Jatropha curcas: Plant of Medical Benefits

Plants are a rich source of many natural products most of which have been extensively used for human welfare, and treatment of various diseases. Jatropha curcas, a multipurpose, drought resistant, perennial plant belonging to Euphorbiaceae family is gaining a lot of economic importance because of its several potentials in industrial application and medicinal values. J. curcas has been used as traditional medicine to cure various infections. Researchers had isolated and characterized numerous biologically active compounds from all parts of this plant. In addition, the mechanisms of action of these active compounds have been studied in relation to the applications in traditional medicine. Before exploiting any plant for medicinal application, it is crucial to have complete information about the medicinal uses of each part of the plant. The medicinal uses of the leaves, fruit, seed, stem bark, branches, twigs, latex and root of J. curcas are discussed in this review. If the full potential of the plant is to be revealed, much more research is required to develop herbal medicine using modern science and technology. A potential aspect based on markets for all of its medicinal products should be conducted thoroughly, to promote the ability of this plant to cure so many illnesses

Effects of Electrode Materials on Power Generation of Microbial Fuel Cell

Energy shortage and environmental pollution mainly caused the global energy crisis which led to serious impact on human survival and development. Microbial fuel cells (MFCs) exactly meet the requirements to alleviate the global energy crisis because it has the ability to treat the wastewater and produce electricity concurrently. MFCs are considered as one of the promising technology in the wastewater treatment technology. The power output depends on various factors such as substrate degradation, electrode material, rate of electron transfer from bacteria to the anode, circuit resistance, proton mass transfer in the liquid, external operating conditions and so on. Electrode material is one of the key factors which affect the performance of MFC. Therefore, it is of great significance to select and develop suitable electrode materials to optimize and promote the performance of MFCs. Each electrode material has its own physical and chemical properties such as surface area, electric conductivity and chemical stability. In this research, we have tested two different electrode materials such as; polyacrlyonitrile carbon felt (PACF) and single forward carbon cloth (SFCC) to study the effects of different electrode materials on MFC performance. The results showed that MFC with SFCC using raw POME showed high power density (102.5mW/m2) compared to PACF (45mW/m2). But COD removal efficiency with raw POME of SFCC (43%) and PACF (45%) were not shown much difference. The coulombic efficiency of 1:50 diluted POME reached upto 26% for SFCC whereas for PACF 24% was achieved. SFCC achieved the highest coulombic efficiency and power output than PACF, indicating SFCC facilitate the biofilm formation and improve power generation

Sulfuric Disazo Dye Stabilized Copper Nanoparticle Composite Mixture: Synthesis and Characterization

A copper nanoparticle–sulfuric disazo dye (Cu–SD1) composite was synthesized using the sol–gel method. Cu–SD1 nanocomposite formation was monitored by ultraviolet-visible spectroscopy (UV-vis). The acquired experimental results suggested that 8 h of reaction is needed for the synthesis Cu0 nanoparticles. Transmission electron microcopy (TEM) and atomic force microscopy (AFM) were employed to elucidate the morphology of the Cu–SD1 nanocomposite. It was found that the diameter of particle sizes were in the range of 2–4 nm. The interaction of SD1 with copper was confirmed by Fourier transform infrared spectroscopy (FTIR). The peak shift of O–H and C–OH functional groups indicated the interaction between SD1 and copper nanoparticles. Moreover, the azo group (N[double bond, length as m-dash]N) peaks were suppressed after the formation of the nanocomposite, suggesting that a strong linkage was formed between the functional groups and the copper nanoparticles. The surface composition and chemical states of the as-synthesized copper nanoparticles were elucidated by X-ray photoelectron spectroscopy (XPS). In addition, photo-switching of the composites was elucidated in the solution state. It was found that the Cu–SD1 nanocomposite has a faster switching response compared to the parent, SD1, in a solution

CeO2-TiO2 for Photoreduction Of CO2 To Methanol Under Visible Light: Effect Of Ceria Loading

A visible light-driven photocatalyst, CeO2-TiO2 catalyst with different ceria loading was synthesized by impregnation method between TiO2 powder and cerium oxide nanoparticles slurry. The prepared catalyst samples were characterized by X-ray diffraction (XRD), surface area analysis, UV-vis absorption spectroscopy and photoluminescence spectroscopy (PL). The band gap of CeO2-TiO2 catalyst was found to be 2.15–2.4 eV. The band gap reduction clearly indicated the successful loading of CeO2 on TiO2. The photocatalytic activity was determined by measuring the photoreduction of CO2 to methanol in aqueous solution under visible light. The effect of cerium loading in the range of 1 to 5 wt% on the photocatalytic activity was studied and 2 wt% CeO2-TiO2 was found to exhibit the maximum photoactivity of 18.6 μmo l/g.catalyst after 6 hours irradiation. Results showed that the prepared photocatalyst is visible light active and may be used as effective catalyst in photoreduction of CO2 to methanol

Photocatalytic degradation of organic pollutant using visible active - boron doped photocatalyst

Boron-doped TiO2 (B-TiO2) nanocatalysts were prepared by the sol-gel method, characterized by X-Ray diffraction (XRD) and diffusive reflectance UV-vis spectroscopy (DRS). XRD results exhibited that the doping of boron element could potentially inhibit the growth of grain and promote the formation of anatase phase and diboron trioxide phase. The photocatalytic activity of the B-TiO2 nanophotocatalyst was evaluated by the degradation test on one of the most widely used organic dyes, methylene blue (MB). The result indicated the doped B-TiO2, with 0.25g/L catalyst loading, were more active than the undoped TiO2 in breaking down the MB. The maximum conversion of MB by the doped TiO2 was 80.60%, approximately 14% higher than the pristine TiO2. The as-synthesized B-TiO2 was calcined at 450°C demonstrated higher photocatalytic activity than undoped TiO2 after 240mins of visible light illumination

Restoration of Liquid Effluent from Oil Palm Agroindustry in Malaysia using UV/TiO2 and UV/ZnO Photocatalytic Systems: A Comparative Study

In this study, we have employed a photocatalytic method to restore the liquid effluent from a palm oil mill in Malaysia. Specifically, the performance of both TiO2 and ZnO was compared for the photocatalytic polishing of palm oil mill effluent (POME). The ZnO photocatalyst has irregular shape, bigger in particle size but smaller BET specific surface area (9.71 m2/g) compared to the spherical TiO2 photocatalysts (11.34 m2/g). Both scavenging study and post-reaction FTIR analysis suggest that the degradation of organic pollutant in the TiO2 system has occurred in the bulk solution. In contrast, it is necessary for organic pollutant to adsorb onto the surface of ZnO photocatalyst, before the degradation took place. In addition, the reactivity of both photocatalysts differed in terms of mechanisms, photocatalyst loading and also the density of photocatalysts. From the stability test, TiO2 was found to offer higher stability, as no significant deterioration in activity was observed after three consecutive cycles. On the other hand, ZnO lost around 30% of its activity after the 1st-cycle of photoreaction. The pH studies showed that acidic environment did not improve the photocatalytic degradation of the POME, whilst in the basic environment, the reaction media became cloudy. In addition, longevity study also showed that the TiO2 was a better photocatalyst compared to the ZnO (74.12%), with more than 80.0% organic removal after 22 h of UV irradiation

Bioelectricity Generation from Palm Oil Mill Effluent in Microbial Fuel Cell Using Polacrylonitrile Carbon Felt as Electrode

Palm oil mill effluent (POME) is an organic waste material produced at the oil palm mills. In its raw form, POME is highly polluting due to its high content of biological and chemical oxygen demand. In the present paper, POME was treated using double chamber microbial fuel cell with simultaneous generation of electricity. Polyacrylonitrile carbon felt (PACF), a new electrode material was used as electrode throughout the MFC experiments. Various dilutions of raw POME were used to analyze the effect of initial chemical oxygen demand (COD) on MFC power generation, COD removal efficiency and coulombic efficiency. Anaerobic sludge was used as inoculum for all the MFC experiments. Since this inoculum originated from POME, it showed higher potential to generate bioenergy from complex POME. Anaerobic sludge enhanced the power production due to better utilization of substrates by various types of microorganisms present in it. Among the raw POME and different concentrations of POME used, the PACF with raw POME showed the maximum power density and volumetric power density of about 45 mW/m2 and 304 mW/m3, respectively, but it showed low coulombic efficiency and low COD removal efficiency of about 0.8 % and 45 %, respectively. The MFC PACF with 1:50 dilution showed higher COD removal efficiency and coulombic efficiency of about 70 % and 24 % but showed low power density and low volumetric power density of about 22 mW/m2 and 149 mW/m3, respectively. The formation of biofilm onto the electrode surface has been confirmed from scanning electron microscopy (SEM) experiments. The results confirm that MFC possesses great potential for the simultaneous treatment of POME and power generation using PACF as electrode and also shows that initial COD has great influence on coulombic efficiency, COD removal efficiency and power generation

Optimization of process parameters for photoreforming of hydrogen evolution via response surface methodology (RSM): A study using carbon@exfoliated g–C3N4

In this present work, Carbon@exfoliated g–C3N4 was fabricated through a facile hydrothermal approach. Detailed characterizations were performed to examine the crystal structure, specific surface area, elementary composition, morphology, optical properties and also photoreforming activities. The deposition of carbon onto the exfoliated g–C3N4 structure shows enhanced surface area of 43.9 m2/g relative to bulk g–C3N4 (34 m2/g). Additionally, UV–vis DRS evidenced the enhancement of light absorption in the visible region. The adequacy of the fitted quadratic model was validated by values such as R–squared, F–value and p–value of 0.9922, 136.45 and <0.0001 respectively. The outcome of the optimized model revealed highest hydrogen yield of 997 μmol/g for time = 8 h, dosage = 0.75 g/L, formaldehyde concentration = 400 ppm and light intensity = 150 W/m2 with error of 1.30% by validation experiment. Overall, the present research could be useful as a benchmark for photoreforming hydrogen production in large scale applications by considering the chosen parameters of this study

Ultrasound Driven Biofilm Removal for Stable Power Generation in Microbial Fuel Cell

Anodic biofilm plays a crucial role in bioelectrochemical system to make it sustainable for long-term performance. However, the accumulation of dead cells over time within the anode biofilm can be particularly detrimental for current generation. In this study, the effect of ultrasound on anode biofilm thickness was investigated in microbial fuel cells (MFCs). Ultrasonic treatment was employed for different durations to evaluate its ability to control the thickness of the biofilm to maintain stable power generation. Cell viability count and field emission scanning electron microscopy (FESEM) analysis of the biofilms over time showed that the number of dead cells increased with the increase of biofilm thickness, and eventually exceeded the number of live cells by many-fold. Electrochemical impedance spectroscopy (EIS) analysis indicated that the high polarization resistance appeared due to the dead layer formation, and thus the catalytic efficiency was reduced in MFCs. The stable power generation was achieved by employing ultrasonic treatment for 30 min every 6 days with some initial exception. The low frequency ultrasound treatment successfully dislodged the ineffective biofilm from the surface of the anode. Moreover, the ultrasound could increase the mass transfer rate of the nutrients and cellular waste through the biofilm leading to the increase in cell growth. Therefore, ultrasonic treatment is verified as an efficient method to control the thickness of the biofilm as well as enhance the cell viability in biofilm thereby maintaining the stable power generation in the MFC

Application of Electroporation Technique in Biofuel Processing

Biofuels production is mostly oriented with fermentation process, which requires fermentable sugar as nutrient for microbial growth. Lignocellulosic biomass (LCB) represents the most attractive, low-cost feedstock for biofuel production, it is now arousing great interest. The cellulose that is embedded in the lignin matrix has an insoluble, highly-crystalline structure, so it is difficult to hydrolyze into fermentable sugar or cell protein. On the other hand, microbial lipid has been studying as substitute of plant oils or animal fat to produce biodiesel. It is still a great challenge to extract maximum lipid from microbial cells (yeast, fungi, algae) investing minimum energy. Electroporation (EP) of LCB results a significant increase in cell conductivity and permeability caused due to the application of an external electric field. EP is required to alter the size and structure of the biomass, to reduce the cellulose crystallinity, and increase their porosity as well as chemical composition, so that the hydrolysis of the carbohydrate fraction to monomeric sugars can be achieved rapidly and with greater yields. Furthermore, EP has a great potential to disrupt the microbial cell walls within few seconds to bring out the intracellular materials (lipid) to the solution. Therefore, this study aims to describe the challenges and prospect of application of EP technique in biofuels processing