Circulation of fibrous microplastic (microfiber) in sewage and sewage sludge treatment processes.

The fate of microplastics (MPs) in the sewage treatment process has been investigated worldwide, and novel results have been reported; few studies have also clarified the fate of MPs in the sewage sludge treatment process. Although most MPs in sewage are transferred to sludge, some flow back from the sludge treatment process to the sewage treatment process. Therefore, throughout the sewage treatment plant, the removal rate of MPs may increase via a countermeasure during the sludge treatment process.

Reduction of ozone dosage by using ozone in ultrafine bubbles to reduce sludge volume.

Sludge ozonation, which promotes sludge disintegration and solubilization, is a promising technology for reducing waste sludge volume from biological wastewater treatment process. However, if this technology is to be widely adopted, reducing the energy consumption associated with ozone generation will be necessary. We used ultra-fine bubbles (UFBs) as ozone carriers to determine if their use could improve the efficiency of ozone treatment and reduce the ozone dose required.

Benthic quality assessment using M-AMBI in the Seto Inland Sea, Japan.

Benthic invertebrates that inhabit the seafloor respond to anthropogenic and natural stresses, and are good indicators for assessing the benthic ecological status. We evaluated the ecosystem health of the Seto Inland Sea based on the multivariate AZTI Marine Biotic Index (M-AMBI), being its first application in a Japanese coastal sea with numerous endemic species. From the 415 locations studied, we were able to use M-AMBI in 384 sites (92.

Strongly correlated oxides for energy harvesting.

We review recent advances in strongly correlated oxides as thermoelectric materials in pursuit of energy harvesting. We discuss two topics: one is the enhancement of the ordinary thermoelectric properties by controlling orbital degrees of freedom and orbital fluctuation not only in bulk but also at the interface of correlated oxides. The other topic is the use of new phenomena driven by spin-orbit coupling (SOC) of materials.

Spatial distribution of hydrogen sulfide and sulfur species in coastal marine sediments Hiroshima Bay, Japan.

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.

Elastic and dynamical structural properties of La and Mn-doped SrTiO studied by neutron scattering and their relation with thermal conductivities.

The electron-doped SrTiO exhibits good thermoelectric properties, which makes this material a promising candidate of an n-type oxide thermoelectric device. Recent studies indicated that only a few percent co-doping of La and Mn in SrTiO substantially reduces the thermal conductivity, thereby greatly improving the thermoelectric figure of merit at room temperature. Our time-of-flight neutron scattering studies revealed that by doping both La and Mn into SrTiO, the inelastic scattering spectrum shows a momentum-independent increase in the low-energy spectral weight approximately below 10 meV.

Effect of ozonated water on the surface roughness of dental stone casts.

Infection control of dental stone cast is an important issue. Ozone is effective for disinfection against microorganisms and inactivation of viruses. However, there is little information regarding the use of ozone.

Water Reclamation Using a Ceramic Nanofiltration Membrane and Surface Flushing with Ozonated Water.

A new membrane fouling control technique using ozonated water flushing was evaluated for direct nanofiltration (NF) of secondary wastewater effluent using a ceramic NF membrane. Experiments were conducted at a permeate flux of 44 L/m²h to evaluate the ozonated water flushing technique for fouling mitigation. Surface flushing with clean water did not effectively remove foulants from the NF membrane.

Optimum reaction ratio of coal fly ash to blast furnace cement for effective removal of hydrogen sulfide.

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.

Spatial and temporal distributions of Secchi depths and chlorophyll a concentrations in the Suo Nada of the Seto Inland Sea, Japan, exposed to anthropogenic nutrient loading.

Thirty years of monitoring data were used to elucidate the spatial and temporal distributions of Secchi depths in the Suo Nada (Suo Sea) and to evaluate how chlorophyll a concentration and reductions of nutrient loading from the watershed affected those distributions. Secchi depths throughout the Suo Nada were positively correlated with water depths. The spatial and temporal variations of Secchi depths could be explained by variations of phytoplankton biomass in areas where the water depth exceeded 20m, but in areas shallower than 10m, other factors affecting light attenuation beside phytoplankton, which include suspended particulate matter and chromophoric dissolved organic matter, obscured relationships between phytoplankton biomass and Secchi depths.

Rapid novel test for the determination of biofouling potential on reverse osmosis membranes.

A novel method was proposed to determine biofouling potential by direct analysis of a reverse osmosis (RO) membrane through fluorescence intensity analysis of biofilm formed on the membrane surface, thereby incorporating fouling tendencies of both feedwater and membrane. Evaluation of the biofouling potential on the RO membrane was done by accelerated biofilm formation through soaking of membranes in high biofouling potential waters obtained by adding microorganisms and glucose in test waters. The biofilm formed on the soaked membrane was quantified by fluorescence intensity microplate analysis.

Evaluation of steelmaking slag as basal media for coastal primary producers.

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.

Production of mono- and di-carboxylated polyethylene glycols as a factor obstacle to the successful ozonation-assisted biodegradation of ethoxylated compounds.

Ozonation is believed to improve the biodegradability of organic compounds. In the present study, degradation of nonylphenol ethoxylates (NPEOs) was monitored in hybrid treatment systems consisting of ozonation and microbial degradation processes. We found that ozonation of NPEOs decreased, rather than increased, the biodegradability under certain conditions.

Solvent-free synthesis and application of nano-Fe/Ca/CaO/[PO4] composite for dual separation and immobilization of stable and radioactive cesium in contaminated soils.

This study assessed the synthesis and application of nano-Fe/Ca/CaO-based composite material for use as a separation and immobilizing treatment of dry soil contaminated by stable ((133)Cs) and radioactive cesium species ((134)Cs and (137)Cs). After grinding with nano-Fe/CaO, nano-Fe/Ca/CaO, and nano-Fe/Ca/CaO/[PO4], approximately 31, 25, and 22 wt% of magnetic fraction soil was separated. Their resultant (133)Cs immobilization values were about 78, 81, and 100%, respectively.

Variations in macrobenthic community structures in relation to environmental variables in the Seto Inland Sea, Japan.

A data set of 425 sites investigated by the Ministry of the Environment in 2001-2005 was used to evaluate the current sediment situation and its effect on macrobenthic community structure in the Seto Inland Sea, Japan. Cluster analysis and principle component analysis of sediments using physico-chemical parameters revealed that total organic carbon, mud, sulfide contents, and oxidation-reduction potential were important parameters influencing macrobenthic population size and biodiversity. A total organic carbon of 1 mg g(-1) interval was highly negatively correlated with two biodiversity indices in the range of 1-20 mg g(-1).

Dynamic immobilization of simulated radionuclide 133Cs in soil by thermal treatment/vitrification with nanometallic Ca/CaO composites.

Although direct radiation induced health impacts were considered benign, soil contamination with (137)Cs, due to its long-term radiological impact (30 years half-life) and its high biological availability is of a major concern in Japan in the aftermath of the Fukushima nuclear power plant disaster. Therefore (137)Cs reduction and immobilization in contaminated soil are recognized as important problems to be solved using suitable and effective technologies. One such thermal treatment/vitrification with nanometallic Ca/CaO amendments is a promising treatment for the ultimate immobilization of simulated radionuclide (133)Cs in soil, showing low leachability and zero evaporation.

Preferential removal and immobilization of stable and radioactive cesium in contaminated fly ash with nanometallic Ca/CaO methanol suspension.

In this work, the capability of nanometallic Ca/CaO methanol suspension in removing and/or immobilizing stable ((133)Cs) and radioactive cesium species ((134)Cs and (137)Cs) in contaminated fly ash was investigated. After a first methanol and second water washing yielded only 45% of (133)Cs removal. While, after a first methanol washing, the second solvent with nanometallic Ca/CaO methanol suspension yielded simultaneous enhanced removal and immobilization about 99% of (133)Cs.

Chemical behavior of sand alternatives in the marine environment.

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.

Removal of coagulant aluminum from water treatment residuals by acid.

Sediment sludge during coagulation and sedimentation in drinking water treatment is called "water treatment residuals (WTR)". Polyaluminum chloride (PAC) is mainly used as a coagulant in Japan. The recycling of WTR has been desired; one method for its reuse is as plowed soil.

Simultaneous decontamination of cross-polluted soils with heavy metals and PCBs using a nano-metallic Ca/CaO dispersion mixture.

In the present work, we investigated the use of nano-metallic calcium (Ca) and calcium oxide (CaO) dispersion mixture for the simultaneous remediation of contaminated soils with both heavy metals (As, Cd, Cr, and Pb) and polychlorinated biphenyls (PCBs). Regardless of soil moisture content, nano-metallic Ca/CaO dispersion mixture achieved about 95-99% of heavy metal immobilization by a simple grinding process. During the same treatment, reasonable PCB hydrodechlorination efficiencies were obtained (up to 97%), though higher hydrodechlorination efficiency by preliminary drying of soil was observed.

Macrobenthic succession and characteristics of a man-made intertidal sandflat constructed in the diversion channel of the Ohta River Estuary.

We compared succession and characteristics of the macrobenthic community in a small-scale experimental intertidal sandflat constructed in the artificial diversion channel of the Ohta River Estuary with those of three natural intertidal sandflats at lower elevation in the same channel. The macrobenthic population density in the man-made intertidal sandflat increased significantly between 3 and 9 months after construction. Simplisetia erythraeensis was dominant (98% of individuals) after 9 months, but its proportion gradually declined with the increase in biodiversity until 26 months, indicating that succession of the macrobenthic community was nearly complete by 26 months.

Chlorophyll and suspended sediment mapping to the Caribbean Sea from rivers in the capital city of the Dominican Republic using ALOS AVNIR-2 data.

This study aims to study the distribution of contaminants in rivers that flow into the Caribbean Sea using chlorophyll-a (Chl-a) and suspended sediment (SS) as markers and ALOS AVNIR-2 satellite sensor data. The Haina River (HN) and Ozama and Isabela Rivers (OZ-IS) that flow through the city of Santo Domingo, the capital of the Dominican Republic, were chosen. First, in situ spectral reflectance/Chl-a and SS datasets obtained from these rivers were acquired in March 2011 (case A: with no rain influence) and June 2011 (case B: with rain influence), and the estimation algorithm of Chl-a and SS using AVNIR-2 data was developed from the datasets.

A green procedure using ozone for Cleaning-in-Place in the beverage industry.

Cleaning-in-Place (CIP) in the beverage industry is typically carried out in production lines with alkaline and acidic solutions with detergents. This cleaning not only produces alkaline and acidic wastewater with detergents but also takes significant time. One of the important targets for CIP is adsorbed odorous compounds on gaskets, hence, we have tried to establish a rapid and green CIP process to remove traces of such compounds, especially d-limonene, an odorous component of orange juice, using two approaches; an ozone cleaning method and a change of gasket material from ethylene propylene diene monomer (EPDM) rubber to silicone rubber.

Photochemical decomposition of perfluorooctanoic acid mediated by iron in strongly acidic conditions.

The performance of a ferric ion mediated photochemical process for perfluorooctanoic acid (PFOA) decomposition in strongly acidic conditions of pH 2.0 was evaluated in comparison with those in weakly acidic conditions, pH 3.7 or pH 5.

Impact of flood events on macrobenthic community structure on an intertidal flat developing in the Ohta River Estuary.

We investigated the effects of river floods on the macrobenthic community of the intertidal flat in the Ohta River Estuary, Japan, from 2005 to 2010. Sediment erosion by flood events ranged from about 2-3 cm to 12 cm, and the salinity dropped to 0‰ even during low-intensity flood events. Cluster analysis of the macrobenthic population showed that the community structure was controlled by the physical disturbance, decreased salinity, or both.