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Mango (Mangifera indica L.) is an important tropical fruit that is grown commercially in many countries of the world. Nowadays, fruit powder is a great alternative source of healthy nutrient and exceptional value-added products. An effective extraction condition can play an important role in minimizing the loss of nutrients, which depends on its perfect selection of effective parameter conditions. In this study, the effects of temperature, the concentration of ethanol, extraction time, and material ratio on the flavonoid contents in mango powder have been investigated. The Response Surface Methodology along with Central Composite Design, was used to get the optimum value of Total Flavonoid Content extracted from mango powder. We have observed from the model that the amount of secondary metabolites (flavonoids) has reached its maxima 501.08 mg QE/100 g extracted at 80oC for 4 h. by using 80% ethanol with a material ratio of 1:1. The accuracy of the developed model was validated by conducting the extraction process of flavonoids in the laboratory using the derived optimum conditions. The experimental value of the total flavonoid content is 498.96 ± 3.45 mg QE/100 g (N = 3), which was very close to the predicted score of the model. This indicates that the model is adequate to optimize the extraction of flavonoids from mango powder.

Arsenic (As) is an environmentally hazardous toxic metalloid. To evaluate As tolerance and assimilation capacity, seedlings of jute (Corchorus capsularis L. var. BJC-7370 and CVE-3), kenaf (Hibiscus cannabinus L. var. HC-95 and HC-3) and mesta (Hibiscus sabdariffa L. var. Samu-93) were grown for 25 days in hydroponic nutrient solution containing four levels of As viz 0, 5, 10 and 15 mg L-1 with four replications. Results were showed that the seedlings of jute, kenaf and mesta were highly potential to tolerate As toxicity. Arsenic had no significant effects on survibility of kenaf, mesta and jute seedlings (var.VE-3). Root and shoot length and dry biomass were decreased with the increasing levels of As. Values of bio-concentration factor indicated the varieties of kenaf, mesta and jute (var.VE-3) were As accumulator. Arsenic accumulation was higher in root than shoot and translocation factor indicated that As is slowly translocated from root to shoot. The rate of translocation is increased with the increasing concentration of As in solution. Highest As contents in shoot (3636.10 mg kg-1) and root (6350.38 mg kg-1) were detected from kenaf HC-3. The highest amount (16.05 mg As pot-1) of As accumulation was also calculated from the variety of kenaf HC-3 with the addition of 45 mg As pot-1. The order of As tolerance and absorption potentiality were kenaf HC-3>mesta Samu-93>jute CVE- 3>kenaf HC-95>jute BJC-7370. These varieties are good cultivar for cultivation and/or phytoremediation of As contaminated environment.

This study aimed to determine the effects of different drying methods on the physicochemical properties of mango powders (Amropali cultivar) and its reconstituted products. Six types of drying methods were employed, which were spray drying (SD), cabinet drying (CD), vacuum drying (VD), tunnel drying (TD), rotary oven drying (RoD) and gas oven drying (GoD). For drying temperature was maintained around 60 to 70°C for all dryers except for SD for which temperature was kept at 150°C. It was found that drying methods affected the physicochemical properties of mango powders (Amropali cultivar) and its reconstituted products. SD and CD powders showed better physicochemical properties (water activity, rehydration, solubility, and porosity) than other mango powder samples. In addition, mango powder produced through SD and CD methods showed lighter color, whereas mango powder prepared using other drying methods showed yellowish, dull, and dark colors. However, reconstituted products of SD and CD powders gave almost similar physicochemical properties compared to other dried samples. The present study concludes that SD powder and CD powder are more preferable in terms of producing high-quality products compared to other drying techniques.

Nanocomposites of carbon and molybdenum disulfide have attracted much attention due to their significant potential in energy conversion and storage applications. However, the preparation of these 0-D MoS2/carbon composites with controllable structures and desirable properties remains a major manufacturing challenge, particularly at low cost suitable for scaling-up. Here, we report a facile solution-based method to prepare porous hierarchical 0-D MoS2/carbon nanocomposites with vertical MoS2 growth on a hollow carbon support, suitable for the electrochemical storage of lithium and sodium ions. The vertically aligned MoS2/hollow carbon material shows excellent performance in the storage of a series of alkali-metal ions (e.g. Li+, Na+, and K+) with high capacity, excellent rate capacity, and stable cyclability. When used for the storage of Li+ ions, it possesses a high capacity of over 800 mA h g−1 at a rate of 100 mA g−1, with a negligibly small capacity decay as low as 0.019% per cycle. At a substantially higher rate of 5 A g−1, this MoS2/carbon nanocomposite still delivers a capacity of over 540 mA h g−1, showing its excellent performance at high rates. Remarkably, this material uniquely delivers high capacities of over 450 mA h g−1 and 300 mA h g−1 for Na+ and K+ ion storage, respectively, which are among the highest values reported to date in the literature. These excellent characteristics confirm the hollow MoS2/carbon nanocomposites to be a primary contender for next generation secondary batteries.

Determination of Mercury in Biological Sample in Muar River Estuary, West Johor, Malaysia. This study was carried out at the Estuary of Muar River, west Johor, Malaysia. Different types of biota species namely Crassostrea irredalei, Perna viridis and Anadara granosa were collected all through the torrential rainy season in November 2005. These biota species were dried and then cooked in an acid solution for Cold Vapour Atomic Absorption Spectrometric (CV-AAS) analysis. CV-AAS) was used for decisive the mercury (Hg++) concentration in the collected biota species. The average Hg++ concentration in C. irredalei, P. viridis and A. granosa were 1.854 ± 1.012 μg g-1, 0.336 ± 1.125 μg g-1 and 1.178 ± 1.182 μg g-1 respectively. These results directed that the biota especially C. irredalei and A. granosa are contaminated by Hg++ and these are not safe to be consumed for publicly used due to the total Hg++ concentration exceeding 0.5 μg g-1 according to WHO.

An attempt was made to assess the status of heavy metals in the Bangshi River water for irrigation usage. River water was sampled from 20 sampling points for chemical analysis of physicochemical parameters and metal ions. Our analyses revealed that water samples were slightly alkaline to alkaline. All samples had reasonable electrical conductivity, and these samples were from low to medium salinity classes as being fit for irrigation on soils having moderate level of permeability. Water samples were categorized freshwater as per total dissolved solids (TDS). All water samples were excellent indicating low alkalinity hazard, based on sodium adsorption ratio (SAR), but most of the samples were doubtful to unsuitable for soluble sodium percentage (SSP). All samples were free from residual sodium carbonate (RSC) suggesting suitability for irrigation purpose. For water hardness, samples were rated as moderately hard, hard, and very hard. The status of Fe, Zn, Pb, Cd, and Ni in water samples were within permissible levels but Cr, Cu, and Mn content in water samples were in excess of recommended limits and these ions would be considered toxic in long-term irrigation system. Significant relationships existed between EC versus TDS, SAR versus SSP, SSP versus RSC, and SAR versus RSC. There were significant correlations between metal ions: Fe–Cu, Fe–Pb, Cu–Pb, Fe–Mn, Cu–Mn, and Mn–Pb. This finding showed that Cr, Cu, and Mn ions were considered contaminants in river water used for irrigation because the present status of these metals may pose a harmful impact on human health.

The aim of the present study was to evaluate the degree of metal contamination of the Turag River water and its suitability for irrigation. Twenty water samples were analyzed for physic℃hemical parameters and metals viz., calcium, magnesium, potassium (K), sodium, copper (Cu), zinc (Zn), iron (Fe), manganese (Mn), lead (Pb), cadmium (Cd), chromium (Cr), and nickel (Ni). All water samples were slightly alkaline to alkaline. Regarding electrical conductivity (EC), all samples were suitable for crop in soils with moderate permeability and leaching. Water samples were medium salinity and low alkalinity hazard classes. In terms of total dissolved solids (TDS), all samples were classified as freshwater. As per sodium adsorption ratio (SAR) and soluble sodium percentage (SSP), all samples were classified as excellent. No residual sodium carbonate (RSC) was detected in any of the samples, indicating suitability for irrigation; and all samples were considered very hard. Cr and Mn contents in all samples were above FAO guideline values and, therefore, these metals were considered toxic. Zn, Cu, Pb, Cd, and Ni concentrations were below acceptable limit for irrigation and do not pose a threat to soil environment. Significant relationships were found between EC and TDS, SAR and SSP, SAR and RSC, and SSP and RSC. The combinations of ions such as K.Zn, K.Fe, K.Cu, K.Mn, K. Pb, Zn.Fe, Zn.Cu, Zn.Mn, Fe.Mn, Cu.Mn, Cu.Pb and Mn.Pb exhibited significant correlation. This study revealed that Turag River water samples are contaminated with Cr and Mn. This fact should not be ignored because water contamination by metals may pose a threat to human health through food chain.

A pot experiment was conducted to investigate the yield and nutrient content of tomato ( Lycopersicon esculentum ) as influenced by the application of vermicompost and chemical fertilizers. The experiment was laid out in a completely randomized design (CRD) with 3 replications and comprised of 8 treatments viz. , T 1 - control, T 2 - recommended dose of NPK fertilizers (CF), T 3 - vermicompost @ 5 t ha -1 (VC 1 ), T 4 - vermicompost @ 10 t ha -1 (VC 2 ), T 5 - VC 1 + 50% CF, T 6 - VC 1 + 75% CF, T 7 - VC 2 + 50% CF and T 8 - VC 2 + 75% CF. Application of vermicompost @ 10 t ha -1 along with 50% chemical fertilizers showed the best performance for plant height, number of leaves plant -1 , number of flowers branch -1 , number of fruits branch -1 , number of fruits plant -1 , fruit size and yield of tomato. Vermicompost treated soils significantly contributed the highest contents of sugar, pH, N, P, K, Ca, Mg, S, Zn & B in tomato, influenced nutrient status of the postharvest soil and conserved more organic C, N, P, K, Ca, Mg, S, Zn & B contents over control. However, soluble solids and vitamin C content in tomato were not significantly influenced by the application of vermicompost and chemical fertilizers. Results of the study demonstrate that the combined application of vermicompost and chemical fertilizers would help to maintain the long-term soil productivity for sustainable tomato cultivation. J. Environ. Sci. & Natural Resources, 8(2): 115-122 2015

The study was carried out using seven varieties of jute, two varieties of kenaf and one variety of mesta to evaluate their germination potential to chromium (Cr) toxicity. Percent germination and primary growth parameters of these varieties in Cr contaminated medium were observed. Six levels (0, 20, 40, 80, 120 and 160 mg Cr L-1) of Cr were applied in artificial germinating medium following CRD with three replication. All the jute, kenaf and mesta varieties showed decreasing trend of germination with increasing levels of Cr. Germination of kenaf (HC-95 and HC-3), mesta (Samu-93) and jute (CVE-3 and BJC-7370) were satisfactory levels up to 160 mgCr L-1. The root and shoot lengths and fresh and dry weights also reduced with increased concentrations of Cr as the toxic effect of Cr retards the growth of meristematic tissues of young roots and shoots. Morphological deformities like twisting, curling of leaves and shoot and rottening of roots appeared at high concentrations of Cr. Due to receiving higher concentrations of Cr the color of the roots became dark brown to black. The potentiality of the varieties to Cr toxicity were kenaf HC-95 > kenaf HC-3 > mesta Samu-93 > jute CVE-3 and > jute BJC- 7370. The findings of the present study can be applied for sowing kenaf, mesta and jute seeds in Cr contaminated soil.J. Environ. Sci. & Natural Resources, 8(1): 51-57 2015

Multivariate analysis of thin-layer chromatography (TLC) images was modeled to predict antioxidant activity of Pereskia bleo leaves and to identify the contributing compounds of the activity. TLC was developed in optimized mobile phase using the ‘PRISMA’ optimization method and the image was then converted to wavelet signals and imported for multivariate analysis. An orthogonal partial least square (OPLS) model was developed consisting of a wavelet-converted TLC image and 2,2-diphynyl-picrylhydrazyl free radical scavenging activity of 24 different preparations of P. bleo as the x- and y-variables, respectively. The quality of the constructed OPLS model (1 + 1 + 0) with one predictive and one orthogonal component was evaluated by internal and external validity tests. The validated model was then used to identify the contributing spot from the TLC plate that was then analyzed by GC-MS after trimethylsilyl derivatization. Glycerol and amine compounds were mainly found to contribute to the antioxidant activity of the sample. An alternative method to predict the antioxidant activity of a new sample of P. bleo leaves has been developed. Copyright © 2015 John Wiley & Sons, Ltd.

Supercritical fluid extraction (SFE) of Pereskia bleo leaves was carried out with systematic experimental study to screen and optimize the factors affecting yield and antioxidant activity. Initially, five factors were studied by Plackett–Burman study to screen the most influential factors. Consequently, three significantly affecting factors were optimized by Box–Behnken study. At the optimum condition (52 °C, 36 MPa and 1.5% ethanol of total CO2) yield and IC50 value obtained by SFE were higher than water extract and lower than methanol extract. GC–MS analysis showed that the ethanol modified supercritical carbon dioxide has increased efficiency for extracting antioxidant compounds, α-tocopherol, β-sitosterol and erythritol.

Total 54 fertilizer samples were randomly collected from the markets of four districts ofBangladeshto assess nutrient and heavy metal (Cd, Cr & Pb) contents in different fertilizers. The chemical analyses of fertilizers were conducted at the Department of Agricultural Chemistry,BangladeshAgriculturalUniversity, Mymensingh. Nutrient status of fertilizers was determined using the standard procedures and heavy metals in the fertilizer extract were analyzed using Atomic Absorption Spectrophotometer (AAS). Nitrogen (N) content in urea collected from different areas ranged from 41.37 to 46.27%. Biuret content of the collected urea samples varied from 1.40 to 2.80%, where the maximum allowable limit (MAL) is 1.50%. Among the six urea samples, biuret content exceeded the MAL in five samples. Phosphorous (P) content in most of the triple superphosphate (TSP) samples was higher than the specified amount. Out of eight samples, only two samples contained less than 20% P. Out of eight diammonium phosphate (DAP) samples, only three samples contained lower amount of P than the specified amount and five samples contained lower amount of N than the specified amount. Chromium content in all theDAPsamples were much higher than the MAL. Potassium (K) content in all five collected muriate of potash (MoP) samples were lower than the specified amount with an average of 45.81% K. The concentration of sulphur (S) in fertilizer samples in the investigated area varied from 16.50 to 21.60%. Out of six magnesium sulphate samples, five samples contained lower than the specified amount (9.5%) of Mg. The concentration of boron (B) in solubor samples varied from 13.55 to 19.56%, which are lower than the standard limit (20.90%). The concentration of zinc (Zn) in all the collected zinc sulphate heptahydrate samples had lower amount of Zn than the standard limit (23%). Only one out of six collected copper sulphate samples, met the specified limit of Cu (25.40%). Total 42 fertilizer samples (77.80%), out of 54, had less than the specified amount of nutrients. Heavy metals like Pb and Cr content exceeded the MAL in 67% and 47% of collected fertilizer samples, respectively. Cadmium content was below the detectable limit of flame in AAS in all the samples. In order to minimize the impact of fertilizer adulteration on food security and safety, continuous monitoring of fertilizer quality is required.J. Bangladesh Agril. Univ. 15(2): 219-225, December 2017

Pereskia bleo is a species of primitive cactus. In the present study, infrared spectroscopy was used to characterize the antioxidant activity of P. bleo leaves by multivariate analysis. A total of twenty-four extracts were prepared in different solvents. Antioxidant activities were measured by 1,1-diphenyl-2-picrylhydrazyl assay and fingerprinted by infrared spectroscopy between 4000 and 400 cm−1 at a resolution of 2 cm−1. A three component multivariate orthogonal partial least squares model with R2Y of 0.88 and Q2 of 0.86 was developed to correlate infrared spectra with antioxidant activity and evaluated by internal cross-validation and a true external test. For external validation, bioactivity of new extracts of P. bleo was predicted using the model, and -OH, -NH, and -CH were identified as functional groups responsible for the activity. In summary, a successful orthogonal partial least squares model was developed using infrared spectroscopy as a rapid method to predict antioxidant activity.

An attempt was made to assess metal ionic toxicity levels of different fishes in the polluted rivers viz., Buriganga and Turag. Fish samples collected from two polluted rivers were analyzed for the levels of metals such as Cd, Cr, Cu, Mn, Pb, and Zn in order to elucidate the status of these contaminants in fish meant for human consumption. The detected concentrations of Cr, Cu, Mn, and Zn ions in fish species collected from the polluted rivers were below the toxic levels and did not appear to pose a threat. Among the analyzed metals, Cd and Pb ions were detected above the permissible levels in liver and muscle tissues of stinging catfish (Heteropneustesfossilis), spotted snakehead (Channapunctata) and wallago (Wallagoattu) collected from the polluted rivers causing toxicity for human consumption. Stinging catfish (Heteropneustesfossilis) was the species found to highly bioaccumulate these metals. Fish species bioconcentrated appreciable amounts of Cd and Pb as toxic metals in the liver as compared to the muscle. Levels of these toxic metals varied depending on different tissues in fish species.

Phaleria macrocarpa (Mahkota dewa) seed was examined to determine the optimal conditions of oil yield by solvent extraction method using n-hexane as extracting solvent. Response surface methodology (RSM) was employed to describe explicitly the influence of extraction time, temperature and solvent-to-feed ratio on the yield of oil using central composite design (CCD). The linear, quadratic and interaction terms of the studied variables have significant (P < 0.05) effect on the oil yield. The temperature of 72 °C, extraction time of 8.4 h and solvent-to-feed ratio of 10.9 ml/g were the optimal conditions for seed oil extraction. The maximum oil yield was 55.32 g/100 g dry weight under these optimal conditions. Main chemical constituents of oil were determined by Gas chromatography–mass spectroscopy (GC–MS) and Fourier transform infrared spectroscopy (FTIR). Twelve components were identified by GC–MS analysis after formation of fatty acid methyl ester (FAME). Total saturated fatty acids were 19.38% whereas monounsaturated fatty acids and polyunsaturated fatty acids were 44.23% and 36.38%, respectively. Oleic acid, 18:1 (43.56%) and linoleic acid, 18:2 (36.25%) were the main fatty acid constituents of Mahkota dewa seed oil. The quantity of unsaturated fatty acids was higher than saturated fatty acids in P. macrocarpa seed oil.

In this study, we introduce a novel all-polymer battery system based on conducting polymer (polypyrrole, PPy) doped with dopants of para (toluene sulfonic acid) ( p TS) and indigo carmine (IC), respectively. The performance of the systems consisting of polypyrrole–para (toluene sulfonic acid) (PPy– p TS) as cathode and polypyrrole–indigo carmine (PPy–IC) as anode in conjunction with either a polymer based electrolyte or a commercial organic electrolyte of 1M LiPF 6 in a 50:50 (v/v) mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC) was evaluated. In the system, all the free-standing PPy– p TS and PPy–IC films were directly used without needing any metal substrate support to hold the electro active material. Electrochemical measurements demonstrated that the PPy– p TS/PPy–IC (commercial electrolyte) system exhibited a reversible discharge capacity of 36 mAh g −1 at 0.05 mA cm −2 after 50 cycles, is 92% of the initial discharge capacity. In the case of PPy– p TS/PPy–IC (polymer electrolyte), the reversible discharge capacity after 50 cycles was 16 mAh g −1 , 76% of the intial discharge capacity. This work deals with the fabrication of a novel all polymer battery system, with significant advantages in terms of capacity and reasonable stability. This may lead to a future generation of all polymer batteries that are suitable for implanted medical devices used in biological and biomedical systems.

In this investigation, the synthesis strategy is involved the creation of LiFePO4–Fe2P–C composites with a porous conductive architecture, which includes distinct regions or clusters containing antiferromagnetic LiFePO4 in close proximity to ferromagnetic Fe2P. The microstructure is achieved by using a simple ultra-fast solvent assisted manual grinding method, combined with solid state reaction, which can replace the time-consuming high energy ball milling method. The crystalline structure, morphology, and electrochemical characterization of the synthesised product are investigated systematically. The electrochemical performance is outstanding, especially the high C rate. The composite cathode is found to display specific capacity of 167 mAh g−1 at 0.2 C and 146 mAh g−1 at 5 C after 100 cycles, respectively. At the high current density of 1700 mA g−1 (10 C rate), it exhibits long-term cycling stability, retaining around 96% (131 mAh g−1) of its original discharge capacity beyond 1000 cycles, which can meet the requirements of a lithium-ion battery for large-scale power applications. The obtained results have demonstrated that the fabrication of samples with strong and extensive antiferromagnetic and ferromagnetic interface coupling of LiFePO4/Fe2P provides a versatile strategy toward improving the electrochemical properties of LiFePO4 materials and also opens up a new window for material scientists to further study the new exchange bias phenomenon and its ability to enhance the electrochemical performance of lithium-ion battery electrode.

Microporous poly(vinylidene fluoride)/poly(methyl methacrylate) (PVDF/PMMA) membranes were prepared using the phase-separation method. Then, the membranes were immersed in liquid electrolyte to form polymer electrolytes. The effects of PMMA on the morphology, degree of crystallinity, porosity, and electrolyte uptake of the PVDF membrane were studied. The addition of PMMA increased the pore size, porosity and electrolyte uptake of the PVDF membrane, which in turn increased the ionic conductivity of the polymer electrolyte. The maximum ionic conductivity at room temperature was 1.21 × 10−3 S cm−1 for Sample E70. The polymer electrolyte was investigated, along with lithium iron phosphate (LiFePO4) as cathode for all solid-state lithium-ion rechargeable batteries. The lithium metal/E70/LiFePO4 cell yielded a stable discharge capacity of 133 mAh g−1 after up to 50 cycles at a current density of 8.5 mA g−1.

Thermal and acid wash treatment of rice husk has been conducted 550 to 600 °C in air atmosphere and chemical treatments consisted of acid, H2SO4. Purity, pore size distribution, FT-IR and SEM micrographs of treated and non-treated samples are presented. In this study the acid treated rice husk ash was used as SiO2 source in the preparation of zeolite Y, a medium siliceous zeolite used as an ion exchanger in water treatment process. Obtained zeolite Y, BET Surface area 621.18 square meters per gram, pore volume is 0.33 cubic centimeters per gram and its average pore diameter is 21.222 Å. Ion-exchange capacities were tested through a column packed in zeolite Y by the artificially polluted water filtration, filtrate was analysed by ICP-MS and elements (As, Ba, Ca, Cd, Co, Cr, Bi, Be, Pb Ni etc.) in filtered waters was found in negative amounts. Zeolite Y is found a highly efficient ion-exchange material. So, mini water filtering system is a good for water treatment, even water is highly polluted by toxic elements.

A simple and less expensive solvent extraction method was used with inductively coupled plasma mass spectrometry (ICP-MS) in the speciation of two environmentally significant, toxic forms of arsenic: arsenite and arsenate. Dissolved inorganic arsenic species in drinking waters from reservoirs and treatment plants were determined by the inductively coupled plasma mass spectrometry analyses. Prior to the analysis the water samples were precocentrated by solvent extraction using APCDT to separate the arsenic species from elemental interferences. The detection limit of this method achieved was 0.059 gL-1. The suitability of the technique in this work is discussed in relation to risk assessment studies of public health.

Mercury concentrations and speciation were determined in surface water samples taken from rivers in the vicinity of industrial area, in Johore Malaysia. Samples were collected from the same sites before and immediately after rainfall. The aim of this study is to assess the influence of seasonal change in river water on the concentration of mercury (Hg) species. Trace concentrations of mercury in water samples were determined by a method involving a simple and rapid procedure involving the flow-injection inductively coupled plasma mass spectrometry (FI-ICP-MS) and graphite furnace atomic absorption spectrometry (GFAAS) techniques. Mercury vapor, generated by sodium borohydride as the reductant, was stabilized by potassium dichromate (K2Cr2O7), then released by controlled heating and detected by FI-ICP-MS. Methyl mercury (II) was preconcentrated using the ammonium pyrolidindithiocarbamate (APDTC)-chloroform extraction procedure and the chloroform extract was introduced into the graphite tube. The absolute detection limits were found to be 0.204 μg L-1 and 0.273 μg L-1 for total mercury and methyl mercury respectively, with thevariability being lower than 5% relative standard deviation (RSD) at the 5 μg L-1 level. Because of the high stability of MeHg (II)-APDTC complexes, it is possible to evaporate the extract in order to obtain a crystalline powder to be dissolved with a few micro liters of chloroform enacting MeHg (II) and Hg (II) can be detected at sub-nanogram levels.

Nickel oxide–polypyrrole (NiO–PPy) composites for lithium-ion batteries were prepared by a chemical polymerization method with sodium p-toluenesulfonate as the dopant, Triton-X as the surfactant, and FeCl3 as the oxidant. The new composite material was characterized by Raman spectroscopy, thermogravimetric analysis, scanning electron microscopy, and field-emission scanning electron microscopy. Nanosize conducting PPy particles with a cauliflower-like morphology were uniformly coated onto the surface of the NiO powder. The electrochemical results were improved for the NiO–PPy composite compared with the pristine NiO. After 30 cycles, the capacities of the NiO and the NiO–PPy composite were about 119 and 436 mAh·g−1, respectively, indicating that the electrochemical performance of the composite was significantly improved.

This work introduces an effective, inexpensive, and large-scale production approach to the synthesis of a carbon coated, high grain boundary density, dual phase Li4Ti5O12-TiO2 nanocomposite anode material for use in rechargeable lithium-ion batteries. The microstructure and morphology of the Li4Ti5O12-TiO2-C product were characterized systematically. The Li4Ti5O12-TiO2-C nanocomposite electrode yielded good electrochemical performance in terms of high capacity (166 mAh g−1 at a current density of 0.5 C), good cycling stability, and excellent rate capability (110 mAh g−1 at a current density of 10 C up to 100 cycles). The likely contributing factors to the excellent electrochemical performance of the Li4Ti5O12-TiO2-C nanocomposite could be related to the improved morphology, including the presence of high grain boundary density among the nanoparticles, carbon layering on each nanocrystal, and grain boundary interface areas embedded in a carbon matrix, where electronic transport properties were tuned by interfacial design and by varying the spacing of interfaces down to the nanoscale regime, in which the grain boundary interface embedded carbon matrix can store electrolyte and allows more channels for the Li+ ion insertion/extraction reaction. This research suggests that carbon-coated dual phase Li4Ti5O12-TiO2 nanocomposites could be suitable for use as a high rate performance anode material for lithium-ion batteries.

The remediation of water contaminated with herbicide oxadiazon was investigated by applying modified Fenton reagent (Fe3+/H2O2) at unadjusted pH. Experimental conditions in various reactions allowed for the disappearance of oxadiazon. When using Fenton reagent, the maximum degradation rate was obtained under exposure to UV irradiation as compared to dark condition in which the concentrations of ferric ion and hydrogen peroxide were 3 and 100 mM, respectively. After 5 h of photocatalytic treatment with Fenton reagent, 98.4% of the oxadiazon was degraded. The high degradation rate of this herbicide was achieved by hydroxyl radicals (OH.), which were generated by the photocatalytic treatment. UV irradiation accelerated the degradation of oxadiazon in the water system in the presence of Fenton reagent. In addition, the disappearance of oxadiazon was enhanced due to the increased concentrations of ferric ion and/or hydrogen peroxide. For the photo-Fenton reaction, one metabolite (m/z 310) was able to be identified using the GC-MS technique due to dechlorination of oxadiazon. Conclusively, a remediation strategy using Fenton reagent could be applied to degrade oxadiazon from contaminated water.

A comparative study was performed to evaluate the removal efficiency of herbicide, oxadiazon as an organic contaminant in treatment processes for drinking water. In this investigation, three major treatment processes such as chlorination, ozonation and activated carbon treatment were applied separately to water system. The level of oxadiazon gradually decreased to 28%, when chloride as a disinfectant was applied to the water supply. Activated carbon treatments showed that this herbicide was removed efficiently from the aqueous solution. The results indicated that the performance of powdered activated carbon was more effective than granular activated carbon in terms of adsorption. The adsorption isotherms exhibited an excellent agreement with the experimental data and they were also well represented by the Langmuir and Freundlich equations, indicating the higher adsorption capacity for activated carbons. During ozone treatment, 50% of oxadiazon was removed but this removal was enhanced by the presence of hydrogen peroxide. The association of ozonation with chloride and activated carbon treatments was considered to be the best-tested treatment for drinking water production. Therefore, if oxadiazon enters into the water ecosystem as an organic contaminant, it could be removed effectively by the drinking water treatment processes.

Anatase TiO2 nanoribbons/nanotubes (TiO2-NRTs) have been synthesised successfully via a reflux method followed by drying in a vacuum oven, and then, silver-coated TiO2 NRTs (Ag/TiO2-NRTs) were prepared by coating silver particles onto the TiO2-NRTs surface by the traditional silver mirror reaction. The physical properties of the synthesised products were examined in detail using X-ray diffraction, field emission gun scanning electron microscopy, energy-dispersive X-ray spectroscopy, and transmission electron microscopy, respectively. The results indicated that the Ag nanoparticles were uniformly deposited on the surface of the TiO2 nanoribbons/nanotubes. The electrochemical properties were investigated by a variety of techniques. The rate capability and cycle durability for the Ag/TiO2-NRTs were improved compared with TiO2-NRTs. It is speculated that the Ag-coated TiO2 nanoribbons/nanotubes are an effective anode candidate for lithium ion batteries.

A simple and sensitive method for the determination of some metalloids and heavy metals in water samples is presented. The method is based on the preconcentration of the attachment of chelating functionalities with metalloids and toxic metals irreversibly and targeted towards toxic metals adsorbed on modified activated carbon, activated carbon and red soil particles at pH 3.0–9.0±0.2, followed by quantitative determination using instrumental neutron activation analysis (INAA), on the absorbers. Attachment results from attraction that may be physical, chemical, electrical, or a combination of all three. The efficient removal of metalloids and toxic metals, especially arsenic, chromium and mercury is anticipated. The adsorption capacity of the chemically modified activated carbon materials was evaluated for the above mentioned metalloid and toxic metal ions in the presence of iron ions and simulated water samples. Red soil particles containing iron was utilized in the control of oxidation-reduction reaction with metalloids and toxic metals. The preconcentration of the elements of interest on red soil particles, activated carbon and modified activated carbon at different depths, pH and oxidation states was investigated. The results obtained showed good agreement with certified values giving relative errors of less than 10%.

Flow-through column experiments were carried out to investigate the influence of pH on the sorption of three phenols (2-methyl-4, 6-dinitrophenol, 2, 4, 6-trichlorophenol, pentachlorophenol) onto a natural sandy aquifer material collected from a bank filtration site of River Elbe, Germany. For the phenols investigated, an increase in sorption (retardation) with decreasing pH is observed indicating a stronger sorption of the neutral species in comparison to that of the anions formed by dissociation. The anions of 2-methyl-4, 6-dinitrophenol and 2, 4, 6-trichlorophenol do not show significant sorption. On the contrary, pentachlorophenol showed sorption not only in neutral form but also in ionic form significantly which should be taken into account while assessing the fate and transport of such compound. A linear model based on the degree of protonation (calculated from pH and pKa) can be used to resolve the apparent (observed) sorption coefficient (Kd, app) into its neutral (Kd, n) and ionised (Kd, i) components. Knowing pKa, Kd, n, and Kd, i the apparent sorption coefficient for pH values other than experimentally investigated can be predicted. Sorptionsverhalten von Phenolen an sandigem Aquifermaterial: Saulenversuche zum Einfluss des pH-Wertes Mit Hilfe von Saulenversuchen wurde der Einfluss des pH-Wertes auf die Sorption von drei Phenolen (2-Methyl-4, 6-dinitrophenol, 2, 4, 6-Trichlorphenol, Pentachlorphenol) an sandigem Aquifermaterial einer Uferfiltrationsstrecke an der Elbe untersucht. Fur alle untersuchten Phenole wurde ein Anstieg der Sorption (Retardation) mit fallendem pH-Wert beobachtet, was auf eine starkere Sorption der neutralen Teilchen im Vergleich zu den durch Dissoziation entstehenden Anionen hinweist. Die Anionen von 2-Methyl-4, 6-dinitrophenol und 2, 4, 6-Trichlorphenol zeigen keine signifikante Sorption. Fur Pentachlorphenol konnte dagegen nachgewiesen werden, dass nicht nur die neutrale, sondern auch die ionische Form sorbiert wird, was bei der Bewertung des Transportverhaltens zu berucksichtigen ist. Zur Aufteilung des scheinbaren (summarischen) Sorptionskoeffizienten (Kd, app) in seinen neutralen (Kd, n) und ionischen Anteil (Kd, i) kann ein Modell auf der Basis des Protonie rungsgrades (berechnet aus pH und pKa) verwendet werden. Sind pKa, Kd, n und Kd, i bekannt, lasst sich der scheinbare Sorptionskoeffizient fur andere als die experimentell untersuchten pH-Werte vorausberechnen.

A new filtering column has been developed on the covalent attachment of chelating functionalities to simple, highly hydrophilic adsorbent material, which can then complex heavy metal ions irreversibly and targeted towards toxic metals removal. The capacity of the chemically modified sorbent (modified charcoal) materials used in this work was evaluated for the above mentioned heavy metal ions in the presence of iron ions and simulated water samples. The methods are based on preconcentrations of the elements of interest on activated carbon and zirconium loaded activated carbon using specific conditions of pH and oxidation states followed by a final determination by neutron activation analysis (NAA). It has been investigated that zirconium loaded activated carbon is able to adsorb As (V), Se (VI), Cr (VI) and Hg (II) at any pH while activated carbon is able to adsorb As (III), Se (IV), Cr (III) and Hg(I) at higher pH.

Background: Salacca zalacca or better known as salak fruit is widely distributed in tropical and subtropical countries, and it is traditionally used to treat diabetes. This study was aimed to investigate the salak peel extracts for their biological and chemical activities. Also, the chemical profile of the most promising extract was analysed on gas chromatography- mass spectrometry (GC-MS). Materials and Methods: The peel extracts were prepared by maceration process at room temperature with different ratio of ethanol/water. All the extracts were determined for their α-glucosidase inhibitory activity using α-glucosidase enzyme. The antioxidant activities of the extracts were determined through their Ferric reducing antioxidant power assay (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH). The chemical constituents of salak peel extracts were analysed using gas chromatography–mass spectrometry (GC MS). Results: Phytochemical screening showed the presence of phenolic and flavonoid contents in all the extracts. About 100% ethanol extract shows the highest phenolic content (116.70 ± 0.764 μg/mL) while 60% ethanol extract has the lowest content 18.65 ± 1.155 μg/ml using gallic acid as a reference. 100% ethanol extract was observed to exhibit highest radical scavenging, ferric reducing antioxidant power (FRAP), and α-glucosidase inhibitory activities (IC50: 49.45 ± 3.87 μg/mL, 144.81 ± 3.72 μg AAE/g, IC50: 11.62 ± 0.67b μg/mL), respectively. Water extracts had the lowest FRAP, radical scavenging activity as well as α-glucosidase activity. The phytochemical investigation on GC-MS showed the presence of active compounds in salak fruit peel extracts. Conclusion: Salak fruit peels showed the highest antioxidant as well as α-glucosidase inhibitory activities. Phytochemical analysis on GC-MS confirms the presence of gallic acid, linoelaidic acid, palmitic acid, α-tocopherol, and steric acid which may contribute to α-glucosidase inhibitory activity. Abbreviations Used: GC-MS: Gas Chromatography–Mass Spectroscopy; FRAP: Ferric reducing antioxidant power assay; TPTZ: 2,4,6-tris (2-pyridyl)-s-triazine; DPPH: 2,2-diphenyl-1-picrylhdroxyl; MSTFA: N-methyl-N-(trimethylsilyl)-trifluoroacetamide; TPC: Total phenolic content; DMSO: Dimethyl sulfoxide; ANOVA: Analysis of variance.

Nonlinear sorption of hydrophobic organic pollutants in soils and sediments can be described by a combination of partitioning and adsorption (pore- filling) mechanisms. Both the partitioning and the pore-filling models plot sorptive uptake vs. solubility-normalized aqueous concentrations, which yields "collapsing" sorption isotherms for similar compounds. With this new concept, sorption of a variety of similar compounds could be predicted based on measured data of one probe chemical. The solubility-normalized Freundlich model predicts an inverse linear relationship between the sorption coefficient measured at a given relative concentration vs. solubility, S, which is demonstrated for 3 partitioning dominated samples from Bangladesh (soil, aquifer sediment, peat) and 4 compounds (carbofuran, trichloroethene, 1,2-dichlorobenzene, phenanthrene) as well as for 2 activated carbons (F300, F400), and a wide variety of compounds (literature data). Future research will focus on the improvement of prediction of sorption in soils and sediments by including other normalization parameters, such as molar volume, polarizability, etc., in addition to the water solubility.

[1] Preferential solute transport coupled with diffusion into the surrounding matrix region has been examined in a silty loam soil by conducting macropore column experiments for various hydrophobic organic compounds (phenanthrene, 1, 2-DCB, TCE, carbofuran) representing the polycyclic aromatic hydrocarbons, chlorobenzenes, chlorinated solvents, and pesticides. A new and ready-to-use analytical solution was developed for this setting to model the breakthrough curves. The model accounts for advection in the macropore region, diffusion into the matrix region, and linear sorption in both regions. In this setting, hydrodynamic dispersion is negligible as proved by a comparison of an advection-dispersion model of finite pulse input. Conservative tracer experiments were predicted very well with independently determined transport parameters except for the tortuosity factor, which was used as a fitting parameter for the pore diffusion coefficient in the matrix. In case of sorbing solutes the sorption coefficient (Kd) was used as additional fitting parameter. The fitted Kd was 65% smaller for less sorbing compounds, e.g., carbofuran, and 80% less for strongly sorbing compounds, e.g., phenanthrene compared to the independently determined Kd from batch experiments. This indicates that sorption equilibrium was not obtained completely during the matrix diffusion at the timescale of the macropore flow experiment.

While the pH effect on sorption equilibrium of weak acids on natural sorbents was investigated in a number of studies, less is known about the pH dependence of sorption kinetics. This paper investigates the impact of pH on sorption kinetics during the transport of some selected phenols through a sandy aquifer material. Breakthrough curves measured in column experiments were analyzed using a mass transfer based nonequilibrium model designated as dispersed flow, film and particle diffusion model (DF-FPDM). In this model, the rate limiting intraparticle diffusion is characterized by the mass transfer coefficient, k S a V , which can be determined from breakthrough curves by curve fitting. The experimental results indicate that the k S a V is pH-dependent and inversely correlated with the pH-dependent distribution coefficient, K d,app . Regression equations are presented that may be used to estimate approximate values of intraparticle mass transfer coefficients on the basis of experimentally determined or LFER predicted distribution coefficients.

Highly flexible, paper-like, free-standing V2O5 and V2O5–polypyrrole (PPy) films were prepared via the vacuum filtration method. The films are soft, lightweight, and mechanically robust. The electrochemical performance of the free-standing pure V2O5 electrode was improved by incorporating conducting polypyrrole. A bendable cell with a novel design was fabricated, consisting of a free-standing V2O5–PPy cathode film, gel electrolyte, and a lithium foil anode. The cell was tested under repeated bending conditions for several cycles. The results show that the battery performance of the repeatedly bent cell was similar to that of the conventional cell.

Complexometric methods for the determination of yttrium and the lanthanons in oxalate precipitates are investigated. In the method recommended, excess EDTA is added to a suspension of the oxalate, and solution is effected at pH 10 with ammonia-ammonium chloride buffer. The excess EDTA is titrated with standard zinc solution to the blue to red colour change of Eriochrome Black T indicator. It is more convenient, and generally more satisfactory, than the method previously suggested, in which magnesium is the back-titrant at pH 10.2 to 10.5. Both of these methods are superior to the back-titration with lanthanum using Arsenazo as indicator at pH 8 to 9 in the presence of oxalate, and more convenient than methods in which the oxalate is removed by wet oxidation before titrating directly with EDTA. The zinc titration method is particularly suitable for chemical-yield measurement in radiometric determinations of yttrium and lanthanons precipitated as oxalates for “counting” purposes.

A comparison is made of a number of direct complexometric titrations previously published for the determination of yttrium and the lanthanons. Working and ‘optimum’ pH ranges are obtained for what are considered to be the best indicators. Alizarin Red S screened with Methylene Blue, Erioehrome Black T, Copper-Naphthyl Azoxine and Xylenol Orange. The precision and accuracy of the selected methods are determined by carrying out replicate titrations on standard solutions of ceriumIII, yttrium and ytterbium. The results, together with additional observations made on the behaviour of indicators in the different methods, suggest that Xylenol Orange at pH 5.8 to 6.4 is most satisfactory and convenient for direct titrations.