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1.
Cureus ; 16(6): e63166, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-39070311

RESUMO

BACKGROUND: Psychiatric day care is a key framework for outpatient rehabilitation in Japanese psychiatric treatment. It targets a wide range of diseases and performs various roles. The current status and utilization of psychiatric day care in Japan have changed owing to an increase in the availability of other social resources and the coronavirus disease 2019 (COVID-19) pandemic. However, no reports have quantitatively analyzed the trends or current situation of psychiatric day care in Japan. Therefore, this study aimed to analyze the status of the operation of psychiatric day care in Japan and its trends by sex, region, and age group. METHODS: Based on the publicly available data from the Japanese National Database of Health Insurance Claims and Specific Health Checkups (NDB Open Data), we investigated changes in the numbers related to psychiatric day care nationwide from fiscal year (FY) 2017-2021. Furthermore, we calculated the numbers of psychiatric day care facilities use per 1,000 people by prefecture, sex, and age group in 2021. A Mann-Whitney U test was conducted to compare the total number of psychiatric day care facilities used in months during periods of emergency declarations and priority preventative measures with those used in months when there were no such periods. Pearson's correlation coefficient test was conducted to examine the correlation between the numbers of psychiatric beds per 100,000 people and the annual numbers of psychiatric day care facilities use per 1,000 people in each prefecture. A Mann-Whitney U test was conducted to compare the number per 1,000 people per year of prefectures with or without capital- and government-designated cities and compare the annual total number (FY 2017-2021) by sex. RESULTS: Overall, the number of psychiatric day care facilities use tended to decrease. The monthly data showed a significant decrease in the total number of psychiatric day care facilities' usage during periods of emergency declarations and priority preventative measures (p=0.02). The numbers of "psychiatric short care" use increased in 2021 and those of psychiatric day-night care (>3 years / >3 days per week) use showed an increasing trend from 2020. The overall number of psychiatric day care facilities' usage per 1,000 people by prefecture was significantly lower in prefectures having cities with populations of 700,000 or more (p<0.01). A significant positive correlation was found between the number of psychiatric day care facilities use per 1,000 people by prefecture and the number of psychiatric beds per 100,000 people by prefecture (r=0.61, p<0.01). The usage of psychiatric day care facilities was significantly lower for women (p<0.01). In terms of age group, the use of psychiatric day care facilities was significantly lower for younger age groups (under 65 years of age) (p<0.01). CONCLUSIONS: Trends in the numbers reflected differences in user attributes and regional differences. It is necessary to establish a management system tailored to individual attributes and in regions where support is difficult to reach.

2.
Chemosphere ; 363: 142943, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39059643

RESUMO

An effective strategy for utilizing anaerobic digestates is required to promote biomass power generation. We developed an anaerobic digestate tablet using liquid dairy cattle manure derived from a small mesophilic anaerobic digester installed on a dairy farm. Anaerobic digestate tablets are intended for use in the fertilization of oligotrophic coastal seas to promote primary production. The purpose of this study was to evaluate (1) the dissolution behavior of nutrients from anaerobic digestate tablets and (2) the effect of the application of anaerobic digestate tablets on the growth of benthic microalgae using a culture experiment. Batch experiments were conducted to investigate the dissolution behavior of the nutrients. Cumulative amounts of dissolved inorganic nitrogen and phosphate in the anaerobic digestate tablet ranged from 110 to 28.9 µg g-1 after 28 days. The dissolved inorganic nitrogen in the anaerobic digestate tablet was mainly ammonium nitrogen and accounted for 92.4-96.9%, which is advantageous for the growth of microalgae. The growth curve of the benthic microalga Nitzchia longissima was monitored using f/2 medium added to the anaerobic digestate tablet. The growth of Nitzchia longissima was two orders of magnitude greater than that of the positive control. The enhanced growth of Nitzchia longissima by the anaerobic digestate tablet was considered a concomitant effect of moderate dissolution of ammonium nitrogen and high affinity for benthic microalgae. In conclusion, the anaerobic digestate tablets prepared in this study have the advantage of supplying nitrogen to benthic microalgae. This study proposes a new method for utilizing anaerobic digestates.


Assuntos
Esterco , Microalgas , Nitrogênio , Microalgas/crescimento & desenvolvimento , Animais , Bovinos , Anaerobiose , Nitrogênio/metabolismo , Biomassa , Indústria de Laticínios
3.
Water Environ Res ; 95(8): e10916, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37533124

RESUMO

Granulated coal ash was prepared by mixing coal ash derived from a coal electric power plant and blast furnace cement, to remove hydrogen sulfide from aquatic environment. In this study, we investigate the effects of the composition of the coal ash used to prepare the granulated coal ash on its hydrogen sulfide removal performance. Manganese, magnesium, and calcium contents in the granulated coal ash were found to be the major factors in controlling the rate of hydrogen sulfide removal. The kinetics of hydrogen sulfide removal by the granulated coal ash were expressed as a first-order equation with a rate constant of 0.0081-0.080 h-1 . The rate constant for hydrogen sulfide removal obtained in this study correlated well with the manganese content in the granulated coal ash. The increasing surface pH attributed to the hydrolysis of calcium and magnesium on the surface of the granulated coal ash slightly increased the hydrogen sulfide removal rate. PRACTITIONER POINTS: Adsorbents for H2 S are prepared by coal ash from different coal blend and coal electric power generation processes. Adsorbents tested in this study could remove hydrogen sulfide effectively. Manganese oxide in the adsorbents enhanced the removal rate of hydrogen sulfide. Adsorbents tested in this study contribute to sustainable development goals in terms of coal fly ash recycling.


Assuntos
Cinza de Carvão , Sulfeto de Hidrogênio , Cinza de Carvão/química , Sulfeto de Hidrogênio/química , Água/química , Cálcio , Manganês , Magnésio , Carvão Mineral
4.
Psychiatr Q ; 94(2): 265-280, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37221417

RESUMO

Improving adherence to medication and quality of life is a challenge in treating bipolar disorder. Therefore, psychoeducation plays an important role. This study examined factors associated with long-term medication adherence in patients with bipolar disorder who participated in a short-term psychoeducation program. Additionally, the relationships between medication adherence and medication attitudes and quality of life (QOL) were assessed. Multiple regression analysis was conducted on 67 inpatients and outpatients using medication adherence (Brief Evaluation for Medication Influences and Beliefs [BEMIB] score) as the dependent variable and clinical and demographic variables before and after the program as explanatory variables, one year after completion of the program. Pearson's correlation coefficients were calculated for associations between patients' BEMIB score and medication attitudes (Drug Attitude Inventory-10 [DAI-10]) and QOL (World Health Organization QOL-26 [WHOQOL-26] score) before and after the program and one year after program completion. The results showed that the CSQ-8 J (Client Satisfaction Questionnaire-8 Japanese) and DAI-10 scores immediately after the program were significantly related to the BEMIB score one year after program completion. Both the BEMIB and DAI-10 showed significant positive correlations with several items of the WHOQOL-26, both after the program and one year after completion of the program. The results suggest that medication attitudes acquired through psychoeducation and program satisfaction impact long-term medication adherence. The study also indicates that medication attitudes and medication adherence after a psychoeducation program are associated with QOL. Thus, patients' subjective views after a psychoeducation program can play an important role in long-term medication adherence and QOL.


Assuntos
Transtorno Bipolar , Humanos , Transtorno Bipolar/tratamento farmacológico , Qualidade de Vida , Adesão à Medicação , Satisfação do Paciente , Pacientes Internados
5.
Environ Sci Pollut Res Int ; 30(19): 56343-56352, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36914929

RESUMO

Anaerobic digestate is an organic effluent from biogas plants that generate renewable energy from organic waste under anaerobic conditions. Cement-bonded digestate composites with digestates based on animal manure and food waste based were subjected to sustained release property tests to investigate their utility as nutrient carriers for phytoplankton grown in oligotrophic coastal seas. Batch experiments showed that inorganic phosphate, ammonium nitrogen, and dissolved organic nitrogen species were released from the cement-bonded digestate composite. The inorganic phosphate and ammonium nitrogen were used directly by phytoplankton. The amount of inorganic phosphate and ammonium nitrogen released from the cement-bonded digestate composite was strongly correlated with the inorganic phosphate or nitrogen levels in the composite. This correlation allowed us to estimate the amount of these compounds released from the cement-bonded digestate composite from their concentration of in the anaerobic digestate reactants. The nutrients released from the cement-bonded digestate composite were taken up by marine microalgae, making these composites an effective terrigenous nutrient carrier for the growth of marine microalgae. The cement-bonded digestate composite developed in this study connects terrigenous anaerobic digestate from biogas plants to oligotrophic coastal seas and thus creates a novel nutrient pathway.


Assuntos
Compostos de Amônio , Microalgas , Eliminação de Resíduos , Animais , Microalgas/metabolismo , Biocombustíveis , Anaerobiose , Alimentos , Preparações de Ação Retardada , Nitrogênio/análise , Fosfatos , Nutrientes , Esterco
6.
J Environ Manage ; 293: 112944, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34107370

RESUMO

To promote primary production in oligotrophic seas, we developed a fertilization composite consisting of blast furnace cement and anaerobic digestate with a high nutrient content derived from biogas power plant byproducts. In this study, we investigated the dissolution behavior of nutrients from the fertilization composite and evaluated the effects of the fertilization composite on the growth of marine primary producers. Batch experiments and tank experiments to simulate oligotrophic coastal seas revealed that the nutrients dissolved from the fertilization composite were taken up by marine microalgae and seaweed. The fertilization composite promoted the growth of both planktonic and benthic micro algae. The total amounts of chlorophyll a in the fertilization composite tank increased by 1.4 times compared to control (p < 0.01). The flow of dissolved inorganic nitrogen uptake by marine microalgae increased 3-5 times when the fertilization composite was applied. In Wakame seaweed culture experiments, the nitrogen contents of Wakame from the fertilization composite tank were 1.2 times higher than those cultured in the control tank (p < 0.01). As a result, Wakame leaves cultured in the fertilization composite tank were 1.4 times longer than those cultured in the control tank. Approximately 44% of dissolved inorganic nitrogen from the fertilization composite was taken up by the seaweed. Hence, the fertilization composite was demonstrated to enhance the growth of marine microalgae and seaweed, which are primary producers in marine ecosystems. The fertilization composite proposed in this study can create novel nutrient mass flow by connecting terrigenous anaerobic digestate from biogas power plants to oligotrophic seas and thus stimulate the recovery of fishery production.


Assuntos
Ecossistema , Microalgas , Anaerobiose , Biocombustíveis , Clorofila A , Fertilização , Metano/análise , Oceanos e Mares
7.
J Hazard Mater ; 406: 124780, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33385762

RESUMO

We develop a high-performance adsorbent for phosphate removal from water or wastewater by impregnating lanthanum (La) on a coal fly ash-blast furnace cement composite (La-FACC). The optimized impregnation percentage of La and calcination conditions of the La-FACC were 1% and 800 â„ƒ for 2 h, respectively. The adsorption kinetics of phosphate onto the La-FACC was well fit by the intra-particle diffusion model, indicating that film and intra-particle diffusion were the rate-controlling step in the adsorption process of phosphate onto the La-FACC. The pseudo second-order kinetic model could also describe the adsorption kinetics of phosphate. Hence, adsorption of phosphate onto the La-FACC occurred mainly via chemisorption. The Langmuir isotherm was appropriate for describing the phosphate adsorption behavior onto the La-FACC. The monolayer maximum adsorption capacity was 24.9 mg-P g-1. The La-FACC showed high adsorption capacity and selectivity for phosphate with a wide range of pH, and with high concentrations of coexisting ions attributed to both formation of inner sphere complexes and electrostatic interaction. Magnesium ion slightly inhibited the adsorption of phosphate. Hence, the La-FACC developed in this study is a promising adsorbent for water treatment with a wide pH range and high ion strength.

8.
Mar Pollut Bull ; 149: 110543, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31543483

RESUMO

Although persistent organic pollutants (POPs) are currently banned or strictly controlled under the Stockholm Convention on Persistent Organic Pollutants, POPs are still distributed worldwide due to their environmental persistence, atmospheric transport, and bioaccumulation. Herein we investigated the current concentrations of POPs in the sediments from Seto Inland Sea, Japan and sought to clarify the factors currently controlling the POPs concentration of the surface sediments from Seto Inland Sea. The concentrations of hexachlorocyclohexane isomers (HCHs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), and chlordane isomers (CHLs) in sediments from Seto Inland Sea were <0.002-1.20 ng g-1, 0.01-2.51 ng g-1, and 0.01-0.48 ng g-1, respectively. Resuspension increased the concentrations of HCHs, HCB, and DDTs in the surface sediment with the release of historically contaminated pollutants accumulated in a lower layer. We speculate that CHLs in air that were removed by atmospheric deposition affects the concentration of CHLs in surface sediments.


Assuntos
DDT/análise , Sedimentos Geológicos/análise , Hexaclorocicloexano/análise , Poluentes Químicos da Água/análise , Clordano/análise , Clordano/química , DDT/química , Monitoramento Ambiental , Hexaclorocicloexano/química , Japão , Oceanos e Mares , Poluentes Químicos da Água/química
9.
Chemosphere ; 223: 399-405, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30784746

RESUMO

Ship fuels are highly associated with the emission of particulate matter and sulfur. Sulfur adsorbed on particulate matter in exhaust gases from fuels is generally considered to be sulfate. However, other chemical species of sulfur adsorbed on particulate matter in ship exhaust gases are not well known. The purpose of this study is to identify sulfur species adsorbed on particulate matter in ship exhaust gases using X-ray absorption fine structure. Particulate matter and soot samples were collected from a container carrier, a tugboat, an electric propulsion vessel, training vessels, and a marine engine, and sulfur species of particulate matter and soot were identified by X-ray absorption fine structure analysis. Sulfur emission adsorbed on particulate matter and sulfur species did not change between high and middle loads. In this study, sulfonate derived from fuel or oxidation of sulfide in fuel was identified in addition to sulfate. Total sulfur and sulfate concentrations in soot increased with increasing fuel sulfur content. The concentration of organosulfurorganosulfurs in soot such as thiophen and sulfonate, which originated mainly from fuel and engine oil, tended to increase with increasing fuel sulfur content.


Assuntos
Material Particulado/química , Enxofre/química , Emissões de Veículos/análise , Adsorção , Poluentes Atmosféricos/análise , Navios , Fuligem/química , Sulfatos/análise , Enxofre/análise , Espectroscopia por Absorção de Raios X
10.
Mar Pollut Bull ; 133: 891-899, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30041392

RESUMO

This study aims to reveal spatial distribution of hydrogen sulfide and sulfur species in marine sediments in Hiroshima Bay, Japan, by direct analyses using a combination of detection tubes and X-ray absorption fine structure spectroscopy. In summer and autumn, the hydrogen sulfide concentration ranged from <0.1 to 4 mg-S L-1. In this study, only hydrogen sulfide was observed in autumn and at two stations in summer. In contrast, some earlier studies reported in all seasons in Hiroshima Bay the presence of acid volatile sulfide, which is used as a proxy of sulfide content. The sulfur species in sediments were mainly identified as sulfate, thiosulfate, elemental sulfur, and pyrite. Thiosulfate was a minor component compared to the other sulfur species. The formation of pyrite and sulfur derived from hydrogen sulfide oxidation played an important role in the scavenging of hydrogen sulfide.


Assuntos
Baías/química , Sedimentos Geológicos/química , Sulfeto de Hidrogênio/análise , Compostos de Enxofre/química , Japão , Oxirredução
11.
Ecotoxicol Environ Saf ; 147: 132-138, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28841528

RESUMO

Copper pyrithione (CuPT) is a biocide, used worldwide to prevent biofouling on submerged surfaces. In aquatic environments it rapidly degrades, however, one of the degradation products (HPT) is known to react with cupric ion back to its parent compound. Not much is known about the behavior and toxicity of CuPT and its degradation product HPT in different water systems. Hence, our aim was to investigate the ecotoxicity of CuPT, HPT as well as Cu2+ to the brine shrimp Artemia salina in natural seawater and organic matter-free artificial seawater. Moreover, in order to elucidate the influence of ionic strength of water on CuPT toxicity, tests were performed in water media with modified salinity. The results showed that CuPT was the most toxic to the exposed crustaceans in a seawater media with the highest salinity and with no organic matter content. HPT in a presence of cupric ion converted to CuPT, but the measured CuPT concentrations and the mortality of A. salina in natural water were lower than in artificial water. The toxicity of CuPT to A. salina was significantly influenced by the organic matter content, salinity, and proportions of constituent salts in water. In a combination with cupric ion, non-hazardous degradation product HPT exhibits increased toxicity due to its rapid transformation to its parent compound.


Assuntos
Artemia/efeitos dos fármacos , Desinfetantes/toxicidade , Compostos Organometálicos/toxicidade , Piridinas/toxicidade , Água do Mar/química , Tionas/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Desinfetantes/análise , Monitoramento Ambiental/métodos , Substâncias Húmicas/análise , Compostos Organometálicos/análise , Piridinas/análise , Salinidade , Tionas/análise , Poluentes Químicos da Água/análise
12.
J Chromatogr A ; 1511: 132-137, 2017 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-28705586

RESUMO

Transient isotachophoresis (tITP) with a system-induced terminator (SIT) was developed for capillary zone electrophoresis (CZE) determination of aniline (An+) and pyridine (Py+) in sewage samples. After sample injection, a water vial was set at the sample-inlet side. Then voltage was applied to generate a system-induced terminator (H+). Experiments and simulations revealed a concentration effect by tITP with an SIT: background electrolyte (BGE) - 100mM acetic acid (AcOH) and 50mM NaOH (pH 4.6); detection wavelength - 200nm for An+ and 254nm for Py+; vacuum injection period - 15s (190nL); SIT generation - 10kV applied for 80s with the sample inlet side anode; separation voltage - 20kV with the sample inlet side anode. The limits of detection (LODs, S/N=3) of An+ and Py+ respectively reached 10 and 42µg/L, with good repeatability (peak area RSDs≤6.9%) and calibration graph linearity (R2=0.9997). The proposed method was applied for determination of An+ and Py+ in sewage samples. Recoveries of An+ (0.50mg/L) and Py+ (2.0mg/L) in spiked sewage samples were 94-104%.


Assuntos
Compostos de Anilina/análise , Eletroforese Capilar/métodos , Isotacoforese/métodos , Piridinas/análise , Esgotos/análise , Condutividade Elétrica , Eletrólitos/química , Limite de Detecção
13.
Chemosphere ; 168: 384-389, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27810538

RESUMO

Reducing hydrogen sulfide concentration in eutrophic marine sediments is crucial to maintaining healthy aquatic ecosystems. Managing fly ash, 750 million tons of which is generated annually throughout the world, is another serious environmental problem. In this study, we develop an approach that addresses both these issues by mixing coal fly ash from coal-fired power plants with blast furnace cement to remediate eutrophic sediments. The purpose of this study is to optimize the mixing ratio of coal fly ash and blast furnace cement to improve the rate of hydrogen sulfide removal based on scientific evidence obtained by removal experiments and XAFS, XRD, BET, and SEM images. In the case of 10 mg-S L-1 of hydrogen sulfide, the highest removal rate of hydrogen sulfide was observed for 87 wt% of coal fly ash due to decreased competition of adsorption between sulfide and hydroxyl ions. Whereas regarding 100 mg-S L-1, the hydrogen sulfide removal rate was the highest for 95 wt% of coal fly ash. However, for both concentrations, the removal rate obtained by 87 wt% and 95 wt% were statistically insignificant. The crushing strength of the mixture was over 1.2 N mm-2 when the coal fly ash mixing ratio was less than 95 wt%. Consequently, the mixing ratio of coal fly ash was optimized at 87 wt% in terms of achieving both high hydrogen sulfide removal rate and sufficient crushing strength.


Assuntos
Carbono/análise , Cinza de Carvão/análise , Carvão Mineral/análise , Sulfeto de Hidrogênio/análise , Material Particulado/análise , Adsorção , Compostos de Cálcio/química , Monitoramento Ambiental , Recuperação e Remediação Ambiental , Eutrofização , Sedimentos Geológicos , Radical Hidroxila , Resíduos Industriais , Íons , Cinética , Microscopia Eletrônica de Varredura , Silicatos/química , Difração de Raios X
14.
Mar Pollut Bull ; 114(2): 837-842, 2017 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-27847166

RESUMO

In order to prove that porous piles are effective in remediating muddy tidal flat sediments and increasing the biomass, field experiments were carried out at the tidal flat of a brackish river located in Hiroshima City, Japan. Porous piles with a diameter of 16cm and height of 50cm were installed in the muddy sediment that covers the sand layer of the tidal flat. After installation, concentrations of dissolved oxygen in interstitial water in and around the porous piles increased to a maximum concentration of 6mg/l due to enhancement of the groundwater flow. The increase of dissolved oxygen in the interstitial water produced a decrease in the concentration of ammonia and an increase in the individual number of benthos at the porous pile site. From these results, we concluded that the porous pile is an effective technology for remediation of muddy tidal flats.


Assuntos
Recuperação e Remediação Ambiental/métodos , Sedimentos Geológicos/química , Água Subterrânea/química , Oxigênio/análise , Movimentos da Água , Japão , Projetos Piloto , Porosidade , Propriedades de Superfície
15.
Mar Pollut Bull ; 107(1): 188-205, 2016 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-27143344

RESUMO

Granulated coal ash (GCA), which is a by-product of coal thermal electric power stations, effectively decreases phosphate and hydrogen sulfide (H2S) concentrations in the pore water of coastal marine sediments. In this study, we developed a pelagic-benthic coupled ecosystem model to evaluate the effectiveness of GCA for diminishing the oxygen-deficient water mass formed in coastal bottom water of Hiroshima Bay in Japan. Numerical experiments revealed the application of GCA was effective for reducing the oxygen-deficient water masses, showing alleviation of the DO depletion in summer increased by 0.4-3mgl(-1). The effect of H2S adsorption onto the GCA lasted for 5.25years in the case in which GCA was mixed with the sediment in a volume ratio of 1:1. The application of this new GCA-based environmental restoration technique could also make a substantial contribution to form a recycling-oriented society.


Assuntos
Cinza de Carvão , Recuperação e Remediação Ambiental/métodos , Eutrofização , Oxigênio/química , Adsorção , Carvão Mineral , Ecossistema , Sedimentos Geológicos , Sulfeto de Hidrogênio/análise , Japão , Fosfatos , Água
16.
Mar Pollut Bull ; 100(1): 240-248, 2015 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-26362456

RESUMO

The use of granular steelmaking slag as a substitute for natural sand in the construction of tidal flats was investigated. Using an intertidal flat simulator, we evaluated dephosphorization slag mixed with 8% by dry weight of dredged sediment (DPS+DS) as a basal medium for the growth of benthic macro- and microalgae in comparison with silica sand mixed with 8% dredged sediment (SS+DS). Species compositions of macro- and microalgae were distinctly different between DPS+DS and SS+DS. The mean dry weight of macroalgae on DPS+DS was three orders of magnitude higher than that on SS+DS. Sediment shear strength and pH were higher in DPS+DS than in SS+DS or in the sediment of natural tidal flats. These results suggest that DPS contributes to changing the sediment environment, thereby changing the algal composition compared to the composition on natural tidal flats.


Assuntos
Sedimentos Geológicos , Metalurgia , Microalgas , Alga Marinha , Resíduos , Biodiversidade , Ecossistema , Desenho de Equipamento , Sedimentos Geológicos/química , Concentração de Íons de Hidrogênio , Dióxido de Silício , Aço
17.
Mar Pollut Bull ; 94(1-2): 55-61, 2015 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-25818857

RESUMO

Hydrogen sulfide generated in eutrophic marine sediment is harmful for living organisms. It is therefore necessary to remove hydrogen sulfide from the sediment to restore benthic ecosystems. Previous studies revealed that granulated coal ash, which is a by-product of coal thermal electric power stations, could remove and oxidize hydrogen sulfide. In this study, we propose a simplified simulation model to estimate the hydrogen sulfide removal efficiency of granulated coal ash. Hydrogen sulfide concentrations in eutrophic marine sediment pore water with and without the application of granulated coal ash were calculated by the proposed model, and the outputs were compared with semi-field or field observation data. The model outputs reproduced the observed data well. Using the proposed model outputs, we suggest an optimum application dosage of granulated coal ash for remediating eutrophic marine sediment.


Assuntos
Cinza de Carvão/química , Recuperação e Remediação Ambiental/métodos , Sedimentos Geológicos/química , Sulfeto de Hidrogênio/análise , Modelos Químicos , Carvão Mineral , Eutrofização
18.
Chemosphere ; 111: 164-8, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24997914

RESUMO

Steel slag and granulated agglomerates from the steelmaking process, clinker ash and granulated agglomerates from thermal power stations, and molten slag from municipal solid waste incineration plants are some of the promising alternatives to marine sand for restoration of coastal marine habitats. In this study, the characteristics of elution of Ca from the six sand alternatives during aging in the marine environment was determined. The maximum calcium elution potentials of decarburized slag, dephosphorized slag, granulated slag, clinker ash, granulated ash, and molten slag were 204, 75, 26, 6, 19, and 5mgg(-1), respectively. However, the elution of Ca from decarburized and dephosphorized slags was limited to depths of about 140 and 300µm from the surface of the slag, whereas there was no limitation in calcium elution in 3mm from granulated agglomerates and ash. The maximum amount of calcium eluted into seawater during 500d was estimated to be almost the same for the four alternatives if the particle diameters were about 4.75mm because of the shallow maximum calcium elution depth of the decarburized and dephosphorized slag, even though their maximum elution potentials were 3-10 times those of granulated slag and granulated ash.


Assuntos
Água do Mar/química , Dióxido de Silício/química , Cálcio/análise , Concentração de Íons de Hidrogênio , Incineração , Eliminação de Resíduos , Espectrofotometria Atômica , Fatores de Tempo
19.
Anal Sci ; 28(10): 985-92, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23059995

RESUMO

Given that the supply of several rare earth elements (REEs) is sometimes limited, recycling REEs used in various advanced materials, such as Nd magnets, is important for realizing efficient use of REE resources. In the present work, the feasibility of using DNA for REE recovery and separation was examined, along with the identification of the binding site of REEs in DNA. In particular, a DNA-cellulose filter paper hybrid was prepared so that DNA-based materials can be used for the separation of REEs using columns loaded with DNA. N,N'-Disuccinimidyl was used as a cross-linker reagent for the fixation of DNA onto a fibrous cellulose filter. The results showed that (i) the DNA-filter hybrid has a sufficiently high affinity to adsorb REEs; (ii) the adsorption capacity was 0.182 mg/g for Nd; and (iii) the affinity of REEs for DNA was stronger for REEs with larger atomic numbers. The difference of the affinity among REEs in the third result was compared with the adsorption patterns of REEs discussed in the literature. The comparison suggests that phosphate in the DNA-filter paper hybrid was responsible for REE adsorption onto the hybrid. The results were supported by the Nd, Dy, and Lu L(III)-edge EXAFS; the REE-P shell was identified for the second neighboring atom, showing the importance of the phosphate site as REE binding sites. The difference in the affinity among REEs suggest that group separation of REEs (such as La, Ce, (Pr and Nd), (Ho, Dy, and Er), (Tb and Gd), (Sm, Eu), Tm, Yb, and Lu) is possible, although complete isolation of each REE from a solution containing all REEs may be difficult. For practical applications, Nd and Fe(III) were successfully separated from a synthetic solution of Nd magnet waste using columns loaded with the DNA-filter hybrid.


Assuntos
DNA/química , Filtração/métodos , Metais Terras Raras/isolamento & purificação , Adsorção , Sítios de Ligação , Celulose/química , Imãs/química , Metais Terras Raras/química , Papel , Água/química
20.
Mar Pollut Bull ; 64(11): 2428-34, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23017947

RESUMO

In order to prove that hot air-dried crushed oyster shells (HACOS) are effective in reducing hydrogen sulfide in muddy tidal flat sediments and increasing the biomass, field experiments were carried out. The concentration of hydrogen sulfide in the interstitial water, which was 16 mg SL(-1) before the application of HACOS, decreased sharply and maintained almost zero in the experimental sites (HACOS application sites) for one year, whereas it was remained at ca. 5 mg SL(-1) in the control sites. The number of macrobenthos individuals increased to 2-4.5 times higher than that in the control site. Using a simple numerical model, the effective periods for suppression of hydrogen sulfide were estimated to be 3.2-7.6 and 6.4-15.2 years for the experimental sites with 4 and 8 tons per 10 × 10 × 0.2m area, respectively. From these results, it is concluded that HACOS is an effective material to remediate muddy tidal flats.


Assuntos
Exoesqueleto/química , Carbonato de Cálcio/química , Recuperação e Remediação Ambiental/métodos , Sedimentos Geológicos/química , Sulfeto de Hidrogênio/química , Poluentes do Solo/química , Animais , Ecossistema , Monitoramento Ambiental , Sulfeto de Hidrogênio/análise , Ostreidae , Poluentes do Solo/análise
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