Hidetoshi Kuramochi

National Institute for Environmental Studies · Material Cycles Divison

Although marine plastic debris are expected to retain various chemical additives, little is known about the additives that are retained. We conducted a screening analysis of additives in 261 macroplastic and micro–mesoplastic debris from two beaches. We detected 52 chemicals—antioxidants, phthalates, ultraviolet stabilizers, hindered amine light st...

Engineered biochar production and utilization in anaerobic digestion (AD) potentially overcome its limited application to the treatment of slowly degradable or inhibitory substrates. Here an attempt was made to develop an optimized biochar production procedure for use in AD to stimulate palmitic acid biodegradation via direct interspecies electron...

Plastic pollution has become one of the most pressing environmental issues. Recycling is a potential means of reducing plastic pollution in the environment. However, plastic fragments are still likely released to the aquatic environment during mechanical recycling processes. Here, we examined the plastic inputs and effluent outputs of three mechani...

This paper is part of the studies that examine the performance of multizonal thermodynamic equilibrium calculation applied to waste incineration, and the primary objective was to obtain experimental data on the fate of elements in a waste incinerator under a controlled condition for comparison with the results of the calculation. We conducted an in...

Tar generated as a by-product during biomass gasification contains a high concentration of refractory organic matters. In this study, a hybrid upflow anaerobic sludge-biochar bed reactor was established for tar treatment, and the methane yield was 120-154 NmL-CH4/g-CODinf, 20-30% higher than the control reactor. COD removal and methane production s...

Nanoplastics are likely ubiquitous in the environment, and their potential toxic effects are a concern. However, quantitative information about the distribution of nanoplastics is still lacking, and toxicity tests are limited to a few select polymers because of the lack of appropriate standard materials, which should be nanoscale particles with sta...

A new method for determining the liquidus pressure of mixtures of C18’s unsaturated fatty acids at constant temperature was systematically measured in this study. The liquidus temperatures of oleic acid, linoleic acid and α -linolenic acid commonly rise above their normal melting temperatures when pressure is increased. This new high-pressure exper...

The separation of the binary unsaturated fatty acids C18:1 + C18:2 system was examined by high-pressure crystallization at 298 K (25 oC). The binary fatty acid mixture containing 0.8 mole fraction of C18:1 was packed in the glass cell with a free piston, and then pressurized by an aqueous ethanol solution around the glass cell up to 200 MPa. The co...

Anaerobic digestion of decabromodiphenyl ether was carried out and compared in two continuously stirred anaerobic bioreactors for 210 days under thermophilic and mesophilic conditions. Results show that the degradation of decabromodiphenyl ether followed the first-order reaction kinetics, which exhibited a higher removal rate in the thermophilic re...

Chlorinated Paraffins (CPs) are a complex group of manmade chemicals detected widely in the environment. To predict their environmental fate and effects, it is important to understand their physical-chemical properties including vapor pressure. In this study, the first direct measurements of the vapor pressure for CP congener groups (C10–16Cl4–11)...

p>Chlorinated Paraffins (CPs) are a complex group of manmade chemicals detected widely in the environment. To predict their environmental fate and effects, it is important to understand their physical-chemical properties including vapor pressure. In this study, the first direct measurements of the vapor pressure for CP congener groups (C<sub>10–16<...

Multizonal thermodynamic equilibrium calculation is one of the methods used in estimating or explaining the fate of elements such as heavy metals during waste incinerations and probably only one method that can estimate the fate of trace elements, but the ability of the calculation as a fate-estimation tool was not fully examined. This study examin...

Highlights  Anaerobic digestion (AD) of radiocesium (RCs)-contaminated crops was investigated.  Anaerobic degradation of crops releases RCs into aqueous phase of digestate.  RCs-solubilization efficiency rose with increase in degradability of feedstocks.  Solid-liquid partition coefficient widely varied depending on the types of adsorbents.  9...

In recent years, concern about the release of anthropogenic organic micropollutants referred to as contaminants of emerging concern (CECs) has been growing. The objective of this study was to find potential CECs by means of an analytical screening method referred to as comprehensive target analysis with an automated identification and quantificatio...

Radioactively-contaminated waste incineration residues were collected from 6 municipal solid waste incineration plants and 3 disaster waste incineration plants in Fukushima Prefecture and nearby from July 2011 to January 2016 to examine the concentration of 90Sr and the leachability of stable strontium from the residues. The wastes examined include...

We investigated the behavior of radioactive cesium (r-Cs) in a direct melting system (DMS), in which decontamination waste (DW) is thermally converted to slag and fly ash. Most of the r-Cs (98.4 %) in the DW was volatilized in the melting furnace and solidified in fly ash (FA), resulting in slag with low radioactivity. To produce even cleaner slag,...

Oily organic waste is a promising feedstock for anaerobic co-digestion. Free long-chain fatty acids (LCFAs) produced from lipids can inhibit methanogenic consortia, so optimal control of LCFA concentration is the key to successful operation of co-digestion. Most LCFAs are present in the solid phase, making them difficult to detect and monitor. This...

Wastes containing short-chain chlorinated paraffins (SCCPs) at concentrations above the Basel Convention low persistent organic pollutant content (LPC) values must be destroyed or irreversibly transformed in an environmentally-sound manner. Here, we developed a novel liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MSM...

To enhance the reaction rate and yield during biodiesel synthesis with Novozym 435 (an immobilized lipase), a co-solvent method was applied, after which the relationships between reaction time and reaction yield during the single-phase enzymatic transesterification of triolein and methanol in the presence of co-solvents such as tetrahydrofuran, ace...

During the transesterification of triglycerides with methanol catalyzed by immobilized lipase resin (Novozym 435 (N435)) in a glass vial, two types of aggregate of N435 particles were observed: a thin-layer aggregate on the glass surface inside the vial, and bulky aggregates. This prompted us to investigate the conditions under which only one type...

While the production and new use of hexabromocyclododecane (HBCD) mostly ceased after being listed as a persistent organic pollutant under the Stockholm Convention in 2013, its emission from treated products in use to indoor environments still deserves attention. To examine the transfer of HBCD diastereomers to dust on the surface of flame-retarded...

By employing an annular‐cylindrical‐type apparatus operated under a constant cooling rate, melt crystallization is studied to condense a saturated fatty acid (FA) from a binary mixture of the saturated FA with unsaturated FA. In the annular space between the stationary outer cylinder and the rotating inner cylinder, counter‐rotating toroidal vortic...

In this study, a 200-day deca-brominated diphenyl ether (deca-BDE) degradation activity experiment was carried out, using consumer-use curtain material as the substrate. During the degradation process, polybrominated diphenyl ether (PBDE) products with fewer bromine atoms were gradually generated by the debromination of deca-BDE. The influences of...

The government has started the construction of thermal treatment facilities in the Interim Storage Facility (ISF). The purpose is not only for incinerating or direct-melting off-site radioactively contaminated wastes such as decontamination waste (DW) from around ISF, but also for ash-melting of DW incineration residues discharged within the Specia...

It is becoming increasingly urgent to investigate the partition coefficients (expressed as log K DOC values) of polybrominated diphenyl ethers (PBDEs) in dissolved organic carbon (DOC) present in wastewater. In the current study, after 72 h of equilibration, the concentrations of four common PBDEs were measured in the presence of four DOC solutions...

Physicochemical properties of POPs (persistent organic pollutants) including POPs candidates and alternatives to POPs, and their environmental partitioning characteristics are of importance for considering the pathways of those compounds to the environment and countermeasures for reducing their emission. In this paper, we introduce how to gather th...

Following the nuclear accident at the Fukushima Daiichi Nuclear Power Plant in 2011, even the municipal solid waste (MSW) and sewage sludge (SS) in northeastern Japan became contaminated by radioactive nuclides such as ¹³⁷Cs and ¹³⁴Cs. To understand the state of radioactive cesium (r-Cs) in the incineration residues of the municipal wastes, researc...

Municipal solid waste (MSW) contaminated by radioactive cesium (r-Cs) has been incinerated since the Fukushima Daiichi Nuclear Power Plant accident. Eight thermal treatment plants with four different types of furnaces were comprehensively investigated to provide fundamental data to improve our understanding of the behavior of r-Cs in various types...

Short-chain chlorinated paraffins are industrial contaminants of great concern due to their persistent and toxic characteristics. The predicted distribution of short-chain chlorinated paraffins in air, water, soils and sediments is unclear because their physiochemical properties are poorly known. Here, we calculated the coefficients that control th...

While vapor pressure is among the most important properties used in the environmental fate assessment of organic contaminants, measured vapor pressures exist only for a few representatives of the group of novel brominated flame retardants (BFRs). To expand on this limited set of data, the vapor pressures of five BFRs—1,2,4,5,-tetrabromo-dimethylben...

Low-quality waste oils and fats such as an oily content of trap grease offer an alternative to fossil fuel oil, but are not fully utilized since they contain saturated fatty acids (SFAs) and saturated triglycerides (STGs), which have relatively high melting points. For practical use of the oily content, it is necessary to remove the components that...

In order to boost the economics of biogas utilization in those small facilities for food waste (FW) digestion, proximate grease trap waste (GTW) was employed to co-digest with FW. A bench-scale continuous stirred tank reactor was set up and operated at mesophilic temperature to investigate the co-digestion limit and lipid/long chain fatty acid (LCF...

The present study evaluates the lipase (Novozym 435)-catalyzed transesterification of triolein and methanol mixtures to generate fatty acid methyl esters (FAMEs) using dimethyl ether (DME) in a batch reactor and a continuous pipe reactor. The addition of DME facilitated the preparation of homogeneous mixtures of triolein and methanol. The effect of...

The biodiesel fuel ethyl oleate (fatty acid ethyl ester, FAEE) was produced using Novozym® 435 (immobilized lipase) by transesterification of a mixture of ethanol and triolein in a fixed-bed reactor operated in circulating batch mode. The miscibility of the mixtures during transesterification was predicted thermodynamically and the conversion ratio...

Three bioenergy technologies, gasification, Biodiesel fuel production, and H2–CH4 fermentation processes, were modeled using ASPEN PLUS. A comparative performance was analyzed for different regions and scales. The proportions of feedstock were set corresponding to urban, suburban and rural regions. Verification of the simulation with our experiment...

Large volumes of decontamination wastes (DW) generated by off-site decontamination activities in Fukushima Prefecture have been incinerated since 2015. The behavior of radioactive cesium during incineration of DW was investigated at a working incineration plant. The incineration discharged bottom ash (BA) and fly ash (FA) with similar levels of rad...

To account for both the growth of solid layer and solute distribution in melt crystallization, we proposed empirical equations involving heat and mass transfer at the solid-liquid interface between the solid layer and melt. With the aim of separating saturated fatty acid as a solid phase from binary mixture of fatty acids as model biofuel, we perfo...

In anaerobic digestion (AD), long-chain fatty acids (LCFAs) produced by hydrolysis of lipids, exhibit toxicity against microorganisms when their concentration exceeds several millimolar. An absorption detection system using a quartz crystal microbalance (QCM) was developed to monitor the LCFA concentration during an anaerobic digester’s operation t...

Solid-liquid equilibria (SLE) for the binary systems of C12-C18 saturated fatty acids or their triglycerides + hexadecane (systems of dodecanoic acid (lauric acid), tetradecanoic acid (myristic acid), hexadecanoic acid (palmitic acid), octadecarioic acid (stearic acid), 1,2,3-propanetriyl tridodecanoate (trilaurin), 1,2,3-propanetriyl tritetradecan...

Melting technique is one of useful separation treatments at a high temperature of 1300-1400ºC. Using the technique, Cs can be volatilized from different solid samples in the melting furnace. In this study, we conducted a laboratory-scale melting test to investigate the radioactive Cs separation performance for decontamination of incineration ash (b...

To study solute distribution at the solid–liquid (S–L) interface during melt crystallization, we examined the applicability of the interfacial solute distribution factor proposed based on a kinetic model involving both mass and heat balances at the interface. The factor derived from the model was compared with the experimental results obtained by e...

Dosage of nutrients for anaerobic digestion is essential to maintain their treatment performance. Kitchen waste generally contains low concentrations of nutrients, especially metals. However, for de-oiled grease trap waste (GTW), such a kitchen waste, little data are available in terms of nutrient supplementation to enhance anaerobic digestion. In...

The present study investigates the charge–discharge processes of a Planté lead–acid battery performed under atmospheric pressure and 10 MPa. The ampere-hour efficiency of the lead electrodes was substantially increased by the secondary formation of the Planté electrode, and the ampere-hour efficiency under 10 MPa was slightly higher than that under...

To make larger capacity of charge-discharge of lead-acid batteries at high pressure after the initial formation of Plante-type electrodes, we studied the effect of high pressure on prolonged life testing. Electrode life was evaluated by determining the time of detachment of active crystals (Pb, PbOx and PbSO4) or the drop in ampere-hour efficiency...

Non-PBDE (polybromodiphenyl ether) brominated flame retardants (BFRs) used as alternatives to PBDEs should be evaluated in terms of their environmental contamination potential. We first used two well-known estimation tools, EPI Suite and SPARC, to estimate the physicochemical properties of 52 non-PBDE BFRs. We assessed the dependence of the propert...

Lead-acid batteries were electrically charged and discharged more quickly under high pressures than under atmospheric pressure due to high-pressure crystallization induced by the former condition. High-pressure crystallization can generate extremely small crystals with large supersaturation and small mass transfer rates. Crystals of PbSO4 on the el...

The hydrogen solubility in triolein and propane solubility in oleic acid were measured up to 20 MPa at the temperature around 353.2, 413.2, and 473.2 K. The hydrogen solubility in triolein was slightly larger than the linear pressure dependence like Henry's law, and it was increased with the temperature. On the contrary, propane solubility in oleic...

Vapor pressures (pi) of selected brominated flame retardants (BFRs), such as three polybrominated diphenyl ethers, PBDEs, 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47), 2,2′,4,4′,5-pentabromodiphenyl ether (BDE-99), and 2,2′,4,4′,5,5′-hexabromodiphenyl ether (BDE-153), and two non-PBDE BFRs, hexabromobenzene (HBB) and 1,2-bis(2,4,6-tribromophenoxy)et...

The electrical charging and discharging of a battery involves the crystallization of electrolytes or metal oxides on both electrodes. Crystallization technology that can control nucleation, growth, and distribution of solute crystals might be effective for improving battery properties. We performed charge/discharge cycling of a lead acid battery un...

Melt crystallization using an annular vessel with two circular cylinders was applied to produce high-quality vegetable oil from waste oil. The inner cylinder was cooled at a constant rate and rotated, and the outer cylinder was heated at a constant temperature. The melt was solidified on the inner cylinder surface. The binary system of triolein and...

The molar equivalent electrical conductivity of aqueous ethanol solutions containing ammonium chloride or ammonium nitrate was measured under high pressure, up to 400 MPa, at 298 K. The concentration range of the ammonium salts in solution was broad because their solubility is relatively high compared with that of other salts. A common result was t...

Trap grease, which is a free-floating aggregate on the surface of the tank between restaurant and sewer, is either an oil or sludge-like grease including food scraps and water. It is a low-quality mixture of fats and oils, and is not recycled as a fuel in Japan. However, oily components such as glycerides and fatty acids in the grease a re consider...

In recent Japan, a new method has been proposed for synthesis of biodiesel fuel (BDF). It is quitedifferent from conventional ones, that is, fats and oils will be perfectly converted to propane, and some blanched alkanes, having 16-18 carbon atoms in a molecule, by hydrodeoxygenation reaction at high temperatures and the pressures. In our previous...

An improved reaction rate of biodiesel fuel formation was observed under microwave irradiation. Such irradiation is effective for not only heating during the reaction but also preheating. The advantages observed in this study suggest that a continuous process, that is, the introduction of reactant preheated by microwave irradiation into reactor wil...

Transesterification in a homogeneous mixture with the volatile co-solvent dimethyl ether (DME) has been proposed as a new fatty acid methyl ester (FAME) processing technique. Ternary feed mixtures of triolein, methanol and DME form a homogeneous solution, but the product mixtures of FAME, glycerin and DME form an emulsion after transesterification....

Hydrodeoxygenation (HDO) of waste cooking oil and trapped grease over sulfide catalysts was examined to produce high quality transportation fuel from low-grade resources. The hydrodeoxygenation of waste oils was carried out in a high pressure batch reactor and a fixed bed flow reactor. Sulfide catalysts showed high HDO activity and all waste oils g...

Used for biofuel production, fatty acids and their corresponding triglycerols are stored in most plants. At room temperature, saturated fatty acids and their triglycerols are solid, whereas unsaturated fatty acids and their triglycerols are liquid. Solid−liquid equilibrium data were measured for various binary systems of fatty acids and their trigl...

Oils upgraded from trap greases were characterized to evaluate their possibility of replacing fossil fuel in terms of impurity content. The heating values of the oils were measured to clarify the input energy required for the upgrading process. The cost and GHG emissions for the present grease-to-oil process were estimated by using a logistic model...

The Japanese government has recently been promoting the recycling of small end-of-life electric and electronic equipment (EEEE) while also being instrumental in the collection of precious metal contents, including rare metals in EEEEs. A standard method for a multi-elemental analysis, however, has not yet been proposed. This report presents a propo...

Slow dispersion at the agitation initiation period in a batch biodiesel fuel (BDF) production vessel was investigated. The emulsified amount of methanol was measured as a function of the agitation period, t. It was found that the weight fraction of the emulsified methanol in the triglyceride phase, wM, slowly increases with increasing t, as shown b...

The transesterification of triglycerides under various conditions was considered in terms of the activation energy obtained from molecular orbital calculations. The transesterification reaction proceeds via a cyclic transition state, consisting of the carboxyl carbon and the alcohol. Moreover, the reaction pathway was shown by an activation energy...

The major marine resources are electrolytes, and they are mainly dissolved as ions. More than 70 wt% of electrolytes are sodium chloride, but other electrolytes are also dissolved in seawater. To develop a separation or recovery of electrolytes in seawater, we discussed the electrolyte solution model applied to several electrolytes in seawater. The...

To promote the biodiesel production, low-quality fats in addition to waste vegetable oils are still required. Low-quality waste vegetable oils and low-quality fats as feed mixtures contain free saturated fatty acids and/or commercial solidifiers in addition to triolein as a main component, and they are solid at room temperature. However, liquid fee...

Conventional alkali-catalyzed BDF production processes have a serious problem because the settling of liquid dispersions after transesterification is slow and requires almost one day. The present study suggests a significant improvement using a simple method called PITE, i.e., strong agitation during transesterification in a fully baffled stirring...

The present study was conducted as part of a series of R&D of gasification and reforming technologies aimed at creating a new energy recovery technology from biomass waste. Special emphasis was placed on the production of hydrogen-rich synthesis gas from waste wood via gasification and sequential reforming technology using catalysts. Experiments we...

Vapor–liquid equilibrium (VLE) of the methanol–biodiesel (BDF)/glycerin binary system and liquid–liquid equilibrium (LLE) of the water–BDF binary system and the methanol–BDF–glycerin and methanol–water–BDF ternary systems were predicted using several UNIFAC models: the latest original UNIFAC model, Kikic’s model, Fornari’s model, Dortmund-UNIFAC mo...

The transesterification of various triglycerides was considered in terms of the activation energy obtained from quantum computational chemistry. According to these values, the effect upon the reactivity of the structure of the triglyceride is not particularly large. Moreover, the transesterification reaction is completed via a transition state, in...

The solubilities and complex phase equilibria for the system of MnSO4·4H2O+MgSO4·7H2O+H2O+CH3OH were determined at the temperatures 291.2 and 301.2K over the methanol mole fraction range of 0.00–0.12.The solubility data were used for modelling with the modified extended electrolyte non-random two-liquid equation. The salting-out effect of MgSO4 and...

The behavior of heavy metals in wood during its carbonization process was examined. Cadmium in wood samples was found to be volatile when the samples were carbonized at 600 degrees C or higher, which demonstrated that removal of cadmium was feasible. Meanwhile, lead was found to be barely volatile even if the wood samples were carbonized at 1,000 d...

Superfast transesterification of triolein (a biodiesel feedstock model) was achieved in the presence of liquefied dimethyl ether using the co-solvent effect and low viscosity. Furthermore, a method for higher ester yield, in which methanol was additionally introduced into the reaction system immediately before the beginning of phase separation due...

The complex phase equilibria for the solubilities of MnSO4 center dot H2O and MgSO4 center dot 7H(2)O in three different organic solvents (methanol, ethanol, and 2-propanol) were predicted by the ion-specific electrolyte NRTL model. The salting-out effect of Mg2+, solventing-out effects of alcohols, and their combined effects on the solubility of M...

In this study, HCl emission during the co-pyrolysis of demolition wood and a small amount of polyvinyl chloride (PVC) film (the Cl content of which ranged from 0.5% to 6% by weight) in an N2 atmosphere at elevated temperatures of up to 600°C was measured using a laboratory-scale cylindrical batch reactor. In the pyrolysis experiments, HCl emission...

Aqueous solubility (Sw), 1-octanol/water partition coefficient (Kow), and vapor pressure of the nonionic form of 2,2',6,6'-tetrabromo-4,4'-isopropylidenediphenol (tetrabromobisphenol A or TBBP-A) were measured. From this, enthalpies of solution and vaporization were estimated. Furthermore, enthalpy of fusion and melting point were measured to estim...

In biodiesel production, transesterification in a homogeneous mixture is possible if a solution of triolein and methanol could be prepared with the use of a cosolvent. The volatile solvent dimethyl ether (DME) can make the immiscible mixture of triolein and methanol miscible; moreover, it can be easily recovered due to its high volatility after rea...

2,4,6-Tribromophenol (TBP) is expected to exist in both ionic and non-ionic forms in the environment due to ionisation of the phenolic group at near neutral pH. In this study, the water solubility (Sw) and 1-octanol-water partition coefficient (Kow) of aqueous solutions of TBP at various pH values were measured using the shake flask method. The ion...

Data on the solubility of manganese sulphate monohydrate in water, and in aqueous alcohols is essential for salting-out crystallization studies. The solubilities of the quaternary system MnSO4·H2O + MgSO4·7H2O + H2O + (CH3)2CHOH were determined in the temperature range 293.2–313.2 K over the 2-propanol mole fraction range of 0.00–0.07. The solubili...