The Effect of Local Biomass Projects on Energy Balance and GHG Emission: A Life Cycle Approach

Emerging attention has been given to the use of biomass in local areas for its contribution to reducing fossil fuel dependence and mitigating global warming. The objective of the present study is to develop a method that quantitatively assesses the effects of local biomass projects on fossil fuel consumption and greenhouse gas (GHG) emission. A practical method based on a life cycle approach is proposed and applied to a case of bioethanol project in Miyako Islands of Japan. The project is aiming to produce bioethanol from molasses within the islands, and to replace the entire gasoline consumed in the islands to E3 fuel (i.e., a mixture of 3% ethanol and 97% gasoline by volume). The assessment using the developed method revealed that, first, the complete shift from gasoline to E3 fuel allows for decreases in fossil fuel consumption and GHG emission. Second, the performance of the project is improved by the integration of the ethanol plant and the sugar factory. Moreover, the assessment found that, in small-scale bioethanol projects, the contribution of capital goods to life cycle fuel consumption and GHG emission is not negligible.     

Water purification with sintered porous materials fabricated at 400℃ from sea bottom sediments

A sintering technology for preparing porous materials from sea bottom sediments was developed for use in water purification. The purpose of the present study was to develop methods for converting the sea bottom sediments dredged from Ago Bay into value-added recycled products. The sintered products fabricated at 400℃ were found to be very effective adsorbents for the removal of heavy metals.     

FCR多级接触氧化系统处理乳品工业废水的研究

为提高乳品工业废水生物处理的去污脱氮能力,以新型螺旋状纤维填料作为载体,采用多级氧化槽内不同种类微生物形成的食物链系统（food chain reactor）,详细考察了不同水力停留时间COD、TN、NH^＋₄-N、TP等的去除率及其去除机理,并对污泥减量化效果进行了初步探讨.结果表明,当进水COD为842～1 843 　mg/L、TN为36.3～92.2 　mg/L、NH^＋₄-N为30.1～52.1 　mg/L,HRT=6　h时,系统COD的平均去除率达到93.3%;TN和NH⁺₄-N的去除效果显著,其平均去除率分别达到73.3%和80.7%,出水COD、TN、NH⁺₄-N平均值分别为79.4　mg/L、9.6 　mg/L、6.1　mg/L,均低于《污水综合排放标准》（GB 8978-2002）的一级标准.该系统不仅具有较高的去污脱氮效果,而且产生的剩余污泥量极少,其污泥产率的平均值为7.7%.该系统运行费用低,操作管理方便,长期运行稳定,可应用于城市污水、中高浓度有机废水（如餐厅污水、食品工业废水）等的处理.     

Effect of transition metal doping under reducing calcination atmosphere on photocatalytic property of TiO2 immobilized on SiO2 beads

TiO₂ immobilized on SiO₂ (TiO₂/SiO₂) have been prepared by sol-gel method and various ions of transition metals (Cr³⁺, Co²⁺, Ni²⁺, Cu²⁺, and Zn²⁺) were doped on the photocatalyst using wet impregnation method under reducing calcination atmosphere. The photocatalytic activity of metal doped TiO₂/SiO₂ towards phenol degradation under black light irradiation were investigated and compared with undoped TiO₂/SiO₂. The results showed that the photoresponse of Cu²⁺ and Zn²⁺ doped TiO₂/SiO₂ were larger than undoped TiO₂/SiO₂, indicating that the photogenerated carriers were separated more efficiently in Cu²⁺ and Zn²⁺ doped TiO₂/SiO₂. The reactivity was in the order of Cu²⁺ > Zn²⁺ > Ni²⁺ > Cr³⁺ > Co²⁺. The different photoreactivity was ascribed to combine effect of the different ionic radii and photocorrison tendency of the dopants. The sample was also characterized by surface analytical methods such as X-ray diffraction, scanning electron micrograph/electron dispersive X-ray analyzer and UV-Vis absorption spectrum.     

Low-dose irradiation by electron beam for the treatment of high-SOx flue gas on a semi-pilot scale—Consideration of by-product quality and approach to clean technology

Attention has been focused on the treatment of lignite-fired flue gas in order to use lignite in an environmentally friendly way – (i) low-CO₂ emission, (ii) production of a valuable by-product, (iii) no discharge of wastewater, (iv) direct removal of SO₃ (strong toxicity), and (v) treatment of high SO₂ concentration. Based on these criteria, electron beam irradiation with ammonia injection was tested on a semi-pilot scale: 800 Nm³ h^?1 flow rate, 5500 ppm SO₂, 70 ppm NO_x, 22% flue gas moisture, and 75–80 °C at the reactor outlet.As an energy-saving measure, a low dose (5 kGy) of irradiation was applied: the problem lay in the by-product quality. It is considered that (NH₄)₂SO₃ and NH₄HSO₃ produced by thermal reactions are oxidized to form (NH₄)₂SO₄ (fertilizer) by an electron beam. However, not all reactions were complete because the by-product contained small amounts of H₂SO₄ and NH₂SO₃NH₄ (herbicide), so a vegetable pot test was performed to study the by-product quality: no adverse effect was observed. It is inferred from the pot test that slightly acidic soil may protect vegetables from disease and a small amount of NH₂SO₃NH₄ probably affects woody species and not herbaceous species.It is concluded that the electron beam system is noted as a multi-component pollution control process (removal of NO_x, SO₃, SO₂ and dioxins) and this system will contribute to environmentally friendly use of lignite as well as agricultural productivity via fertilizer supply.     

Separation and characterization of the colored material from sugarcane molasses

The colored material (X) was effectively separated from sugarcane molasses using reversed-phase chromatography. Characterization of the molecular structure of sample X was performed using infrared absorption (IR) spectrometry, mass spectrometry (MS), and dynamic light scattering (DLS). The IR spectrum was similar to that of commercial humic acid, and the MS analysis showed that the sample possessed relatively small heterogeneous molecules with molecular masses around 234, 446, 657, 868, and 1079 Da. On the other hand, X sample showed an inhibitory activity toward the cysteine proteinase papain. Furthermore, the inhibitory (G-1) and weak inhibitory (G-2) fractions were separated from sample X using gel permeation chromatography. Samples G-1 and G-2 inhibited papain partial-noncompetitively and had the inhibition constants of 5.01 x 10(-5) and 1.08 x 10(-3)M, respectively. Interestingly, in the DLS experiment, the Stokes radius of sample G-1 was approximately 2 nm, about twice one of sample G-2.     

Influence of chemical characteristics of humic substances on the partition coefficient of a chlorinated dioxin

The partition coefficients (Koc) of 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin (HpCDD) with respect to a variety of humic substances (HSs) were evaluated by a method involving solid-phase microextraction and gas chromatography-electron capture detection. The log Koc values for each of the HS samples were in the range of 6.4-7.7. The log Koc values for HAs from tropical peat, brown forest and ando soils were in the range of 7.3-7.6, similar to the calculated value for the octanol-water partition coefficient (log Koc=7.56). In contrast, the log Koc values for FAs and peat HAs were 0.5-1 unit lower than the calculated value. The parameters for the polarity of HSs, as calculated from (N+O)/C, O/C atomic ratios and the carboxyl group content, were numerically similar related to the log Koc for HpCDD. These results show that the Koc values for HpCDD are significantly influenced by the polarity of HSs.