One of the primary sources of drinking water and for non-potable applications is saline (sea) water. Conversely, a vast amount of wastewater is currently produced that needs to be treated before using or discharging. Ocean sea water is considered to be a raw material used in the desalination process and converted to usable water. In the initial stage of the study, a microbial fuel cell (MFC) with a cation exchange membrane (CEM) and an anion exchange membrane (AEM) were used as separators, in the experiments under different (1, 10, 100 and 1000 Ω) loads of resistance, to measure the efficiency in wastewater treatment and electricity production. The system using a CEM produced the maximum or optimal current of 1.8 mA, a columbic efficiency (CE) of 42% and 80% of chemical oxygen demand (COD) removal at 1 Ω external resistance. While the system running with an AEM achieved a maximum current of 1.8 mA, 40% CE and 77% COD removal at 1 Ω. It highlighted the minimal difference between the performances of the MFC either by using an AEM or CEM. In the second stage of this study, a microbial desalination cell (MDC) used as a novel bioelectrochemical system, was developed by modifying the enriched and optimised MFC system. The MDC was investigated for the desalination of salt water and wastewater treatment. The performance of the MDC with 10 g/l of NaCl salt was measured for desalination of brackish water and COD removal for wastewater treatment, CE and electrical current production. The COD removal of the system was greater than 80%, and the percentage of desalination was 100% after running for five days. The MDC system produced a maximum current of 1.3 mA. Therefore, the results from the study confirmed that the MDC was an appropriate technology used for simultaneous desalination and wastewater treatment applications and facilitating the production of green energy.
Oxy-tetracycline (OTC) has been recognized as not only a good antibiotic but also environmental contamination resulted from over-dosage and leakage from agricultural activities. Among various alternatives, catalytic ozonation is a promising method because of its simplicity and effectiveness. In this work, magnetic carbon nanoparticles (M-CNPs) synthesized by nebulizing pyrolysis of glycerol and ferrocene has been applied as a catalyst for enhancing ozonation of OTC. Effects of catalyst loading and initial concentration of tetracycline on degradation of oxy-tetracycline have been experimentally examined in comparison with other typical carbonaceous powders which are carbon black and graphite. While the change of OTC concentration were analyzed using high performance liquid chromatography (HPLC) analyzer for examining its characteristics, fresh and spent carbonaceous catalysts were also characterized using electron microscopy, surface area and porosity analyzer, and x-ray diffraction (XRD) analyzer.It was found that M-CNPs could exhibit a superior performance in the removal of OTC by adsorption and catalytic ozonation, resulting a faster completion of OTC removal within 30 min or 2 times faster when compared with the cases of carbon black and graphite powder as well as ozonation alone.
The flame emission spectra were measured from the combustion of biomass in a boiler, from which the ratio of the alkali metals’ number densities (sodium and potassium) were precursory derived. Fly and bottom ash samples were collected to determine their composition via scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDX). A comparison of the alkali metals’ number density ratios (from the flame emission spectra) and the ash composition provided information on potential pathways for the alkali metals. The comparison also showed that the number density ratio can be taken as a tentative in-situ indicator of the alkali metals’ ratio. The ash composition also allowed the determination of several slagging and fouling indices.
本論文では，鉄鋼スラグ：製鋼スラグ（SMS）および高炉スラグ（BFS）施用による淡水性微細藻ボトリオコッカスBotryococcus brauniiの増殖促進と，B. brauniiが生産する脂質の生産性向上を検討した。BG-11培地にSMS 5 g L-1を添加したところ，対照区と比較して約1.74倍の増殖促進効果が得られた。また，脂質濃度は対照区の約2.16倍であった。BFSの場合にも，5 g L-1の添加により，対照区の約2.39倍の増殖促進効果が得られた。さらに，脂質濃度も対照区の約4.47倍であった。いずれのスラグでも，バイオマス生産性と共に脂質生産性が向上する結果が得られたが，BFSの方がより脂質生産性を向上する結果が得られた。SMSにおいては鉄成分溶出の効果が示され，一方，BFSにおいては鉄以外の成分の効果が示唆された。
Ionic liquids (ILs) pretreatment has emerged as the promising technology toward environmentally benign conversion of lignocellulosic residues into high value cellulosic fiber as sustainable raw material for biocomposite manufacturing. In this work, the impact of an ionic liquid (IL) 1-ethyl-3-methylimidazolium diethylphosphate ([emim] [dep]) pretreatment of oil palm frond (OPF) on the flexural properties of the composite board has been reported. Ionic liquid pretreatment of OPF fiber under high solids loading (IL/biomass ratio = 1.0) was conducted prior to compounding with thermoplastic starch which was used as binder polymer. Effect of IL pretreatment on OPF fiber was assessed by employing Fourier Transform Infrared Spectroscopy technique. IL treated composite board was found to exhibit superior flexural properties than that of untreated board. Flexural strength was increased from 10 MPa for untreated composite to 12.75 MPa for composites fabricated from IL treated OPF particles.The obtained results evidenced that the IL pretreatment could be a promising, cost-efficient and benign approach for conversion of agricultural waste into high value engineered composite panels. The study plainly demonstrates that IL based pretreatment could be a green technology for effective utilization of lignocellulosic waste biomass in the biocomposite manufacturing.
Production of furfural from biomass has attracted many research interests due to its usefulness as important chemical solvent and chemical feedstock for value-added products. Conversion of D-xylose to furfural via dehydration reaction enhanced by heterogeneous catalyst has also been an interesting issue. In this work, singlewalled carbon nanohorns (CNHs) hybridized with metal nanoparticles were proposed for catalytic dehydration of D-xylose to furfural for the first time. CNHs hybridized with Ni and Cu nanoparticles were in-house prepared by Gas-inject arc-in-water (GI-AIW) and then used as a catalyst for D-xylose dehydration. Physical and chemical properties of the catalyst samples were investigated by transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analyzer and BET analyzer. It is notable that Ni/CNHs provided the highest D-xylose conversion and furfural yield.