Determination of nonylphenol ethoxylates and octylphenol ethoxylates in environmental samples using 13C-labeled surrogate compounds

Alkylphenol polyethoxylates (APEOs) have been widely used as nonionic surfactants in a variety of industrial and commercial products. Typical compounds are nonylphenol polyethoxylates (NPEOs) and octylphenol polyethoxylates (OPEOs), which serve as precursors to nonylphenol (NP) and octylphenol (OP), respectively. NP and 4-t-OP are known to have endocrine disrupting effects on fish (medaka, Oryzias latipes), so it is important to know the concentrations of APEOs in the environment. Because the analytical characteristics of these compounds depend on the length of the ethoxy chain, it is necessary to use appropriate compounds as internal standards or surrogates. We synthesized two 13C-labeled surrogate compounds and used these compounds as internal standards to determine NPEOs and OPEOs by high-performance liquid chromatography (LC)-mass spectrometry. Method detection limits were 0.015 microg/L for NP (2)EO to 0.037 microg/L for NP(12)EO, and 0.011 microg/L for OP(3,6)EO to 0.024 microg/L for OP (4)EO. NPEO concentrations in water from a sewage treatment plant were less than 0.05-0.52 microg/L for final effluent and 1.2-15 microg/L for influent. OPEO concentrations were less than 0.05-0.15 microg/L for the final effluent and less than 0.05-1.1 microg/L for influent.     

Recycling process for yttria-stabilized tetragonal zirconia ceramics using a hydrothermal treatment

The recycling process for 3 mol% yttria-stabilized tetragonal zirconia polycrystals (3Y-TZP) sintered at 1450°–1550°C was examined by applying low-temperature degradation of zirconia ceramics under hydrothermal conditions. Hydrothermal treatment at a temperature from 200° to 240°C can lead to the spontaneous disintegration of 3Y-TZP sintered bodies into powdery particles. The hydrothermally obtained zirconia powder was found to consist of primary particles and aggregated particles. Detailed X-ray diffraction measurement revealed the formation of a cubic zirconia phase in the 3Y-TZP sintered bodies, which seemed to inhibit the disintegration of aggregated particles toward the primary particle level. The reclaimed 3Y-TZP powder was sintered again through a conventional powder processing route. The mechanical properties and microstructure of recycled 3Y-TZP sintered specimens were examined by comparison with those of the original 3Y-TZP sintered bodies. Dense recycled 3Y-TZP sintered at a higher temperature exhibited higher fracture toughness to some degree than the original 3Y-TZP.     

Effects of the tsunami on fisheries and coastal livelihood: a case study of tsunami-ravaged southern Sri Lanka

Beyond the death toll, the tsunami of 26 December 2004 crippled many of the livelihood assets (human, social, physical, financial and natural) available to assist those directly affected. Drawing on surveys of three villages in three districts in the south of Sri Lanka, this paper describes the livelihood asset building capacity of the fishing communities. Assessments are also made of the impact of the tsunami on coastal communities and the impact of government policy on rebuilding. A livelihood asset score was calculated for each village by comparing their strengths in capacity building. In all aspects of capital building, including human, social, financial, physical and natural capital, the fishing community in Tangalle was significantly ahead of the fishing communities in Hikkaduwa and Weligama. Experienced fishermen with better educational backgrounds had a significant influence on the capacity building of livelihood assets. Relocation and resettlement plans brought persistent uncertainty to fishermen in Hikkaduwa and Weligama and threatened to disrupt their community bonds and social networks.     

Biobased Contents of Organic Fillers and Polycaprolactone Composites with Cellulose Fillers Measured by Accelerator Mass Spectrometry Based on ASTM D6866

The biobased contents of raw materials such as starches, sugar, chitin, or wood powders for biomass plastics were measured using Accelerator Mass Spectrometry (AMS) based on ASTM D6866. AMS measures the isotope carbon ratio of ¹⁴C to ¹²C and ¹³C in graphite derived from sample powders. The biobased contents of starches, sugar or chitin were almost 100% which means that they are fully biobased. The biobased contents of the wood powders were over 140% due to the effect of the post 1950s ¹⁴C injection due to nuclear testing. Poly(ε-caprolactone) (PCL) composite samples were prepared using the polymerization and direct molding method. The starting compound was the ε-caprolactone monomer liquid combined with cellulose and inorganic fillers using aluminum triflate as a catalyst at 80 °C for 6 or 24 h. PCL cylinder-shaped composite samples with a homogeneously dispersed cellulose filler were prepared with M_n = 4,600 (M_w/M_n = 2.9). The biobased content of the PCL composite with 50 wt% cellulose filler (51.67%) measured using AMS was slightly higher than the carbon ratio of cellulose in the starting powder samples (41.3 mol%). This is due to the higher biobased content (112.70%) of the cellulose filler used in this study. The biobased content of the polymer composite powders by AMS was found not to be affected by the presence of inorganic fillers, such as talc.     

Blue carbon in human-dominated estuarine and shallow coastal systems

Estuarine and shallow coastal systems (ESCS) are recognized as not only significant organic carbon reservoirs but also emitters of CO₂ to the atmosphere through air–sea CO₂ gas exchange, thus posing a dilemma on ESCS’s role in climate change mitigation measures. However, some studies have shown that coastal waters take up atmospheric CO₂ (C_atm), although the magnitude and determinants remain unclear. We argue that the phenomenon of net uptake of C_atm by ESCS is not unusual under a given set of terrestrial inputs and geophysical conditions. We assessed the key properties of systems that show the net C_atm uptake and found that they are often characteristic of human-dominated systems: (1) input of high terrestrial nutrients, (2) input of treated wastewater in which labile carbon is highly removed, and (3) presence of hypoxia. We propose that human-dominated ESCS are worthy of investigation as a contributor to climate change mitigation.     

Fungal levels in houses in the Fukushima Daiichi Nuclear Power Plant evacuation zone after the Great East Japan Earthquake

Residences located within 20 km of the damaged Fukushima Daiichi Nuclear Power Plant were evacuated shortly after the Great East Japan Earthquake. The levels of airborne and surface fungi were measured in six houses in the evacuation zone in August 2012 and February 2013. Airborne fungal levels in all of the houses in the summer were higher than the environmental standard levels for residential houses published in Architectural Institute of Japan (>1000 colony-forming units [CFU]/m³). In two houses whose residents rarely returned to visit, fungal levels were extremely high (>52,000 CFU/m³). Although fungal levels in the winter were much lower than those in the summer, they were still higher than environmental standard levels in several houses. Indoor fungal levels were significantly inversely related to the frequency with which residents returned, but they were not correlated with the air exchange rates, temperature, humidity, or radiation levels. Cladosporium spp. and Penicillium spp. were detected in every house. Aspergillus section Circumdati (Aspergillus ochraceus group) was also detected in several houses. These fungi produced ochratoxin A and ochratoxin B, which have nephrotoxic and carcinogenic potential. The present study suggests that further monitoring of fungal levels is necessary in houses in the Fukushima Daiichi Nuclear Power Plant evacuation zone, and that some houses may require fungal disinfection.

Implications: The results suggest that residents’ health could be at risk owing to the high levels of airborne fungi and toxic fungi Aspergillus section Circumdati. Therefore, monitoring and decontamination/disinfection of fungi are strongly recommended before residents are allowed to return permanently to their homes. In addition, returning to home with a certain frequency and adequate ventilation are necessary during similar situations, e.g., when residents cannot stay in their homes for a long period, because fungal levels in houses in the Fukushima Daiichi Nuclear Power Plant evacuation zone were inversely correlated with the frequency with which residents returned to visit their houses.     

Screening of endophytic bacteria against fungal plant pathogens

Bacterial endophytes were found from 6 plant leaves among 35 plant leaves screened. Two of the isolated bacteria showed antagonistic activity against fungal plant pathogens. An isolate named KL1 showed the clear inihibition against plant pathogens, Fusarium oxysporum and Rhizoctonia solani, on PDA as well as TSA plate. Supernatant of the bacterial culture also showed the clear inhibition against the fungal growth on the plate and the antibiotic substance was identified as iturin A by HPLC analysis. KL1 was identified as Bacillus sp. from the 16S rRNA gene analysis. Very thin hyphae of R. solani was miccroscopically observed when the fungus was co-cultivated with KL1.     

Rate of hexabromocyclododecane decomposition and production of brominated polycyclic aromatic hydrocarbons during combustion in a pilot-scale incinerator

Here, we examined the incineration of extruded polystyrene containing hexabromocyclododecane(HBCD) in a pilot-scale incinerator under various combustion temperatures(800–950℃) and flue gas residence times(2–8 sec). Rates of HBCD decomposition ranged from 99.996%(800℃, 2 sec) to 99.9999%(950℃, 8 sec); the decomposition of HBCD, except during the initial stage of combustion(flue gas residence time 2 sec), followed a pseudo-first-order kinetics model. An Arrhenius plot revealed that the activation energy and frequency factor of the decomposition of HBCD by combustion were 14.2 kJ/mol and 1.69 sec~(-1),respectively. During combustion, 11 brominated polycyclic aromatic hydrocarbons(BrPAHs)were detected as unintentional by-products. Of the 11 BrPAHs detected, 2-bromoanthracene and 1-bromopyrene were detected at the highest concentrations. The mutagenic and carcinogenic BrPAHs 1,5-dibromoanthracene and 1-bromopyrene were most frequently detected in the flue gases analyzed. The total concentration of BrPAHs exponentially increased(range,87.8–2,040,000 ng/m~3) with increasing flue gas residence time. Results from a qualitative analysis using gas chromatography/high-resolution mass spectrometry suggest that bromofluorene and bromopyrene(or fluoranthene) congeners were also produced during the combustion.     

High-solids anaerobic mono-digestion of riverbank grass under thermophilic conditions

The purpose of this study was to investigate the potential of high-solids anaerobic mono-digestion of riverbank grass under thermophilic conditions, focusing on the effects of the strength and the amount of inoculum. Ensiled grass was inoculated with three different inocula; inoculum from liquid anaerobic digester (LI), inoculum from dry anaerobic digester (DI), and mixture of LI and DI (MI), at feedstock-to-inoculum ratio (FIR) of 1, 2 and 4. The ensiling process of riverbank grass reduced moisture content (p > 0.05), while the hemicellulose content was significantly increased from 30.88% to 35.15% (p < 0.05), on dry matter basis. The highest methane production was at an FIR of 2 with MI (167 L/kg VS_added), which was significantly higher (p < 0.05) than with DI, but not significant compared to LI (p > 0.05). At an FIR of 4, digesters inoculated with LI and DI failed to produce methane, whereas 135 L_CH4/kg VS_added was obtained with MI. The kinetic studies showed that at an FIR of 1 with LI and MI, the inoculum had less of effects on the hydrolysis rate constant (0.269 day^− 1 and 0.245 day^− 1) and methane production (135 versus 149 L/kg VS_added); rather, it affected the lag phase. In a thermophilic HS-AD of riverbank grass, the mixture of inoculum with low and high total solids content (TS) helps increase the TS of inoculum and digestion process. An FIR of 2 was deducted to be the limit for a better startup time and higher volumetric productivity of methane.     

Enhancement of biodegradation of oil adsorbed on fine soils in a bioslurry reactor

Techniques for enhancing the biodegradation of oil-contaminated fine soils in a slurry-phase bioreactor were investigated. Using a model system consisting of kaolin particles containing adsorbed n-dodecane as a diesel fuel surrogate, we investigated how increasing the temperature and adding a surfactant and various hydrophobic support media affected the biodegradation rate of n-dodecane. Increasing the temperature from 25 to 35 degrees C decreased the time required for complete degradation of n-dodecane by 30%, from 110h to 80h. Addition of the surfactant polyethylene glycol p-1,1,3,3-tetramethylbutylphenyl ether decreased the degradation time to less than 48h at 35 degrees C, although a high concentration of the surfactant (3000mgl(-1)) was required. We suspect that the surfactant increased the degradation rate by solubilizing the n-dodecane into the solution phase in which the microorganisms were suspended. We tested five types of organic polymers as support media for the microorganisms and found that the biodegradation time could be reduced by approximately 50% with a support medium made from polyurethane; in the presence of this medium, only 36h was required for complete decomposition at 35 degrees C. The reduction in the degradation time was probably due to transfer of the n-dodecane from the soil to the support medium, which improved contact between the n-dodecane and the microorganisms. The polyurethane support medium bearing the microorganisms was stable and could be reused.