± 5 °C against a positive control (α-tocopherol at 500 ppm level) using Free Fatty Acid (FFA) and Peroxide Value (PV). Oils without FIPE were used as the control. Antioxidant efficacy (IC50) and Total Phenol Content (TPC) of FIPE were determined by DPPH assay and the Folin-Ciocalteu method. Fourier transform infrared spectroscopy was used to monitor the oxidative stability. The IC50 value and TPC of FIPE were 227.14 ± 4.12 µg·mL-1 and 4.87 ± 0.01 mg GAE/g extract, respectively. After 21 days, VCO (control) sample exhibited significantly (p < 0.05) higher FFA and PV than the treatments. FIPE exhibited comparable results with α-tocopherol. Conclusively, FIPE had strong antioxidant properties and thus, could be used as an alternative to α-tocopherol to improve the oxidative stability of virgin coconut oil and sunflower oil. However, only minor differences in the FTIR spectra were detected in treated and untreated virgin coconut and sunflower oil samples after 21 days storage at 65 ± 5 °C.

Pelatihan Pembuatan Nata de coco di Perkebunan Kelapa Desa Margomulyo Kecamatan Seyegan Kabupaten Sleman

Coconut plants are very potential commodities, all parts of the coconut plant are beneficial to the needs of human life. All parts of coconuts are not wasted and can be used to produce industrial products. The partners are coconut farmers who sell peeled coconut and coconut flesh. Farmers in Margomulyo village have difficulty in handling the waste of untreated coconut water. Sometimes the coconut water causes inundated land without being used. Sometimes when the coconut water is not directly absorbed in the ground, it will cause bad odor in the environment. Therefore, the use of coconut water is a way to optimize the use of coconut fruit. The content of sucrose sugar in coconut water will be used by Acetobacter xylinum as a source of energy, as well as a carbon source to form metabolite compounds such as cellulose that form Nata de Coco. In conclusion, Nata de coco making training in Margomulyo village gave positive response for the community to establish business unit. The barrier to the implementation of this activity was that there was no solution for handling waste production of Nata de coco of which aroma was quite disturbing. Thus, the implementation of nata de coco waste treatment program will be overcomed in further implementation of community service program which will be held in the next period

Adsorptive removal of Safranin-O dye from aqueous medium using coconut coir and its acid-treated forms: Adsorption study, scale-up design, MPR and GA-ANN modeling

Coconut coir (Cocos nucifera L.), particle size 300–850 μm, has been identified as an adsorbent for safranin-O dye removal from aqueous solution. Bioadsorption efficiency is improved by modifying untreated coconut coir (UCC) with 1 N phosphoric acid (PCC) and 1 N sulphuric acid (SCC). The acid treatment enhances the surface area of adsorbents and accelerates more dye uptake. The adsorption process is optimized by varying the physicochemical conditions like initial pH, adsorbent amount, contact time, initial dye concentration, and temperatures. The adsorption process's optimum pH is 4, 6, and 6, respectively, using UCC, PCC, and SCC adsorbents.In contrast, more than 98% of dye removal has been observed at the lower concentration of dyes up to 200 mg/L at 303 K. Maximum dye removal is possible at 75 mg/L of dye concentration. UCC, PCC, and SCC adsorbents’ adsorption capacity is 80.32 mg/g, 96.81 mg/g, and 89.53 mg/g, respectively, at 303 K temperature. Langmuir and Tempkin model and the pseudo-second-order model are the best-fitted models for isotherm and kinetic study. Thermodynamic parameters indicate the adsorption process is viable, spontaneous, exothermic. 75% glacial acetic acid is the most potent solvent for safranin-O dye extraction from dye loaded biomass. The functional groups and different interactions are identified to establish the adsorption mechanism. The PCC adsorbent has been used for scale-up design. The multiple polynomial regression (MPR) successfully predicts the dye removal efficiency for individual adsorbents. The modeling of the Genetic Algorithm has also been done successfully.

Metagenomic Study of Bacterial and Archaeal Populations during Anaerobic Digestion of Lignocellulosic Waste in Lab-scale Biogas Reactors

This study evaluated using 16S rDNA gene-based metagenomics technique the populations of bacteria and archaea in digestate samples from lab-scale anaerobic bioreactors digesting pretreated and untreated coconut husk fiber, pineapple floret and banana stem. Result of biodegradability experiment indicated high microbial activity in digestate (biogas slurry), with untreated banana stem having the highest total solids (TS) and volatile solids (VS) removal efficiencies of 78.3 % and 92.9 % respectively. Similarly, all pretreated substrates exhibited higher TS and VS losses with corresponding TS (77.8 %) and VS (87.2 %) removal efficiencies. This TS and VS removal rates signaled increased rate of organic matter decomposition with concomitant biogas productivity. Diversity comparisons performed between samples showed rich microbial diversity in untreated sample than the pretreated sample. Taxonomic composition revealed that, for untreated samples at the phylum level, the bacterial community was predominantly Firmicutes (relative abundance 97.0 %), with 0.30 % Actinobacteria and 0.10 % Proteobacteria. The genus Oxobacter (35.0 %), Clostridium (12.0 %) and Ethanoligenens (10.0 %) were ubiquitous and abundant in the untreated sample. The archaeal community was however dominated by the Euryarchaeota with one methanogenic order Methanomicrobiales, and a high abundance of the genera Thermacetogenium. For pretreated samples, at the phylum level, bacterial community was also dominated by Firmicutes (95.0 %), followed by Proteobacteria (1.02 %), Actinobacteria (0.18 %) and Tenericutes (0.06 %). The genus Clostridium (41.0 %), Ethanoligenens (29.0 %) and Lactobacillus (15.0 %) were also ubiquitous and abundant in the pretreated sample. Archaeal community was also dominated by Euryarchaeota with the two methanogenic orders Methanomicrobiales and Methanosarcinales dominating. The major microbial groups were hydrolyzing and fermenting populations. These findings revealed rich microbial assemblage and diversity among microbial communities in biogas digestate.

Properties of Sandcrete Block Produced with Coconut Husk as Partial Replacement of Sand

Sandcrete block is the most popular building material in construction industry. However, with the high and increasing cost of building materials experienced nowadays, it has been difficult to achieve affordable housing especially in developing countries. Also, significant dredging of sand for block production and the large amount of coconut husk thrown away as waste have increased the level of concern due to their adverse effect on environment. This work, therefore, sought to produce solid core sandcrete blocks in which sand component is partially replaced with coconut husk and investigate the suitability of using such blocks for building designs. The block samples produced using untreated and also treated coconut husks at various levels of sand replacement were subjected to bulk density, water absorption and compressive strength tests at 7 days and 28 days of curing. It was found that sand replacement with 20% of untreated coconut husk or 30% of treated coconut husk could yield a solid core sandcrete block suitable for non-load bearing walls of satisfactory performance. Since coconut husk is cheaply available, sustainable, and recyclable, utilising such promising material in this case can enhance production of cost-effective and optimally performing sandcrete blocks for building purposes. This will in turn help to boost the development of housing, minimise loss of agricultural lands, and reduce environmental pollution level, and so on.

Development of effective and sustainable adsorbent biomaterial from an agricultural waste material: Cu(II) removal

Motivated by the significant scope which exists to generate value-added products from agricultural waste materials, in this work a comprehensive study was performed on the microstructure of alkali-treated coconut coir in order to evaluate its potential as an environmentally friendly absorbent. By investigating the influence of the alkali concentration, temperature and treatment time through a systematic Design of Experiments (DOE) approach, it was found that alkali-treated coconut coir possessed greatly improved water and moisture absorption properties (27% and 30% increases, respectively, compared to those of untreated coconut coir). The efficiency of heavy metal removal of treated coconut coir samples has been studied by investigating Cu (II) removal performance of selected samples with higher water and moisture absorbency. The effect of contact time and concentration of Cu (II) on the Cu (II) removal efficiency of samples have been investigated. The results show almost five times higher Cu (II) removal performance for the treated sample compared to raw coconut coir under optimized conditions. These findings highlight that the alkali treatment of biomaterials such as coconut coir can be used to tailor their water-absorbency properties as well as their adsorption properties, providing facile and effective adsorbent materials from readily available agricultural waste materials.

Compressive Behaviour of Coconut Fibre (Cocos nucifera) Reinforced Concrete at Elevated Temperatures

Fire outbreaks in buildings have been a major concern in the world today. The integrity of concrete is usually questioned due to the fact that after these fire outbreaks the strength of the concrete is reduced considerably. Various methods have been adopted to improve the fire resistance property of concrete. This study focused on the use of coconut fibre to achieve this feat. In this study, varying percentages of treated and untreated coconut fibres were incorporated into concrete and the compressive strength was tested for both before heating and after heating. The percentages of replacement were 0.25, 0.5, 0.75 and 1% fibre content by weight of cement. Concrete cubes that had 0% fibre served as control specimens. After subjecting these concrete cubes to 250 °C and 150 °C for a period of 2 h, the compressive strength increased when compared to the control. The compressive strength increased up to 0.5% replacement by 3.88%. Beyond 0.5% fibre, the compressive strength reduced. Concrete having coconut fibre that had been treated with water also exhibited the highest compressive strength of 28.71 N/mm². It is concluded that coconut fibres are a great material in improving the strength of concrete, even after it was exposed to a certain degree of elevated temperature.

Assessment of Thermal and Mechanical Properties of Composite Board Produced from Coconut (Cocos nucifera) Husks, Waste Newspapers, and Cassava Starch

Bulk density (ρ), specific heat capacity (c), thermal conductivity (k), thermal resistivity (r), thermal diffusivity (α), water absorption (WA), flexural strength (σ), and compressive strength (CS) were determined for composite boards produced using cassava starch with the graduated percentage of waste newspaper paste and treated coconut husk as well as waste newspaper paste and untreated coconut husk. The results show that ρ, k, α, WA, σ, and CS are higher in value for samples containing waste newspaper paste and treated coconut husk than for those made with waste newspaper paste and untreated coconut husk. Also, c and r of samples containing waste newspaper paste and untreated coconut husk are observed to be higher in value than in the case with samples developed with treated coconut content. The values of the physical parameters determined are within the range specified for good thermal insulators suitable for interior building design.