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This work assessed both the fractionation and the seasonal mobility variations of Ga and In in systems impacted by acidic thermal waters. This was accomplished by performing thermodynamic calculations using the PHREEQC algorithm and by assessing the activity of acidophilic iron-oxidizing bacteria. The pH of the Kusatsu thermal waters in Gunma Prefecture, central Japan, is rapidly increased following the addition of a lime suspension. After an abrupt pH increase, under which conditions free ions of Ga and In and their complexes with Cl− and SO42− exist only in negligible quantities, the majority of dissolved Ga and In is removed by sorption onto suspended hydrous ferric oxides (HFOs). These HFOs are then transported to an artificial lake without significant sedimentation along the river. Subsequently, the suspended HFOs settle out and are added to sediments without significant fractionation between Ga and In. The Tamagawa thermal waters in Akita Prefecture, northeast Japan, are also treated with lime. However, complete neutralization requires mixing with some tributary streams, leading to a gradual downstream increase in pH. Dissolved Ga is, in general, sorbed by HFOs in upstream areas, leading to wide dispersal of Ga across the entire watershed. In comparison, In is transported to the lake inlet predominantly as a Cl− complex species without significant removal along the river, with the majority being precipitated in an artificial lake, where Cl− concentrations are too low to form stable complex species with In, and thus, dissolved In is sorbed by HFOs. As a result, In is effectively concentrated within downstream lakebed sediments, whereas Ga is dispersed along the river. Seasonal variations in Ga mobility within the Tamagawa field between snowmelt and low-flow seasons are primarily controlled by pH, because hydrolysis reactions of these metals, which are related to sorption reactions, tend to occur in the upstream regions in the snowmelt season. However, under warmer conditions, HFO formation preferably occurs due to the activity of acidophilic iron-oxidizing bacteria. Thus, under similar pH variations, dissolved Ga is more effectively removed by HFOs during warmer seasons. On the contrary, because HFOs are abundantly formed in low-flow season, even under colder conditions, before In hydrolysis reaction starts to occur, In mobility is less affected by water temperature and then bacterial activity.

Stable degrading 1,2-dichlorobenzene (1,2-DCB) enrichments were generated from original contaminated soil and groundwater via enrichment procedures using a mineral salt medium containing 1,2-DCB as the sole carbon and energy source. Four transferred enrichments showed stable 1,2-DCB-degrading ability and completely degraded 1,2-DCB within 32 h. PCR-denaturing gradient gel electrophoresis (DGGE) and 16S rRNA gene clone library analyses indicated that two bacterial strains, belonging to Acidovorax spp. and Ralstonia spp., respectively, were the predominant organisms in each enrichment. Moreover, these strains maintained a stable coexistence in the four transferred enrichments. These two bacteria were subsequently identified as Acidovorax sp. strain sk40 and Ralstonia sp. strain sk41. Strain sk40 was more tolerant to higher concentrations of 1,2-DCB than strain sk41, while strain sk41 maintained a shorter degradation time under lower concentrations of 1,2-DCB. Notably, however, both strains exhibited similar growth rates and degradation rates in media containing 40 mg/l 1,2-DCB, as well as complete degradation of the 1,2-DCB (40 mg/l) within 32 h. It is expected that these two strains will be used in future applications of bioremediation of 1,2-DCB contamination.

During Li recovery from salar brines, Li concentration is typically increased to about 60,000 mg L−1 by evaporation. We investigated the concentration changes of Li, Na, K, Mg, Cl, SO4, and B during evaporation of both natural Uyuni and artificial Atacama brines. The Uyuni brine exhibited a maximum Li concentration of 6810 mg L−1 at 31 days of evaporation, at which point the majority of the Na and K in the brine was removed. The Li concentration decreased with further evaporation due to precipitation as Li2SO4, such that the level at the 56 day mark was approximately 4130 mg L−1. In contrast, the artificial Atacama brine showed no pronounced Li precipitation, even after 54 days, at which point the Li concentration was 21,800 mg L−1. The initial concentrations of Na and K in the Atacama brine were higher than those in the Uyuni brine, and the Atacama solution still retained K after 54 days of evaporation. The order of precipitation of cation species during the evaporation of both brines was: Na, followed by K, Mg, and Li. Thus, Li precipitation in the Atacama brine might be prevented due to the more favored precipitations of Na and K, such that significant Li removal did not occur in this brine.

Mangroves constitute valuable coastal resources that are vulnerable to oil pollution. One of the major processes to remove oil from contaminated mangrove sediment is microbial degradation. A study on heavy oil- and hydrocarbon-degrading bacterial consortia from mangrove sediments in Okinawa, Japan was performed to evaluate their capacity to biodegrade and their microbial community composition. Surface sediment samples were obtained from mangrove sites in Okinawa (Teima, Oura, and Okukubi) and enriched with heavy oil as the sole carbon and energy source. The results revealed that all enriched microbial consortia degraded more than 20% of heavy oil in 21 days. The K1 consortium from Okukubi site showed the most extensive degradative capacity after 7 and 21 days. All consortia degraded more than 50% of hexadecane but had little ability to degrade polycyclic aromatic hydrocarbons (PAHs). The consortia were dominated by Pseudomonas or Burkholderia. When incubated in the presence of hydrocarbon compounds, the active bacterial community shifted to favor the dominance of Pseudomonas. The K1 consortium was a superior degrader, demonstrating the highest ability to degrade aliphatic and aromatic hydrocarbon compounds; it was even able to degrade heavy oil at a concentration of 15%(w/v). The dominance and turn-over of Pseudomonas and Burkholderia in the consortia suggest an important ecological role for and relationship between these two genera in the mangrove sediments of Okinawa.

The aims of this study were to identify the bacteria responsible for the rapid degradation of aromatic hydrocarbons, and to determine the roles of bacterial species in the microbial consortium. The population changes of the four major bacterial groups, namely Burkholderia spp., Achromobacter spp./Alcaligenes spp., Cupriavidus spp., and Rhodanobacter spp. in the Y consortium that preferentially degraded petroleum oil-derived aromatic hydrocarbons were assessed using quantitative real-time polymerase chain reaction (q-PCR). P-xylene was used as a representative aromatic compound, decane as a representative aliphatic compound, p-xylene-decane as a representative hydrocarbon mixture, and kerosene as a representative petroleum-based oil. The results showed that the remarkable increase of Burkholderia spp. coincided with the rapid degradation of aromatic hydrocarbons in kerosene, and p-xylene in single and dual-substrate cultures. Cupriavidus spp. significantly increased when decane was rapidly depleted. Achromobacter spp.,/Alcaligenes spp., and Rhodanobacter spp. were initially inhibited by the presence of aromatic hydrocarbons and seemed not to be active in hydrocarbon degradation, but utilized the metabolic products. This work provided an alternative way to explain the contribution of different microbial species in the degradation of hydrocarbon fractions. The behavior of the consortium is of interest in the context of the bioremediation of the more toxic aromatic hydrocarbons in environments contaminated by petroleum products.

A dechlorinating consortium (designated as TES-1 culture) able to convert trichloroethene (TCE) to ethene was established from TCE-contaminated groundwater. This culture had the ability of complete dechlorination of TCE within about one month. From the clone library analysis of 16S rRNA gene, this culture was mainly composed of fermentation bacteria, such as Clostridium spp., and Desulfitobacterium spp. known as facultative dechlorinator. PCR using specific primers for Dehalococcoides spp. and the dehalogenase genes confirmed that the culture contained the Dehalococcoides spp. 16S rRNA gene and three dehalogenase genes, tceA, vcrA and bvcA. Dechlorination experiments using cis-dichloroethene (cis-DCE) at concentrations of 37-146 μM, revealed that the gene copy numbers of tceA, vcrA, and bvcA increased up to 10⁷ copy/mL, indicating that Dehalococcoides spp. containing these three dehalogenase genes were involved in cis-DCE dechlorination. However, in the culture to which 292 μM of cis-DCE was added, only the tceA gene and the Dehalococcoides spp. 16S rRNA gene increased up to 10⁷ copy/mL. The culture containing 292 μM of cis-DCE also exhibited about one tenth slower ethene production rate compared to the other cultures.

Numerous studies on the biodegradation of petroleum products using total petroleum hydrocarbons (TPH) have been carried out; however, the biodegradation of equivalent carbon number (EC) based hydrocarbon fractions in mineral oil has attracted little attention. This study investigated the ability of a microbial consortium to degrade the EC fractions in kerosene, which was used as a representative mineral oil. Based on the cloning and sequencing of the 16S rRNA gene, the microbial community was predominantly identified as Betaproteobacteria of the genera Achromobacter , Alcaligenes , and Cupriavidus . Degradation experiments in sealed 120-ml vials containing 1% (w v −1 ) kerosene revealed that aromatic fractions were degraded faster than aliphatic fractions. Aromatic fractions EC >7–8 and EC >8–10 were completely degraded after three days while aliphatic fractions EC >6–8 and EC >8–10 were only partially degraded. The aromatic EC >10–12 fraction was the third most degraded, and the aliphatic EC >10–12 and EC >12–16 fractions were the least degraded fractions. The first-order rate constants for the aromatic fractions ranged from 0.12 d −1 to 0.51 d −1 and from 0.06 d −1 to 0.32 d −1 for the aliphatic fractions. The microbial consortium preferentially utilized aromatic fractions, which are more toxic than aliphatic fractions. This finding is useful when considering risk-based bioremediation: A microbial community could potentially degrade the more toxic aromatic hydrocarbon components in petroleum-contaminated environments.

In this study, the abilities of two microbial consortia (Y and F) to degrade aliphatic–aromatic hydrocarbon mixtures were investigated. Y consortium preferentially degraded the aromatic hydrocarbon fractions in kerosene, while F consortium preferentially degraded the aliphatic hydrocarbon fractions. Degradation experiments were performed under aerobic conditions in sealed bottles containing liquid medium and n-octane or n-decane as representative aliphatic hydrocarbons or toluene, ethylbenzene or p-xylene as representative aromatic hydrocarbons (all at 100 mg/l). Results demonstrated that the Y consortium degraded p-xylene more rapidly than n-octane. It degraded toluene, ethylbenzene and p-xylene more rapidly than decane. In comparison, the F consortium degraded n-octane more rapidly than toluene, ethylbenzene or p-xylene, and n-decane more rapidly than toluene, ethylbenzene or p-xylene. 16S rRNA gene sequencing revealed that the Y consortium was dominated by Betaproteobacteria and the F consortium by Gammaproteobacteria, and in particular Pseudomonas. This could account for their metabolic differences. The substrate preferences of the two consortia showed that the aliphatic–aromatic hydrocarbon binary mixtures, especially the n-decane–toluene/ethylbenzene/p-xylene pairs, reflected their degradation ability of complex hydrocarbon compounds such as kerosene. This suggests that aliphatic–aromatic binary systems could be used as a tool to rapidly determine the degradation preferences of a microbial consortium.

高濃度嫌気性消化槽において攪拌機の混合性能を定量的に評価できるようにするため，嫌気性消化汚泥のレオロジー特性を記述するための擬塑性流体モデルを組み込んだCFDモデルと槽内の均一化の度合いを定量化するためのパラメーター（UI）を用いて，ドラフトチューブ式機械攪拌の実規模嫌気性消化槽の混合を検討した．トレーサーの均一化の進捗はUIによって定量化され，槽内に形成される渦の大きさによって左右される低速度域の大きさが均一化時間に影響した．本検討の範囲においては汚泥濃度（X）と均一化時間-汚泥循環時間比（TH/TR）の間には直線関係が認められた．

This paper describes hydrogen sulfide generation, isolation and characterization of sulfate-reducing bacteria in the activated sludge obtained from wastewater treatment plant. The sludge, collected from aerobic treatment system, was used as inoculums for hydrogen sulfide generation and for isolation of sulfate-reducing bacteria. Hydrogen sulfide was generated when the sludge was inoculated into a pH controlled medium. Two strains G2 and G3 of sulfate-reducing bacteria were isolated from the sludge. The characteristics and identification of these isolates was based on culture of the experiments and molecular analysis. Reduced sulfate rates in G2 and G3 is 0.39 and 0.41 mmol/dm3 respectively. Two isolates located in the genus Desulfovibrio in the phylogenetic tree based. First one was 16S rRNA gene analysis with the highest homology, 96.6 %, as Desulfovibrio carbinoliphilus (DSM 17524T) . However, the branch of the isolates was separated from the relatives and no strain was recognized in this branch. Also the dsr gene of isolate G3 had the highest homology with Desulfovibrio fructosovorans (DSM 3604T) , 92.7 %. The isolates G2 and G3 belonged to the genus Desulfovibrio as confirmed by the results of these analyses, however, these isolates oxidized organic compounds to carbon dioxide completely although relative strain oxidized it completely. Therefore, these isolates have high possibility that they should be recognized as a new strain.

The pathways and kinetics of trichloroethylene (TCE) degradation in aerobic pyrite suspension were investigated. The detection of hydroxyl radical in aqueous pyrite suspension suggested that TCE was degraded by this strong oxidant The reaction pathways of TCE degradation were proposed in which the degradation of TCE to formic acid and finally to CO2 was the main route. Degradation of TCE to oxalic acid and to dichloroacetic acid were found as minor pathways. Degradation rates of TCE to formic acid, glyoxylic acid, and dichloroacetic acid were obtained using kinetic model at 1.2 x 10(-2), 9.8 x 10(-4) and 4.6 x 10(-4) h(-1), respectively.

In a series of studies, various aspects of thermophilic bioleaching of chalcopyrite minerals and concentrates have been analyzed. Although the main objective was the elucidation of the catalytic effect of thermophiles in leaching chalcopyrite, various other new findings contributed to a better understanding of interactions among chemical, physicochemical and biological factors, which influence the bioleaching of chalcopyrite with thermophiles. Additionally, in order to bridge laboratory results and field applications, novel mathematical models as well as an alternative method to efficiently leach chalcopyrite without thermophiles are the contributions of this research.

2005年8月, 妊娠41週で血小板数4.0×104/μlが判明. 骨髄の巨核球数192/μl, PAIgG 220ng/107cellsで特発性血小板減少性紫斑病と診断された. 翌月から23カ月間プレドニソンを服用したが完全寛解には至らなかった. 2006年3月以来, 深部静脈血栓症による肺梗塞のためワーファリンを服用している. 2007年7月血小板数 3.9×104/μlで脾臓摘出術を目的として当院を受診した. 来院時, 手指振顫, 甲状腺腫あり. 検査ではFT4 5.17ng/dl, TSH

This paper described that relationship between Acidithiobacillus feroooxidans T23-3 and fungus TEF1-1 in an enrichment culture. In order to evaluate the relationship, some culture experiments using cell-free extracts from T23-3 and TEF1-1 were carried out. Chemolitotrophic iron-oxidizing bacterium, A. ferrooxidans T23-3, was able to grow using inorganic compounds in cell-free extract of fungus TEF1-1 or A. ferrooxidans T23-3. Since the fungus TEF1-1 was able to grow using cell-free extract of the both microorganisms at pH 1.5, the fungus used some organic compounds in the cell-free extract as energy and carbon sources. When the cell-free extract of TEF1-1 used for the cultivation of A. ferrooxidans T23-3, lag-phase was observed because of lack of magnesium ion. Minimum concentration of magnesium ion for complete growth of A. ferrooxidans T23-3 was found to be 2.0 x 10-5 mol/dm3 from the experiments using synthetic medium. Also the cell-free extract contained enough nutritious components except magnesium ion for the growth of A. ferrooxidans T23-3. It was suggested that fungi grew using organics and inorganic ions released from the cell of chemolithotrophic iron-oxidizing bacteria by bacteriolysis and/or metabolisum and that the bacteria grew using inorganic ions from the lysis of fungi cells in the enrichment culture of iron-oxidizing bacteria. In addition, chemolithotrophic iron-oxidizing bacterium fixes carbon dioxide to convert some organic compounds in the culture. Therefore, it was evaluated that the relationship between chemolithotrophic iron-oxidizing bacteria and fungi was mutualistic symbiosis in the enrichment culture.

Previous studies identifying Fe 3+ as the main oxidizing agent in CuFeS 2 bioleaching suggests that if the precipitation of additional Fe 3+ could be prevented, the Cu extraction yields should be enhanced. In this respect, the acid-generating nature of the biologically mediated oxidation of additional S 0 to H 2 SO 4 should theoretically serve as a pH regulator as well as biomass generator. This should prevent the precipitation of Fe 3+ and attenuate the biomass reduction caused by the inhibitory effect of high Fe 3+ concentrations. To prove the former hypothesis, three thermophile strains were employed for bioleaching of chalcopyrite under various additional S 0 and Fe 3+ concentrations. The hypotheses about additional S 0 application were fully confirmed; the addition of S 0 alone enhanced the leaching rates with A. brierleyi and M. sedula in media at initial pH 2. Although higher initial leaching rates were obtained with additional Fe 3+ , its role as the main leaching factor is questioned; leaching with thermophiles appears to depend on the availability of protons and ORP rather than on the prevention of Fe 3+ precipitation. Additional S 0 in media with high Fe 3+ concentrations has shown the best improvements in the case of bioleaching with A. brierleyi , whereas improvements in bioleaching with M. sedula and S. metallicus were less notable.

A model was formulated to study the auto-thermal performance of a bioleaching heap that employs mixed mesophilic and thermophilic microbes for Cu extraction from CuFeS2. The preference of mesophiles for dissolving additional FeS2 in conjunction with the capacity of thermophiles to dissolve CuFeS2 enables the transition from a mesophilic to thermophilic bioleaching state where CuFeS2 is leached at higher rates without the necessity of additional energy supply. In this sense, the mathematical description of this transition takes into consideration the dependence of the activity of both types of microbe on physicochemical factors such as the temperature and O2 availability. The leaching kinetics is assumed to be proportional to the activity of both types of microbes and not to be dependent on the Fe3+ concentration in solution because of the additional FeS2 which provides Fe3+ in excess. It was found that auto-thermal performance of a heap occurs under combined threshold conditions of minimum biomass irrigation concentrations, and maximum flow rates of leaching solution. Under these threshold conditions, the effect of the aeration rate on the Cu extractions appears to be mild. Apparently high leaching solution flow rates (> 2 kg m2 h) decrease the heat accumulation in the heap by convection. This is reflected by prolonged transition periods to the thermophilic state where the highest Cu extractions are observed because of the simultaneous contribution of mesophiles and thermophiles. The continuous application of mixed mesophiles and thermophiles leads to uniform temperature distributions. The model is validated by comparing reported heat generations estimated from column experiments against the heat generation calculated from simulating the auto-thermal performance of a heap.

A hydrogen generation process using photocatalytic reactions has been proposed. In this process, hydrogen sulfide is a source of hydrogen and is turned into polysulfide. In order to establish the cyclic operation of a photocatalytic hydrogen generation system, it is necessary to convert polysulfide back into hydrogen sulfide with a small energy input. This paper proposes the use of sulfate-reducing bacteria (SRB) for the regeneration of hydrogen sulfide. Batch cultivation of natural source SRB samples were carried out using a culture medium containing polysulfide as the only sulfur compound source. SRB produced hydrogen sulfide from several kinds of polysulfide sources, including a photocatalytic hydrogen generation-produces solution. Production lag phase and production rate of hydrogen sulfide were affected by initial polysulfide concentration. SRB activity was inhibited at high initial polysulfide concentrations. SRB enrichment culture T2, exhibited the highest hydrogen sulfide production rate, and was able to utilize several kinds of organic matter as the electron donor. The results suggest the possibility of using large biomass sources, such as sewage sludge and the raw garbage in a hydrogen generation system. We developed speculative estimates that an SRB based hydrogen generation system is feasible.

The transformation of trichloroethylene (TCE) in natural mineral iron disulfide (pyrite) aqueous suspension under different oxygen conditions was investigated in laboratory batch experiments. TCE transformation was pursued by monitoring its disappearance and products released with time. The effect of oxygen was studied by varying the initial dissolved oxygen concentration (DO(i)) inside each reactor. Transformation rates depended strongly on DO(i) in the system. In anaerobic pyrite suspension, TCE did not transform as it did under aerobic conditions. The transformation rate increased with an increase in DO(i). The TCE transformation kinetics was fitted to a pseudo-first-order reaction with a rate constant k (h(-1)) varying from 0.004 to 0.013 for closed systems with DO(i) varying from 0.017 to 0.268 mmol/L under the experimental conditions. In the aerobic systems, TCE transformed to several organic acids including dichloroacetic acid, glyoxylic acid, oxalic acid, formic acid, and finally to CO2 and chloride ion. Dichloroacetic acid was the only chlorinated intermediate found. Both TCE and the pyrite surface were oxidized in the presence of O2. Oxygen consumption profiles showed O2 was the common oxidant in both TCE and pyrite oxidation reactions. Ferric ion cannot be used as an alternative oxidant to oxygen for TCE transformation.

The copper extraction yield from thermophilic bioleaching of chalcopyrite depends on temperature, pH, and the oxidation-reduction potential (ORP), as well as on the activity of the thermophile used. The copper extraction yields obtained with three thermophiles under various pH and temperature conditions and with different initial amounts of Fe 3+ were studied. The results indicated that because of the low ability of Acidianus brierleyi to leach iron as Fe 3+ , high biomass concentrations were reflected by ORP close to a critical value (450 mV, Ag 0 /AgCl reference), at which copper extractions were highest. By contrast, because of the higher ability of Sulfolobus metallicus and Metallosphaera sedula to leach iron as Fe 3+ , high biomass concentrations were reflected by high ORP which in combination with the precipitation of Fe 3+ as jarosite attenuated the leaching rates. Therefore, optimum temperatures for the growth of thermophiles did not always mean high copper extraction yields. Generally, highest copper extractions were obtained at initial pH 1.5. However, higher copper extractions were observed at initial pH 2.5 than at pH 2.0, suggesting that at high pH the bioleaching of chalcopyrite is controlled by the ORP rather than by the pH or temperature. The bioleaching capacity of A. brierleyi was reduced or suppressed when insufficient initial Fe 3+ was provided to trigger the leaching reaction, whereas S. metallicus and M. sedula were less sensitive to the initial availability of Fe 3+ . This result confirmed that a direct enzymatic attack on the mineral surface could initiate the leaching reaction, but later ORP governed the leaching rate of chalcopyrite.

This paper describes about microbial diversity in an iron oxidation tank of an AMD treatment plant established at an abandoned sulphur mine in Japan. Since the mining operation was stopped, this mine has produced strong acidic mine drainage, pH 1.8, including a high concentration of ferrous iron, 301mg/L, and the flow rate was about 4m3/min. In 2006, a pilot scale microbial iron oxidizing system was installed to remove total iron more easily from the AMD by oxidizing ferrous iron to ferric iron. From the start of this pilot operation, microbial diversity in the iron oxidation tank was investigated using a PCR-DGGE method for about two months. In the PCR, V3 region of 16S rRNA gene for Bacteria was amplified. The profiles of DGGE showed that there were three dominant species in the iron oxidation tank through the experimental period. Number of bands on DGGE profiles decreased with dates of sampling so that the microbial population became less diverse because of the iron oxidizing operation. There was a wide variety of bacterial species of even though conditions were strongly acidic.

A model was prepared to study the performance of a thermophilic bioleaching heap that employs mixed mesophilic and thermophilic microbes for copper extraction from CuFeS2. Mesophiles’ preference for and ease of dissolving additional FeS2 provided to the heap enables the transition from a mesophilic to a thermophilic bioleaching state without the necessity of additional energy supply. In this sense, the mathematical description of the bioleaching process is done taking into consideration the dependency of both microbes’ biological states on physicochemical factors such as the temperature and O2 availability. With regard to the flow rates of the liquid and air phases, simulation results have shown that these flow rates govern not just the heat transfer and variation of cell distribution, but also the leaching rate regardless of the fraction of CuFeS2 per FeS2 leached (FCP) which is the other variable influencing to the heat accumulation in the heap.

Chlorinated organic compounds such as trichloroethene (TCE) have caused soil and ground water pollution on a lot of sites. Oxidation processes which are produced hydroxyl radical are effective to remediate these contaminated sites, because they are able to degrade TCE. This paper describes photochemical oxidation of TCE with citrate ion and iron ion. Citrate ion and iron ion form some complexes (Fe-citrate complexes) which absorb the light of wavelength below 450nm. The Fe-citrate complexes were able to be decomposed TCE with black light lamp (wavelength: 320-400 nm). Approximately 50% of initial TCE concentration (100mg/L) decomposed within about 7 hours when the molar ratio of iron ion to TCE is 4 and the molar ratio of citrate ion to TCE is 4. The degradation rate of TCE using citrate ion and iron ion was lower than using oxalate ion and iron ion. The excess iron ions inhibited the TCE degradation because some of iron ions formed iron hydroxide and it absorbed lights essential for the photochemical reaction. Therefore, the photodegradation of TCE needs sufficient citrate ion to ensure for forming Fe-citrate complex formation. TCE was degraded between initial pH 2.5 and 10.6. The degradation rate of TCE was higher in the condition of acidity than the condition of alkalinity. In acidic condition, the dominant iron species was [Fe(III)(C6H5O7)] which is the important species for TCE photodegradation. On the other hand, even in alkaline condition, [Fe(II)(C6H5O7)]- existed as an Fe-citrate complex. So, this fact shows strongly that [Fe(II)(C6H5O7)]- photochemically degrades TCE under the condition of alkalinity.

A simple two-dimensional mathematical model capable of describing the interactions taking place in the bulk fluid and biofilm between sulfate reducing bacteria (SRB), substrates and biocide agents was used for the numerical evaluation of biocide treatment against SRB. The characteristics inherent to thick biofilms formed in large diameter oilfield pipelines were taken into account by assuming that the biocide treatment will remove little of the biofilm and not kill the SRB present in the biofilm. The evaluation model considered SRB disinfection/proliferation, and biocide deactivation within the bulk fluid, as well as many features of biofilm interactions with the bulk fluid such as mass transfer, live SRB detachment and biocide agent deactivation. These interactions are represented by simple coefficients as far as possible. Simulation results, using reported kinetic parameters for SRB, acetate and biocide agents such as chlorine and glutaraldehyde, showed that biocide treatments in oilfield water pipelines are sensitive to the disinfection rate coefficient and the biocide agent concentration as well as to the decay rate coefficient of the biocide agent in the bulk fluid, but are not sensitive to the biocide deactivation rate on the biofilm surface, nor to the SRB concentration in the biofilm. Various extreme conditions of biocide treatments were simulated using the proposed discretization method, which was adapted to take into account the biofilm interactions with the bulk fluid, to investigate the sensitivity of the numerical method and the suitability of the model developed to determine minimum effective biocide concentrations.

Carbon dioxide(CO2) removal from exhaust combustion gas and biogas is recognized as an important technology to CO2 reduction. We are developing a new technology of CO2-removal with a hollow-fiber gas-liquid contactor. In the contactor, the gas flows in the lumen side of hollow fiber, and liquid in the shell side. The gas-liquid interface is formed right outside of hollow fibers because the hollow fibers used are hydrophobic and microporous. The contactor contains a lot of hollow fibers which internal diameters are 320μm, and can produce huge gas-liquid interface area per unit volume. It is so efficient to transfer carbon dioxide between gas and liquid.To confirm an overall mass transfer coefficient (hereinafter referred to as K), the following experiments on carbon dioxide transfer in the laboratory were made: In the soli-recovery test, an inactive gas swept carbon dioxide from carbonated water. In the soli-supply test, a mixed gas contained carbon dioxide contact with static water excluding carbon dioxide, and with agitated water. In the supply-recovery test, a mixed gas contained carbon dioxide contact with static water and an inactive gas swept carbon dioxide from the carbonated water concurrently.In each test, the water was sampled from the contactor, and the concentrations of dissolved carbon dioxide were measured with a gas chromatography. Using mathematical model of the test equipment, the value of K was calculated. These results showed that K depends on ‘water temperature’ and ‘water flow’ without relation to a flux direction and the distance between hollow-fibers, and the water flow system was more effective. Comparing with another technology(packed tower), it was proved that the new one had large dominant CO2-removal forces.

This paper describes that evaluation of soil remediation contaminated with oil on quicklime process and the effect of the treatment for oil degradable bacteria in the soil. In this paper, two different contaminated sites were used. When quicklime method was applied for a contaminated site, the temperature of soil increased over 60 °C by reaction heat and the pH value also rose to about 12. Although the density of bacteria in the contaminated soil decreased from 40 to 5 - 10 x 1010 cells/g-dry soil, they could survive against the increasing of heat and alkalinity caused by the treatment. Some oil degradable bacteria were isolated from original contaminated and treated soil and the abilities of oil degradation were evaluated. These bacteria might contribute the degradation of remained oil in the treated soil. On another site, the oil concentration in soil decreased from 3,555 to 1,430 mg-oil/kg-soil by the treatment. In this case, some light parts of oil, C6 to C10 and C10 to C28, were almost volatized to below 5 and 35% respectively, but the heavy part, C28 to C44 was still remained. However the remained oil decreased gradually after the treatment to 250 mg-oil/kg-soil within 6 month. This shows the high possibility of oil remediation by oil degradable bacteria which survive in contaminated soil against the treatment.

A lot of contaminated site with many kinds of pollutants exists all over the world and it makes the earth environment seriously. Oil is the one of the most common pollutants for shoreline, groundwater and soil. This paper describes about on-site remediation technologies, which are using physical, chemical and biological methods, for contaminated soil with oil particularly. In addition, it shows the present condition of oil contamination and analytical methods in Japan.

The dechlorination of trichloroethene (TCE) with metallic iron is an advantageous method for the remediation of contaminated groundwater and soil. The toxic reaction intermediates such as dichloroethenes (DCEs) and vinyl chloride (VC), however, occasionally accumulate in the pathway of the reaction. We have been trying to suppress these intermediates by using metallic iron powder containing impurities. In order to investigate the reaction pathways, we measured the production rates of the intermediates and the final products of the dechlorination of TCE such as DCEs, VC, ethyne or ethene. Ethyne, ethene, ethane and cis-DCE were observed as the major products, and trans-DCE, 1,1-DCE, VC, C3-hydrocarbons (such as propane, propylene), C4-hydrocarbons (such as n-butane) and methane were observed as the minors. Also the rate constants of TCE to ethyne and ethyne to ethene were larger than any other constants. These fact show the production of ethene/ethane via ethyne is the main pathway of the dechlorination of TCE using the metallic iron powder.

Background. Preoperative portal embolization (PE) is used to stimulate liver hypertrophy in the nonembolized lobe. We studied liver volume and function with computed tomography and technetium-99m-galactosyl human serum albumin (99mTc-GSA) scintigraphy before PE and at 1 or 2 weeks after PE. Methods. Right PE was performed in 30 patients. Morphologic and functional hypertrophy in the left lobe after PE was determined and related to the presence or absence of cholestasis, biliary drainage of the embolized lobe, and postoperative liver failure. Results. The volume of the left lobe and 99mTc-GSA uptake increased rapidly for the first week after PE, but no significant increase was seen during the second week. Morphologic hypertrophy was less pronounced in patients with jaundice (P =.03). When PE was performed at a total bilirubin level above 2 mg/dL, the interval between PE and surgery was prolonged because of cholangitis and liver abscess formation. The net morphologic hypertrophy ratio was significantly higher in livers that had undergone left lobe drainage only (9.1% ± 0.9%) compared with those in which there was drainage of the embolized lobes (5.7% ± 0.9%; P =.03). The volume and 99mTc-GSA uptake of the left lobe in the second week after PE was significantly smaller in patients with postoperative liver failure (33.7% ± 2.4% and 18.0% ± 2.1%, respectively) than in patients without liver failure (46.2% ± 1.4% and 38.4% ± 2.3%; P =.003 and P =.01, respectively). Conclusion. In the nonembolized lobe, the functional increase in 99mTc-GSA uptake is more pronounced than suggested by the degree of morphologic hypertrophy. Whenever possible, biliary drainage should not be performed in the lobe undergoing hepatectomy. 99mTc-GSA SPECT scintigraphy is useful for the evaluation of postoperative liver failure. (Surgery 2003;133:495-506.)

Polychlorinated ethanes and methanes were reductively dechlorinated using iron powder E-200 (supplied by Dowa Iron Powder Co., Ltd.) in the aqueous layer. Time courses of their concentrations were observed and the intermediates and final degradation products were determined quantitatively. The degradation reaction of these compounds showed a pseudo-first-order rate process and the rate constants were calculated. Tetrachloroethanes and tetrachloromethane were easily degraded in the aqueous layer, but dichloroethanes, chloroethane, dichloromethane and chloromethane were only slightly degraded. The rate constants and the reaction products of polychlorinated ethane isomers, that is, 1,1,2,2-tetrachloroethane and 1,1,1,2-tetrachloroethane, or 1,1,1-trichloroethane and 1,1,2-trichloroethane, were significantly different from each other. This denotes that the main degradation pathways of these compounds are different. The possibility of using iron powder for the remediation of soil and groundwater contaminated with chlorinated organic compounds is discussed.

1977年から2001年7月までに当科で経験した直腸脱20例(11例に他施設での手術既往あり.再発による再手術例3例を含むと23手術例となる)を対象とし,病悩期間,各術式の成績を検討した.検討項目は再発率・合併症および長期経過後の症状の改善度・満足度とした.追跡調査は電話を使用した.術式の内訳は会陰式が6例でGant-三輪法4例,粘膜縫縮法2例であった.腹式は17例で直腸剥離仙骨前固定術13例,腹腔鏡下直腸固定術2例,人工肛門造設術2例であった. Thiersch法は21例に併用した.再発率は会陰式33%(2/6),腹式(人工肛門造設術を除く)6.7%(1/15)であった.合併症はThiersch法固定糸の感染2例,弛み5例,イレウスが1例に認められた.追跡可能であった13例は全て腹式手術の症例であり,全例で満足しているとの結果であった.腹腔鏡下手術の2例も経過良好であった.直腸固定術の長期経過後の満足度は高く,再発率も低かった.

Preoperative portal embolization (PE) is useful for the prevention of postoperative liver failure after extended hepatectomy. However, clinical evaluation of liver function in the hypertrophying lobe after PE has not been studied. Here we report functional changes in the hypertrophying lobe using a 80% portal-branch-ligation rabbit model. Liver function was evaluated by the expression of liver-specific genes detected by Northern blot analysis and plasma disappearance rate of indocyanine green (ICG). The weight of the unligated lobe after portal ligation increased about twofold on the 7th postoperative day (POD) and about threefold on the 14th POD. The mRNA levels of the liver-specific genes (albumin, aldolase B, and tyrosine aminotransferase) in the unligated lobe decreased to about 50% on the 1st POD and returned to the preoperative levels on the 7-14th POD. In contrast, the expression of histone H2B mRNA increased on the 3rd-7th POD. The plasma disappearance rate of ICG (K-ICG) in the rabbit that has only the unligated lobe did not significantly change during the first 7 days, but then improved and recovered to 80% of that in the rabbit that has whole liver on the 14th POD. These results indicate that liver function of the hypertrophying lobe after portal branch ligation does not increase during the first 7 days despite an increase in liver weight. This finding suggests that the compensatory hypertrophying liver is enlarging without functional augmentation in the early period after PE.

Diatomaceous earth is an effective carrier with a large surface area on which Thiobacillus ferrooxidans adsorbs, and enhances the oxidation rate of ferrous ions by the bacterium. The adsorption of T. ferrooxidans on diatomaceous earth was expressed by the Henry isotherm, and reached equilibrium within five minutes. The enhancement was due to an increase in the growth rate of the adsorbed cells, which were so active that their specific growth rate calculated using a Monod-type equation was higher than that of the free cells in the liquid phase.

Fourteen different alkaline coal fly ashes (CFAs) were used for the experiment, in which each sample was mixed with water to be 28.6% of water content (wt/wt) and aged for 1-4 weeks at 10-30 °C. This simple treatment is advantageous for decreases in water-soluble B, F, Cr, and As. Compared to non-aged CFAs, their water-soluble fractions remained 0.56-88%, 21-85%, 0.37-93% and 2.6-88%, respectively, after aging for a week at 20 °C, although the amounts of Cr and As released from some CFA samples increased. Considering the significant decrease in elution of sulfate, Ca and Al after aging, the immobilization, namely prevention of toxic element elution, could be related to formation of secondary minerals such as portlandite, gypsum and ettringite. Immobilization of B and Cr tends to proceed preferentially under colder conditions. Aging at higher temperatures enhances the leachability of Cr in some CFA samples. Contrary to the behavior of B and Cr, water-soluble F effectively decreases under warmer conditions.

This paper describes the development of a new dissolved air flotation (DAF) separator with a flow streamlining baffle to improve solid separation efficiency. The analysis of the RTD (residence time distribution) curves indicated that the parameter θ10 (dimensionless time at which 10% of tracer has discharged) increased from 0.38 for control reactor to 0.54 for the test reactor, suggesting significant reduction in short circuit flow. The RTD curves were also used to develop a compartment model for white water (rich in micro-bubbles and water flow is turbulent) and clear water (little or no air content and water flow is quiescent) zones in the reactor using a series of CSTR (continuous stirred tank reactors) and plug flow regime respectively. The proportion of the volume occupied by the white water zone was different in control and test configurations. In the test reactor, the fraction of the clear water zone was found to increase from 6 to 37%, resulting in improvement of the suspended solid (SS) removal efficiency from 97 to 99%.

In the enrichment culture of the sulfur-oxidizing bacteria collected from an acid mine drainage, we have confirmed protozoa that belongs to Bodo edax. This paper describes an interaction between the bacteria and the protozoa in the presence of cupric ion. The SO42- produced by the bacteria from S0 and the cell numbers of the bacteria and the protozoa were measured as a function of time in the culture containing Cu2+ of 0, 1, 10, 100 and 1, 000mg dm-3. The results obtained were as follow;(1) the bacterial oxidation rate and the yield factor of the bacteria growth became small due to the protozoa;(2) in the cultivation of the bacteria alone, the lag phase of the bacteria growth became long over 1 mg dm-3 of Cu2+ concentration but the growth rate was not affected;(3) in the culture coexisting the bacteria and the protozoa the bacteria grew, but the protozoa did not grow at Cu2+ concentration of 100mg dm-3;(4) preincupation in the culture containing Cu2+ gave the ability to resist Cu2+ to the bacteria, but did not to the protozoa.

This paper describes a fundamental examination of a quicklime mixing treatment combined with carbon dioxide ventilation for the remediation process of soils polluted with volatile organic compounds (VOCs). The quicklime mixing treatment is widely applied to remove volatile pollutants in soils using the heat of reaction with quicklime and pore water. To maintain a higher temperature and to ensure that most of the VOCs are volatilized, quicklime is usually mixed at a ratio of 10% with soils in this treatment. However, a surplus of added quicklime results in higher (alkaline) soil pH and causes serious damage to the soil ecosystems. To solve this problem, the simultaneous ventilation of carbon dioxide during quicklime mixing with polluted soil was examined. Under these conditions calcium hydroxide is generated by the reaction of quicklime with pore water; the calcium hydroxide then reacts with carbon dioxide to produce additional heat of reaction. It is expected that the heat from the second reaction can be used for the pollutant treatment, allowing the amount of quicklime addition for the treatment to be reduced. Laboratory experiments showed that more than half of the calcium hydroxide was changed to calcium carbonate when the mixed soil sample was ventilated by carbon dioxide, using mixing ratios of 5% quicklime and 5% water in the soil. The maximum soil temperature reached with this treatment was the same as that for the treatment using 10% quicklime. Scale-up experiments confirmed the effectiveness of using carbon dioxide ventilation.

Sulfur is almost insoluble in water at ambient temperatures, and therefore polysulfide (S(n)(2-)) has been considered as a possible intermediate that is used directly by bacteria in sulfur respiration. Sulfur-reducing reductases have been purified and characterized from a few sulfur reducers. However, polysulfide reduction has only been confirmed in Wolinella succinogenes. In our previous study, the direct production of hydrogen sulfide from polysulfide was confirmed by an enrichment culture obtained from natural samples under sulfate-reducing conditions. The present study attempted to isolate and identify polysulfide-reducing bacteria from the enrichment cultures. Almost all the isolated strains were classified into the genus Clostridium, based on 16S rRNA gene sequence analysis. The isolates, and some closely related strains, were able to reduce polysulfide to hydrogen sulfide. During production of 1 mol of hydrogen sulfide, approximately 2 mol of lactate was converted to acetate. Thus, dissimilatory polysulfide reduction occurred using lactate as an electron donor. The ability to reduce elemental sulfur was also examined with the isolates and the related strains. Although elemental sulfur reducing strains can reduce polysulfides, not all polysulfide-reducing strains can reduce elemental sulfur. These results demonstrate that the conversion of elemental sulfur to polysulfide seems to be important in the reduction process of sulfur.

Adult-onset type II citrullinemia (CTLN2) is a rare disorder of the urea cycle resulting in hyperammonemia, with a poor prognosis. Here we report a 48-year-old Japanese man who showed abnormal nocturnal behavior. Laboratory data indicated raised plasma concentrations of ammonia and citrulline, and a definitive diagnosis of CTLN2 was made by DNA analysis. Hyperammonemia was not improved by oral intake of branched-chain amino acids (BCAA), whereas venous infusion of BCAA was effective. Western blotting revealed heterozygotic expression of citrin protein in a liver biopsy specimen from the patient's brother. However, as symptomatic CTLN2 is very unusual in a heterozygotic carrier, we considered the brother suitable as a living-donor liver transplantation (LDLT) donor. The recipient's entire liver was removed, and replaced with the left liver graft. The plasma ammonia level remained low without infusion of BCAA after liver transplantation. From this case we conclude that venous infusion, rather than oral administration, of BCAA is useful for conservative treatment of CTLN2. However, liver transplantation is the only effective therapeutic option for CTLN2, and should be performed before irreversible encephalopathy occurs. Use of a graft from heterozygotic donors is permissible treatment for CTLN2.

Polycyclic aromatic hydrocarbons (PAHs) have polluted soil and groundwater widely and for long term because of their low solubility at normal temperature. Several microorganisms, such as Pseudomonas sp., Sphigomonas sp., a white‐rot fungus and so on, being able to decompose PAHs, have been isolated and researched. This study reported to investigate biodegradation of low molecule PAH by isolated bacteria from light oil polluted soil. 12 isolates were obtained from a light oil polluted soil using naphthalene, fluorene and anthracene as sole carbon source, of which 4 isolates grew with naphthalene, 4 isolates did with fluorene and 4 isolates did with anthracene. Among them 3 isolates showed the ability to degrade phenanthrene additionally. These phenanthrene degradation and growth rates were almost same as that of S. yanoikuyae (DSM6900), which is the typical bacteria of PAHs degrader. Therefore, the isolate seemed to have an expectation for PAHs degradation.

Recently, both surfactant extraction of chlorinated compounds from contaminated soils and chemical reduction of chlorinated compounds by pyrite have had received a lot of attention. The reaction of the natural mineral pyrite was found as a surface controlling process which strongly depends on absorption of contaminants on the surface. Surfactants were not only aggregated into micelle which increase solubility of hydrophobic compounds but also tend to absorb on the solid surface. This study investigated effects of different kinds of Surfactants on absorption of chlorobenzene on pyrite surface in order to identify coupling potential of surfactant application and remediation by pyrite. Surfactants used including non‐ionic, anionic and cationic which were Polyoxyethylene (23) Lauryl Ether (Brij35), Sodium Dodecyl Sulfate (SDS) and Cetyl TrimethylAmmonium Bromide (CTAB) respectively were investigated with a wide range of surfactant concentration up to 4 times of each critical micelle concentration (CMC). Chlorobenzene was chosen as a representative compound. The enhancement or competition effects of Surfactants on absorption were discussed.

An anaerobic mixed microbial culture was enriched from soil and groundwater taken from a site contaminated with trichloroethene (TCE). This enrichment culture could dechlorinate TCE sequentially to cis‐dichloroethene (cis‐DCE), vinyl chloride (VC), and ethene rapidly within 2 weeks. This enrichment culture could utilize various organic compounds, such as methanol, ethanol, and sodium acetate and so on, as electron donor. This culture had maintained high ability of TCE dechlorination for about 3 years since the start of enrichment cultivation. The optimum pH value for the dechlorination activity of this culture, which reacts from TCE to ethene, was 6.7. However above the pH value 7.1, it lost the dechlorination ability of cis‐DCE and VC. So cis‐DCE was remained at that pH conditions. From the DNA sequencing analysis of 16SrRNA gene, this enrichment culture includes Dehalococcoides sp. which has the ability to dechlorinate TCE to VC completely with hydrogen. It suggested that this Dehalococcoides sp. takes part in the dechlorination of chloroethenes.