Estimation of faecal pollution based on the amounts of urobilins in urban rivers

An attempt was made to establish a new indicator for faecal pollution in aquatic environments using a sensitive determination method for urobilins, which are only present in mammalian faeces and urine. Assessment of urobilin stability was followed by determination of the amount of urobilins in river water. When river water containing urobilins was shaken at room temperature, the number of total and faecal coliforms increased, while urobilins decreased only in small amounts, indicating that urobilin is relatively stable in river water and hence can serve as a useful indicator for the estimation of faecal pollution of river water. The amount of urobilins in the river waters increased steeply from the mid-point of a stream near a sewage treatment plant, while amounts in the upper stream were very low. The amount of urobilins in river water increased after rainfall. Findings suggested that urobilin, i.e. sewage, originated from the output of the sewage treatment plant and raw sewage.     

Photochemical mutagen formation from aerobically treated night-soil effluent and the contributive substances

Effluents from a night-soil treatment plant, where night-soil was aerobically treated by an activated sludge process, were irradiated with a UV lamp excluding short wavelengths less than 300 nm as a model of exposure to sunlight and the mutagenicities of the ethylacetate extracts from the irradiated effluents were assayed using Salmonella typhimurium TA98. The extracts exhibited mutagenicity toward S. typhimurium TA98 in the absence of rat liver S9 fraction only when the effluents were fortified with nitrite ion (more than 6 ppm) by over aeration or by artificial addition of nitrite, indicating that a limiting factor for mutagen formation is nitrite ion concentration. Nine organic-N-containing compounds as models of the organic components in the effluent were also irradiated and direct-acting potent mutagens were found to be produced from such compounds having indole moiety as indole, oxindole, tryptophan and tryptamine.     

Coral skeletal tin and copper concentrations at Pohnpei, Micronesia: possible index for marine pollution by toxic anti-biofouling paints

We present 40 year-long skeletal chronologies of tin (Sn) and copper (Cu) from an annually-banded coral (Porites sp.) collected from Pohnpei Island, Micronesia (western equatorial Pacific). Both the elements are present in antifouling marine paints and are released inadvertently into ambient seawater. Especially, Sn has often been used in the form of tributyltin (TBT). Based on a stepwise pretreatment examination, Sn and Cu both inside and outside the aragonite lattice of the coral skeleton show a potential for providing marine pollution indicators. High values of extra-skeletal Cu/Ca and Sn/Ca atomic ratios were found between late 1960s and late 1980s during a period of active use of TBT-based antifouling paints worldwide. However, a significant decrease in both the ratios in the beginning of 1990s can be attributed to regulation of the use of TBT on cargo ships by countries such as the USA, Japan and Australia.     

中国与全球性环境问题

本文系作者对中国环境问题十几年研究成果的总结。作者重点阐述了全球环境问题、地球变暖与中国的现状、酸雨与中国的现状、臭氧层破坏与中国现状、野生生物种的灭绝与中国现状等。     

Potential of Co2 emission reductions by carbonizing biomass waste from industrial tree plantation in South Sumatra,Indonesia

Approximately half of the carbon in trees can be fixed to charcoal by carbonization. Porous charcoal is useful as a soil amendment for crop fields and forests, and also as a water purifying agent. Given these facts, charcoal production should be recognized as one of the most promising CO₂ sequestration methods. A project on biomass utilization and forest conservation is proposed as a Clean Development Mechanism (CDM) project, by incorporating the carbonization of biomass residue and waste from tree plantations and pulp mills, and also the utilization of carbon products in various fields. A feasibility study was conducted with the existing project of an industrial tree plantation and pulp production in Indonesia. If conventional charcoal-making methods are used, a total of 368,000 t yr^-1 of biomass residue and waste could be transformed into charcoal of77,000 t yr^-1, and the carbon emission reductions by the project reaches 62,000t-C yr^-1 (or 230,000 t-CO₂yr^-1) in consideration of the project baseline. This charcoal project could provide jobs for approximately 2,600people. The soil fertility in man-made forests could be maintained by returning charcoal to the original forests. Therefore, the project would be beneficial to the regional economy. In addition, the present charcoal project is expected to give more positive impacts than negative ones, or leakage, beyond the project boundary. This revised version was published online in August 2006 with corrections to the Cover Date.     

Development of highly active coated monolith SCR catalyst with strong abrasion resistance for low-temperature application

Monolith SCR catalysts coated with V₂O₅-WO₃/TiO₂ were prepared by varying binder and coating thickness. Comparing with a monolith extruded with 100% V₂O₅-WO₃/TiO₂ powder, a coated monolith with a catalyst-coating layer of 260 μm in thickness exhibited the similar initial NO_x reduction activity at 250°C. After 4 h abrasion (attrition) in an air stream containing 300 g·m⁻³ fine sands (50–100 μm) at a superficial gas velocity of 10 m·s⁻¹, the catalyst still has the activity as a 100% molded monolith does in a 24-h activity test and it retains about 92% of its initial activity at 250°C. Estimation of the equivalent durable hours at a fly ash concentration of 1.0 g·m⁻³ in flue gas and a gas velocity of 5 m·s⁻¹ demonstrated that this coated monolith catalyst is capable of resisting abrasion for 13 months without losing more than 8% of its initial activity. The result suggests the great potential of the coated monolith for application to de-NO_x of flue gases with low fly ash concentrations from, such as glass and ceramics manufacturing processes.     

High seagrass diversity and canopy-height increase associated fish diversity and abundance

Seagrass species function as typical foundation species that unifies most ecosystem processes. This ecosystem role depends largely on the morphological characteristics and structural complexity of seagrass beds, including their ecological importance for fish species. This study examined relationships between seagrass bed characteristics and associated fish communities in mixed seagrass beds. Correspondence analysis (CA) and canonical correlation analysis (CCoA) were performed to estimate relationships for individual seagrass bed characteristics. The CCoA results revealed that species richness and three-dimensional structure of seagrass had great effect on the biomass and richness of the associated fish community. The CA results revealed that the relative importance of seagrass bed characteristics differed among fish functional groups including fishes appearing on the surface of, inside, and on the bottom of seagrass beds. The fishes found on the surface of the beds preferred beds with low seagrass biomass and high three-dimensional structure, those inside the beds preferred beds with high seagrass biomass and high three-dimensional structure, and those on the bottom of the beds preferred locations with low seagrass biomass and low three-dimensional structure. The results of this study provide compelling evidence that seagrass beds with high species diversity and high three-dimensional structure, but intermediate biomass, may provide the great benefit to the associated fish community. Such niche complementarity among fishes may be a process facilitated by seagrass diversity for secondary production as an ecosystem functioning.     

Rate of iodine volatilization and accumulation by filamentous fungi through laboratory cultures

Five strains of basidiomycetes (Lentinula edodes, Coprinus phlyctidosporus, Hebeloma vinosophyllum, Pleurotus ostreatus and Agaricus bisporus), one strain of ascomycete (Hormoconis resinae) and six strains of imperfect fungi (Penicillium chrysogenum, Penicillium roquefortii, Cladosporium cladosporioides, Alternaria alternata, Aspergillus niger and Aspergillus oryzae) were cultured in a liquid medium containing a radioactive iodine tracer (¹²⁵I), and were tested for their abilities to volatilize or accumulate iodine. Of the fungal strains tested, 11 strains volatilized a considerable amount of iodine, with L. edodes showing the highest volatilization rate of 3.4%. The volatile organic iodine species emitted from imperfect fungi cultures was identified as methyl iodide (CH₃I). In contrast, six fungal strains in 12 strains accumulated a considerable amount of iodine from the medium with concentration factors of more than 1.0. Among these, Alt. alternata and Cl. cladosporioides accumulated more than 40% of the iodine in their hyphae, and showed high concentration factors of 22 and 18, respectively. These results suggest that filamentous fungi have a potential to influence the mobility and speciation of iodine by volatilization and accumulation. Considering their great biomass in soils, filamentous fungi may contribute to the global circulation of stable iodine and also the long-lived radioiodine, ¹²⁹I (half-life: 1.6 × 10⁷ years), released from nuclear facilities into the environment.