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Two types of biomass adsorbents have been developed in this study using Palm Kernel Shell Activated Carbon (PKS-AC), iron oxide, and zeolite. Micrographs and the adsorbent’s chemical composition were identified using a scanning electron microscopy with a energy-dispersive X-ray (SEM-EDX), and a Brunauer–Emmett–Teller analysis was used to determine the specific surface area of the adsorbents. The newly developed adsorbents have been used for the adsorption of Palm Oil Mill Effluent (POME). The effects of adsorbent dosage, contact time, and initial solution pH were identified using Design of Experiment. The Iron Oxide Palm Kernel Shell Activated Carbon (Fe/PKS-AC) shows the highest color removal efficiency (93.2 percent) compared to Zeolite Iron Oxide Palm Kernel Shell Activated Carbon (Zeolite-Fe/PKS-AC) using 5 g/L of adsorbent dosage, an initial pH of 3 and a retention time of 40 min and 60 min, respectively. Besides, Zeolite-Fe/PKS-AC reported higher degradation efficiency (62.6%) than Fe/PKS-AC within an hour of contact time. The reusability study also shows that Zeolite-Fe/PKS-AC could retain its adsorbent capability over five cycles and had a minimal decrease of 5.6 %. It can be deduced that the newly developed biomass adsorbents from palm kernel shells can provide a cost-effective alternative for the treatment of POME and other recalcitrant wastewaters.

This article aimed at determining the optimum coagulant dose for various coagulants. This is to ascertain coagulant with the potential for higher removal of contaminants. By fixing the initial pH, settling time, coagulant aid dose, rapid mixing speed & time, slow mixing speed & time as constant parameters, the study assessed the process efficiency in terms of percentage removals for TSS, oil & grease, COD, NH3-N, turbidity and colour. The results indicated that the optimum dosage for FeCl3, moringa oleifera, aluminum sulphate, chitosan and zeolite was found to be 1000, 2000, 4000, 400 and 1000 mg/L, respectively. Results were analysed using the one-way analysis of variance (One-Way ANOVA) of Statistical Package for Social Sciences (SPSS) Version 17 where P-values for all contaminants tested across various coagulants and their dosages found to be

A magnetic composite was synthesized using palm kernel shell-based activated carbon, graphene oxide (GO) and iron oxide. The morphology, textural properties, magnetic properties, crystal structure and functional groups of the composite were studied. The characterization shows the successful formation of the ternary composite with a high specific surface area (280.39 m2/g) and abundant surface functional groups. The magnetic properties of the composite indicate a saturation magnetization of 33.72 emu/g, signifying that the composite can be easily separated with an external magnetic field. The performance of the composite was then investigated through the removal of an anionic azo dye, Acid Blue 113, from aqueous solution. The effect of initial pH of the solution, adsorbent dosage and adsorption contact time was studied. The composite achieved an adsorption capacity of 32.2 mg/g and 96.3% dye removal. Effective dye removal was still achieved after five cycles of adsorption-regeneration, with the dye removal of 74% after the fifth cycle. The analyses of adsorption isotherm and kinetics show that the adsorption process fits pseudo-second-order kinetic and Langmuir isotherm models, indicating a monolayer chemisorption process. The excellent adsorption performance and reusability of the composite and its magnetic separability signify its potential as an adsorbent for wastewater treatment.

Kitchen wastewater that is discharged to the environment is one of the contributing factors to water pollution in developing countries. Adsorption is one of the emerging technology of biological treatments that is an environmentally friendly for the removal of pollutants. Banana trunk fiber with chitosan as an adsorbent was investigated for minimizing COD and ammonia from the kitchen wastewater. The raw kitchen wastewater sample used in the study was collected from the Arked food court located in Universiti Tun Hussein Onn Malaysia in Johor (Malaysia). The optimum of ratio, pH, shaking speed and contact time for COD and ammonia removal were determined. The result indicated the optimum mix ratio of fiber with chitosan, pH, shaking speed and contact time respectively was 50:50, pH 7, 125 rpm and 120 minutes based on the adsorption of COD (87%) and ammonia (90%) by banana trunk fiber with chitosan. Kinetic study of the results gave a pseudo-second order the R2 was closed to unity which was 0.998. It will significantly be considered for efficient removal of organic and nutrient pollutants present in kitchen wastewater treatment.

Chitosan-magnetic-graphene oxide (CMGO) nanocomposite was prepared for arsenic adsorption. The nanocomposite was characterized through BET, FTIR, FESEM, EDX, and VSM analyses. These characterizations confirmed the formation of CMGO nanocomposites with high specific surface area (152.38 m2/g) and excellent saturation magnetization (49.30 emu/g). Batch adsorption experiments were conducted to evaluate the performance of the nanocomposite in the adsorption of arsenic from aqueous solution. The effects of operational parameters, adsorption kinetic, equilibrium isotherm and thermodynamics were evaluated. The removal efficiency of arsenic increased with increasing adsorbent dosage and contact time. However, the effect of pH followed a different pattern, with the removal efficiency increasing from acidic to neutral pH, and then decreasing at alkaline conditions. The highest adsorption capacity (45 mg/g) and removal efficiency (61%) were obtained at pH 7.3. The adsorption kinetic followed a pseudo-second-order kinetic model. The analysis of adsorption isotherm shows that the adsorption data fitted well to Langmuir isotherm model, indicating a homogeneous process. Thermodynamic analysis shows that the adsorption of As(III) is exothermic and spontaneous. The superparamagnetic properties of the nanocomposite enabled the separation and recovery of the nanoparticles using an external magnetic field. Thus, the developed nanocomposite has a potential for arsenic remediation.

The interaction of carriers (SiO2) and Fenton’s reagent during the degradation of recalcitrant pollutant by fluidized-bed Fenton process was investigated. Reactive Black 5 (RB5) was selected as a model pollutant since dyes are recalcitrant to conventional treatment technologies. Quantum chemical simulation and experimental approach were employed to predict the potential interactions among the chemical species involved in the process. Quantum chemical parameters such as highest occupied molecular orbital (HOMO) energy, lowest unoccupied molecular orbital (LUMO) energy, HOMO–LUMO energy gaps were computed and analyzed. Response surface methodology was utilized to investigate the effect of operational parameters and optimize the process performance. The analysis of quantum chemical parameters shows that with a comparatively higher EHOMO of − 8.72 eV, SiO2 can interact with Fe3+ (EHOMO = − 18.74 eV), which explains the crystallization of iron oxide on the carriers. The higher EHOMO–LUMO energy gap value of SiO2 (7.92 eV) indicates its potential interaction with Fe2+, Fe3+ and RB5 due to their lower EHOMO–LUMO energy gaps. RB5 exhibited the lowest hardness value (1.23 eV), indicating that it can be degraded by the hydroxyl radical (2.11 eV). For the experimental part, the process can remove up to 80% and 99.94% of the initial COD and color, respectively, under optimum conditions. The most significant parameters affecting the process performance are [Fe2+] and [Dye]. This study has provided insights into the potential interactions occurring in fluidized-bed Fenton process. The results will be useful toward optimization and scale-up of fluidized-bed Fenton process.

Hydrogen peroxide (H2O2) is commercially produced by catalytic oxidation of anthrahydroquinone, which is energy-intensive. Electrochemical production of hydrogen peroxide production through oxygen reduction reaction (ORR) is a sustainable approach, primarily due to its significance in energy conversion systems such as fuel cells. Low temperature fuel cells use graphite as a cathode for H2O2 synthesis. However, the catalytic activity of a graphite cathode for a two-electron oxygen reduction reaction must be improved. Nitrogen doping is an efficient approach to modify the electrochemically active surface of the graphite cathode. Therefore, quantum chemical approaches are essential to comprehend the molecular nature of the processes at the cathode. DFT/B3LYP/6-31G* method was employed and bond dissociation energy (BDE) analysis was performed to determine the feasibility of H2O2 production at graphite and nitrogen-doped graphite (Graphite-N) cathodes. According to the suggested mechanism, oxygen adsorption is the first step of the ORR. Calculated values showed that with energy value of 23.50 kcal/mol oxygen adsorption at the Graphite-N cathode is energetically more favorable than the graphite cathode (Ead = 65.08 kcal/mol). Considering the ORR mechanism, a second-electron oxygen reduction is identified as a key step for both H2O and H2O2 production. Therefore, BDEs were compared at the second-electron oxygen reduction step. On average, − 320.92 and − 286.04 kcal/mol of BDEs for graphite and Graphite-N cathodes showed the feasibility of H2O2 production at the Graphite-N cathode. The results are in agreement with the literature. Thus, it is concluded that nitrogen doping of the graphite cathode increases the feasibility of H2O2 production.

This work aimed at providing additional information and knowledge on the possibility to overcome the limitation of conventional advanced oxidation processes (AOPs) through hybridization. In the present work, a number of photochemical and non-photochemical AOPs such as direct photolysis (UV), photolysis of hydrogen peroxide using UV light (UV/H2O2), UV assisted coagulation (UV Fe2+ coagulation), Fenton process, Fe2+ coagulation and photo-Fenton process were compared to determine their feasibility to treat real textile wastewater. The Batik industry, which is a textile cottage industry in Malaysia has reported problems related to safe environmental disposal of its pollutants, mainly dyestuff. The comparison was made in terms of Chemical oxygen demand (COD), Total organic carbon (TOC) and colour removal together with electricity consumption. Among the processes evaluated, the highest COD removal was achieved for photo -Fenton oxidation (91.2%), followed by Fenton oxidation (81.4%), UV/H2O2 (68.0%), UV- Fe2+ coagulation (55.0%), Fe2+ coagulation (43.0%) and UV photolysis (10.0%). At the optimal operating conditions (room temperature, undiluted contaminants), the photo-Fenton hybrid process achieved complete decolourization and higher removal of COD (91.2%) and TOC (78.5%) with minimum electrical energy per order of 0.02 kWhr/m3 compared to other AOPs. About 13% reduction in the total chemical cost and 10% increase in the degradation were observed by combining the Fenton process with UV radiation compared to the conventional Fenton process. The GC/MS analysis revealed that the photo-Fenton process successfully removed 87% of organic compounds. The sludge characterization studies by Particle Size Distribution proved that the Fenton-generated sludge achieved quality suitable for disposal. Photo-Fenton is the cheapest option with highest removal (91%) as its required only $0.0016 to degrade 1 g of COD compared to Fenton which cost $0.0021. Therefore, this study concluded that the photo-Fenton process was an economically viable and appropriate treatment method for enhancing biodegradability of recalcitrant contaminants.

Metal nanoparticles are often used as an alternative to conventional adsorbents for water purification. They have higher adsorptive capabilities and affinity towards pollutants while being required in lower amounts than conventional adsorbents. Nano-adsorbents have shown superior adsorption efficiencies towards trace heavy metals in water, which are a significant pollutant in industrial wastewaters. It is desirable to synthesize the nano-adsorbents in a rapid, controlled, eco-friendly, and low-cost manner, using agro-industrial residues and size-controllable irradiation methods. In this work, silver nanoparticles were synthesized through ultrasonic irradiation in the presence of cellulose derived from sugarcane bagasse. The cellulose functioned as the capping agent to promote the synthesis of uniform, monodisperse silver nanoparticles. The nanoparticles were characterized by field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and Fourier-transform infrared spectroscopy. The result indicates that the newly developed cellulose-based adsorbent can be used as a potential heavy metal adsorbent. The adsorptive capability of the nano-adsorbent solution towards trace amounts of lead was then tested using inductively coupled plasma mass spectrometry. It can be concluded that the newly developed biomass-based silver nanoparticle has significant potential as a versatile heavy metal adsorbent for effective remediation. © 2020 Curtin University and John Wiley & Sons, Ltd.

For every ton of biodiesel produced, about 100 kg of glycerol is also generated as a by-product. The traditional method of removing glycerol is mainly by gravity separation or centrifugation. This method generates crude glycerol, which may still contain impurities such as methanol, oil, soap, salt, and other organic materials at ppm levels. The effective usage of crude glycerol is important to improve the economic sustainability of the biodiesel industry while reducing the environmental impacts caused by the generated waste. The application and value of crude glycerol can be enhanced if these impurities are removed or minimized. Thus, it is important to develop a method which can increase the economic and applicable value of crude glycerol. Therefore, in the present study, the dual step purification method comprised of acidification and ion exchange techniques has been used to purify the crude glycerol and convert it into higher-value products. The acidification process started with the pH adjustment of the crude glycerol, using phosphoric acid to convert soap into fatty acid and salts. Then, the pretreated glycerol was further purified by ion exchange with a strong cation H+ resin. Gas chromatography (GC) was used to analyze both crude and purified glycerol and expressed as the weight percentage of glycerol content. A maximum glycerol purity of 98.2% was obtained after the dual step purification method at the optimized conditions of 60% of solvent, the flow rate of 15 mL/min and 40 g of resin. Further, the glycerol content measured being within the accepted amount of BS 2621:1979. Therefore, this study has proven that the proposed crude glycerol purification process is effective in improving the glycerol purity and could enhance the applicability of glycerol in producing value-added products which bring new revenue to the biodiesel industry.

A visible light responsive photocatalyst, nano-sized copper doped TiO2/ZnO, was synthesized by sol gel method. It was characterized in terms of thermal stability, crystalline phase, crystal size, morphology, surface area, UV–Vis DRS and band gap. The results showed that the synergistic effect of copper ions considerably narrowed the band gap of the synthesized photocatalyst compared to TiO2/ZnO. Its photoactivity was then evaluated by measuring degradation efficiency of methyl orange (MO) and methylene blue (MB) in terms of colour, COD and TOC removal. The synergistic or antagonistic effects of different combinations of dye and catalyst concentrations, pH, intensity of light irradiation and reaction time on photoactivity of Cu-TiO2/ZnO were also investigated. The highest photoactivity achieved was 85.45% of colour, 70.56% of COD and 48.70% of TOC removal for MO and 73.20% of colour, 59.92% of COD and 38.77% of TOC removal for MB under optimal conditions.

Oxidative treatment of a cationic dye solution, methylene blue, was investigated using magnetite nanoparticles and goethite in heterogeneous Fenton-like reaction, and ferrous ions in homogeneous Fenton-reaction. The aim was to compare the degradation efficiencies of the studied catalysts for decolorization of methylene blue solution as the model organic pollutant. Response surface methodology (RSM) was applied to determine the optimal operational conditions for magnetite/H2O2 and goethite/H2O2 systems. The [H2O2] of 0.2 M, catalyst dosage of 1 g/L, pH 9.0 and reaction time of 5h were chosen by RSM. The pH value of 3.0 was used in the case of Fe+2/H2O2 system. The experimental results showed that homogeneous Fenton oxidation system was the most effective system under both acidic and neutral conditions but decreased at pH value of 9.0 due to the decrease in available Fe2+ ions in the solution and generation of ferric hydroxide sludge. Fe3O4/H2O2 system represented better removal efficiency than FeO(OH)/H2O2 system that could be attributed to the presence of FeII cations in magnetite structure and its larger surface area.

Cu–ZnO/TiO2 nanoparticles were prepared by entrapping copper ions into crystalline matrix of ZnO/TiO2 through sol–gel synthesis method. The photocatalyst matrix loaded with different copper concentrations was calcined at 500 and 700 °C. Thermal property, crystalline structure, surface morphology and absorption spectra of Cu–ZnO/TiO2 were characterized by thermogravimetric analysis, X-ray diffraction, scanning electron microscopy, transmission electron microscope and UV–Vis spectrophotometry. Besides, its specific surface area and band gap energy level were estimated through BET surface area method, Kubelka–Munk model and Planck’s equation. The results revealed that Cu–ZnO/TiO2 had a more thermally stable lattice compared to TiO2/ZnO and hence the phase transformation from anatase to rutile is retarded under higher calcination temperature in Cu–ZnO/TiO2 lattice. The photoactivity of Cu–ZnO/TiO2 was then evaluated through degradation of methyl orange under visible light irradiation. Among different samples, the samples that were calcined at 500 °C exhibited the highest photocactivity compared to those calcined at 700 °C. Cu–ZnO/TiO2 with a Cu content of 3 wt% was observed to have the maximum activity, giving C/C0 value of 0.03 after 150 min. This value was about 12 and 28.3 times higher than that of ZnO/TiO2 and TiO2, respectively.

A microbial fuel cell (MFC) is a sustainable technology which commonly uses graphite as cathode for the production of hydrogen peroxide. Besides, water formation through four-electron oxygen reduction mechanism is a commonly observed product. Determining the selectivity of H2O2/H2O reaction through experimental means is time consuming because of the slow kinetics of oxygen reduction reaction. Therefore, quantum chemical approaches are essential to comprehend the molecular nature of this process. Thus, density functional theory (DFT) was employed and quantum chemical calculations were performed to predict the chemical reactivity, stability, and thermodynamic properties of molecules participating in oxygen reduction reaction at graphite cathode. The calculations showed that graphene with higher value of “highest occupied molecular orbital” (HOMO), i.e., −4.544 eV has a higher tendency to donate electron for oxygen reduction reaction Furthermore, with an aim of predicting the most favorable conditions for H2O2 production, two different points, i.e., at the edge and middle of graphene plane were investigated. Calculated values showed that oxygen adsorption with the lowest energy requirement of 43.638 kcal/mol is energetically favorable at the edge of graphene plane. Nevertheless, oxygen complexes (O2*, HOO*, and HO*) characterized by high HOMO values −4.96, −4.37, and −4.34 eV are highly polarizable in the middle of the graphene plane. Furthermore, thermodynamic feasibility analysis showed that oxygen reduction required for hydrogen peroxide production had lower ΔG values of −90.94 (edge) and −98.44 (middle) kcal/mole than that of water synthesis (i.e., ΔG = −48.37(edge), −48.97 (middle) kcal/mole) at two-electron reduction step. Therefore, it was concluded that H2O2 which followed the lowest energy pathway would be more thermodynamically feasible compared to water synthesis. © 2017 American Institute of Chemical Engineers Environ Prog, 2017

In textile wastewater, ions such as Cl−, NO3−, SO42− added as salts (dye-enhancers), were reported to exacerbate the deactivation of TiO2 surface in aqueous media. The rate of degradation of a model cationic dye methylene blue (MB) with or without NaCl and nature of adsorbed species on pure anatase TiO2 were investigated, other factors considered were pH4 and pH10, ultraviolet light (UV). XPS analysis of samples T1–T8, shows varying values of percent atomic concentration (PAC) from fresh sample Tf. For Tf, Ti (25.88%) and O (68.07%) values were higher than in any other sample and has the least C (4.11%) with no traceable amount of N, S and Na. For the deactivated samples, in addition to basic elements Ti, O and C, there were traces of new elements, nitrogen (N) in T1 (N: 1.16%), no nitrogen or sulfur (S) in T2, in T3 (N: 3.34%, S: 0.84%), T4 (N: 3.17%, S: 1.72%), T5 (N: 1.46%), T6 (N: 1.16%), T7 (N: 3.21%, S: 0.97%) and T8 (N: 3.02%, S: 1.11%, Na: 3.02%), no Cl− was found in any sample. Shifts were observed in the XPS high resolution spectra (HRS) in C1s, O1s, Ti2p, N1s, S2p and Na1s regions. FTIR confirmed the new adsorbed species on deactivated samples (T1–T8).

We prepared a number of heterogeneous catalysts by exchanging the structural iron of magnetite with molybdenum ions. To obtain the optimum value, Mo at various concentrations was coprecipitated with iron species (Fe3−x Mo x O4, x = 0.028, 0.069, 0.13, and 0.21). Characterization revealed that all the samples had inverse spinel structure with excellent stability and magnetic properties. Higher Mo contents (x = 0.13 and 0.21) significantly improved the specific surface area of magnetite, leading to higher capacity for methylene blue (MB) adsorption. The catalytic performance of the samples for degradation of MB solution through Fenton reaction was then assessed. The Fe2.62Mo0.21O4 sample showed substantial activity, removing MB completely within 150 min. This enhanced activity is discussed based on the enlarged surface area, the role of surface Mo4+/Mo6+ redox pairs, and oxygen vacancies. Kinetic studies revealed that MB degradation by Fe3−x Mo x O4 nanoparticles in presence of H2O2 was well fit by a zeroth-order kinetics model. These results support use of such Fe3−x Mo x O4 materials as active magnetically separable heterogeneous catalysts, capable of degrading various contaminants through Fenton reaction.

Advanced oxidation process involves production of hydroxyl radical for industrial wastewater treatment. This method is based on the irradiation of UV light to photocatalysts such as TiO2 and ZnO for photodegradation of pollutant. UV light is used for irradiation in photocatalytic process because TiO2 has a high band gap energy which is around 3.2 eV. There can be shift adsorption to visible light by reducing the band gap energy to below 3.2 eV. Doped catalyst is one of the means to reduce band gap energy. Different methods are used for doped catalyst which uses transition metals and titanium dioxide. The band gap energy of three types of transition metals Fe, Cd and Co after being doped with TiO2, are around 2.88 ev, 2.97ev and 2.96 ev, respectively which are all below TiO2 energy. Some of the transition metals change the energy level to below 3.2 eV and the adsorption shifts to visible light for degradation of industrial pollutant after being doped with titanium dioxide. This paper aims at providing a deep insight into advanced oxidation processes, photocatalysts and their applications in wastewater treatment, doping processes and the effects of operational factors on photocatalytic degradation.

Microbial fuel cell is a sustainable and renewable technology which commonly uses graphite as cathode for hydrogen peroxide production. One of the limitations of using graphite cathode is the slow kinetics of oxygen reduction reaction. Nitrogen doping has been demonstrated to be an efficient approach to regulate the electronic as well as surface characteristics of graphite cathode. Therefore, in this study nitrogen doping of graphite cathode was performed to determine the feasibility of H2O2 production and energy generation in a dual chamber MFC. An integrated approach of quantum chemical calculation in combination with experimental investigation was used. Quantum chemical calculations confirmed the production of H2O2 with the lowest Gibb's free energy of −63 kcal/mol. For validation, ammonia treatment of graphite cathode was performed. The XPS analysis of doped cathode revealed the presence of Graphitic-N functionalization with overall N1s content of 2.96%. Cyclic voltammetric analysis of nitrogen doped cathode further confirmed the production of H2O2 at the peak current value of −4.0 mA and on-set potential of −0.55 V. Following CV analysis, hydrogen peroxide production experiments were performed in a dual chamber MFC. Maximum of 175 mg/L of H2O2 was obtained with simultaneous power generation of 47.61 W/m3, indicating the synergetic effect of nitrogen doped cathode. Thus, from the findings of quantum chemical evaluation and experimental investigation, it is concluded that nitrogen doping of graphite cathode is an efficient approach to improve the performance of MFC in terms of H2O2 production and power generation.

BACKGROUND Microbial fuel cells (MFCs) offer a sustainable and energy efficient solution for in situ hydrogen peroxide (H2O2) production with simultaneous power generation. In MFCs, H2O2 is produced as a result of two-electron oxygen reduction at graphite cathode surface. However, due to poor catalytic properties of graphite cathode high yields of H2O2 are not attained. Therefore, this study investigates the feasibility of in situ H2O2 production in MFC for recalcitrant wastewater treatment. METHODOLOGY AND RESULTS In this study, a dual chamber MFC was used. A heat-treated graphite electrode was used as cathode and Nafion-117 as membrane. Cyclic voltammetric analysis was also performed to study the potential of heat-treated graphite cathode for H2O2 production. Experimentally, a maximum of 140 mg L−1 of H2O2 was produced with simultaneous power generation of 33.52 W m−3. Consequently, in situ Fenton oxidation experiments were performed and compared with conventional Fenton oxidation using a recalcitrant pollutant i.e. Acid Blue 113 dye. On average, 24% difference between the performance of the Fenton and in situ Fenton oxidation was observed while 42% reduction in the cost of process was obtained in the case of the in situ Fenton oxidation process. CONCLUSION The current study proved that MFC is a sustainable solution for in situ Fenton oxidation (followed by H2O2 production) with less requirement of H2O2. © 2017 Society of Chemical Industry

In this work, a study was conducted to estimate carbon dioxide (CO2) emission of plastic resins produced from recycled plastic wastes in a medium-sized plant in Malaysia. The feasibility of using cleaner production (CP) strategies to reduce CO2 was evaluated. For this purpose, a CP audit was conducted to quantitatively identify major entities that contributed to CO2 inside the boundary of the plant. The result showed that the plant generated 0.84 kg CO2/kg resins produced, which contributing to 1.9 million tons of overall annual CO2 generated from Malaysian plastic industry. In detail, 73.8% of the emission generated in the studied plant was contributed by electricity consumption, followed by solid waste generation (23.3%) and diesel consumption (2.3%). The value is lower than a virgin plastic resins producing plant, which has a CO2 value of 2 kg CO2/kg resins produced. After the audit, a total of four potential CP options were generated focusing on reducing energy consumption. Implementation of these options was expected to reduce CO2 generated from energy consumption by 0.11 kg CO2/kg resins produced, a reduction of about 18%. The study proved that CP strategies could be implemented to reduce CO2 of recycled-plastic resins producing plant.

Microalgae biomass is well known as a potential sustainable product for bio-based industry, which has reported encountering numerous difficulties during biomass harvesting and recovering. This study examined the effect of pH (5–12) and alum dosage (30–180 mg/L) for microalgae Botryococcus sp. harvested via flocculation technique. The optimum pH condition for Botryococcus sp. harvesting was measured to be 9.2, and the alum dosage was 100 mg/L. Both optimum values successfully harvested up to 95% microalgae biomass. This study revealed that flocculation efficiencies for alum are highly dependent on the range of pH and coagulant dosage that were applied during the process. Use of flocculation technique with alum as a coagulant represents a convenient technique for Botryococcus sp. biomass harvesting and is recommended for use in both small- and large-scale biomass industries.

In this work, quantum chemical analysis was used to predict the degradation potential of a recalcitrant dye, Acid blue 113, by hydrogen peroxide, ozone, hydroxyl radical and sulfate radical. Geometry optimization and frequency calculations were performed at 'Hartree Fock', 'Becke, 3-parameter, Lee-Yang-Parr' and 'Modified Perdew-Wang exchange combined with PW91 correlation' levels of study using 6-31G* and 6-31G** basis sets. The Fourier Transform-Raman spectra of Acid blue 113 were recorded and a complete analysis on vibrational assignment and fundamental modes of model compound was performed. Natural bond orbital analysis revealed that Acid blue 113 has a highly stable structure due to strong intermolecular and intra-molecular interactions. Mulliken charge distribution and molecular electrostatic potential map of the dye also showed a strong influence of functional groups on the neighboring atoms. Subsequently, the reactivity of the dye towards the oxidants was compared based on the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy values. The results showed that Acid blue 113 with a HOMO value -5.227 eV exhibits a nucleophilic characteristic, with a high propensity to be degraded by ozone and hydroxyl radical due to their lower HOMO-LUMO energy gaps of 4.99 and 4.22 eV respectively. On the other hand, sulfate radical and hydrogen peroxide exhibit higher HOMO-LUMO energy gaps of 7.92 eV and 8.10 eV respectively, indicating their lower reactivity towards Acid blue 113. We conclude that oxidation processes based on hydroxyl radical and ozone would offer a more viable option for the degradation of Acid blue 113. This study shows that quantum chemical analysis can assist in selecting appropriate advanced oxidation processes for the treatment of textile effluent.

The increase in agricultural waste has been one of the main concerns today. Usually, the excessive waste is dumped in the landfill without any consideration to the environment. Previous research has found that waste containing highly reactive silica can react with calcium hydroxide in concrete resulting in a compact concrete microstructure. Hence, this paper focuses on the mechanical properties of concrete containing Palm Oil Fuel Ash (POFA) and Rice Husk Ash (RHA) as replacement of cement in concrete and also the combination of both materials as pozzolan in one concrete mix. Properties studied include its workability for fresh concrete, and compressive strength of hardened concrete. Replacement level for POFA and RHA was at 10%, 15%, 20%, 25%, and 30% by weight of Ordinary Portland Cement (OPC). Results show that the addition of 10% to 30% of POFA and RHA reduces concrete workability from 35 mm to 20 mm for POFA and 39 mm to 21mm for RHA. Replacement of POFA and RHA at 10% has the highest compressive strength compared to other replacement level. Finally, the optimum combination for POFA and RHA to achieve the targeted strength of 30 MPa was recorded at 10% POFA and 15% RHA.

This present research aims to synthesize and investigate the adsorption potential of sugarcane bagasse (SCB) impregnated with iron oxide (Fe3O4) for dye removal. The surface morphology and functional groups of the newly developed adsorbent (ISCB) were studied using Scanning Electron Microscopy/Energy-dispersive X-ray spectroscopy (SEM/EDX), Fourier transforms infrared spectroscopy (FTIR), and X-ray powder diffraction (XRD) analysis. The effects of the operating parameters, including initial dye concentration, adsorbent dosage, contact time and initial pH of the dye solution on the adsorption efficiency were investigated to identify an optimal condition. The characterization of SEM-EDX and FTIR analyses shows that ISCB has a porous structure and carbon-containing functional groups. The adsorption result revealed that ISCB removed 93.7% of dye, 88.8% of color and had a dye adsorption capacity of 7.2 mg/g within 6 h of contact time using 0.7 g/L of ISCB at pH 8.4. The result obtained fitted well for Langmuir isotherms, and adsorption process followed the pseudo-second-order kinetic model. In conclusion, this study proved that ISCB has the potential to be used as an effective and low-cost adsorbent to remove dyes from wastewater.

There is a renewed interest in the application of chitosan-based drug delivery systems over the last few years. In this study, the ionic gelation method was used to prepare chitosan-engaged tripolyphosphate ions, as the cross-linking molecule, (Chit-TPP) and concurrent loading of the biomolecules of the ethanolic extract of fennel, Foeniculum vulgare, seed (FEC@NBC). The samples were characterized by SEM, DLS, TGA, FTIR, XRD, GC-MS, and zeta potential, and their effects on the related hormonal and biochemical factors of the rats with polycystic ovarian syndrome (PCOS) were assessed. The estradiol valerate-induced PCOS in female rats was confirmed by vaginal smear test and subsequent histological screening. The PCOS-induced rats were treated by fennel seed extract (FSX), Chit-TPP, and FEC@NBC. The process of treatment was monitored by measuring the serum levels of testosterone, luteinizing hormone, follicle-stimulating hormone, insulin, glucose, high-density lipoprotein cholesterol, total cholesterol, and total triglyceride after 16 days of treatment and compared with healthy control and untreated PCOS-control groups. The FEC@NBC administration contributed to the remarkable hormonal, glucose, and lipid profile regulation in the rats with PCOS. The significance of FEC@NBC performance in dealing with PCOS complications compared to that of the only extract could be resulted from the effective targeted delivery and stability of phytomolecules when encapsulated in Chit-TPP.

Microbial fuel cell (MFC) is a sustainable and energy efficient technology, which uses graphite as cathode for hydrogen peroxide (H2O2) production often with simultaneous power production. Nevertheless, slow kinetics of oxygen reduction reaction (ORR) at the surface of graphite often results in poor performance of MFC. In an attempt to improve the performance of MFC for in-situ H2O2 production, a treatment of graphite cathode using nitric acid was performed. The treatment was conducted in three steps (i) heat treatment at 450°C for 2 h; (ii) acid treatment with concentrated nitric acid for 5 h; and (iii) drying at 120°C for 2 h. After the treatment, four times increase in surface area of treated cathode (GR-HA) was observed. Energy-dispersive X-ray spectroscopy (EDX) and Fourier transform infrared (FTIR) analysis revealed the presence of nitrogen and quinone based functional groups on the surface of GR-HA. Cyclic voltammetric (CV) analysis of GR-HA cathode further confirmed the production of H2O2 at the peak current value of −3.7 mA and on-set potential of −0.1 V. Following CV analysis, H2O2 production experiments were performed in a dual chamber MFC using GR-HA as cathode. Maximum 150 mg/L of H2O2 was produced with simultaneous power production of 36.438 mW/m2. Approximately, 25% increase in both H2O2 and power production was observed in the case of G cathode. Subsequently, Fenton oxidation experiments were performed (with GR-HA and GR-CA cathodes) to determine the efficacy of in-situ produced H2O2. This resulted in an increase of 8.28%, 11.04%, and 31.32% in decolorization, chemical oxygen demand (COD), and Total Organic Carbon (TOC) removal efficiency, respectively. © 2016 American Institute of Chemical Engineers Environ Prog, 36: 382–393, 2017

This paper reports the leaching behaviour of pineapple skins incorporated in the artificial reef fabricated from recycle aggregate concrete. Pineapple skin was mixed with the concrete as added material which produce nutrients to attract fish habitat. Material test was conducted on the concrete reef specimens to determine its compressive strength. The nutrients dispersed were measured by using total phosphorus and nitrate test of the water sample collected from each of the artificial reef within the six days duration. Results showed the compression strength of the reef decreased with the increase of percentage pineapple skin used. However, it was found that the total phosphorus and nitrate leached from the reef increased gradually with time as the percentage of pineapple skin used increased.

One of the most pivotal limitations of TiO 2 or ZnO based lattices is their photocatalysis activity under visible light irradiation. In this study, a hybrid photocatalyst was generated by doping TiO 2 /ZnO lattice with copper in order to improve their photo-activity. The main aim was to analyse the sensitivity of photoactivity of Cu–TiO 2 /ZnO toward operating conditions in advanced oxidation reaction for photodegradation of two different dyes under visible light irradiation. The sol–gel-prepared composite was characterized in detail to confirm its properties in terms of band gap, crystalline structure/size, optical absorption and surface area. Then, ANFIS (Adaptive Neuro Fuzzy Inference System) was employed to investigate the effects of five independent variables including dye and catalyst concentrations, pH, intensity of light irradiation and reaction time on the photocatalytic performance of Cu–TiO 2 /ZnO. This process includes several ways of discovering a subset from the group of the recorded parameters and predicting which variable has the strongest effect on the response of interest. Besides, variable search was performed using the ANFIS network. According to variable selection using ANFIS analysis, catalyst concentration and reaction time were the most effective parameters for MO degradation whereas dye concentration and pH were the most influential factors on MB removal using Cu–TiO 2 /ZnO. Furthermore, Cu–TiO 2 /ZnO photocatalyst presented the maximum removal efficiency of: color: 83.35%, COD: 73.54% and TOC: 54.46% for MO degradation and color: 75.50%, COD: 68.00% and TOC: 46.41% for MB degradation.

Iron based heterogeneous catalysts are widely used in many industrial applications including Fenton Oxidation Processes (FOPs) to treat the effluents containing recalcitrant contaminants such as dyes. In this work, Metal–Organic Framework (MOF) derived iron nano oxide particles supported on ZSM-5 zeolite were synthesized under optimized experimental conditions. The Central Composite Design (CCD) method was employed to optimize the yield of the catalyst. The catalyst was then characterized using EDX, SEM, HRTEM, FTIR, STA and BET. Subsequently, the catalytic activity of the catalyst in the Fenton oxidation process was evaluated based on the degradation of the model azo dyes Acid Blue 113, Methyl Orange, and Reactive Black. The optimized experimental yield was 81.5%, which was in agreement with the CCD prediction. Apart from high catalyst yield, excellent mineralization efficiency was obtained where 77%, 71% and 68% of Total Organic Carbon (TOC) removal were achieved for Acid Blue 113, Methyl Orange, and Reactive Black 5, respectively. Based on the yield and activity, it was concluded that the synthesized Fe-ZSM-5 is a promising catalyst for the Fenton oxidation process.

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.

Deep oxidative desulfurization of model diesel consisting of thiophene, dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) was investigated with various oxidants followed by extraction step using dimethylformamide (DMF). Response surface methodology based on Box–Behnken design was used to evaluate the effects of the main operating parameters, including the oxidant to sulfur molar ratio (2.0–4.0), oxidation temperature (40–60 °C) and oxidation time (10–60 min), on the 4,6-dimethyldibenzothiophene conversion. Among the oxidants used; tert -butyl hydroperoxide (TBHP) was led to the highest oxidation of model sulfur compounds. Meanwhile, the statistical results revealed that TBHP/sulfur ratio was the most important parameter followed by oxidation time and oxidation temperature. The optimum oxidative desulfurization conditions for 4,6-DMDBT conversion had been attained at TBHP/sulfur ratio of 3.0, temperature of 48 °C and period time of 31 min, respectively with the highest conversion of 4,6-DMDBT of 84.5%. The experimental optimum yield fitted-well with the predicted value with less than 5% error. The mechanistic study showed that the reaction between TBHP and 4,6-DMDBT was efficient to produce corresponding sulfoxide, instead of sulfone compound.

The electrocoagulation (EC) of Congo red dye-containing wastewater was investigated, focusing on the optimization of operational parameters and process mechanism. The EC was conducted using iron electrodes and utilizing Congo Red (CR) dye as a model pollutant. Response surface methodology (RSM) was used to investigate the effect of operational parameters (initial dye concentration, pH and inter-electrode distance) and optimize the process. To provide insight into the process mechanism, quantum chemical analysis and FTIR were utilized. The process achieved 89% and 97% COD and color removal respectively under optimum conditions (1000 mg/L initial dye concentration, pH 3 and 3 cm inter-electrode distance). The electrical energy required to achieve the optimum COD removal was estimated to be about 36.9 kJ. The quantum analysis showed that CR with HOMO energy of −5.58 eV and Fe3+ LUMO energy of −15.09 eV exhibit electron donating and electron accepting tendency respectively. In addition, Fe3+ shares its LUMO with the HOMO of HO– due to the lower energy gap of −19.47 eV, which leads to the formation of monomeric coagulant such as Fe(OH)3 and the subsequent polymeric flocculants including Fe2(OH)24+ and Fe6(OH)153+. The FTIR analysis of the sludge indicates the presence of coagulant species i.e. Fe(OH)3, Fe(OH)2+, Fe(OH)2+ and Fe2(OH)24+ that are generated from the EC. The findings of this study show that quantum chemical analysis and RSM are suitable for investigating the mechanism and optimization of EC as applied to textile effluents.

In this research, a milk thistle seed extract (MTSE)-rich medium was used as a capping and reducing agent for the one-pot biosynthesis of ZnO/Ag (5 wt%) nanostructure. The sample was systematically characterized through various techniques and its strong biomolecule‒metal interface structure was supported by the results. The efficacy of the derived nanostructure (MTSE/ZnO/Ag) was evaluated in vivo on the basis of its therapeutic effects on the main complications of Type 1 diabetes (hyperglycemia, hyperlipidemia, and insulin deficiency). For this purpose, the changes in the plasma values of fasting blood glucose, total cholesterol, total triglyceride, high-density lipoprotein cholesterol, and insulin in alloxan-diabetic Wistar male rats were compared with those in healthy and untreated diabetic controls after a treatment period of 16 days. The antidiabetic results of MTSE/ZnO/Ag were compared with those obtained from pristine ZnO, MTSE, and insulin therapies. The health conditions of the rats with Type 1 diabetes were significantly enhanced after treatment with MTSE/ZnO/Ag (p 0.05), which is owing to the enhanced interface structure and participatory functions of the united compartments of MTSE/ZnO/Ag.

Landfills generate leachate that contains elevated concentration of contaminants and is hazardous to human health and the ecosystem. In this study, the mixture of granular feldspar and cockle shells was investigated for remediation of COD and ammonia from landfill leachate. All adsorbent media were sieved to a particle size between 2.00 and 3.35 mm. The results revealed that the optimum mixing ratio of feldspar and cockle shells was 20:20, shaking speed was 150 rpm, pH level was 6, shaking time was 120 min, and dosage was 30 g. The adsorption isotherm analysis reveals that the Langmuir isotherm yielded the best fit to experimental data as compared to the Freundlich isotherm. The media produce encouraging results and can potentially be used as a good and sustainable adsorbent.

A magnetic graphene oxide (MGO) was developed for the adsorption of As(III) from aqueous solution. The characteristics of MGO were investigated using Fourier-transform infrared (FTIR), X-ray diffraction and field emission scanning electron microscope-E/energy-dispersive X-ray analyses. Batch adsorption experiments were designed using central composite design, and the effects of adsorbent dosage, pH, contact time and concentration of As(III) were investigated. The MGO showed an excellent performance, removing up to 99.95% of As(III) under the following condition: initial As(III) concentration = 100 mg/L, pH = 7, adsorbent dosage = 0.3 g/L and contact time = 77 min. MGO dosage and initial pH were the most significant parameters influencing the process performance. FTIR analysis of the used adsorbent confirms the adsorption of As(III) through complexation between surface functional groups of the MGO and the oxyanions of As(III). The adsorbent maintained a significant level of performance even after four cycles of adsorption. Thus, the developed MGO has the potential to be used for the abatement of arsenic pollution.

The presence of recalcitrant organic pollutants in the environment has become a source of concern due to their detrimental effects. Effective technologies are therefore necessary. The combination of adsorption and advanced oxidation processes is emerging as a green technology for removing organic pollutants. Here, we review the applications of adsorption-advanced oxidation processes to remove organic pollutants from waters. We discuss the fundamentals and synergistic performance of adsorption-Fenton, adsorption-photocatalysis, ultrasound-adsorption and adsorption-Ozonation. There is a growing trend in using bifunctional materials that can act both as adsorbents and catalysts in photocatalysis and heterogeneous Fenton oxidation. Ultrasound irradiation is commonly combined with adsorption to enhance mass transfer through cavitation. However, the contribution of the cavitation-generated radicals has not received much attention. While previous studies have given more emphasis on the synergy of the combined processes in pollutants removal, we highlight the potential of the oxidation processes to simultaneously regenerate adsorbents in the combined processes.

Systematic experiments were conducted to investigate the most appropriate extraction conditions for sulfur reduction. Initial extraction studies showed that DMF was the most potentially effective solvent. The influence of DMF to diesel ratios, extraction times and temperatures, addition of co-solvent, solvent mixtures, double extractions were explored. The use of co-solvent and solvent mixtures showed poor efficiencies of sulfur removal. A two-stage extraction with ratio of 1:1 (DMF/Diesel) was successfully removed over 88.0% of sulfur in diesel. Under Box–Behnken design, the model showed that maximum extraction ability was observed at 30 °C, 30 min and 1.0 of DMF/diesel ratio to achieved 67.5%.

The altered activity of the fructose transporter GLUT5, an isoform of the facilitated-diffusion glucose transporter family, has been linked to disorders such as type 2 diabetes and obesity. GLUT5 is also overexpressed in certain tumour cells, and inhibitors are potential drugs for these conditions. Here we describe the crystal structures of GLUT5 from Rattus norvegicus and Bos taurus in open outward- and open inward-facing conformations, respectively. GLUT5 has a major facilitator superfamily fold like other homologous monosaccharide transporters. On the basis of a comparison of the inward-facing structures of GLUT5 and human GLUT1, a ubiquitous glucose transporter, we show that a single point mutation is enough to switch the substrate-binding preference of GLUT5 from fructose to glucose. A comparison of the substrate-free structures of GLUT5 with occluded substrate-bound structures of Escherichia coli XylE suggests that, in addition to global rocker-switch-like re-orientation of the bundles, local asymmetric rearrangements of carboxy-terminal transmembrane bundle helices TM7 and TM10 underlie a 'gated-pore' transport mechanism in such monosaccharide transporters., 糖分を細胞内に輸送する膜たんぱく質の立体構造と動きを解明 -肥満やがんの抑制策に役立つ新たな知見-. 京都大学プレスリリース. 2015-10-01.

Greywater (GW) is identified as waste disposal from home activites that is discharging from laundry, bath and wash-basin. GW useful in irrigation of a garden and aids to reduce cost as well as maintain the environmental prosperity. This paper discussed the effectiveness of Botryococcus sp. to clean GW in phycoremediation treatment. This process involves as growing the Botryococcus sp. in the GW which is contributing to utilize supplements in GW for its grow. The results indicated that Botryococcus sp. is effective to reduce COD (88%), BOD (82%), TIC (76%), TC (58%), TN (52%), TOC (39%), Phosphate (37.5%) and pH (7%) for 100% concentration of GW. Meanwhile, for the 50% of GW concentration Botryococcus sp. capable to remove such as COD (83%), TIC (82%), BOD (68%), TN (67%), Phosphate (36.8%), TC (34%), TOC (31%) and pH (1.2%). Then, the study concludes that Botryococcus sp. can grow effectively in GW and be able to reduce the rate of nutrient in GW.

Coagulation and flocculation are essential processes in a number of diverse disciplines, including biochemistry, cheese manufacturing, rubber manufacturing, and in water and waste water treatment. Coagulation-flocculation is effective for removing high concentration organic pollutants and heavy metals in water and wastewater. However, limited information exists on the efficiency of this coagulation-flocculation process for biodiesel wastewater treatment. The biodiesel wastewater is basic (alkaline), with a high content of oil and grease, and a low content of nitrogen and phosphorus. As such, biological treatment of the biodiesel wastewater is expected to be very difficult. For this reason supportive physic-chemical methods are often used. Although one of the most frequently employed method is coagulation. Therefore, this study was conducted to investigate the efficiency of coagulation and flocculation processes for removing suspended solid (SS), color, COD and oil and grease from biodiesel wastewater. Aluminum sulfate, polyaluminum chloride, ferric chloride and ferric sulfate as a coagulant in biodiesel wastewater treatment were studied using a standard jar test apparatus. The result shows that, at the optimum dose of PAC (300 mg/L), the percentage removal of SS, color, COD and oil and grease respectively 97%, 95%, 75% and 97% compared to only 92%, 92%, 53% and 99% at the optimal dose alum (500 mg/L), 95%, 93%, 63% and 97% at the optimum dose of ferric chloride (350 mg/L) and 88%, 88%, 54% and 94% at the optimum dose of ferric sulfate (450 mg/L). The effect of coagulant dosages on suspended solid (SS), color, COD and oil and grease removal showed similar trend and PAC was found to be superior was observed at reasonable lower amount of coagulant i.e. 300 mg/L. The results showed that coagulation-flocculation is effective as a pre-treatment for treating biodiesel wastewater.

Dairy wastewater are usually much polluted due to the high level of nutrient content such as phosphate, nitrate, sulfate etc. The pollution level are indicated by few characteristics such as BOD (243 mg/L), COD (324 mg/L), pH (9.08), Total Nitrogen (65.06 mg/L), Total Organic Carbon (143.3 mg/L), Total Carbon (312.9 mg/L) and Inorganic Carbon (169.6 mg/L). In this study, Botryococcus sp., a species of green microalgae are used to determine whether it can purify dairy wastewater. In spite of that, the microalgae growth over phycoremediation process also determined daily based on hemocytometer counting. From 100% concentration of dairy wastewater, Botryococcus sp. was capable to reduce the parameters such as BOD of 73.3%, TOC of 65.1%, TC of 61.4%, IC of 58.3% and COD of 48.8% on the 15 days of phycoremediation. Meanwhile, for the 50% of dairy wastewater, the same microalgae be able to remove the parameter such as phosphate of 78.7%, BOD of 73.8%, TOC of 70%, TC of 68,8%, IC of 59.4% and COD of 50%. The overall result from this study shown that the Botryococcus sp. is useful to reduce the inorganic and organic pollutant in dairy wastewater and could be potential to be used for any different wastewater.

Fenton Process, a type of Advanced Oxidation Processes is an efficient method for treating textile wastewaters. However, excessive use of hydrogen peroxide and catalyst has made this process economically non-feasible. Besides, industrial grade hydrogen peroxide costs 390-500 per ton. One of the means to overcome this problem is the in-situ production of hydrogen peroxide. In this paper, a detailed review was conducted on the generation methods, degradation potential and optimum operating parameters for in-situ production of hydrogen peroxide/hydroxyl radicals. Additionally the scavenging aspect for hydroxyl radicals was also investigated. From this review, it can be concluded that hydroxyl radical is highly oxidative and non selective in nature and its in-situ production can be performed through application of catalyst, ozonation, photocatalysis, electro and microbial fuel cells. Furthermore, optimization of operating parameters can result in an increase in the yield of hydroxyl radicals/hydrogen peroxide. Sonolysis as an auxiliary tool has potential to induce synergetic effects in combination with Advanced Oxidation Processes to increase in-situ hydrogen peroxide production. However, the problem of the scavenging effect is an aspect that needs to be dealt with, as hydroxyl radicals are prone to deactivation by scavengers. Therefore based on the review, it is concluded that insitu production of hydrogen peroxide/hydroxyl radical for treating textile wastewater is economically viable and practically feasible if careful selection of process is conducted through selective research. (C) 2014 Elsevier Ltd. All rights reserved.

The hydrodesulfurization (HDS) technique available is no longer suitable for the purpose of achieving ultra-low sulfur diesel. Therefore, in this study, the catalytic oxidative desulfurization of model diesel was carried out using tert-butyl hydroperoxide along with inexpensive alumina-supported manganese-based oxide catalysts, and later, the oxidized sulfur compounds were extracted by dimethylformamide, a polar solvent. The effect of dopant ratio, calcination temperature, reaction time, and reaction temperature were investigated in detail. The oxidation reactivity of different substrates was in the following order: DBT > Th > 4,6-DMDBT. The best desulfurization efficiency of model diesel, under mild reaction conditions, was 85.3 % thiophene, 85.0 % dibenzothiophene, and 74.5 % 4,6-dimethyldibenzothiophene using the 2.14 %Co/13.17 %Mn/Al2O3 catalyst calcined at 400 °C. Besides, this catalyst retained a high conversion of sulfur after three rounds of reaction cycles and can be used as a reusable active catalyst in ODS treatment. Under the optimal conditions, the S-content in the commercial diesel could be decreased from 415 to less than 10 ppmw. The oxidation mechanism was studied in detail, and TBHP-Co/Mn catalyst was the main active oxidizing species on the oxidation of DBT.

Graphene-based adsorbents have attracted wide interests as effective adsorbents for heavy metals removal from the environment. Due to their excellent electrical, mechanical, optical and transport properties, graphene and its derivatives such as graphene oxide (GO) have found various applications. However, in many applications, surface modification is necessary as pristine graphene/GO may be ineffective in some specific applications such as adsorption of heavy metal ions. Consequently, the modification of graphene/GO using various metals and non-metals is an ongoing research effort in the carbon-material realm. The use of organic materials represents an economical and environmentally friendly approach in modifying GO for environmental applications such as heavy metal adsorption. This review discusses the applications of organo-functionalized GO composites for the adsorption of heavy metals. The aspects reviewed include the commonly used organic materials for modifying GO, the performance of the modified composites in heavy metals adsorption, effects of operational parameters, adsorption mechanisms and kinetic, as well as the stability of the adsorbents. Despite the significant research efforts on GO modification, many aspects such as the interaction between the functional groups and the heavy metal ions, and the quantitative effect of the functional groups are yet to be fully understood. The review, therefore, offers some perspectives on the future research needs.

The usage of precast aerated concrete panel as an IBS system has become the main alternative to conventional construction system. The usage of this panel system contributes to a sustainable and environmental friendly construction. This paper presents an overview of the precast aerated concrete panel with added fibrous material (PACP). PACP is fabricated from aerated foamed concrete with added Polypropylene fibers (PP). The influence of PP on the mechanical properties of PACP are studied and reviewed from previous research. The structural behaviour of precast concrete panel subjected to flexure load is also reviewed. It is found that PP has significant affects on the concrete mixture’s compressive stregth, tensile strength and flexural strength. It is also found that PP manage to control the crack propagation in the concrete panel.

An experimental study was conducted to improve the strength of foamed concrete by adding fibres reinforced material, polypropylene (PP) fibres. The aim of the study was to determine the effect of PP fibres on the microstructure and tensile strength of foamed concrete. Foamed concrete with density 1600 kg/m 3 and 1800 kg/m 3 were cast and tested with 0.05%, 0.10% and 0.15% percentage of PP fibres. The findings shows that foamed concrete added by PP fibres gave better performance in tensile strength compared to foamed concrete without PP fibres. With the addition of 0.05% of PP fibres, the tensile strength increased by 35.06% and 40.30% for foamed concrete with densities 1600 kg/m 3 and 1800 kg/m 3 , respectively. Through the study of microstructure of foamed concrete, the air voids of foamed concrete with various densities and the interfacial adhesion between concrete and fibres were observed. The foamed concrete added by PP fibres gave better performance in tensile strength compared to foamed concrete without PP fibres.

Due to the rising demand of infrastructure development, concrete has been one of the vital ingredients in this field considering its flexibility to mould any structural shape and design. This paper investigates the effect of adding polypropylene fibres on the mechanical and fresh properties of self-compacting concrete (SCC). The mechanical property tests were conducted on various SCC specimen which include cubes, cylinders and beams to determine its compressive strength, splitting tensile strength and flexural strength of concrete. The workability of self-compacting concrete in terms of viscosity is determined from slump flow test (Diameter and T500), and V-funnel. The results indicated that the addition of polypropylene fibres improved the mechanical properties of SCC at almost every volume fraction considered in this study. It was also observed that the addition of 0.1% fibre significantly enhanced the splitting tensile strength and flexural strength of concrete. Finally, the overall results indicated that introducing fibres to concrete would result in a noticeable decrease in workability and fresh state properties.

Iron oxides are conventionally used as adsorbent and/or heterogeneous catalyst because of their abundance, easy magnetically separation, affordability, and applicability in broad pH range. This is especially reported for magnetite due to the presence of Fe2+ cations in its structure. However, the pure magnetite has lower adsorption capacity and degradation rate in Fenton reaction, which led to the introduction of transition metal-substituted magnetite (TMSM). This section gives an overview on the adsorption potential and Fenton catalysis performance of various transition metal-substituted magnetite samples. This recently introduced group is produced with incorporation of appropriately identified transition metal/metals into the naturally available magnetite with simple synthesis method. TMSM has showed a great capacity for treating polluted water bodies using physical and chemical processes. A combination of factors affects the activity: the increased adsorption capacity of the samples evidenced by larger surface area, the participation of thermodynamically favorable redox pairs in regeneration of Fe2+ and •OH radical generation, and the presence of oxygen vacancies serving as active sites on the surface of TMSM. Nevertheless, there is a need for further understanding and expansion of this class of adsorbents and heterogeneous catalysts.

Application of the Fenton process for textile wastewater treatment is limited due to high treatment cost, substantially contributed by the un-availability of cheap hydrogen peroxide. Therefore, alternative methods for hydrogen peroxide production are in demand. One such option is in situ hydrogen peroxide production using a wastewater based microbial fuel cell (WBMFC). However, not much have been published regarding in situ production of hydrogen peroxide for textile wastewater treatment in a WBMFC. Therefore, in this work the concept, advantages, challenges and prospects of using WBMFC to treat textile wastewater by simultaneously producing hydrogen peroxide (hence in situ hydrogen peroxide) and power are reviewed. The concept of WBMFC is the reduction of oxygen in the presence of electrons and protons from the anode chamber to produce hydrogen peroxide with simultaneous power production. This review confirms that use of dual chambers, proton exchange membrane, domestic or municipal wastewater/Geobacter Sulfurreducens or Shewanella species, pure graphite cathode, ammonia and heat treated carbon-based anode can treat most textile wastewaters. However, single chamber WBMFCs can be used as a low power source for an electro-Fenton reactor. Power produced can be used to provide energy for aeration required in the WBMFC, thus providing an integrated and sustainable solution for textile wastewater treatment. © 2014 Society of Chemical Industry