Leaching of brominated flame retardants in leachate from landfills in Japan

Leachate samples were taken from seven different landfills and concentrations of brominated flame retardants (BFRs), i.e. polybrominated diphenyl ethers (PBDEs) and tetrabromobisphenol A (TBBPA), were quantified. Leaching characteristics of BFRs, especially factors affecting leachability, were clarified to obtain basic information regarding the release of BFRs into the environment. The results obtained for observed levels of the sum of PBDE-47, -99 and -100 were n.d.--4000 pg/l for the raw leachate and n.d. for the treated one, respectively, and those of TBBPA were n.d.--620,000 pg/l for the raw leachate and n.d.--11,000 pg/l for the treated one, respectively. Three sites that not only had crushed material from bulk wastes such as waste electric and electronic equipment, but also were under operation or within a year since closure, indicated a higher concentration of BFRs than the other sites. In particular extremely high concentration of PBDEs was observed at a site with a large amount of organics. Considering the leaching characteristics of BFRs, there exists the possibility that leachability of PBDEs is influenced by the presence of dissolved humic matter (DHM) in the leachate. The high removal efficiency for BFRs in the leachate treatment process was also confirmed.     

Influence of coexisting surface-active agents on leachability of dioxins in raw and treated fly ash from an MSW incinerator

The leaching behavior of dioxins from raw and treated fly ash (FA) under the coexistence of several types of surface-active agents (SAAs) was examined by batch leaching tests to obtain significant information not only for evaluating leachability of dioxins as hydrophobic organic pollutants (HOPs) under the severe environment in which SAAs coexist, but also for evaluating the reduction efficiency of dioxin-leachability from the treated FA. Enhancement of dioxin-leachability by sufficient addition of SAAs was observed in the leaching test, whereas addition of a smaller quantity depressed the leachability. The higher the degree of chlorination in PCDDs/PCDFs homologues, the more effectively the SAAs enhanced the leachability. Moreover, there was a large difference in the potential for leachability enhancement due to each surface activity, based on critical micelle concentration (CMC) of the SAAs although Aldrich humic acid enhanced the leachability at a much lower concentration than CMC. A comparison of the leachability in FA treated by several methods showed a difference in the reduction efficiency of leachability, depending on the adsorption of SAAs by each treated FA.     

Ecological effects of imidacloprid on arthropod communities in and around a vegetable crop

To elucidate the ecological impacts of imidacloprid [1-(6-chloro-3-pyridylmethyl)-N-nitroimidazolidin-2-ylideneamine] on vegetable crops and their surrounding areas, arthropods on eggplant patches treated with this insecticide were monitored throughout two cultivation seasons, spring and autumn, and the results compared with those of control crops. Residues of imidacloprid in soil accounted for 4-8% of total applied, and concentrations outside the crop were always below 5 micro g/kg. Communities of the crop vegetation experienced significant density reductions, mostly of aphids, and had fewer species diversity during the first month. Those in the surrounding pasture were similarly affected though with less intensity, while non-target ground arthropods both inside and outside the crop only showed significant impacts in the two weeks after planting.     

Comparative analysis on the genetic population structures of the deep-sea whelks <Emphasis Type="Italic">Buccinum tsubai</Emphasis> and <Emphasis Type="Italic">Neptunea constricta</Emphasis> in the Sea of Japan

The population structures of Buccinum tsubai and Neptunea constricta were compared using partial sequences of the mitochondrial COI gene. B. tsubai included four genetically distinguishable subpopulations (Hokkaido, Yamagata-Toyama, Yamato Bank, and San’in), which is consistent with the results of our previous study using mitochondrial 16SrRNA sequences. The genetic structure of N. constricta was also clear, but the lineage sorting corresponding to the geographical distribution was not as clear as that of B. tsubai. The difference between the genetic structures of these two species might be due to a difference in either their dispersal abilities or the historic distribution patterns in the Sea of Japan. The fossil record and nested clade analyses support the latter alternative. The four subpopulations of B. tsubai are estimated to have diverged 0.42–1.46 million years ago, providing support for the existence of intermediate water of normal salinity and oxygen concentration capable of sustaining B. tsubai between the low-salinity surface water and anoxic deep water during the Pleistocene glacial periods. The genetic diversity of the Yamato Bank subpopulation of B. tsubai was lower than that of the other subpopulations, which is likely attributable to the small size of the Yamato Bank subpopulation.     

Trace metal contamination in commercial fish and crustaceans collected from coastal area of Bangladesh and health risk assessment

Environmental Science and Pollution Research - Trace metals contamination in commercial fish and crustaceans have become a great problem in Bangladesh. This study was conducted to determine seven...     

Improvement of production of lipopeptide antibiotic iturin A using fish protein

To enhance the production of lipopeptide antibiotic iturin A, nutrient contents of the culture mediums were investigated in both submerged and biofilm fermentations. As a carbon source maltose and as nitrogen source, fish protein was used. In submerged fermentation maltose uptake was found lower (12%) compared to biofilm fermentation (15%) that was associated with higher cellular growth in biofilm. However, requirement of nitrogen (fish protein) concentration was found similar in both submerged and biofilm fermentations. Production of iturin A in submerged fermentation with 12% maltose and 5% fish protein was 4450 mg/L, and in biofilm fermentation it was 5050 mg/L when 15% maltose and 5% fish protein was used.     

Isolation of antifungal bacteria from Japanese fermented soybeans,natto

An inhibitory effect of a traditional Japanese fermented food, natto, was found against plant pathogens such as Rhizoctonia solani and Fusarium oxysporum, and the bacteria which showed inhibition were isolated from the natto. Among isolated bacteria, BC-1 and GAc exhibited a strong antagonistic effect in vitro against plant pathogens on an agar medium. The supernatant of bacterial culture also showed strong activity against R. solani, which meant the antimicrobial substances were produced and secreted into the medium. Both of the bacteria were estimated as Bacillus amyloliquefaciens from a partial sequence of the 16s rRNA gene. High performance liquid chromatography analysis clearly showed the production of the lipopeptide antibiotic iturin A by BC-1 and GAc.     

Study of the Determination of the Ultimate Aerobic Biodegradability of Plastic Materials Under Controlled Composting Conditions

Several ISO standards for determining the ultimate aerobic/anaerobic biodegradability of plastic materials have been published. In particular, ISO 14855-1 is a common test method that measures evolved carbon dioxide using such methods as continuous infrared analysis, gas chromatography or titration and others (ISO 14855-1(2005.9)). This method is a small-scale test for determining the ultimate aerobic biodegradability of plastic materials, where the amounts of compost inoculum and test sample in one tenth comparing with that of ISO 14855-1. This method is well versed in ISO/DIS 14855-2 which the carbon dioxide evolved from test vessel is determined by gravimetric analysis of carbon dioxide absorbent. The focus of this study is to elucidate statistically the results of round robin test by seven countries used MODA, which were various deviations among the experiments.