Produced water or oilfield wastewater is the largest volume ofa waste stream associated with oil and gas production. The aim of this study was to investigate the biological pretreatment of synthetic and real produced water in a sequencing batch reactor (SBR) to remove hydrocarbon compounds. The SBR was inoculated with isolated tropical halophilic microorganisms capable of degrading crude oil. A total sequence of 24 h (60 min filling phase; 21 h aeration; 60 min settling and 60 min decant phase) was employed and studied. Synthetic produced water was treated with various organic loading rates (OLR) (0.9 kg COD m(-3) d(-1), 1.8 kg COD m(-3) d(-1) and 3.6 kg COD m(-3) d(-1)) and different total dissolved solids (TDS) concentration (35,000 mg L(-1), 100,000 mg L(-1), 150,000 mg L(-1), 200,000 mg L(-1) and 250,000 mg L(-1)). It was found that with an OLR of 0.9 kg COD m(-3) d(-1) and 1.8 kg COD m(-3) d(-1), average oil and grease (O&G) concentrations in the effluent were 7 mg L(-1) and 12 mg L(-1), respectively. At TDS concentration of 35,000 mg L(-1) and at an OLR of 1.8 kg COD m(-3)d(-1), COD and O&G removal efficiencies were more than 90%. However, with increase in salt content to 250,000 mg L(-1), COD and O&G removal efficiencies decreased to 74% and 63%, respectively. The results of biological treatment of real produced water showed that the removal rates of the main pollutants of wastewater, such as COD, TOC and O&G, were above 81%, 83%, and 85%, respectively.

This purpose of this paper was to reveal characteristics of a composite structure containing carbon fiber as a reinforcement and blended synthetic epoxy/bio-epoxy derived from crude jatropha oil as resin and compared with fully synthetic epoxy. The composite structure was prepared by the vacuum-assisted resin transfer molding technique and was left to cure for 24 h at room temperature. Both were characterized for their thermal, chemical, and flammable characteristics. The incorporation of jatropha bio-epoxy into the matrix significantly improved the thermal stability between 288–365 °C as obtained by thermogravimetric analysis (TGA) test. Dynamic mechanical analysis (DMA) curves showed slight diminution of performances and Tg from DMA tests confirmed well with the trend of Tg obtain by differential scanning calorimetry (DSC) curves. On the other hand, the flammability property was rated horizontal burning (HB) which was the same as the fully synthetic composite, but the duration to self-extinguish was halved for the composite with jatropha bio-epoxy. Fourier transform infrared attenuated total reflectance (FT-IR/ATR) was conducted to determine the difference of functional groups’ spectrum due to bonding type existing on both specimens. Overall, the composite specimen with blended bio-epoxy exhibited better thermal stability, comparable flammability characteristics, and performances. The aim of this paper was to introduce bio-based epoxy as a potential alternative epoxy and to compete with synthetic epoxy so as to minimize the footprint of non-renewable composite.

An improved method for essential oil extraction was developed with the application of ohmic heated hydro distillation. In this study the parameters affecting citronella oil extraction by ohmic heated hydro distillation such as power input, extraction time, solvent to solid ratio and chopping frequency were investigated to achieve maximum oil yield. The kinetics of extraction was assumed and verified based on a second-order mechanism. The initial extraction rate, the saturated extraction capacity and the rate constant of extraction were calculated using the second-order model. The optimum parameters were found at voltage input of 77 V up to boiling point and 50 V until the end of extraction, 120 minutes extraction time, solvent to solid ratio of 3:1 and once chopping frequency. The kinetics and mechanism of ohmic heated hydro distillation of citronella oil has proved follow second-order model. The initial extraction rate (h) was 0.134 gL-1 min-1 ; the extraction capacity (C s) was 5.787 gL-1 ; the second order extraction constant (k) was 0.004 Lg-1 min-1 and the coefficient of determination (R 2) was 0.976. Index Terms-Ohmic heating; hydro distillation; citronella oil; optimization; kinetics I. INTRODUCTION Citronella grass is native to India and Sri Lanka; whereby the plant can be found growing wild in most tropical Asian countries including Malaysia. Citronella belongs to the genus Cymbopogon, which very closely resembles and formerly was included in the genus Andropogon [1]. Cymbopogon, which is native to warm temperate and tropical regions of the Old World and Oceania, is a genus comprising about 180 species, subspecies, varieties and subvarieties [2]. The plant is also growing wild in most tropical Asian countries, America and Africa. There are two cultivated types of citronella grass, which are Ceylon (Mahapengiri) and Java (Lenabatu) citronella. Java citronella known as Cymbopogon winterianus Jowitt while Ceylon citronella known as Cymbopogon nardus (L) Rendle [3]. Normally, the plant is planted in the kitchen gardens in Malaysia. Recently, the plants are planted commercially by entrepreneurs for essential oils extraction [4]. The citronella oil is comparatively high demand due to its

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Synthesis of carbon nanotubes (CNTs) below 600°C using supporting catalyst chemical vapor deposition method was reported by many research groups. However, the floating catalyst chemical vapor deposition received less attention due to imperfect nanotubes produced. In this work, the effects of varying the preheating temperature on the synthesis of CNT were investigated. The reaction temperature was set at 570°C. The preheating set temperature was varied from 150 to 400°C at 50°C interval. Three O-ring shape heating mantels were used as heating source for the preheater. In situ monitoring device was used to observe the temperature profile in the reactor. Benzene and ferrocene were used as the carbon source and catalyst precursor, respectively. Vertically aligned CNTs were synthesized when the preheating temperature was set at 400°C. When the preheating temperature was increased up to 400°C, both the length and the alignment of CNTs produced were improved.