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Azizur Rahman, Mohammad ; Hasegawa, Hiroshi
概要:
Phytoremediation, a plant based green technology, has received increasing attention after the discovery of hyperaccumula
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ting plants which are able to accumulate, translocate, and concentrate high amount of certain toxic elements in their above-ground/harvestable parts. Phytoremediation includes several processes namely, phytoextraction, phytodegradation, rhizofiltration, phytostabilization and phytovolatilization. Both terrestrial and aquatic plants have been tested to remediate contaminated soils and waters, respectively. A number of aquatic plant species have been investigated for the remediation of toxic contaminants such as As, Zn, Cd, Cu, Pb, Cr, Hg, etc. Arsenic, one of the deadly toxic elements, is widely distributed in the aquatic systems as a result of mineral dissolution from volcanic or sedimentary rocks as well as from the dilution of geothermal waters. In addition, the agricultural and industrial effluent discharges are also considered for arsenic contamination in natural waters. Some aquatic plants have been reported to accumulate high level of arsenic from contaminated water. Water hyacinth (Eichhornia crassipes), duckweeds (Lemna gibba, Lemna minor, Spirodela polyrhiza), water spinach (Ipomoea aquatica), water ferns (Azolla caroliniana, Azolla filiculoides, and Azolla pinnata), water cabbage (Pistia stratiotes), hydrilla (Hydrilla verticillata) and watercress (Lepidium sativum) have been studied to investigate their arsenic uptake ability and mechanisms, and to evaluate their potential in phytoremediation technology. It has been suggested that the aquatic macrophytes would be potential for arsenic phytoremediation, and this paper reviews up to date knowledge on arsenic phytoremediation by common aquatic macrophytes.. © 2011 Elsevier Ltd.
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| 3.
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Hasegawa, Hiroshi ; Sohrin, Yoshiki ; Seki, Kayoko ; Sato, Mayuko ; Norisuye, Kazuhiro ; Naito, Kanako ; Matsui, Masakazu
概要:
金沢大学工学部<br />Arsenic transformations by freshwater algae have been studied under laboratory conditions. By the use of a
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new analytical method, we identified methylarsenic(III) species in the growth medium of green-alga Closterium aciculare incubated under axenic conditions. The arsenate concentration in the experimental medium began to decrease just after inoculation, and the levels of arsenite and methylarsenicals increased with the growth of C. aciculare. Initially, most of the arsenate was converted into arsenite, which peaked in concentration during the exponential phase. Methylarsenicals accumulated rapidly in the stationary phase. DMAA(V) production was enhanced when the ratio of phosphate to arsenate decreased in the culture medium. The levels of DMAA(V) increased continuously toward the end of the experiment. On the other hand, methylarsenic(III) species remained relatively steady during the stationary phase. Methylarsenic(III) species accounted for 0-35% of methylarsenicals. These results suggest that arsenite and methylarsenicals (containing methylarsenic(III) species) are supplied by phytoplankton, and serve as evidence of the origin of methylarsenic(III) species in natural waters. © 2001 Elsevier Science Ltd.
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Hasegawa, Hiroshi ; Rahman, Ismail M. M. ; Kinoshita, Sanae ; Maki, Teruya ; Furusho, Yoshiaki
概要:
金沢大学理工研究域物質化学系<br />A new technique for the separation and pre-concentration of dissolved Fe(III) from the ligand-rich a
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queous system is proposed. A solid phase extraction (SPE) system with an immobilized macrocyclic material, commonly known as molecular recognition technology (MRT) gel and available commercially, was used. Synthetic Fe(III) solution in aqueous matrices spiked with a 100-fold concentration of EDTA was used. Dissolved iron that was 'captured' by the MRT gel was eluted using hydrochloric acid and subsequently determined by graphite furnace atomic absorption spectrometry. The effect of different variables, such as pH, reagent concentration, flow rate and interfering ions, on the recovery of analyte was investigated. Quantitative maximum separation (~100%) of the dissolved Fe(III) from synthetic aqueous solutions at a natural pH range was observed at a flow rate of 0.2mLmin-1. The extraction efficiency of the MRT gel is largely unaltered by the coexisting ions commonly found in natural water. When compared with different SPE materials, the separation performance of MRT gel is also much higher. © 2010 Elsevier Ltd.
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| 5.
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論文
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Hasegawa, Hiroshi ; Rahman, Ismail M. M. ; Kinoshita, Sanae ; Maki, Teruya ; Furusho, Yoshiaki
概要:
金沢大学理工研究域物質化学系<br />A new technique for the separation and pre-concentration of dissolved Fe(III) from the ligand-rich a
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queous system is proposed. A solid phase extraction (SPE) system with an immobilized macrocyclic material, commonly known as molecular recognition technology (MRT) gel and available commercially, was used. Synthetic Fe(III) solution in aqueous matrices spiked with a 100-fold concentration of EDTA was used. Dissolved iron that was 'captured' by the MRT gel was eluted using hydrochloric acid and subsequently determined by graphite furnace atomic absorption spectrometry. The effect of different variables, such as pH, reagent concentration, flow rate and interfering ions, on the recovery of analyte was investigated. Quantitative maximum separation (~100%) of the dissolved Fe(III) from synthetic aqueous solutions at a natural pH range was observed at a flow rate of 0.2mLmin-1. The extraction efficiency of the MRT gel is largely unaltered by the coexisting ions commonly found in natural water. When compared with different SPE materials, the separation performance of MRT gel is also much higher. © 2010 Elsevier Ltd.
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| 6.
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論文
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Hasegawa, Hiroshi ; Rahman, Ismail M. M. ; Kinoshita, Sanae ; Maki, Teruya ; Furusho, Yoshiaki
概要:
金沢大学理工研究域物質化学系<br />A new technique for the separation and pre-concentration of dissolved Fe(III) from the ligand-rich a
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queous system is proposed. A solid phase extraction (SPE) system with an immobilized macrocyclic material, commonly known as molecular recognition technology (MRT) gel and available commercially, was used. Synthetic Fe(III) solution in aqueous matrices spiked with a 100-fold concentration of EDTA was used. Dissolved iron that was 'captured' by the MRT gel was eluted using hydrochloric acid and subsequently determined by graphite furnace atomic absorption spectrometry. The effect of different variables, such as pH, reagent concentration, flow rate and interfering ions, on the recovery of analyte was investigated. Quantitative maximum separation (~100%) of the dissolved Fe(III) from synthetic aqueous solutions at a natural pH range was observed at a flow rate of 0.2mLmin-1. The extraction efficiency of the MRT gel is largely unaltered by the coexisting ions commonly found in natural water. When compared with different SPE materials, the separation performance of MRT gel is also much higher. © 2010 Elsevier Ltd.
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| 7.
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論文
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Tang, Ning ; Sato, Kousuke ; Tokuda, Takahiro ; Tatematsu, Michiya ; Hama, Hirotaka ; Suematsu, Chikako ; Kameda, Takayuki ; Toriba, Akira ; Hayakawa, Kazuichi
概要:
Airborne particulates were collected at a background site (Wajima Air Monitoring Station; WAMS) on the Noto Peninsula, J
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apan from January 2006 to December 2007. 1-, 2-nitropyrenes (1-, 2-NPs) and 2-nitrofluoranthene (2-NFR), in the particulates were determined with a sensitive HPLC method with chemiluminescence detection. The average concentrations were higher in winter than in summer. A meteorological analysis indicated that the air samples collected in winter were transported mainly from Northeast China over the Japan Sea. Both the concentration ratios of 2-NFR to 1-NP and 1-NP to pyrene were similar to those in Shenyang in Northeast China which located along the air transportation route to WAMS, but not in Kanazawa which near WAMS. These results strongly suggest that most of the atmospheric 1-, 2-NPs and 2-NFR at WAMS in winter were long range transported from Northeast China. © 2014 Elsevier Ltd. All rights reserved.
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| 8.
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Rahman, Ismail M. M. ; Begum, Zinnat A. ; Sawai, Hikaru ; Maki, Teruya ; Hasegawa, Hiroshi
概要:
Sand filters devised with iron-rich adsorbents are extensively promoted and deployed in the arsenic-prone south and sout
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h-east Asian countries (e.g., Bangladesh). The approach offers superior performance in removing arsenic while the spent sludge from the sand filters is an issue of concern due to the possibility of toxic releases after being discarded. In this work, a new technique is proposed for the treatment of spent iron-oxide coated sand (IOCS) from filters used in arsenic removal. Chelant-washing of the arsenic-loaded IOCS is combined with the solid phase extraction treatment to accomplish the objective. The unique point of the proposed process is the cost-effective scheme, which includes the option of recycling of the washing solvent beside the decontamination of the spent arsenic-rich sludge. © 2013 Elsevier Ltd.
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| 9.
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Maki, Teruya ; Hirota, Wakana ; Motojima, Hiroyuki ; Hasegawa, Hiroshi ; Rahman, Mohammad Azizur
概要:
金沢大学理工研究域物質化学系<br />Aquatic arsenic cycles mainly depend on microbial activities that change the arsenic chemical forms
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and influence human health and organism activities. The microbial aggregates degrading organic matter are significantly related to the turnover between inorganic arsenic and organoarsenic compounds. We investigated the effects of microbial aggregates on organoarsenic mineralization in Lake Kahokugata using lake water samples spiked with dimethylarsinic acid (DMA). The lake water samples converted 1μmolL-1 of DMA to inorganic arsenic for 28d only under anaerobic and dark conditions in the presence of microbial activities. During the DMA mineralization process, organic aggregates >5.0μm with bacterial colonization increased the densities. When the organic aggregates >5.0μm were eliminated from the lake water samples using filters, the degradation activities were reduced. DMA in the lake water would be mineralized by the microbial aggregates under anaerobic and dark conditions. Moreover, DMA amendment enhanced the degradation activities in the lake water samples, which mineralized 50μmolL-1 of DMA. The DMA-amended aggregates >5.0μm completely degraded 1μmolL-1 of DMA with a shorter incubation time of 7d. The supplement of KNO3 and NaHCO3 to lake water samples also shortened the DMA-degradation period. Presumably, the bacterial aggregates involved in the chemical heterotrophic process would contribute to the DMA-biodegradation process in Lake Kahokugata, which is induced by the DMA amendment. © 2011 Elsevier Ltd.
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| 10.
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論文
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Azizur Rahman, Mohammad ; Mamunur, Rahman ; Kadohashi, K. ; Maki, Teruya ; Hasegawa, Hiroshi
概要:
This study was conducted to investigate the effect of external iron status and arsenic species on chelant-enhanced iron
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bioavailability and arsenic uptake. Rice seedlings (Oryza sativa L.) were used as model plant, and were grown in artificially contaminated sandy soils irrigated with Murashige and Skoog (MS) culture solution. Arsenate uptake in roots and shoots of rice seedlings were affected significantly (p > 0.05) while dimethylarsinic acid (DMAA) was not by the additional iron and chelating ligand treatments. Regardless of iron concentrations in the soil solution, HIDS increased arsenic uptake for roots more than EDTA and EDDS. Chelating ligands and arsenic species also influenced iron uptake in rice roots. Irrespective of arsenic species, HIDS was found to be more effective in the increase of iron bioavailability and uptake in rice roots compared to other chelants. There was a significant positive correlation (r = 0.78, p < 0.05) between arsenate and iron concentrations in the roots of rice seedlings grown with or without additional iron indicating that arsenate inhibit iron uptake. In contrast, there was no correlation between iron and DMAA uptake in roots. Poor correlation between iron and arsenic in shoots indicated that iron uptake in shoots was neither affected by additional iron nor by arsenic species. Compared to the control, chelating ligands increased iron uptake in shoots of rice seedlings significantly (p < 0.05). Regardless of additional iron and arsenic species, iron uptake in rice shoots did not differed among EDTA, EDDS, and HIDS treatments. © 2011 Elsevier Ltd. All rights reserved.
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| 11.
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Hasegawa, Hiroshi ; Rahman, Ismail M.M. ; Kinoshita, Sanae ; Maki, Teruya ; Furusho, Yoshiaki
概要:
金沢大学理工研究域物質化学系<br />Although the excellent metal-binding capacities of aminopolycarboxylate chelants (APCs) facilitate t
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heir extensive use, pre- and post-toxicity of APCs and their high persistence in aquatic environments evoke concerns. Several treatment techniques with a principal focus on the degradation of APCs at the pre-release step have been proposed. Here, we report a technique for the separation of metal ions from waste solution containing excess APCs using a solid phase extraction system with an ion-selective immobilized macrocyclic material, commonly known as a molecular recognition technology (MRT) gel. Synthetic metal solutions with 100-fold chelant content housed in H2O matrices were used as samples. The MRT gel showed a higher recovery rate compared with other SPE materials at 20 °C using a flow rate of 0.2 mL min-1. The effects of solution pH, metal-chelant stability constants and ionic radii were assessed for 32 metals. Compared to the conventional treatment options for such waste solutions, our proposed technique has the advantage of non-destructive separation of both metal ions and chelants. © 2010 Elsevier Ltd. All rights reserved.
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| 12.
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論文
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Rahman, M. Azizur ; Hasegawa, Hiroshi ; Kadohashi, K. ; Maki, Teruya ; Ueda, K.
概要:
金沢大学理工研究域物質化学系<br />The influence of biodegradable chelating ligands on arsenic and iron uptake by hydroponically grown
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rice seedlings (Oryza sativa L.) was investigated. Even though the growth solution contained sufficient Fe, the growth of rice seedlings gradually decreased up to 76% with the increase of pH of the solution from 7 to 11. Iron forms insoluble ferric hydroxide complexes at neutral or alkaline pH in oxic condition. Chelating ligands produce soluble 'Fe-ligand complex' which assist Fe uptake in plants. The biodegradable chelating ligand hydroxyiminodisuccinic acid (HIDS) was more efficient then those of ethylenediaminetetraacetic acid (EDTA), ethylenediaminedisuccinic acid (EDDS), and iminodisuccinic acid (IDS) in the increase of Fe uptake and growth of rice seedling. A total of 79 ± 20, 87 ± 6, 116 ± 15, and 63 ± 18 mg dry biomass of rice seedlings were produced with the addition of 0.5 mM of EDDS, EDTA, HIDS, and IDS in the nutrient solution, respectively. The Fe concentrations in rice tissues were 117 ± 15, 82 ± 8, 167 ± 25, and 118 ± 22 μmol g-1 dry weights when 0.25 mM of EDDS, EDTA, HIDS, and IDS were added to the nutrient solution, respectively. Most of the Fe accumulated in rice tissues was stored in roots after the addition of chelating ligands in the solution. The results indicate that the HIDS would be a potential alternative to environmentally persistent EDTA for the increase of Fe uptake and plant growth. The HIDS also increased As uptake in rice root though its translocation from root to shoot was not augmented. This study reports HIDS for the first time as a promising chelating ligand for the enhancement of Fe bioavailability and As phytoextraction. © 2009.
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13. Seasonal dynamics of biodegradation activities for dimethylarsinic acid (DMA) in Lake Kahokugata
Maki, Teruya ; Hirota, Wakana ; Ueda, Kaori ; Hasegawa, Hiroshi ; Rahman, Mohammad Azizur
概要:
金沢大学理工研究域物質化学系<br />The microbial activities in aquatic environments significantly influence arsenic cycles such as the
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turnover between inorganic arsenic and organoarsenic compounds. In Lake Kahokugata, inorganic arsenic was detected at concentrations ranging from 2.8 to 23 nM in all seasons, while the concentrations of dimethylarsinic acid (DMA) produced by microorganisms such as phytoplankton changed seasonally and showed a peak in winter. The changes in the concentrations of methylarsenic species did not correlate with the changes in phytoplankton abundance (chlorophyll a contents), suggesting that DMA-degradation is related to this inconsistency. DMA (1 μM) added into the lake water was converted to inorganic arsenic at 20 °C only under anaerobic and dark conditions, while DMA degradation was diminished under aerobic or light conditions. Moreover, DMA added to the lake water samples collected through four seasons was degraded at the same rates under anaerobic and dark conditions at 20 °C. However, at 30 °C, 1 μM of DMA in the summer lake water samples was rapidly degraded in 7 and 21 d. In contrast, DMA degradation was diminished in the winter lake water samples at 4 °C of incubation. Presumably, DMA-biodegradation activities are mainly controlled by changes in the water temperature in Lake Kahokugata, where the arsenic concentrations change seasonally. © 2009 Elsevier Ltd. All rights reserved.
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論文
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Maki, Teruya ; Hirota, Wakana ; Motojima, Hiroyuki ; Hasegawa, Hiroshi ; Rahman, Mohammad Azizur
概要:
金沢大学理工研究域物質化学系<br />Aquatic arsenic cycles mainly depend on microbial activities that change the arsenic chemical forms
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and influence human health and organism activities. The microbial aggregates degrading organic matter are significantly related to the turnover between inorganic arsenic and organoarsenic compounds. We investigated the effects of microbial aggregates on organoarsenic mineralization in Lake Kahokugata using lake water samples spiked with dimethylarsinic acid (DMA). The lake water samples converted 1 μmol L-1 of DMA to inorganic arsenic for 28 d only under anaerobic and dark conditions in the presence of microbial activities. During the DMA mineralization process, organic aggregates >5.0 μm with bacterial colonization increased the densities. When the organic aggregates >5.0 μm were eliminated from the lake water samples using filters, the degradation activities were reduced. DMA in the lake water would be mineralized by the microbial aggregates under anaerobic and dark conditions. Moreover, DMA amendment enhanced the degradation activities in the lake water samples, which mineralized 50 μmol L-1 of DMA. The DMA-amended aggregates >5.0 μm completely degraded 1 μmol L-1 of DMA with a shorter incubation time of 7 d. The supplement of KNO3 and NaHCO3 to lake water samples also shortened the DMA-degradation period. Presumably, the bacterial aggregates involved in the chemical heterotrophic process would contribute to the DMA-biodegradation process in Lake Kahokugata, which is induced by the DMA amendment. © 2011 Elsevier Ltd. All rights reserved.
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| 15.
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15. Seasonal dynamics of biodegradation activities for dimethylarsinic acid (DMA) in Lake Kahokugata
Maki, Teruya ; Hirota, W. ; Ueda, Kazumasa ; Hasegawa, Hiroshi ; Rahman, Mohammad Azizur
概要:
金沢大学理工研究域物質化学系<br />The microbial activities in aquatic environments significantly influence arsenic cycles such as the
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turnover between inorganic arsenic and organoarsenic compounds. In Lake Kahokugata, inorganic arsenic was detected at concentrations ranging from 2.8 to 23 nM in all seasons, while the concentrations of dimethylarsinic acid (DMA) produced by microorganisms such as phytoplankton changed seasonally and showed a peak in winter. The changes in the concentrations of methylarsenic species did not correlate with the changes in phytoplankton abundance (chlorophyll a contents), suggesting that DMA-degradation is related to this inconsistency. DMA (1 μM) added into the lake water was converted to inorganic arsenic at 20 °C only under anaerobic and dark conditions, while DMA degradation was diminished under aerobic or light conditions. Moreover, DMA added to the lake water samples collected through four seasons was degraded at the same rates under anaerobic and dark conditions at 20 °C. However, at 30 °C, 1 μM of DMA in the summer lake water samples was rapidly degraded in 7 and 21 d. In contrast, DMA degradation was diminished in the winter lake water samples at 4 °C of incubation. Presumably, DMA-biodegradation activities are mainly controlled by changes in the water temperature in Lake Kahokugata, where the arsenic concentrations change seasonally. © 2009 Elsevier Ltd. All rights reserved.
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論文
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Tawaraa, Kenji ; Nishijo, Muneko ; Maruzeni, Shoko ; Nakagawa, Hideaki ; Kido, Teruhiko ; Naganuma, Rie ; Suzuki, Hiroyuki ; Nhu, Dang Duc ; Hung, Nguyen Ngo ; Thomd, Le Thi Hong
概要:
This study evaluated residual congener patterns of dioxin/furan (=PCDD/DF) related to tactical herbicides aerially spray
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ed over the regions of southern Vietnam through Operation Ranch Hand. The study focused on Cam Chinh (CC) commune, Quang Tri province (an area sprayed with tactical herbicides), and the Cam Phuc (CP) commune, Ha Tinh province (a non-sprayed area). Breast milk samples for analysis were collected in September 2002 and July 2003 from lactating primiparous and multiparous mothers born after the war (<31 years old). We found the levels of each congener in the CC commune were higher than in the CP commune, and determined specificity in the PCDD/DF congener pattern in CC commune samples by cluster analysis. The congener pattern is characterized by higher (the hexa-, the hepta-, and the octa-) chlorinated PCDD/DFs; this appears to be the same profile as that presented by pentachlorophenol (PCP), rather than 2,4,5-trichlorophenoxy acid (2,4,5-T) contaminated with 2,3,7,8-TCDD. A GC/MS study in the 1970s detected the chlorophenols 2,4-di and 2,4,6-trichlorophenol in some Agent Orange samples, which contained, like PCP, a wide variety of PCDD/DF congeners. In this context, it may be expected that certain tactical herbicides contaminated with various chlorophenol impurities, have a unique congener pattern when compared with pure 2,4,5-T formulations. © 2011 Elsevier Ltd. All rights reserved.
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| 17.
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論文
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Rahman M., Mamunur ; Rahman M., Azizur ; Maki, Teruya ; Nishiuchi, Takumi ; Asano, T. ; Hasegawa, Hiroshi
概要:
Iron (Fe) is one of the vital limiting factors for phytoplankton in vast regions of the contemporary oceans, notably the
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high nutrient low chlorophyll regions. Therefore, it is apparent to be acquainted with the Fe uptake strategy of marine phytoplankton under Fe-limited condition. In the present study, marine phytoplankton Prymnesium parvum was grown under Fe-deplete (0.0025 μM) and Fe-rich (0.05 μM) conditions, and proteomic responses of the organism to Fe conditions were compared. In sodium dodecyl sulfate (SDS) gel electrophoresis, 7 proteins (16, 18, 32, 34, 75, 82, and 116 kDa) were highly expressed under Fe-deplete condition, while one protein (23 kDa) was highly expressed under Fe-rich condition. These proteins were subjected to 2-dimensional gel electrophoresis (2-D DIGE) to differentiate individual proteins, and were identified by matrix-assisted laser desorption-ionization-time of flight-mass spectrometer (MALDI-TOF-MS) analysis. The results showed that under Fe-deplete condition P. parvum increases the biosynthesis of ATP binding cassette (ABC) transporters, flagellar associated protein (FAP), and Phosphoribosylaminoimidazole-succinocarboxamide synthase. These proteins are assumed to be involved in a number of cellular biochemical processes that facilitate Fe acquisition in phytoplankton. Under Fe-deplete condition, P. parvum increases the synthesis of ribulose biphosphate carboxylase (RuBisCo), malate dehydrogenase, and two Fe-independent oxidative stress response proteins, manganese superoxide dismutase (MnSOD) and Serine threonine kinase (STK). Thus, marine phytoplankton may change their Fe acquisition strategy by altering the biosynthesis of several proteins in order to cope with Fe-limitation. © 2013 Elsevier Ltd. All rights reserved.
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| 18.
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Mamunur, Rahman M. ; Azizur, Rahman M. ; Maki, Teruya ; Nishiuchi, Takumi ; Asano, Tomoya ; Hasegawa, Hiroshi
概要:
Iron (Fe) is one of the vital limiting factors for phytoplankton in vast regions of the contemporary oceans, notably the
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high nutrient low chlorophyll regions. Therefore, it is apparent to be acquainted with the Fe uptake strategy of marine phytoplankton under Fe-limited condition. In the present study, marine phytoplankton Prymnesium parvum was grown under Fe-deplete (0.0025 μM) and Fe-rich (0.05 μM) conditions, and proteomic responses of the organism to Fe conditions were compared. In sodium dodecyl sulfate (SDS) gel electrophoresis, 7 proteins (16, 18, 32, 34, 75, 82, and 116. kDa) were highly expressed under Fe-deplete condition, while one protein (23. kDa) was highly expressed under Fe-rich condition. These proteins were subjected to 2-dimensional gel electrophoresis (2-D DIGE) to differentiate individual proteins, and were identified by matrix-assisted laser desorption-ionization-time of flight-mass spectrometer (MALDI-TOF-MS) analysis. The results showed that under Fe-deplete condition P. parvum increases the biosynthesis of ATP binding cassette (ABC) transporters, flagellar associated protein (FAP), and Phosphoribosylaminoimidazole-succinocarboxamide synthase. These proteins are assumed to be involved in a number of cellular biochemical processes that facilitate Fe acquisition in phytoplankton. Under Fe-deplete condition, P. parvum increases the synthesis of ribulose biphosphate carboxylase (RuBisCo), malate dehydrogenase, and two Fe-independent oxidative stress response proteins, manganese superoxide dismutase (MnSOD) and Serine threonine kinase (STK). Thus, marine phytoplankton may change their Fe acquisition strategy by altering the biosynthesis of several proteins in order to cope with Fe-limitation. © 2013 Elsevier Ltd.
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| 19.
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Begum, Zinnat A. ; Rahman, Ismail M. M. ; Tate, Yousuke ; Sawai, Hikaru ; Maki, Teruya ; Hasegawa, Hiroshi
概要:
Ex situ soil washing with synthetic extractants such as, aminopolycarboxylate chelants (APCs) is a viable treatment alte
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rnative for metal-contaminated site remediation. EDTA and its homologs are widely used among the APCs in the ex situ soil washing processes. These APCs are merely biodegradable and highly persistent in the aquatic environments leading to the post-use toxic effects. Therefore, an increasing interest is focused on the development and use of the eco-friendly APCs having better biodegradability and less environmental toxicity. The paper deals with the results from the lab-scale washing treatments of a real sample of metal-contaminated soil for the removal of the ecotoxic metal ions (Cd, Cu, Ni, Pb, and Zn) using five biodegradable APCs, namely [S,S]-ethylenediaminedisuccinic acid, imminodisuccinic acid, methylglycinediacetic acid, DL-2-(2-carboxymethyl) nitrilotriacetic acid (GLDA), and 3-hydroxy-2,2'-iminodisuccinic acid. The performance of those biodegradable APCs was evaluated for their interaction with the soil mineral constituents in terms of the solution pH and metal-chelant stability constants, and compared with that of EDTA. Speciation calculations were performed to identify the optimal conditions for the washing process in terms of the metal-chelant interactions as well as to understand the selectivity in the separation ability of the biodegradable chelants towards the metal ions. A linear relationship between the metal extraction capacity of the individual chelants towards each of the metal ions from the soil matrix and metal-chelant conditional stability constants for a solution pH greater than 6 was observed. Additional considerations were derived from the behavior of the major potentially interfering cations (Al, Ca, Fe, Mg, and Mn), and it was hypothesized that use of an excess of chelant may minimize the possible competition effects during the single-step washing treatments. Sequential extraction procedure was used to determine the metal distribution in the soil before and after the extractive decontamination using biodegradable APCs, and the capability of the APCs in removing the metal ions even from the theoretically immobilized fraction of the contaminated soil was observed. GLDA appeared to possess the greatest potential to decontaminate the soil through ex situ washing treatment compared to the other biodegradable chelants used in the study. © 2012 Elsevier Ltd.
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| 20.
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Rahman, M. Azizur ; Hasegawa, Hiroshi ; Mahfuzur, Rahman M. ; Nazrul, Islam M. ; Majid, Miah M.A. ; Tasmin, A.
概要:
金沢大学大学院自然科学研究科物質情報解析<br />金沢大学工学部<br />A glass house experiment was conducted to investigate the effect of soil arsenic
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on photosynthetic pigments, chlorophyll-a and -b, and their correlations with rice yield and growth. The experiment was designed with three replications of six arsenic treatments viz. control, 10, 20, 30, 60, 90 mg of As kg-1 soil. Arsenic concentration in initial soil, to which the above mentioned concentrations of arsenic were added, was 6.44 ± 0.24 mg kg-1. Both chlorophyll-a and -b contents in rice leaf decreased significantly (p < 0.05) with the increase of soil arsenic concentrations. No rice plant survived up to maturity stage in soil treated with 60 and 90 mg of As kg-1. The highest chlorophyll-a and -b contents were observed in control treatment (2.62 ± 0.24 and 2.07 ± 0.14 mg g-1 were the average values of chlorophyll-a and -b, respectively of the five rice varieties) while 1.50 ± 0.20 and 1.04 ± 0.08 mg g-1 (average of five rice varieties) of chlorophyll-a and -b, respectively were the lowest. The content of photosynthetic pigments in these five rice varieties did not differ significantly (p > 0.05) from each other in control treatment though they differed significantly (p < 0.05) from each other in 30 mg of As kg-1 soil treatment. Among the five rice varieties, chlorophyll content in BRRI dhan 35 was found to be mostly affected with the increase of soil arsenic concentration while BRRI hybrid dhan 1 was least affected. Well correlations were observed between chlorophyll content and rice growth and yield suggesting that arsenic toxicity affects the photosynthesis which ultimately results in the reduction of rice growth and yield. © 2006 Elsevier Ltd. All rights reserved.
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| 21.
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Rahman, M.A. ; Hasegawa, Hiroshi ; Rahman, M.M. ; Miah, M.A.M.
概要:
金沢大学大学院自然科学研究科物質情報解析<br />A study was conducted to investigate the accumulation and distribution of arsenic in different
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fractions of rice grain (Oryza sativa L.) collected from arsenic affected area of Bangladesh. The agricultural soil of study area has become highly contaminated with arsenic due to the excessive use of arsenic-rich underground water (0.070 ± 0.006 mg l-1, n = 6) for irrigation. Arsenic content in tissues of rice plant and in fractions of rice grain of two widely cultivated rice varieties, namely BRRI dhan28 and BRRI hybrid dhan1, were determined. Regardless of rice varieties, arsenic content was about 28- and 75-folds higher in root than that of shoot and raw rice grain, respectively. In fractions of parboiled and non-parboiled rice grain of both varieties, the order of arsenic concentrations was; rice hull > bran-polish > brown rice > raw rice > polish rice. Arsenic content was higher in non-parboiled rice grain than that of parboiled rice. Arsenic concentrations in parboiled and non-parboiled brown rice of BRRI dhan28 were 0.8 ± 0.1 and 0.5 ± 0.0 mg kg-1 dry weight, respectively while those of BRRI hybrid dhan1 were 0.8 ± 0.2 and 0.6 ± 0.2 mg kg-1 dry weight, respectively. However, parboiled and non-parboiled polish rice grain of BRRI dhan28 contained 0.4 ± 0.0 and 0.3 ± 0.1 mg kg-1 dry weight of arsenic, respectively while those of BRRI hybrid dhan1 contained 0.43 ± 0.01 and 0.5 ± 0.0 mg kg-1 dry weight, respectively. Both polish and brown rice are readily cooked for human consumption. The concentration of arsenic found in the present study is much lower than the permissible limit in rice (1.0 mg kg-1) according to WHO recommendation. Thus, rice grown in soils of Bangladesh contaminated with arsenic of 14.5 ± 0.1 mg kg-1 could be considered safe for human consumption. © 2007 Elsevier Ltd. All rights reserved.
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| 22.
論文 |
論文
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Rahman, M. Azizur ; Hasegawa, Hiroshi ; Kadohashi, K. ; Maki, Teruya ; Ueda, Kazumasa
概要:
金沢大学理工研究域物質化学系<br />The influence of biodegradable chelating ligands on arsenic and iron uptake by hydroponically grown
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rice seedlings (Oryza sativa L.) was investigated. Even though the growth solution contained sufficient Fe, the growth of rice seedlings gradually decreased up to 76% with the increase of pH of the solution from 7 to 11. Iron forms insoluble ferric hydroxide complexes at neutral or alkaline pH in oxic condition. Chelating ligands produce soluble 'Fe-ligand complex' which assist Fe uptake in plants. The biodegradable chelating ligand hydroxyiminodisuccinic acid (HIDS) was more efficient then those of ethylenediaminetetraacetic acid (EDTA), ethylenediaminedisuccinic acid (EDDS), and iminodisuccinic acid (IDS) in the increase of Fe uptake and growth of rice seedling. A total of 79 ± 20, 87 ± 6, 116 ± 15, and 63 ± 18 mg dry biomass of rice seedlings were produced with the addition of 0.5 mM of EDDS, EDTA, HIDS, and IDS in the nutrient solution, respectively. The Fe concentrations in rice tissues were 117 ± 15, 82 ± 8, 167 ± 25, and 118 ± 22 μmol g-1 dry weights when 0.25 mM of EDDS, EDTA, HIDS, and IDS were added to the nutrient solution, respectively. Most of the Fe accumulated in rice tissues was stored in roots after the addition of chelating ligands in the solution. The results indicate that the HIDS would be a potential alternative to environmentally persistent EDTA for the increase of Fe uptake and plant growth. The HIDS also increased As uptake in rice root though its translocation from root to shoot was not augmented. This study reports HIDS for the first time as a promising chelating ligand for the enhancement of Fe bioavailability and As phytoextraction. © 2009 Elsevier Ltd. All rights reserved.
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| 23.
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論文
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Rahman, Ismail M. M. ; Begum, Zinnat A. ; Nakano, Masayoshi ; Furusho, Yoshiaki ; Maki, Teruya ; Hasegawa, Hiroshi
概要:
金沢大学理工研究域物質化学系<br />A combination of solid phase extraction (SPE) columns was used for selective separation of water-sol
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uble arsenic species: arsenite, arsenate, monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA). The SPE columns, namely AnaLig TE-01 (TE-01), AnaLig AN-01 Si (AN-01) and AnaLig As-01 PA (As-01), contain immobilized macrocyclic material as the sorbent and commonly known as molecular recognition technology (MRT) gel. The retention, extraction and recovery behavior of the MRT gel SPE columns were studied at pH 4-10. Fortified deionized water spiked with 100μM of arsenic species were treated at the flow rate of 0.2mLmin-1. HNO3 (1.0 and 6.0M) was used as eluent to recover the retained arsenic species from TE-01 and AN-01 SPE columns. Arsenic species retained in the As-01 column were eluted with HNO3 (0.1M) followed by NaOH (2.0M). Likely interference from the various coexisting ions (Na+, K+, Ca2+, Mg2+, Cl-, NO3-, CH3COO-, PO43-, SO42-, ClO4-) (10mM) were negligible. Quantitative separation of As(III), As(V), MMA and DMA was achieved based on the differences in extraction and recovery behavior of the MRT gel SPE columns with pH for different arsenic species. Complexation between arsenic species and MRT gel is the core phenomenon of the proposed technique as the complexation of MRT gels is expected to be stronger than the resin-based separation processes. MRT gel SPE columns are advantageous as compared with other reported SPE columns in terms of its performance with As(III). Effortless regeneration and unaltered separation performance of the sorbent materials for more than 100 loading and elution cycles are other sturdy characteristics to consider the MRT gel SPE columns for sensitive and selective arsenic species separation. © 2010 Elsevier Ltd.
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| 24.
論文 |
論文
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Rahman, Ismail M.M. ; Begum, Zinnat A. ; Nakano, Masayoshi ; Furusho, Yoshiaki ; Maki, Teruya ; Hasegawa, Hiroshi
概要:
金沢大学理工研究域物質化学系<br />A combination of solid phase extraction (SPE) columns was used for selective separation of water-sol
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uble arsenic species: arsenite, arsenate, monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA). The SPE columns, namely AnaLig TE-01 (TE-01), AnaLig AN-01 Si (AN-01) and AnaLig As-01 PA (As-01), contain immobilized macrocyclic material as the sorbent and commonly known as molecular recognition technology (MRT) gel. The retention, extraction and recovery behavior of the MRT gel SPE columns were studied at pH 4-10. Fortified deionized water spiked with 100 μM of arsenic species were treated at the flow rate of 0.2 mL min-1. HNO3 (1.0 and 6.0 M) was used as eluent to recover the retained arsenic species from TE-01 and AN-01 SPE columns. Arsenic species retained in the As-01 column were eluted with HNO3 (0.1 M) followed by NaOH (2.0 M). Likely interference from the various coexisting ions (Na+, K+, Ca2+, Mg2+, Cl-, NO3-, CH3COO-, PO43 -, SO42 -, ClO4-) (10 mM) were negligible. Quantitative separation of As(III), As(V), MMA and DMA was achieved based on the differences in extraction and recovery behavior of the MRT gel SPE columns with pH for different arsenic species. Complexation between arsenic species and MRT gel is the core phenomenon of the proposed technique as the complexation of MRT gels is expected to be stronger than the resin-based separation processes. MRT gel SPE columns are advantageous as compared with other reported SPE columns in terms of its performance with As(III). Effortless regeneration and unaltered separation performance of the sorbent materials for more than 100 loading and elution cycles are other sturdy characteristics to consider the MRT gel SPE columns for sensitive and selective arsenic species separation. © 2010 Elsevier Ltd. All rights reserved.
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| 25.
図書 |
図書
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新潟県社会科教育研究会編著
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| 26.
図書 |
図書
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新潟県社会科教育研究会編
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