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The agriculture waste material can give benefit to many production industries. The studied crop is corn (Zea Mays)stalk. The objective of this work was to analysis the chemical composition; to study chemical pulping and papermaking properties of corn stalk and; to investigate the fiber morphology of properties of those crops. Firstly, the chemical composition of corn stalk were determined and compared with other non-woods. After that, chemical corn stalk was conducted in this analysis followed the physical and mechanical properties. The result showed that, corn stalk have cellulose (39.0%) and lignin content is the lowest (7.3%) content rather than other composition. In chemical pulping, reached high pulp yields had been produced and the strength properties: tear index, tensile index, burst and fold verified that they were of an acceptable quality for papermaking. This crop morphology was observed by Scanning Electron Microscopic (SEM), which showed a condensed composition of fiber structure. This study can developed a friendly product and promote the green technology, suitable to be used as an alternative pulp in paper making industry.Keywords:Fiber, Corn stalk, Composition, Green technology, Pulp and paper making.

The aim of this study was to study the morphology and structural characteristic of NCC hydrolyzed from filter paper. The NCCs were extracted by acid hydrolysis at 50°C for 1 hour, using 55% conc. H2SO4 under vigorous mechanical stirring, centrifugation at 12000 rpm in distillate water and followed by homogenizing at 7000 rpm. The morphology and surface profiles of the NCC suspension was characterized using field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM). The crystalline structure of the NCC was evaluated by using X-ray diffraction (XRD) technique. As a result, hydrolysed NCC was found to have a rod liked shape with diameter in the range of 100-300nm length and 10-50nm width, with the aspect ratio value of 10.3 nm. According to XRD investigations, the semi-crystalline cellulose was observed with the presence of an amorphous broad hump and crystalline peaks at 2θ of 15o and 22.7o, respectively. The crystalinity index of the raw filter paper was calculated as 86.7 % and increased to 94.4 % as it was extracted to NCC. Crystallite size of raw filter paper and NCC was calculated as 20.6 nm and 11.4 nm, respectively

This project investigated the use of facile pulping methods to produce pulp from mixed bio-plantation waste fibres using sodium hydroxide, ethanol and garbage enzyme. Papers were successfully made from mixture of corn husk fibres with other bio-based green fibres such as banana stems and pineapple leaves. Soda pulping was found to be efficient in converting the cellulosic bio-fibres to the pulps used for paper making. The papers produced have low tensile strength, high water absorption, high bio-decomposition and degradation rate, as compared to commercial papers. SEM observation revealed that paper made from mixed bio-fibres have lightly cross-linked structures compared to heavily cross-linked or compact network structures found in commercial papers. The paper can be used in applications that require high water absorbency. The paper making process is more environmental friendly as it reduces the usage of wood fibres and hence reduces the environmental problem caused by deforestation.

The pectin/functionalized silica coated filter paper (FILPSL2) was used for copper ion adsorption. Silica sol (1), prepared by mixing ethanol, water, TEOS and hydrochloric acid, was slowly added into pectin solution. A piece of filter paper (2 cm x 2 cm) was immersed in the silica-pectin solution for 1 hr. The coated filter paper was dried at room temperature and then oven-dried at 50 °C for 6 hrs to obtain FILPS. The silica sol (2) was subsequently prepared by mixing ethanol, water, N-[3-(Trimethoxysilyl) propyl] ethylenediamine (L2) and hydrochloric acid. The FILPS was immersed in silica sol (2) and the coated paper was oven-dried at 50 °C for 6 hrs to obtain FILPSL2. The SEM micrograph of uncoated Filter paper (FIL) and FILPSL2 showsa characteristic woven pattern. For copper ion adsorption, FILPSL2 was put into 0.1 M of CuCl2solution (pH 2, 25 °C). The color of the paper changes from off-white to intense blue within 5 min due to the complex between amino group of functionalized silica and Cu2+ as evidenced from IR spectroscopy.The equilibrium adsorption percentage and adsorption capacity were 27.10 and 5.5 x 10-3 respectively. The concentrations of copper ion solutions were varied to 10-2and 10-3M at this pH. The lower concentration of copper ion results in the higher adsorption percentage. While the lower concentration of copper ion results in the lower adsorption capacity. The adsorption was also experimented at pH 3.The similar trend was obtained. The optimum pH for adsorption for all concentrations was 2. The effect of interferences on the copper ion adsorption depends on the pH. At pH 2, Ni2+ has a stronger effect. While Cd2+ has a stronger effect at pH 3. The desorption was performed using 0.2 M CH3COOH solution. The complete desorption occurred within 30 min.

In this paper, soy protein papermaking process conditions as dry strength agents were studied. The results show that a part of the three parts of soy protein and a mixed system with a cationic starch alone, or cationic starch, soy protein, as compared to dry strength additives will significantly increase the strength. The optimum conditions were: pulp types E, defatted soy protein, dry vacuum drying method is 105°C, adding ways to add the pulp, the best reaction time was 10min, the optimum dosage of 2%. Soy protein sources are widely readily available, and environmentally friendly and easily biodegradable, paper dry strength agents as a good material.

For the conversion of cellulose into biofuel by microorganisms is being studied intensively. This research isolate and screen efficient cellulolytic microorganism from bamboo forest soil based on growth rate on CMC plate, the size of transparent circle, disintegration effect of filter paper, and CMC enzyme activity assay. As a result, efficient cellulose-decomposing fungus J6-1 was obtained. The strains possessed higher filter paper degrading ability and CMC enzyme activity, disintegrating the filter paper into 42.3% at the 5th days and reaching the highest CMC enzyme activity 6.87IU/mL after 120 hours of shake flask fermentation. Strains J6-1 is preliminarily identified asPenicilliumby morphological observation and a great potential cellulolytic strains.

The manufacturing of furniture using rattan is becoming common nowadays, and creates high amount of waste that can be value-added into binderless particleboards (BPB). In order to determine the suitability of the rattan waste for production of BPB, characterization of rattan waste is executed and reported in this paper. The physical properties such as density and moisture content of the rattan waste, together with its morphological study and thermal analysis as well as lignin content are evaluated. It is observed that density and moisture content for rattan waste are in the range of 0.64g/cm3, and 11.3% respectively. On the other hand, the morphology of rattan stem showed that rattan waste has various diameters of vascular bundles along with wide metaxylem vessels as well as thin-walled fibres. Thermal analysis of rattan waste explicated that rattan waste went through endothermic process with peak melting point of 177.80 °C during heating. The greatest weight loss occurred at 257.03 °C. Rattan waste has high lignin content of 21.2% that obtained through Klason lignin test. These promising preliminary results show that the rattan waste is appropriate to be used as raw materials in producing BPB.

This study aimed to analyze the kinetics of enzymatic hydrolysis of cellulose. Cellulase enzyme was obtained fromAspergillusnigergrown on filter paper and the hydrolysis process was carried out in solid state. The kinetic reviewed here was the relationship between glucose production and cellulose mass reduction to optimize the parameters of Monod equation at various moisture levels.

This document demonstrates how to affect the brightness of liquid package recycled pulp by hydrogen peroxide bleaching and FAS beaching. The optimum H2O2 bleaching process conditions: 8% H2O2, 4% NaOH, bleaching temperature 80 °C, bleaching time 1.5h. The best FAS bleaching conditions was FAS dosage of 0.5%, NaOH dosage of 0.25%, bleaching temperature at 80 °C, time for 30min. And bleaching had no adverse effect on the performance of bleached pulp fiber.

In this research, the laccase mediator system (LMS) was used to modify the unbleached triploid populus tomentosa alkaline hydrogen peroxide pulp (APMP). The changes of pulp brightness were measured and the effects of LMS on the subsequent hydrogen peroxide bleaching were also determined. Besides, the fiber morphology was analyzed by ESEM, and then the obvious changes of pulp have been recovered. In a word, the LMS has obvious effect on cellulose.

This paper made the detailed discourse for the study on using cellulase, hemicellulase hydrolysis of poplar fiber raw material to make glucose. The raw material used in this experiment is poplar, cellulase and hemicellulase enzymes are used. Hemicellulase is a complex system, xylose is regarded as the main chain for a lot of hemicellulose. The experiment used dry poplar as raw material, through the ball mill, ground poplar into wood powder. In the experiment, the optimal condition of enzyme hydrolysis of wood powder has been discussed based on reaction temperature, reaction time, enzyme concentration, and the pH value of reaction. Finally, under the optimal condition, use enzyme to hydrolyse wood powder, measure reducing sugar content by the DNS method, and calculate the rate of hydrolysis.

In this paper, synthesis and fluorescence performance of graphene oxide have been primarily studied. Fistly, graphene oxide with remarkable fluorescence performance was prepared by modified hummer’s method. Secondly, changing the reaction time, the structure and size of graphene oxide were analyzed using X-ray diffraction (XRD) and Malvern Zeta-Size Analyzer, and the effects of different reaction conditions on the XRD patterns of graphene oxide were discussed. Finally, the fluorescence performance of graphene oxide solution were analyzed using fluorescence spectrometer.

The Polyacrylamide (PAM) is a frequently used flocculant for high concentration suspensions removal in water treatment characterized by the generation of large and dense flocs. In this paper, by using the anionic PAM as flocculant, a full-scale experimental study was carried out on flocculating ferric flocs sludge with pelleting flocculation blanket process under scale of 19~38 m3/h. The investigation aimed to optimum the dosage of the PAM and evaluate the application of the PAM in ferric flocs sludge treatment. The experimental results indicated that the increasing of PAM dosage could improve both outlet turbidity and thicken sludge concentration obviously, under the raw wastes concentration of 285~1022 mg/L, the system could achieve ideal operation effect with PAM dosage of 0.3~2.7 mg/L and treatment unit surface loading of 19~38 m3/m2·H. The investigation results also proved that there exists an approximately linear relationship between optimal PAM dosage and raw sludge concentration, that is, the increasing of raw sludge concentration would require synchronously rising of the optimal dosage. While the relationship between maximum surface loading and raw sludge concentration appeared negatively linear dependence, the maximum surface loading would decreased linearly with the increasing of inlet sludge concentration.

Delignification of banana peel, agricultural waste, is considered in the pulp production because lignin is a major obstacle to the gain of cellulose. The soda process as a conventional method and micro-morphology observed by scanning electron microscopy were fulfilled to investigate an optimal condition in this study. The results pointed the potent sequence of operating factors was delignification temperature > solid-liquid ratio > soda concentration > time. The removal of lignin could achieve 92% under the optimal condition using 12%w soda concentration with 1:8 solid-liquid ratio at 100°C for 40 min. This shows that the alkaline delignification is productively sufficient for the pulp production.

This paper mainly researched on preparation and the setting time of Magnesium Phosphate Cement (MPC). The method of orthogonal experiment was adapted to determine the best ratio of MPC, and change the content and types of the material according to the influence of various factors, so as to get the longer setting time of MPC. The results showed that, when the water cement ratio is 0.12, the factors significantly influencing the setting time is magnesium phosphorus ratio (M/P), fly ash and borax. The optimal mixture ratio was obtained through the orthogonal analysis, namely M/P is 3/1, borax content is 16%, and the amount of fly ash is 40%. When M/P is 1/1 and 2/2, borax content is not more than 22%, and the amount of fly ash was less than 60%, the longer setting time of MPC can be produced.

Coal gasification wastewater, as a typical industrial wastewater has poor biodegradability and high toxicity. In this paper, simple anaerobic shaker test was conducted to investigate the degradation of hydroquinone in coal gasification wastewater. Anaerobic sludge shaker test were run for 27, 50 and 73 days, the phenol concentration were adjusted to 300 mg/L and 500 mg/L with pH 7.5, respectively. The experimental results also showed that this system could effectively deal with COD and phenol removal and remain in a stable level when the operational parameters altered while the hydrolysis acidification at 45h is appropriate. Organics degradation and transformation of anaerobic coal gasification wastewater samples at 12h, 24h, 36h, 48h, and 60h were analyzed by GC/MS and it was found that hydrolysis acidification played an important role in degradation of methyl phenol, hydroquinone and refractory compounds. Therefore, the results illustrated that the simple anaerobic shaker process is an easy way for pollutant degradation and treat coal gasification wastewater effectively.

Oil contamination has caused more public anxiety than other waste or spilt materials into the marine environment. Oil sorbents of high sorption capacity, biodegradable, readily available and low cost, are important for protection of water environment, especially from oil spillage. This work deals with raw and modified corn silk, an agricultural waste, as a low cost sorbent for oil-products spill cleanup in the aquatic environment. Corn silk was modified using fatty acid (oleic acid) to improve its sorption capacity. The chemical functional groups of raw and modified corn silk were analyzed by Fourier transform infrared (FTIR) spectroscopy. Kinetic tests were conducted with a series of contact times. The kinetic studies showed good correlation coefficients for a pseudo-second-order kinetic model. The oleic acid treated corn silk (OTCS) showed high degree of hydrophobicity and oil sorption capacity of approximately 10.7 and 11.90 g oil/g sorbent for Tapis and Arabian crude oil, respectively. Corn silk is a cheap waste material that can be treated to have an acceptable sorption capacity which can be used as an alternative to the commercial synthetic sorbents such as polypropylene.

Groundwater contamination due to mining, industrial and agricultural activities is a source of concern, especially with the advent of more stringent environmental legislation. Water sources in South Africa are multi-functional as the same water used in industrial processes is also used in agriculture.[1] Mining activities in the Northern Cape of South Africa, is largely as a result of manganese mining where Mn (II) and Fe (II) is removed. The treatment of the effluent discharged to the environment is therefore seen as a priority.Biosorption has proven to be a viable alternative to the use of conventional heavy metal removal methods. [2, 3] The re-usability of the biomaterial was investigated using a batch system. The biomaterial was contacted with Mn (II) sulfate, after which the supernatant was analysed for metal content. The biosorbent was then dried and desorbed using HCl. This process was repeated 3 times to investigate whether the biomaterial deteriorated and whether the biosorption process was affected by multiple use of the same biomaterial. The results showed that the biosorption capacity reduced with each successive use of the biomaterial.

The biopolymer material, lignin, was recovered from the black liquor by acidification of the black liquor using sulfuric acid. Several purification techniques were carried out to produce the high purity of lignin such as gradual precipitation of lignin from black liquor (first stage: precipitation at pH 7, second stage: precipitation at pH 2) and the diluting of crude lignin by sodium hydroxide then followed by re-precipitation at different temperature. Subsequently, the impurities of lignin product resulted from each purification techniques was determined as ash content that analyzed using temperature program furnace; and the content of lignin was investigated using spectrophotometer UV-Vis. The result showed that the content of lignin of material produced from gradual precipitation was approximately 77.6%. It was higher than the content of lignin about 3.4% of material produced from direct precipitation to pH 2. In addition, the elevating of temperature from 40 to 60°C was no considerably affect to the content of lignin in precipitate produced from re-precipitation of crude lignin solution in sodium hydroxide. Nonetheless, the content of lignin of precipitate improved 15% when the temperature of re-precipitation of crude lignin solution in sodium hydroxide was raised from room temperature to 40-60°C.

The application of photodegradable polyethylene is increasingly important for agricultural uses due to its ability to degrade after suggested shelf life and to counter measure pollution issue caused by conventional polyethylene films. The photodegradable polyethylene (PE) mixtures were formulated with added polypropylene (PP) and photodegradant (RM master batch) and tested in oil palm seedlings cultivation. PP is known to have photodegradable ability and RM master batch is proven to induce photo degradation of polyethylene. Thus, the mixture of these three components according to different ratios was processed into agricultural plastic films. There are four formulations that are tested in this study, namely T1 (80% PE:20% PP:5% RM master batch), T2 (70% PE:30% PP:5% RM master batch), T3 (80% PE:20% PP:3% RM master batch) and T4 (70% PE:30% PP:3% RM master batch). All formulations except control sample were added with photodegradant to impart degradation reaction and compatibiliser was also affixed to allow coalesce between polyethylene and polypropylene. Carbon black was added 0.5% into the formulation as for poly bags application, dark environment of soil is crucial for root development and growth. Penetration of sun light into the planting soil could commence development of shoot instead of root growth. All four formulations showed observable morphological changes on microscopic images on the surfaces after being used in oil palm nursery. From the study, it is shown that T1 and T3, with 20% of additional polypropylene had demonstrated clear surface disintegration when viewed microscopically. The addition of 3% and 5% of photodegradant into the formulations did not show any expressive difference thus suggesting that 3% of photodegradant is the optimum amount to induce photo degradation.

The objective of this study is to investigate the ability of Elaeis guineensis fruit fiber or known as oil palm mesocarp fiber (OPMF) to adsorb nickel from aqueous solution. As one of the major oil palm producer, Malaysia has abundantly oil palm waste that potentially be used as biosorbent. Limited studies used OPMF as biosorbent to remove nickel, thus it was used in this study. The effects of pH, initial metal concentration and contact time on nickel uptake were studied. The OPMF was soaked in nickel nitrate aqueous solution and the Ni-loaded OPMF being digested to analyse the nickel concentration by using ICP-OES. The adsorption was investigated in the pH range of 2.0-8.0 and the optimum pH for nickel removal was found to be 7.0. The contact time was varied between 5 to 120 mins and the nickel adsorption was found to achieve equilibrium in a very short time (i.e. R2 of 0.98. The kinetic studies showed that the pseudo-second order model is the best model with the correlation coefficients of > 0.99 for all concentrations. Overall, the adsorption of nickel by OPMF gave positive results and the used of OPMF as biosorbent has great potential to be applied in the future.

PBO (p-phenylene benzobisoxazole) short fibers, attached fine fibrils that are called PBO pulp, may precipitate directly from stirred PBO/methanesulfonic acid (MSA) solution by the use of water coagulant in fibrous pulp form. Scanning electron micrographs show that the precipitated PBO pulps have a ribbon-like structure similar to Kevlar pulps. The thermalgravimetric analysis (TGA) show there were no appreciable mass changes until 550 °C in the air. The process yields PBO pulps with different specific surface areas (SSA) depending on the stirring speed, stirring time and the concentration of the PBO/MSA solution. High SSA PBO pulps can be produced by increasing the stirring speed, prolonging the stirring time and reducing the concentration of the PBO/MSA solution.

The microalgae Chlorella sp. grows well in POME medium sparged with a mixture of carbon dioxide (CO2) gas and air under 10,000 lx of lighting. The percentage of CO2 in the mixture, and the flow rate of the mixture (representing agitation) have important effects on the microalgae biomass yield. However, the percentage recovery of CO2 as microalgae biomass was very low in all cases, indicating that most of the sparged CO2 did not dissolve in the POME and was not sequestered by the microalgae but has in fact escaped with the bubbles into the head-space and out into the atmosphere. This result indicates that in order to increase the percentage of CO2 recovered, the area of improvement is mainly in the mass transfer of CO2 from the gas phase into the liquid phase. To ensure that dissolved CO2 does not re-form bubbles, the mass transfer has to be demand-driven, where the rate of uptake of dissolved CO2 by the microalgae has to be higher than the rate of mass transfer of CO2 from gas phase into the liquid medium.

Graphene oxide (GO) reduction is a promising way for graphene large scale synthesis. Pre-exfoliated graphite was oxidized and reduced. The material was compared to commercial graphene oxide and its reduced sample. The reduction process of graphene oxide is accomplished using sodium borohydride (NaBH4) with variable-valence metal ion – cobalt – assistance. The reduced graphene oxide (RGO) was characterized by Raman spectroscopy. The particle size and suspension stability were determined. Electrical conductivity measurements of GO and RGO samples have been done in temperature range from-150°C to 85°C. Pre-exfoliation effect was determined.

A reduced graphene oxide/nickel (rGO/Ni) composite has been succesfully synthesized using a combination of Marcano’s method for synthesizing graphene oxide (GO), subsequently followed by a facile microwave assisted reduction method. X-ray diffraction results show the presence of graphene and nickel on the prepared samples. In addition, the Fourier Tansform Infrared Spectroscopy measurement showed that the absorption peaks of O-H, C=O, C-OH, and C-O only appear in the GO sample. A Scanning Electron Microscope photograph shows that the morphology of the rGO samples contain nano-layered forms. A Raman spectroscopy characterization of the prepared rGO samples show a peak of G band’s wave number at 1586.5 cm-1. From the calculation of the G band’s wave number, the average number of graphene layers is 1.15.

In this study, three different concentration of organic loading rate (OLR) were investigated to examine the effect of the change in the organic loading rate on the efficiency of the biogas production. Daily amount of biogas of different type of organic loading rate (OLR), rates of production of biogas, removal efficiencies of chemical oxygen demand (COD), total solid (TS) matter, volatile solids (VS) matter from the slurry were investigated in 30 days retention tyme using 50 L digester. The digester was operated at different organic feeding rates of 25000 mg/L COD, 50000 mg/L COD, and 75000 mg/L COD. The material used in this system is the fruits waste, vegetables waste and cow dung. The system operated in continuous system. The reactor showed stable performance with the highest quality of methane (concentration about70.3% of CH4) and rate of biogas production is 38.1 L/day with COD reduction of 52.1% during organic loading rate 50000 mg/L COD. As the organic loading rate was increased, the COD degradation and biogas yield decreased. Based on this result, the OLR of 50000 mg/L COD is suggested as design criteria for pilot biogas production.

This study aims to directly analyze the production of hydrogen and methane gas from POME via high frequency ultrasonication atomization. The advantage of the currently common process was studied in regards to the application of low frequency ultrasonic pretreatment prior to biological processes; anaerobic digestion and fermentation for the production of methane and hydrogen gases respectively. Existing ultrasonic application is limited to sludge disintegration, reducing chemical oxygen demand (COD) values and total solid, while subsequent biological processes take several days to produce gases. However, in this study, high frequency (2.4 MHz) ultrasonic atomization process was able to produce methane and hydrogen gases directly without any biological process. These gases were detected by using an online gas chromatography. The results from the ultrasonication process show that the production gases are consisted majorly of hydrogen compared to methane. Thus, high frequency ultrasonication process can be considered as an alternative method in rapid production of methane and hydrogen gases.

Calculated carbon dioxide emission from WPT, using equations derived from the UNFCC report, found that the average amount of CO2 emitted from the decomposition of WPT annually for 2011-2032 is equivalent to 14.19 million tonnes. The amounts of CO2 that can be sequestered from the manufacture of the potential products were also calculated. Assuming 50% of the annual availability of WPT in Malaysia from year 2011-2032 is converted into products such as plywood/flooring, bio-ethanol from OPT sap, timber, animal feed and micro-crystalline cellulose, GHG emissions would be reduced by 8.11%; 1.95%; 21.35% and 20.50% respectively. The conversion of WPT into biofuel such as fuel pellets and bio-ethanol could provide more impactful effect through indirect and direct carbon offsets from the displacement of fossil fuel use. Up to 48.26 percent CO2 reduction may be achieved.

Esterification and trans-esterification reactions are an alternative solution for the production of biodiesel from Crude Palm Oil waste. The two previous studies show that the yield obtained was less than 80%. It is necessary to investigate the optimum condition of trans-esterification operation in biodiesel production from CPO waste. Variables used are temperature, time, ratio of molar triglyceride with methanol, and catalyst concentration. According to preliminary temperature treatment variations, it is determined that optimum temperature is 55°C. Meanwhile, the time treatment variations showed that optimum time is 60 minutes. For the ratio of molar triglyceride with methanol, it is determined that 1:10 is the optimum ratio. And last, for the experiment variations of NaOH concentrations it is discovered that the optimum concentration is 1.25%-b. And to conclude the research, the optimum condition for each variable was used where biodiesel’s yield can reach up to 96.67%.

A new carbon material called graphene has been attracting an increasing research interest owing to its unique electrical and mechanical properties that is useful for the various device applications. The synthesis of graphene from graphene oxide usually involves harmful chemical reducing agents that are toxic and undesirable to human and the environment. By avoiding the use of toxic and environmentally harmful reductants, we report a green approach for the reduction of graphene oxide by using reducing sugars to synthesis graphene. Graphite oxide was synthesized from graphite powder using modified Hummers method. Graphite oxide then further exfoliated to graphene oxide by using ultrasonic irradiation. Graphene then was obtained by the mild reduction of graphene oxide with reducing sugars (glucose, lactose and maltose). The structural study of the as-prepared graphene is characterized by Raman spectroscopy and fourier infra red spectroscopy. Raman and FTIR spectra indicates the partial removal of oxygen functional groups from the surface of GO. Characterizations indicate that graphene oxide is successfully reduced to graphene by sugar.

We measured the resistivity and conductivity behavior of activated carbon and an activated carbon – graphene oxide (GO – AC) hybrid using two point probe method. As graphene oxide is well known as insulator, the effects of different ratio of activated carbon on conductivity of hybrid GO – AC was investigated.

Green composites of Glucose-reduced graphene oxide (GrGO) and manganese (IV) oxide (MnO2) were prepared in a typical chemical synthesis route assisted with ultrasonic irradiation. Conductivity studies conducted via 2-point probe method shows GrGO/MnO2(4:1) possessed electrical conductivity of 30.29 S cm-1with energy band gap of 8.47×10-1eV. The increase of D/G intensity ratio of GrGO with increase MnO2loading indicates more disorder carbon or defects are introduced from the reaction of carbon with MnO4-.

Today, research on graphene and other two-dimensional sp2-hybridized carbon nanomaterials has tremendously impacted the areas of modern chemistry, physics, and materials science and engineering. The significant attraction of these materials can be attributed to the outstanding electrical, optical, electrochemical, and mechanical properties of graphene-like materials, especially in comparison to other carbon materials. In this manner, graphene oxide as a substrate for graphene-like materials reduction process is getting more and more interesting. Although early routes to these materials were challenging, significant advances in synthetic and processing methods have enabled access to high-quality exfoliated graphene oxide sheets in appreciable quantities. Herein, we introduced a simple and efficient method for the high-conversion preparation of graphene oxide using a simplified hummer’s method from large graphite flakes (an average flake size of 100 μm). One-pot chemical oxidation of graphite was carried out at room temperature for the preparation purpose. It was found that different degree of oxidation of graphite flakes could be realized by stirring graphite in a mixture of sulphuric acid and potassium permanganate under different oxidation durations, resulting in exfoliated graphene oxide sheets with large lateral dimension and area. The simplified Hummer’s method provides a facile approach for the preparation of large-area exfoliated graphene oxide sheets.

Hydrogen sulfide is a common composition of natural gas. It is an important problem to develop suitable natural gas desulfurization technology for the present situation of China. Now, a novel process of H2S abatement from gas streams has been investigated for chemical absorption of H2S using a weak alkaline solution followed by the oxidation of the absorbed sulfide to elemental sulfur by naturally occurring microorganisms and alkaline solution regeneration for recycle and reuse in the process. This method is currently attracting more and more interests of researchers, because it requires little equipment, is inexpensive and produces only elemental sulfur, thus minimizing the production of pollutants. The biological oxidation process of the absorbed sulfides to elemental sulfur by Thiobacillus thioparus TYY-1 was studied in an airlift-loop reactor (effective volume=20L).Two efficiency factors including hydraulic remain time and the air aeration quantity were inspected. The air aeration quantity is key influence factor of desulfuration rate and elemental sulfur production rate. The investigation demonstrated that the optimum hydraulic remain time was 4—6h under the influent concentration of S2- for 200 mg/L, and the best treatment effect of aeration was obtained at 120 —160L/h. With these conditions after 20 days of operation, the result showed superior performance of the bioreactor for desulfuration rate and elemental sulfur production rate, the conversion products were mainly sulfur and the production rate of SO42- was low. The removal efficiency of sulfide was more than 99.5% while the maximum yield of sulfur was 88% approximately.

The double membrane bio-reactor was used to treat the simulated wastewater under aerobic conditions, and the aerobic activated sludge system was set as the control. At the beginning of acclimation, COD removal efficiency in double membrane bio-reactor was higher than that of aerobic activated sludge system, but difference between two systems was little in later stage. The ammonia nitrogen removal rate in double membrane bio-reactor was significantly higher than aerobic activated sludge throughout the whole acclimation stage and nitrite concentration in the effluent from double membrane bio-reactor was lower than that of from aerobic activated sludge, while the nitrate concentration was higher. The nitrite was not accumulated in double membrane bio-reactor through the whole process of acclimation, while the accumulation of nitrate happened in aerobic activated sludge system.

This article is devoted to investigation of the synthesis process of exfoliated graphite. Exfoliated graphite was obtained from graphite oxide using thermal exfoliation. Graphite oxide samples were synthesized using modified Hummers method. The influence of the synthesis process parameters such as heating rate, temperature, exposure time on the properties of graphite oxide were investigated. The as-received exfoliated graphite were tested as electrode for supercapacitors. The capacitance of the supercapacitors based on exfoliated graphite varied in a range of 17-129 F/g.

Graphene oxide (GO) is extracted from graphite oxide synthesized using modified Hummers method. The extracted GO solution is then drop casted onto a p type silicon substrate and dried in hot air oven. The dried solution is annealed at a temperature of about 200 degree Celsius for about one hour to obtain thermally reduced graphene oxide (RGO). Such thermally synthesized RGO usually have a lot of structural defects which can act as a binding site for hydrogen. The binding efficiency of hydrogen to defect centers can be increased by applying electric field to RGO as it changes the carrier concentration (doping) on the surface. This induces more polarization in the hydrogen molecule resulting in strong binding force, thereby increasing its hydrogen storage efficiency. In our experiment we have demonstrated room temperature electric field doping in RGO films by modulating the channel current by changing the back gate voltage which is a precursor for employing RGO in hydrogen storage applications.KeywordsGraphene oxide, Reduced graphene oxide, Field effect, Hydrogen storage, and Defects

The study on potential-controlled flotation test of differential flotation process was carried out in the light of the change of a certain ore properties. The test used self-developed EMZ-91, as well as conventional collectors of ethyl thio carbamate and butyl xanthate for the flotation of copper, lead and zinc ores respectively, in which the copper sulfate was used as the activator of zinc mineral. The new differential flotation process, which is using lime to regulate pulp potential, produced the copper concentrate grading 27.18% copper at 73.37% recovery, the lead concentrate grading 66.00% lead at 63.00% recovery, and the zinc concentrate grading 55.27% zinc at 87.69% recovery.

Azithromycin wastewater has high ammonia, high COD and high salt content characteristics. By ammonia stripping-Fenton oxidation pretreatment of azithromycin wastewater, the effect is obvious. The optimum technological conditions are determined by experiments, the effluent COD can be reduced to 5000mg/L or less, the total removal of up to 85.6%. After pretreatment of wastewater, the BOD5/COD value was increased from 0.12 to 0.38, and the biodegradability of the wastewater was improved.

External carbon sources provide additional nutrients that improve the efficiency of nitrate removal in constructed wetlands. Typha angustifolia L. were planted in four vertical subsurface-flow constructed wetlands. Different external carbon sources were fed into the columns, to investigate and compare their treatment of nitrate in synthetic wastewater, with initial influent C/N ratio of 1:1. Wetland A (WA) with 50g wheat straw as external carbon source, wetland B (WB) with 50g woodchips, wetland C (WC) with additional 10mg/L glucose and wetland D (WD) without external carbon source to serve as the control, were used in the lab-scale experimental study. WA, WB, WC and WD within a period of 24 days, cumulatively removed 109.38mg/L, 93.75mg/L, 85.14mg/L, and 64.01mg/L nitrate, respectively, from the influent. The nitrate-nitrogen (NO3–N) removal efficiency as aided by the external carbon sources was in the order: wheat straw > woodchips > glucose > control. Wheat straw treated 93% NO3–N, woodchips 78%, glucose 72% and the control 53%. The results indicate that WA, WB and WC outperformed the control system, due to the additional carbon sources. In general, the wheat straw had a better performance than wood chips and glucose. Thus, wheat straw as low cost biological waste product is recommended for the treatment of nitrate in wetlands.

We introduced a facile method to construct new ternary hierarchical nanocomposites by combining MnO2coated one dimensional (1D) conducting polyaniline (PANI) nanowires with 2D graphene oxide sheets (GOs). The hierarchical nanocomposite structures of PANI@MnO2/Graphene oxide were further proved by XRD, SEM and TEM measurements. The ternary composites possessed higher electrochemical capacitance than each individual component as supercapacitor electrode materials.Such intriguing electrochemical performance is mainly attributed to the synergistic effects of MnO2, PANI and GOs. The hierarchical ternary nanocomposites show excellent electrochemical properties for energy storage applications, which evidence their potential application as supercapacitors.

The torrefaction of rice husk was performed in a laboratory-scale torrefaction reactor at different temperatures (200, 230, 260, and 290 °C) for 30 min. It was found that the decomposition of hemicellulose was the direct reason for changes in the fuel properties of solid products after torrefaction. As the torrefaction temperature rose from 200 °C to 290 °C, the yield of torrefied rice husk decreased gradually from 97.47% to 67.03%, whereas the yields of liquid and noncondensable gas products increased from 2.01% to 15.67% and from 0.52% to 17.30%, respectively. Liquid products contained water and a small amount of acetic acids. CO2 and CO were the main gas products of rice husk torrefaction.

A renovated hybrid membrane bioreactor (HMBR) was investigated for its capability of coking wastewater treatment. The HMBR combined biofilm process and membrane filtration process. The system was efficient in degrading COD and phenol in coking wastewater and controlling membrane. It was found that the coking wastewater could be effectively treated with 88.6% of COD removal efficiency and 98.3% of phenol removal efficiency at hydraulic retention time (HRT) of 16 h. The removal efficiency of COD and phenol decreased gradually down to 83.2% and 97.7% when HRT decreased to 8 h. The long term experiments indicated that the degree of membrane fouling for HMBR was far lower than that for MBR. The scrubbing effect of suspended carrier in HMBR was observed to be capable of reducing the cake fouling of membrane. The operation time of HMBR was 8.4-fold longer than that with MBR.

For the principle of green sizing, the key research on sizing technology which reduce the degree of COD in wastewater of sizing was carried out. PVA and modified starch slurry was gradually replaced by hemp pole cellulose ether and modified starch slurry, and the original formula was optimized. After valuing viscosity and COD of the slurry, several suitable formulas were chosen. Then experiments on the same batch of hemp/cotton blended yarn sizing were carried out, and the sizing enhancement rate, stretching rate and the increasing grinding rate were tested. Through the comparative analysis, the COD of hemp pole cellulose ether slurry with modified starch is lower than that of PVA slurry with modified starch. Meanwhile, with the certain compound rate, the former sizing performance is better than the later.

Reed Pulp was Raw Material that Pretreated by Four Methods {ultrasonic, Microwave, N, N-Dimethyl Acetamide (DMAc) and Tetrahydrofuran (THF)}. Reed Microcrystalline Cellulose (MCC) was Prepared by the Dilute Hydrochloric Acid Hydrolysis from Pretreated Reed Pulp. the Influences of Pretreatment Methods on Crystalline Type, Crystallinity and Crystallite Size of MCC were Investigated by X-Ray Diffraction (XRD). the Results Showed that the Crystallinity of MCC with Four Pretreatment Methods was 68.45%, 62.28%, 63.21% and 69.56%, Respectively. the Average Crystallite Size of MCC Prepared by Hydrolysis after Pretreated by Dmac was the Largest. whereas, the Crystal Type of MCC was Not Changed, it was still the Cellulose Type I. Comprehensive Analysis Indicated that the Effects of MCC Prepared by Hydrolysis after Pretreated by Ultrasonic were the Best.

Graphene/platinum composite gel was prepared with chloroplatinic acid and graphene oxide (GO) as precursors by in-situ reduction method. Grapheme/platinum composite film as counter electrode was prepared on fluorine-doped tin oxide (FTO) glass by electro-hydrodynamic (EHD) method. Battery was assembled with nanoTiO2film as anode, N3 dye, and ionic liquid electrolyte. It was characterized by Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM) and X-ray Diffraction (XRD). Graphene/platinum composite film include very thin graphene layers, with platinum particles of an average dimension dispersed evenly in graphene layers. This device shows similar photoelectric conversion efficiency compared with platinum electrode under 100 mWcm-2(1 sun) AM1.5 illumination.

Graphene-bismuth oxide composite were fabricated through a facile hydrothermal method. The SEM, XRD, EDS, FTIR were performed to characterize the morphology, composition, structure and surface functional groups. It was found that the Bi2O3 evenly spread on the surface of graphene. What is interesting is that two kinds of bismuth oxide can be generate in an experiment. One is spherical Bi2O3 with a diameter of 1~2 μm, the other is about 40 nm particle-size growed on the surface of the graphene. The possible growth mechanism was discussed. Under UV-pulsed illumination, graphene-Bi2O3 composite electrodes can produce an extracurrent of about 52.92 μA/cm2 under 0.3 V bias voltage, this value is higher than the existing report, indicating potential applications in optoelectronic devices. The possible reasons are explained.

Fe3O4microspheres and its composities with graphene are prepared by the controlled thermal decomposition of an iron alkoxide precursor, which are obtained via an ethylene glycol (EG) mediated solvothermal reaction of ferric chloride hexahydrate (FeCl3·6H2O) and sodium acetate (NaAc) with graphene dopings. The resulting Fe3O4microspheres are uniform with a diameter of 0.2-0.5μm. Electrochemical properties of both Fe3O4microspheres and Fe3O4/graphene composites are discussed. SEM analysis shows that a large number of Fe3O4particles with spherical morphologies are homogeneously anchored to the rGO sheets surface. Electrochemical results showed that charge and discharge capacities for Fe3O4/graphene composites are larger than those for Fe3O4microspheres electrodes after the 30th cycles which due to the synergistic effect of Fe3O4and graphene. Graphene improves the electronic conductivity of Fe3O4microspheres and increases the interfacial contact area between the Fe3O4microspheres and electrolyte which is benefitable for lithium ion battery. So Fe3O4/graphene composites are better anode materials than Fe3O4microspheres.

We utilized pressure-, vacuum-, and evaporation-assisted self-assembly techniques through which graphene oxide (GO) was deposited on modified polyacrylonitrile (mPAN). The fabricated composite GO/mPAN membranes were applied to dehydrate 1-butanol mixtures by pervaporation. Varying driving forces in the self-assembly techniques induced different GO assembly layer microstructures. XRD results indicated that the GO layer d-spacing varied from 8.3 Å to 11.5 Å. The self-assembly technique with evaporation resulted in a heterogeneous GO layer with loop structures; this layer was shown to be hydrophobic, in contrast to the hydrophilic layer formed from the other two techniques. From the pressure-assisted technique, the composite membrane exhibited exceptional pervaporation performance at 30 °C: concentration of water at the permeate side = 99.6 wt% and permeation flux = 2.54 kg m-2 h-1. This excellent separation performance stemmed from the dense, highly ordered laminate structure of GO.

In the present study, cotton fabric has been dyed with natural indigo (Indigofera tentoria) in absence and present ferrous sulfate mordant by using post-mordanting and pad-batch processes. It was observed that with an increase in the dye concentration, the ultraviolet (UV) protection factor (UPF) values good for the cotton fabric. Cotton fabrics dyed with natural indigo showed greenish-blue shade. The fastness properties ranged from good to very good, level. The results confirmed that natural dyes from natural indigo with ferrous sulfate have potential applications in fabric dyeing and in producing UV-protective cotton fabrics.