The biomass of Urochloa mutica was subjected to thermal degradation analyses to understand its pyrolytic behavior for bioenergy production. Thermal degradation experiments were performed at three different heating rates, 10, 30 and 50°Cmin-1 using simultaneous thermogravimetric-differential scanning calorimetric analyzer, under an inert environment. The kinetic analyses were performed using isoconversional models of Kissenger-Akahira-Sunose (KAS) and Flynn-Wall-Ozawa (FWO). The high heating value was calculated as 15.04MJmol-1. The activation energy (E) values were shown to be ranging from 103 through 233 kJmol-1. Pre-exponential factors (A) indicated the reaction to follow first order kinetics. Gibbs free energy (ΔG) was measured to be ranging from 169 to 173kJmol-1 and 168 to 172kJmol-1, calculated by KAS and FWO methods, respectively. We have shown that Para grass biomass has considerable bioenergy potential comparable to established bioenergy crops such as switchgrass and miscanthus.
Remediating inorganic pollutants is an important part of protecting coastal ecosystems, which are especially at risk from the effects of climate change. Different Phragmites karka (Retz) Trin. ex Steud ecotypes were gathered from a variety of environments, and their abilities to remove inorganic contaminants from coastal wetlands were assessed. The goal is to learn how these ecotypes process innovation might help reduce the negative impacts of climate change on coastal environments. The Phragmites karka ecotype E1, found in a coastal environment in Ichkera that was impacted by residential wastewater, has higher biomass production and photosynthetic pigment content than the Phragmites karka ecotypes E2 (Kalsh) and E3 (Gatwala). Osmoprotectant accumulation was similar across ecotypes, suggesting that all were able to successfully adapt to polluted marine environments. The levels of both total soluble sugars and proteins were highest in E2. The amount of glycine betaine (GB) rose across the board, with the highest levels being found in the E3 ecotype. The study also demonstrated that differing coastal habitats significantly influenced the antioxidant activity of all ecotypes, with E1 displaying the lowest superoxide dismutase (SOD) activity, while E2 exhibited the lowest peroxidase (POD) and catalase (CAT) activities. Significant morphological changes were evident in E3, such as an expansion of the phloem, vascular bundle, and metaxylem cell areas. When compared to the E3 ecotype, the E1 and E2 ecotypes showed striking improvements across the board in leaf anatomy. Mechanistic links between architectural and physio-biochemical alterations are crucial to the ecological survival of different ecotypes of Phragmites karka in coastal environments affected by climate change. Their robustness and capacity to reduce pollution can help coastal ecosystems endure in the face of persistent climate change.
Concentrations of uranium-238 and thorium-232 in soil, water, grass, moss and oil-palm fruit samples collected from an area of high background radiation were determined using neutron activation analysis (NAA). U-238 concentration in soil ranged from 4.9 mg kg(-1) (58.8 Bq kg(-1)) to 40.4 mg kg(-1) (484.8 Bq kg(-1)), Th-232 concentration ranged from 14.9 mg kg(-1) (59.6 Bq kg(-1)) to 301.0 mg kg(-1) (1204 Bq kg(-1)). The concentration of U-238 in grass samples ranged from below the detection limit to 0.076 mg kg(-1) (912 mBq kg(-1)), and Th-232 ranged from 0.008 mg kg(-1) (32 mBq kg(-1)) to 0.343 mg kg(-1) (1.372 Bq kg(-1)). U-238 content in water samples ranged from 0.33 mg kg(-1) (4.0 Bq L(-1)) to 1.40 mg kg(-1) (16.8 Bq L(-1)), and Th-232 ranged from 0.19 mg kg(-1) (0.76 Bq L(-1)) to 0.66 mg kg(-1) (2.64 Bq L(-1)). It can be said that the concentrations of environmental U-238 and Th-232 in grass and water samples in the study area are insignificant. Mosses were found to be possible bio-radiological indicators due to their high absorption of the heavy radioelements from the environment.
A study was conducted to determine the effect of sugarcane maturation on the contents of chlorophyll, tannin, and polyphenol oxidase (PPO) activity and on color change of sugarcane juice. The maturation period of the cane studied was between 3 and 10 months after planting. Different parts of the cane, namely, the top, middle, and bottom portions, were analyzed. Results obtained indicated that there were significant (P < 0.01) decreases in total chlorophyll a and b and tannin contents during maturity followed by slower rates of decrease of both parameters at the end of maturity stages. There were no significant differences (P > 0.05) in chlorophyll and tannin contents between the middle and bottom portions. On the other hand, the top portion of the stem had a significantly (P < 0.01) lower concentration of chlorophyll and a significantly (P < 0.01) higher content of tannin. PPO activity of sugarcane juice was determined using chlorogenic acid as a substrate. There was a highly significant difference (P < 0.01) in PPO activity of cane juice during maturity. PPO activity was high at the early development stage, decreased during maturation, and then remained relatively constant at the end of maturity. PPO activity was higher when chlorogenic acid was used as substrate. There were also significant differences (P < 0.01) in juice color (L*, a*, b* values) from different portions at different maturity stages. At the early stages, the color of extracted juice was dark, and then the juice turned to yellowish green during maturity. The decrease in green color or the increase in the yellow color could be associated with the decline in chlorophyll. The overall color change (DeltaE) at maturity indicated that the color of the middle and bottom portions was lower than that of the top portion.
This work investigates the extraction of cellulose nanocrystals (CNC) from bamboo fibre as an alternative approach to utilize the waste bamboo fibre. In this study, bamboo fibre was subjected to acid hydrolysis for efficient isolation of CNC from bamboo fibre. The extracted CNC's were morphologically, characterized via Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Atomic Force Microscopy (AFM). The energy Dispersive X-rays (EDX) provided the elemental composition of the prepared CNC's and X-ray diffractometer (XRD) exhibited their crystallinity. The physiochemical analysis was done via Fourier Transform Infrared (FTIR); and their thermal analysis was revealed by Thermogravimetric Analysis (TGA) and Differential scanning calorimetry (DSC). As from their morphological investigations, rod like structures of CNC's were observed under SEM analysis with higher carbon content as demonstrated by EDX, while needle shaped CNC's were observed from TEM and AFM studies. Acid hydrolysis for 45 min resulted into higher degree of crystallinity and higher yield of CNC's about 86.96% and 22% respectively. Owing to higher quality of CNC's obtained as a result of efficient and modified techniques, these can find potential usage in nanocomposites for biomedical and food packaging application.
The aim of the present work was to investigate the feasibility of grass waste (GW) for methylene blue (MB) adsorption. The adsorption of MB on GW material was studied as a function of GW dose (0.05-1.20 g), solution pH 3-10, contact time and initial concentration (70-380 mg/L). The influence of these parameters on the adsorption capacity was studied using the batch process. The experimental data were analyzed by the Langmuir and Freundlich isotherms. The adsorption isotherm was found to follow the Langmuir model. The monolayer adsorption capacity was found to be 457.640 mg/g. The kinetic data were fitted to the pseudo-first-order and pseudo-second-order models, and were found to follow closely the pseudo-second-order kinetic model. The results revealed that GW adsorbent is potentially low-cost adsorbent for adsorption of MB.
In this study, the treatment of septage (originating from septic tanks) was carried out in a pilot-scale, two-staged, vertical-flow engineered wetland (VFEW). Palm kernel shells (PKS) were incorporated as part of the VFEW's substrate (B-PKS), to compare its organic matter (OM) and nitrogen (N) removal efficiency against wetlands with only sand substrates (B-SD). The results revealed satisfactory OM removal with >90% reduction efficiencies at both wetlands B-PKS and B-SD. No increment of chemical oxygen demand (COD) concentration was observed in the effluent of B-PKS. Ammonia load removal efficiencies were comparable (>91% and 95% in wetland B-PKS and B-SD, respectively). However, nitrate accumulation was observed in the effluent of B-SD where PKS was absent. This was due to the limited denitrification in B-SD, as sand is free of carbon. A lower nitrate concentration was associated with higher COD concentration in the effluent at B-PKS. This study has shown that the use of PKS was effective in improving the N removal efficiency in engineered wetlands.
The contribution of chitosan/nanocellulose (CS-NC) to the enzymatic activity of Candida rugosa lipase covalently bound on the surface of CS-NC (CRL/CS-NC) was investigated. Cellulosic material from oil palm frond leaves (OPFL) were bleached, alkaline treated and acid hydrolyzed to obtain the purified NC and used as nano-fillers in CS. XRD, Raman spectroscopy and optical fluorescence microscopic analyses revealed existence of strong hydrogen bonds between CS and the NC nanofillers. The CRLs were successfully conjugated to the surface of the CS-NC supports via imine bonds that occurred through a Schiff's based mechanism. Process parameters for the immobilization of CRL were assessed for factors temperature, concentration of glutaraldehyde and pH, to afford the highest enzyme activity to achieve maximum conversion of butyl butyrate within 3h of incubation. Conversion as high as 88% was reached under an optimized condition of 25°C, 0.3% glutaraldehyde concentration and buffer at pH7. Thermal stability of CRL/CS-NCs was 1.5-fold greater than that of free CRL, with biocatalysts reusability for up to 8 successive esterification cycles. This research provides a promising approach for expanding the use of NC from OPFL for enhancing enzyme activity in favour of an alternative eco-friendly means to synthesize butyl butyrate.
Thermoplastic cassava starch (TPCS) is a promising alternative material to replace the non-biodegradable petroleum based polymer due to its good environmental-friendly aspect i.e. abundant, sustainable, recyclable and biodegradable in nature. However, TPCS have some limitation such as poor mechanical properties. Therefore, in the present study, cogon grass fibre (CGF) were incorporated into TPCS using compression molding. Then the fundamental properties of CFG/TPCS biopolymer composites were carried out in order to evaluate their potential as a biodegradable reinforcement. From the study it was found that, the incorporation of CFG has improved the tensile and flexural properties of the TPCS composites, while the impact strength and elongation were reduced. The thermal properties of the biocomposite were reduced as the cogon grass fibres increase from 0 to 5%. In term of morphological, SEM shows good fibre adhesion between CGF and TPCS. Soil burial test shows that incorporation of CGF into TPCS has slow down the biodegradation process of the composites. Thus, CGF/TPCS biopolymer composites can be classified as composites with great potential as environmental-friendly material that biodegradable and renewable.
In the current study, changes in secondary metabolite synthesis and the pharmaceutical quality of sabah snake grass leaves and buds were considered in relation to plant age (1 month, 6 months, and 1 year old). The activity of the enzyme chalcone synthase (CHS, EC 2.3.1.74) was measured, as it is a key enzyme for flavonoid production. Significant differences in total flavonoid (TF) production were observed between the three plant growth periods and the different plant parts. The highest contents of TF (6.32 mg/g dry weight [DW]) and total phenolic (TP) (18.21 mg/g DW) were recorded in 6-month-old buds. Among the flavonoids isolated in this study the most important ones based on concentration were from high to low as follows: catechin > quercetin > kaempferol > luteolin. Production of phenolic acids increased from 1 to 6 months, but after 6 months up to 1 year of age, they decreased significantly. The highest contents of caffeic acid (0.307 mg/g DW) and gallic acid (5.96 mg/g DW) were recorded in 1-year and 6-month-old buds, respectively. The lowest and highest activity of CHS was recorded in 1-month and 6-month-old buds with values of 3.6 and 9.5 nkat/mg protein, respectively. These results indicate that the increment in flavonoids and phenolic acids in 6-month-old buds can be attributed to an increase in CHS activity. The highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) activity was observed in the extract of 1-year-old buds followed by 6-month-old buds, with 50% of free radical scavenging (IC50) values of 64.6 and 73.5 µg/mL, respectively. Interestingly, a ferric reducing antioxidant power (FRAP) assay showed a higher activity in 6-month-old buds (488 μM of Fe(II)/g) than in 1-year-old buds (453 μM of Fe(II)/g), in contrast to the DPPH result. Significant correlations (p < 0.05) were observed between CHS enzyme activity and FRAP activity, TF, catechin, and kaempferol content. Extracts of 6-month-old bud exhibited a significant in vitro anticancer activity against HeLa cancer cells with IC50 value of 56.8 µg/mL. These results indicate that early harvesting of snake grass (6-month-old) may yield increased concentrations of secondary metabolites, which are potent antioxidant compounds.